It was pretty hot today. While driving, I noticed my warning light flicker-signaling knock retard. I gave it a few test pulls and was indeed seeing this pretty consistently. Between 1st and 4th, showing anywhere from 1.2-3.4.
From the reading I've done, some KR is normal, but above 2 probably isn't good. Is that correct?
Should I be concerned?
Should I be concerned?
one and one makes two, together we are free
You are correct sir. Some KR is appropriate during transition, like when you stomp on the gas at low rpms or the intake temps are extremely hot.
Your mods are not helping the situation either. You are getting more air in than at stock and that air is very warm causing a bit of KR. Is it for prolonged periods, or is it a brief reaction from your car to the hot air?
It may be time to invest in some tuning, or just take it easy whenit is really hot out there.
Your mods are not helping the situation either. You are getting more air in than at stock and that air is very warm causing a bit of KR. Is it for prolonged periods, or is it a brief reaction from your car to the hot air?
It may be time to invest in some tuning, or just take it easy whenit is really hot out there.
2006 SPEED6 Liquid Platinum Sport w/ Nav
Mods Completed - VG Sharkfin, 3M Clear Bra, SU Motor Mount, SU Test Pipe, 35% tint, VEI Digital Boost Gauge, Custom Defrost Vent Pod, PG Exhaust Manifold, CPE Turbo Inlet Pipe, CPE FMIC, Hacked Mazdaspeed CAI into SRI, Synapse BOV, Cobb Accessport EMS Tuner, CPE Dual 3" Catback Exhaust
Mods Needed - Catted Downpipe and finally a tune.
Mods Completed - VG Sharkfin, 3M Clear Bra, SU Motor Mount, SU Test Pipe, 35% tint, VEI Digital Boost Gauge, Custom Defrost Vent Pod, PG Exhaust Manifold, CPE Turbo Inlet Pipe, CPE FMIC, Hacked Mazdaspeed CAI into SRI, Synapse BOV, Cobb Accessport EMS Tuner, CPE Dual 3" Catback Exhaust
Mods Needed - Catted Downpipe and finally a tune.
bobopud wrote:You are correct sir. Some KR is appropriate during transition, like when you stomp on the gas at low rpms or the intake temps are extremely hot.
Your mods are not helping the situation either. You are getting more air in than at stock and that air is very warm causing a bit of KR. Is it for prolonged periods, or is it a brief reaction from your car to the hot air?
It may be time to invest in some tuning, or just take it easy whenit is really hot out there.
Thanks for the info P:)
Yeah, I haven't really been seeing it consistantly per se. But its not my daily, so that's not saying much either, lol. To answer your question though, it does seem to be more of a brief reaction to the hot temps. It's been pretty hot out when I've seen this, and its usually once I stomp on the gas, or when I'm really getting on it.
1.) I can't seem to boost over 13psi either. Is this normal, or could a leak somewhere contribute?
2.) I was so close to getting the AP, but never pulled the trigger.
3.) Could the stock plugs be an issue with the few mods I do have?
4.) Any suggestions on the following, and perhaps what order you/anyone woud recommend me going?
- ETS TMIC (pros: easier install/uninstall, cheaper)
- (or) Cobb FMIC (better results, but more extensive and expensive)
- AP
one and one makes two, together we are free
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chickenwafer
- Posts: 2515
- Joined: Wed Mar 11, 2009 9:14
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You should also consider a water/meth injection kit. The powers of water/meth are incredible- drastically lower IAT's, increase knock resistance, and basically lets you run race gas, so you can run higher boost (I wouldn't without a tune). The big point is the lower intake temps.
I don't have an MS3 but from what I've seen by wrenching on friends MS3/MS6's and being in a club with a lot of them, the AP doesn't seem to do too much for your cars.... or mainly not a lot of people are pursuing tuning with it. Not to say it isn't good, I love my AP.
I would vote for FMIC and water/meth kit. The water/meth kit will be much cheaper- you can get a good AEM kit for around $400 bucks.
I don't have an MS3 but from what I've seen by wrenching on friends MS3/MS6's and being in a club with a lot of them, the AP doesn't seem to do too much for your cars.... or mainly not a lot of people are pursuing tuning with it. Not to say it isn't good, I love my AP.
I would vote for FMIC and water/meth kit. The water/meth kit will be much cheaper- you can get a good AEM kit for around $400 bucks.
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roninsoldier83
- Posts: 664
- Joined: Wed Sep 24, 2008 9:14
- Location: Lakewood, CO
- Contact:
IMO, you have a few options if you want to get rid of knock/at least make it less likely:
1. Tuning. IMO, this is the ultimate solution. I would recommend an AP & having someone protune your car, HOWEVER, I don't know any local Protuners that tune the Speed6. With an AP, if you can also buy some sort of street tuner software (not sure if it's available for the Speed6) and find a tuner willing to tune it, that's the route I would take. Alternately, the Standback is user adjustable, so if you can find a tuner that will be willing to tune a Standback, that's another route you might take. If your car is knocking, you have a few real tuning options:
A)Turn down the boost/WGDC's.
B)Find the RPM/load range it's knocking at (for instance 3000-3400rpm under 70-100% load), and retard timing.
C)At the RPM/load range you're seeing knock, richen up the fuel trims/add fuel to help cool your head/decrease chance of det. Note: this might not be a viable option if your HPFP is running out of fuel down low.
2. Run an alternate fuel/cooling source. E85 is AWESOME, here lately is has been proving itself to be more knock resistant than meth/water injection kits:
http://legacygt.com/forums/showpost.php?p=2025879&postcount=1
http://www.drivingsports.com/site/2008/07/e85-vs-methanol-injection/
http://www.importtuner.com/tech/impp_0904_e85_vs_conventional_gasoline/index.html
^^^It has a latent heat of about 310 BTU's/LB (gasoline is around 110 BTU's/LB), is rated around 105 octane, there are over 50 E85 stations in Colorado, and it's dirt cheap (IIRC my last fill up was at $1.99/gallon). However, this might not be a viable option for your Direct Injection motor, as running it will require you to have about a 30% increase in fuel overhead in order to run the same boost levels (aka 30% larger fuel injectors on a port injection car & a pump with the ability to flow it without burning up the pump), and since I don't know if you can get that kind of fuel overhead increase in the 2.3 DISI motor, this might not be an option.
Alternately, meth/water injection is a GREAT way to go! For just about the exact same reasons as E85, cooling charge, added knock resistance, extra "fuel" overhead ect. You'll have to tap your nozzle somewhere (preferably post IC), and tune for it to fully take advantage of it's benefits, but it's good stuff for sure. Only a few drawbacks of running meth/water injection:
A)When you tank runs out, if you don't have an alternate map for your car, you need to stay out of boost/going WOT. A motor tuned for meth (more boost, more timing advance & leaner AFR's) without the meth is a recipe for engine damage. Although many newer kits employ various means of warnings, boost limitations, ect, something to keep in mind.
B)If your pump dies unexpectantly you face the same potential issues as not having any meth/water left in the tank obviously.
C)You have to refill the tank occasionally. For many, not a big deal, but still another fluid you have to refill.
As a side note, I've heard of people running water injection without tuning just for added knock resistance (cooling charge), which won't really make anymore power, but just an added safety buffer FWIW.
3. Get a larger intercooler. If you're interested, Perrin did a pretty good write-up with pre & post IC IAT's (intake air temperatures) not too long ago:
http://perrinperformance.com/pages/show/92
^^^Even though it's a Subaru, the same theory directly applies. Most interesting are the TMIC post IC IAT's vs the FMIC post IC IAT's, pretty big difference under sustained boost. Depending on where in your powerband you're seeing knock & under what conditions, an upgraded IC isn't a bad idea. A larger core will take longer to heat soak (aka more pulls), which is helpful, as high post IC IAT's will make the car more likely to knock. Although, if going with a larger TMIC, keep something in mind, even though it will take longer to heat soak, due to it essentially being a heat exchanger (heat sink lol), it will also take longer to cool down FWIW. Whereas with a FMIC, not only will you have a larger core (takes longer to heat soak) it will also have a more direct air flow path, helping it to stay "cool" for longer, and cool down faster after heat soaked (and yes, FMIC's do heat soak, it's just not something people normally talk about, takes considerably longer than your average TMIC under boost/load).
Just like meth/water injection, you can technically run a FMIC without tuning per se, and it will increase det resistance, but without tuning you will not see the full effects/gains normally associated with a FMIC. As a matter of fact, I've seen plenty of people in the Subaru world (both have TMIC's stock), swap over to FMIC's without tuning, and lose power in places throughout the powerband. A big advantage of running a FMIC: being able to turn up the boost without heat soaking easily, enabling you to push more timing in the upper RPM's specifically where a TMIC would normally have much higher charge temps.
4. If fuel overhead is not an issue, and tuning is not an option, running a smaller diameter MAF housing would technically alter your fuel trims & make your car run richer. Kind of like putting a band aid on a broken arm IMO, but it works.
Overall, I think your best option is just to find a tuning device you like as well as a tuner you trust who is willing to tune your car. Either that or just live with the occasional knock. FWIW, with my former Speed6 upping the boost (don't remember peak, IIRC, somewhere around 16psi or so) resulted in a nice lean spot around 3000rpm that I would constantly see 1-3 counts of knock under WOT at that RPM. Attempting to add fuel didn't do shit (POS DTEC FCBC) as I think the stock HPFP was maxed, and my DTEC didn't have control over timing so that wasn't an option (too bad), I was forced to just turn down the boost to make the car stop running so lean, which resulted in no more knock. I think with timing control on a better tuning device (Standback & AP) I could have tuned it out.
My vote is for engine management and a tuner who is capable & willing to tune with it. Hope that helps. Just my $.02
1. Tuning. IMO, this is the ultimate solution. I would recommend an AP & having someone protune your car, HOWEVER, I don't know any local Protuners that tune the Speed6. With an AP, if you can also buy some sort of street tuner software (not sure if it's available for the Speed6) and find a tuner willing to tune it, that's the route I would take. Alternately, the Standback is user adjustable, so if you can find a tuner that will be willing to tune a Standback, that's another route you might take. If your car is knocking, you have a few real tuning options:
A)Turn down the boost/WGDC's.
B)Find the RPM/load range it's knocking at (for instance 3000-3400rpm under 70-100% load), and retard timing.
C)At the RPM/load range you're seeing knock, richen up the fuel trims/add fuel to help cool your head/decrease chance of det. Note: this might not be a viable option if your HPFP is running out of fuel down low.
2. Run an alternate fuel/cooling source. E85 is AWESOME, here lately is has been proving itself to be more knock resistant than meth/water injection kits:
http://legacygt.com/forums/showpost.php?p=2025879&postcount=1
http://www.drivingsports.com/site/2008/07/e85-vs-methanol-injection/
http://www.importtuner.com/tech/impp_0904_e85_vs_conventional_gasoline/index.html
^^^It has a latent heat of about 310 BTU's/LB (gasoline is around 110 BTU's/LB), is rated around 105 octane, there are over 50 E85 stations in Colorado, and it's dirt cheap (IIRC my last fill up was at $1.99/gallon). However, this might not be a viable option for your Direct Injection motor, as running it will require you to have about a 30% increase in fuel overhead in order to run the same boost levels (aka 30% larger fuel injectors on a port injection car & a pump with the ability to flow it without burning up the pump), and since I don't know if you can get that kind of fuel overhead increase in the 2.3 DISI motor, this might not be an option.
Alternately, meth/water injection is a GREAT way to go! For just about the exact same reasons as E85, cooling charge, added knock resistance, extra "fuel" overhead ect. You'll have to tap your nozzle somewhere (preferably post IC), and tune for it to fully take advantage of it's benefits, but it's good stuff for sure. Only a few drawbacks of running meth/water injection:
A)When you tank runs out, if you don't have an alternate map for your car, you need to stay out of boost/going WOT. A motor tuned for meth (more boost, more timing advance & leaner AFR's) without the meth is a recipe for engine damage. Although many newer kits employ various means of warnings, boost limitations, ect, something to keep in mind.
B)If your pump dies unexpectantly you face the same potential issues as not having any meth/water left in the tank obviously.
C)You have to refill the tank occasionally. For many, not a big deal, but still another fluid you have to refill.
As a side note, I've heard of people running water injection without tuning just for added knock resistance (cooling charge), which won't really make anymore power, but just an added safety buffer FWIW.
3. Get a larger intercooler. If you're interested, Perrin did a pretty good write-up with pre & post IC IAT's (intake air temperatures) not too long ago:
http://perrinperformance.com/pages/show/92
^^^Even though it's a Subaru, the same theory directly applies. Most interesting are the TMIC post IC IAT's vs the FMIC post IC IAT's, pretty big difference under sustained boost. Depending on where in your powerband you're seeing knock & under what conditions, an upgraded IC isn't a bad idea. A larger core will take longer to heat soak (aka more pulls), which is helpful, as high post IC IAT's will make the car more likely to knock. Although, if going with a larger TMIC, keep something in mind, even though it will take longer to heat soak, due to it essentially being a heat exchanger (heat sink lol), it will also take longer to cool down FWIW. Whereas with a FMIC, not only will you have a larger core (takes longer to heat soak) it will also have a more direct air flow path, helping it to stay "cool" for longer, and cool down faster after heat soaked (and yes, FMIC's do heat soak, it's just not something people normally talk about, takes considerably longer than your average TMIC under boost/load).
Just like meth/water injection, you can technically run a FMIC without tuning per se, and it will increase det resistance, but without tuning you will not see the full effects/gains normally associated with a FMIC. As a matter of fact, I've seen plenty of people in the Subaru world (both have TMIC's stock), swap over to FMIC's without tuning, and lose power in places throughout the powerband. A big advantage of running a FMIC: being able to turn up the boost without heat soaking easily, enabling you to push more timing in the upper RPM's specifically where a TMIC would normally have much higher charge temps.
4. If fuel overhead is not an issue, and tuning is not an option, running a smaller diameter MAF housing would technically alter your fuel trims & make your car run richer. Kind of like putting a band aid on a broken arm IMO, but it works.
Overall, I think your best option is just to find a tuning device you like as well as a tuner you trust who is willing to tune your car. Either that or just live with the occasional knock. FWIW, with my former Speed6 upping the boost (don't remember peak, IIRC, somewhere around 16psi or so) resulted in a nice lean spot around 3000rpm that I would constantly see 1-3 counts of knock under WOT at that RPM. Attempting to add fuel didn't do shit (POS DTEC FCBC) as I think the stock HPFP was maxed, and my DTEC didn't have control over timing so that wasn't an option (too bad), I was forced to just turn down the boost to make the car stop running so lean, which resulted in no more knock. I think with timing control on a better tuning device (Standback & AP) I could have tuned it out.
My vote is for engine management and a tuner who is capable & willing to tune with it. Hope that helps. Just my $.02
AKA- [color="Blue"]arctic_blue83[/color]
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Thanks for the replies; a lot of good info in there...understanding everything is the hard part, lol.
I haven't (personally) heard of anyone with an MS3 running water/meth (besides Eric [MS6] ). Not to say there aren't though: CMCZ is the primary place I visit for info. I will do research on other forums, but it stops there, as I don't know anyone from Adam. The benefits of W/M are intriguing, but such a step is also intimidating for a novice such as myself.
My story is no different than most. The MS3 was a monster when I first got it (compared to my 1.8t). Then it slowly became inadequate, so a few small mods relieved the itch for more zoom zoom....only for a short time though. I'm not looking for some super HP beast- nor do I have any interest in taking this car to the track or strip. I'm just looking to take advantage of the Speed's innate attributes; all while keeping the engine safe and reliable. I'm not looking to mod it to death, drive the piss out of it, then trade it in once the manufacturer's warranty ends. I don't want to mess with things so much, that I'm constantly having to trouble shoot the possibilities/potential problems that the new mods caused in the first place:huh: I plan on keeping the car, paying my way out of being upside down, not having to worry about blowing the engine up from being overzelous, but also being able to have the power there when I want it. I generally drive pretty conservatively, but if/when I stomp on it, I want to feel the PULL without any flashing lights:p
I realize mods come with issues, and HP has its price. I just don't have the resources, knowledge, mechanical background, etc. that most of you all have. I'm basically looking to improve performance without effecting the longevity of the vehicle. <-- This was the reason why I decided against the AP. ...and why the standback is a bit more of a risk (in my mind) as well.
I feel like I'm waist deep in a cold pool. I've already gotten my huevos wet, but still have the option of getting back out without diving all the way in:D
...the FMIC does sound nice, but will take me awhile to get the dough.
I haven't (personally) heard of anyone with an MS3 running water/meth (besides Eric [MS6] ). Not to say there aren't though: CMCZ is the primary place I visit for info. I will do research on other forums, but it stops there, as I don't know anyone from Adam. The benefits of W/M are intriguing, but such a step is also intimidating for a novice such as myself.
My story is no different than most. The MS3 was a monster when I first got it (compared to my 1.8t). Then it slowly became inadequate, so a few small mods relieved the itch for more zoom zoom....only for a short time though. I'm not looking for some super HP beast- nor do I have any interest in taking this car to the track or strip. I'm just looking to take advantage of the Speed's innate attributes; all while keeping the engine safe and reliable. I'm not looking to mod it to death, drive the piss out of it, then trade it in once the manufacturer's warranty ends. I don't want to mess with things so much, that I'm constantly having to trouble shoot the possibilities/potential problems that the new mods caused in the first place:huh: I plan on keeping the car, paying my way out of being upside down, not having to worry about blowing the engine up from being overzelous, but also being able to have the power there when I want it. I generally drive pretty conservatively, but if/when I stomp on it, I want to feel the PULL without any flashing lights:p
I realize mods come with issues, and HP has its price. I just don't have the resources, knowledge, mechanical background, etc. that most of you all have. I'm basically looking to improve performance without effecting the longevity of the vehicle. <-- This was the reason why I decided against the AP. ...and why the standback is a bit more of a risk (in my mind) as well.
I feel like I'm waist deep in a cold pool. I've already gotten my huevos wet, but still have the option of getting back out without diving all the way in:D
...the FMIC does sound nice, but will take me awhile to get the dough.
one and one makes two, together we are free
-
roninsoldier83
- Posts: 664
- Joined: Wed Sep 24, 2008 9:14
- Location: Lakewood, CO
- Contact:
kingtut wrote:Thanks for the replies; a lot of good info in there...understanding everything is the hard part, lol.
I haven't (personally) heard of anyone with an MS3 running water/meth (besides Eric [MS6] ). Not to say there aren't though: CMCZ is the primary place I visit for info. I will do research on other forums, but it stops there, as I don't know anyone from Adam. The benefits of W/M are intriguing, but such a step is also intimidating for a novice such as myself.
My story is no different than most. The MS3 was a monster when I first got it (compared to my 1.8t). Then it slowly became inadequate, so a few small mods relieved the itch for more zoom zoom....only for a short time though. I'm not looking for some super HP beast- nor do I have any interest in taking this car to the track or strip. I'm just looking to take advantage of the Speed's innate attributes; all while keeping the engine safe and reliable. I'm not looking to mod it to death, drive the piss out of it, then trade it in once the manufacturer's warranty ends. I don't want to mess with things so much, that I'm constantly having to trouble shoot the possibilities/potential problems that the new mods caused in the first place:huh: I plan on keeping the car, paying my way out of being upside down, not having to worry about blowing the engine up from being overzelous, but also being able to have the power there when I want it. I generally drive pretty conservatively, but if/when I stomp on it, I want to feel the PULL without any flashing lights:p
I realize mods come with issues, and HP has its price. I just don't have the resources, knowledge, mechanical background, etc. that most of you all have. I'm basically looking to improve performance without effecting the longevity of the vehicle. <-- This was the reason why I decided against the AP. ...and why the standback is a bit more of a risk (in my mind) as well.
I feel like I'm waist deep in a cold pool. I've already gotten my huevos wet, but still have the option of getting back out without diving all the way in:D
...the FMIC does sound nice, but will take me awhile to get the dough.
I completely understand where you're coming from, however still think you should consider a tuning device & good conservative tune if nothing else.
Case in point: Do a search on Nasioc or IWSTI for "2007 STI blown motor", and you'll be surprised at how many threads pop up. Then, look in the threads and you'll be doubly surprised at how many of them are bone stock. This is common. In 2007 the EPA mandated stricter emissions & fuel economy standards, as such the tunes on the 2007+ Subarus were changed. I've seen with my own eyes bone stock STI dyno graphs: with 14:1 AFR's under FULL LOAD/BOOST at as high as 4500rpm (past peak torque), the open loop/closed loop delays are HORRID, and the fact that the car tries to hold near stoich AFR's under peak torque is downright scary. In short: the stock tune is shit/dangerous. Now, not to say the same of the MS3/MS6, but OEM tunes aren't always the safest. This is the SAME reason why I don't trust OTS maps (base maps loaded into an AP or Standback), as I believe the best tune for your car is a map that was actually made for your car/setup.
I've seen AP OTS (off the shelf) maps that were DEAD on, perfect AFR's, hitting targeted boost, timing tables that fit the tune, no knock anywhere, making good power, it's rare but I've seen it. I've also seen cars running the EXACT same map, with the EXACT same mods, that are running lean, or not hitting targeted boost, knocking all over/pulling timing, making less power than they should. All cars are NOT created equal, what works for one car, doesn't necessarily work for another. The best route to take? Having a custom map made for your car specifically.
Just because someone makes you a custom map doesn't mean it's going to be aggressive or shorten the life of your motor. In many cases, on the contrary, a 2007 STI being one of those, where most people recommend getting a custom tune even if you're going to leave the car otherwise stock.
Ultimately, it's your car, and you should do whatever makes you most comfortable, but remember, it's your car. If you do have it tuned, you can specify to your tuner not to hit over XXpsi or run leaner than XX.X:1, or simply just trust the tuner to tune your car conservatively (you can request a conservative tune, I know MANY people that auto-X & run road courses regularly that request conservative tunes). Often a tuner if asked to be conservative will leave a little bit of power on the table for the sake of your piece of mind/or to make sure you can run a 20 minute road course session without popping a motor/having any issues. Often a road course/autoX tune will be more conservative than a 1/4 mile tune, for obvious reasons. 12-14 seconds (1/4 mile) vs 2-20 minutes of hard driving (autoX/road race).
Again, just something to keep in mind.
AKA- [color="Blue"]arctic_blue83[/color]
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
roninsoldier83 wrote:
Again, just something to keep in mind.
Definitely gives me somthing to think about. As always, good info B- that makes perfect sense. Well, except for all the ratios/numbers/etc., lol
So, has anyone done a "custom" tune, and/or know of any good shops around town specific to the MS3?
- What's a tune entail? Leaving your car with a shop for a day/s?
- During the "tune", are they constantly making aggressive pulls? Or is it more computer-type management than actual spirited driving?
- Any ideas what a shop would charge for such work?
one and one makes two, together we are free
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roninsoldier83
- Posts: 664
- Joined: Wed Sep 24, 2008 9:14
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No problem buddy 
I can even help explain a few of the "numbers"
AFR's (air to fuel ratios)- How many air molecules there are in your engine vs fuel molecules. So for 11.5:1 AFR there would be 11.5 molecules of air for each 1 molecule of fuel. The more air, the "leaner" the mixture, the leaner the mixture, the hotter cylinder temperatures are. Under low "load"/closed loop, just about every modern day car on the market will try to target 14.7:1 on gasoline. They target this AFR for fuel economy, emissions & longevity. This works fine for low load scenarios, idling, cruising with little throttle, extremely light acceleration (we're talking barely touching the gas pedal), however when you increase the amount of load a motor is seeing, aka boost pressure (pressurizes cylinders, increasing heat), timing advance, throttle position (how much air the TB is allowing into the manifold/head(s)/motor) this AFR is far too lean (too hot) on pump gas, and will greatly increase your chances of detonation. So, when you press the happy pedal/go WOT, your ECU senses the change, and to avoid motor damage, adds fuel, in stock form I've seen fuel trims drop into the 9:1 range, but typically targets around 10.0-10.5:1 AFR getting richer as RPM's rise. This extra fuel it's adding is to take down cylinder temperatures to avoid engine damage from detonation.
Detonation/knock/pre-ignition is caused when cylinder temps are too high combined with cylinder pressures that are too high. There's more to it, but I'll leave it at that. They are small uncontrollable explosions inside your cylinder walls that happen prior to your spark plug firing. Although instead of burning the cylinder in a smooth motion and pushing the piston down, these explosions can happen when the piston is on it's ascent (heading towards the spark plug), which is a bad thing. Detonation can crack ringlands, burn holes in pistons, snap rods in half ect. AKA, destroy motors.
Boost is pretty self explanatory, a turbocharger takes atmospheric air and pressurizes, routing it into your motor. Normal atmospheric pressure at sea level it 14.7psi (a lot of 14.7's in this stuff haha). So, if your car is pushing 15psi of boost at sea level, that's actually not the pressure your motor is seeing, it would be seeing 14.7psi+15psi=29.7psi total pressure. Pressure=friction=heat. More heat=more likely to detonate. There's a pattern here
Timing... this is just a bit tougher to explain. Timing is basically in a nutshell when the spark plug is firing in relation to the piston's position to TDC (top dead center). I'll steal this from Wiki:
"'Timing advance' refers to the number of degrees before top dead center (BTDC) that the spark will ignite the air-fuel mixture in the combustion chamber during the compression stroke."
"Timing advance is required because it takes time to burn the air-fuel mixture. Igniting the mixture before the piston reaches top dead center (TDC) will allow the mixture to fully burn soon after the piston reaches TDC. If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches TDC allowing the ignited mixture to push the piston down the cylinder with the greatest force. Ideally, the time at which the mixture should be fully burnt is about 20 degrees ATDC. This will utilize the engine's power producing potential. If the ignition spark occurs at a position that is too advanced relative to piston position, the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing detonation and lost power. If the spark occurs too retarded relative to the piston position, maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, high emissions, and unburned fuel."
^^^In a nutshell, those are the 3 primary parameters tuners are going to tune for WOT. There will be tables that typically reference RPM vs load (load can be calculated via throttle position-not recommended, MAF voltage/grams of air per second, or boost pressure/MAP sensor). You manipulate these tables for fuel & timing, and sometimes boost depending on what you're tuning. Once you learn to read them, they're not too difficult to understand at all. You set your "axes", typically RPM something like:
200rpm
350rpm
500rpm
650rpm
Ect.
Ect.
7000rpm (whatever your redline is)
^^^So, if you want to make minute adjustments, setup close RPM points.
Then you'll setup your load reference. To make this simple, we'll assume you're running Speed Density (these cars don't from the factory haha), which reference boost, would be something like this:
10%= 2psi 20%=4psi 30%=6psi ect ect 100%=20psi
This works the same way with referencing via MAF, but instead of boost, it would reference the amount of air that flows over the MAF, either via MAF volts (0-5V common) or G/S (grams of air per second), which we'll say for argument sake is 300gs peak in this case. It would follow the same logic:
10%=30gs 20%=60gs 30%=90gs ect ect100%=300gs
This was make a large graph. Keep in mind, this is a piss poor graph, RPM points IMO should be closer than 500rpm apart, but for simplicity sake:
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
500
1000
1500
2000
2500
3000 0 0 0 0 +12
3500
4000
4500
5000
5500 0 0 0 0 0 0 -15 -15
6000
6500
7000
^^^Sorry if they don't line up correctly
^^^With that, let's say that at 3000rpm your car is seeing 50% load (either 10psi or 150gs going by the "axes" we made above) and the car is running leaner than you want, and in order to get your targeted AFR's, we need to add 12% additional fuel at that RPM, you can see it above, but let's say at 5500rpm you're seeing between 70-80% load, your car is running too rich, and to reach your target AFR's you need to remove 15%, you can see that above. BTW, assume all the blank space in between is set to 0.
I think I may have gotten too far into this, but I hope you get the idea.
I can even help explain a few of the "numbers"
AFR's (air to fuel ratios)- How many air molecules there are in your engine vs fuel molecules. So for 11.5:1 AFR there would be 11.5 molecules of air for each 1 molecule of fuel. The more air, the "leaner" the mixture, the leaner the mixture, the hotter cylinder temperatures are. Under low "load"/closed loop, just about every modern day car on the market will try to target 14.7:1 on gasoline. They target this AFR for fuel economy, emissions & longevity. This works fine for low load scenarios, idling, cruising with little throttle, extremely light acceleration (we're talking barely touching the gas pedal), however when you increase the amount of load a motor is seeing, aka boost pressure (pressurizes cylinders, increasing heat), timing advance, throttle position (how much air the TB is allowing into the manifold/head(s)/motor) this AFR is far too lean (too hot) on pump gas, and will greatly increase your chances of detonation. So, when you press the happy pedal/go WOT, your ECU senses the change, and to avoid motor damage, adds fuel, in stock form I've seen fuel trims drop into the 9:1 range, but typically targets around 10.0-10.5:1 AFR getting richer as RPM's rise. This extra fuel it's adding is to take down cylinder temperatures to avoid engine damage from detonation.
Detonation/knock/pre-ignition is caused when cylinder temps are too high combined with cylinder pressures that are too high. There's more to it, but I'll leave it at that. They are small uncontrollable explosions inside your cylinder walls that happen prior to your spark plug firing. Although instead of burning the cylinder in a smooth motion and pushing the piston down, these explosions can happen when the piston is on it's ascent (heading towards the spark plug), which is a bad thing. Detonation can crack ringlands, burn holes in pistons, snap rods in half ect. AKA, destroy motors.
Boost is pretty self explanatory, a turbocharger takes atmospheric air and pressurizes, routing it into your motor. Normal atmospheric pressure at sea level it 14.7psi (a lot of 14.7's in this stuff haha). So, if your car is pushing 15psi of boost at sea level, that's actually not the pressure your motor is seeing, it would be seeing 14.7psi+15psi=29.7psi total pressure. Pressure=friction=heat. More heat=more likely to detonate. There's a pattern here
Timing... this is just a bit tougher to explain. Timing is basically in a nutshell when the spark plug is firing in relation to the piston's position to TDC (top dead center). I'll steal this from Wiki:
"'Timing advance' refers to the number of degrees before top dead center (BTDC) that the spark will ignite the air-fuel mixture in the combustion chamber during the compression stroke."
"Timing advance is required because it takes time to burn the air-fuel mixture. Igniting the mixture before the piston reaches top dead center (TDC) will allow the mixture to fully burn soon after the piston reaches TDC. If the air-fuel mixture is ignited at the correct time, maximum pressure in the cylinder will occur sometime after the piston reaches TDC allowing the ignited mixture to push the piston down the cylinder with the greatest force. Ideally, the time at which the mixture should be fully burnt is about 20 degrees ATDC. This will utilize the engine's power producing potential. If the ignition spark occurs at a position that is too advanced relative to piston position, the rapidly expanding air-fuel mixture can actually push against the piston still moving up, causing detonation and lost power. If the spark occurs too retarded relative to the piston position, maximum cylinder pressure will occur after the piston is already traveling too far down the cylinder. This results in lost power, high emissions, and unburned fuel."
^^^In a nutshell, those are the 3 primary parameters tuners are going to tune for WOT. There will be tables that typically reference RPM vs load (load can be calculated via throttle position-not recommended, MAF voltage/grams of air per second, or boost pressure/MAP sensor). You manipulate these tables for fuel & timing, and sometimes boost depending on what you're tuning. Once you learn to read them, they're not too difficult to understand at all. You set your "axes", typically RPM something like:
200rpm
350rpm
500rpm
650rpm
Ect.
Ect.
7000rpm (whatever your redline is)
^^^So, if you want to make minute adjustments, setup close RPM points.
Then you'll setup your load reference. To make this simple, we'll assume you're running Speed Density (these cars don't from the factory haha), which reference boost, would be something like this:
10%= 2psi 20%=4psi 30%=6psi ect ect 100%=20psi
This works the same way with referencing via MAF, but instead of boost, it would reference the amount of air that flows over the MAF, either via MAF volts (0-5V common) or G/S (grams of air per second), which we'll say for argument sake is 300gs peak in this case. It would follow the same logic:
10%=30gs 20%=60gs 30%=90gs ect ect100%=300gs
This was make a large graph. Keep in mind, this is a piss poor graph, RPM points IMO should be closer than 500rpm apart, but for simplicity sake:
10% 20% 30% 40% 50% 60% 70% 80% 90% 100%
500
1000
1500
2000
2500
3000 0 0 0 0 +12
3500
4000
4500
5000
5500 0 0 0 0 0 0 -15 -15
6000
6500
7000
^^^Sorry if they don't line up correctly
^^^With that, let's say that at 3000rpm your car is seeing 50% load (either 10psi or 150gs going by the "axes" we made above) and the car is running leaner than you want, and in order to get your targeted AFR's, we need to add 12% additional fuel at that RPM, you can see it above, but let's say at 5500rpm you're seeing between 70-80% load, your car is running too rich, and to reach your target AFR's you need to remove 15%, you can see that above. BTW, assume all the blank space in between is set to 0.
I think I may have gotten too far into this, but I hope you get the idea.
AKA- [color="Blue"]arctic_blue83[/color]
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
-
roninsoldier83
- Posts: 664
- Joined: Wed Sep 24, 2008 9:14
- Location: Lakewood, CO
- Contact:
I'll answer your questions the best I can:
- What's a tune entail? Leaving your car with a shop for a day/s?
A. Making multiple WOT pulls on a dyno. The number of pulls & amount of time spent will depend on how far off your tune is to begin with. Most dyno tunes I've seen on a stock turbo car are anywhere from 5-20 WOT pulls (not counting partial throttle pulls trying to get your MAF scaled if necessary). Obviously, if your AFR's & timing tables are less than optimum you will be there longer, as the tuner will have to make more pulls to set everything correctly. A tuner usually does these things:
-Scale the MAF. Involves getting your ECU to accept the size of your MAF in order to not have to add/remove fuel in closed loop/partial throttle.
-Tune closed loop, which is mostly just scaling your MAF to make sure your long term fuel trims stay at 0% (ECU's can add or subtract 15% in Subaru's case), as well as setting your injector pulse width if you've changed injectors.
-Set your OL/CL (open loop/closed loop) delays. The time it takes for your ECU to switch to your open loop map after you give XX amount of throttle.
-Set your fuel cut limits. If you're targeting let's say 17psi/more than the ECU will allow for factory, a tuner must raise the limit before fuel cut kicks in. For a 17psi peak, a tuner will likely set your fuel cut at 19-21psi or so.
-Turn off any CEL's (check engine lights) that might occur, like if you've removed your cats, all the codes that would apply to running catless.
-Tune your AFR's with a lower-medium boost/timing setting. This involves those tables I was talking about above.
-Slowly increase boost & advance timing while monitoring your AFR's, knock/knock retard, injector duty cycle & horsepower/torque. Typically, a tuner after hitting peak boost, will advance timing until the car sees a count or 2 of knock, then retard 2 degrees and call it a day. Unless of course the car never knocks, but just stops making power, in which case, you're done tuning pretty much if there's no knock but you can't make anymore power. Another way to end a tuning session: Run out of fuel overhead. Many tuners don't want to go over let's say 85% IDC peak, so if your car is seeing 90% peak IDC (injector duty cycle) at 17psi with your targeted AFR's, your tuner will likely turn down the boost to avoid running over a certain duty cycle. Some will tune at higher IDC's than others.
When tuning, depending on how many of these parameters need to be changed, and to what degree, this can take anywhere from 1-4 hours. Commonly, most dynos tunes on stock cars I know of take around 2-3 hours. This is usually done all in one day with you there, unless something goes wrong, or you specify otherwise (like you want to drop your car off for the day or something).
- During the "tune", are they constantly making aggressive pulls? Or is it more computer-type management than actual spirited driving?
When tuning for WOT (wide open throttle), yes, they make multiple full throttle pulls. Usually, after tuning partial throttle maps/scaling MAF/injectors (no WOT), they will make a WOT pull while datalogging, then after the pull, examine the log (load/boost/MAF gs, AFR, knock retard/knock if any ect), make corrections needed (this takes a few minutes typically), then make another pull and repeat this process over and over until you're finished. Now, even though they're making WOT pulls, that does NOT necessarily mean it's really that hard on your car. If they're doing their job correctly, they're trying to AVOID knock, and make your car's tune be able to take abuse without damaging your motor. Most tuners if they see a large knock count during a pull, will cut the pull short rather than risk damaging a motor, and will only make another pull when they've made changes that should hopefully result in reducing/eliminating the knock you're experiencing. That's the point, the make your car run at an optimum level SAFELY!
- Any ideas what a shop would charge for such work?
Depending on the shop. Most charge anywhere from $150-$175/hr, and an average tune takes about 2-3 hours. Some shorter, some longer. Some offer flat rate deals, like MAC offers $350 flat rate on AP or OpenECU tune. Revolutions Performance offers a very similar deal. It's really just depending.
I know this all really long winded and probably confusing, but I hope it helps! Have a good one buddy!
-Brandon
- What's a tune entail? Leaving your car with a shop for a day/s?
A. Making multiple WOT pulls on a dyno. The number of pulls & amount of time spent will depend on how far off your tune is to begin with. Most dyno tunes I've seen on a stock turbo car are anywhere from 5-20 WOT pulls (not counting partial throttle pulls trying to get your MAF scaled if necessary). Obviously, if your AFR's & timing tables are less than optimum you will be there longer, as the tuner will have to make more pulls to set everything correctly. A tuner usually does these things:
-Scale the MAF. Involves getting your ECU to accept the size of your MAF in order to not have to add/remove fuel in closed loop/partial throttle.
-Tune closed loop, which is mostly just scaling your MAF to make sure your long term fuel trims stay at 0% (ECU's can add or subtract 15% in Subaru's case), as well as setting your injector pulse width if you've changed injectors.
-Set your OL/CL (open loop/closed loop) delays. The time it takes for your ECU to switch to your open loop map after you give XX amount of throttle.
-Set your fuel cut limits. If you're targeting let's say 17psi/more than the ECU will allow for factory, a tuner must raise the limit before fuel cut kicks in. For a 17psi peak, a tuner will likely set your fuel cut at 19-21psi or so.
-Turn off any CEL's (check engine lights) that might occur, like if you've removed your cats, all the codes that would apply to running catless.
-Tune your AFR's with a lower-medium boost/timing setting. This involves those tables I was talking about above.
-Slowly increase boost & advance timing while monitoring your AFR's, knock/knock retard, injector duty cycle & horsepower/torque. Typically, a tuner after hitting peak boost, will advance timing until the car sees a count or 2 of knock, then retard 2 degrees and call it a day. Unless of course the car never knocks, but just stops making power, in which case, you're done tuning pretty much if there's no knock but you can't make anymore power. Another way to end a tuning session: Run out of fuel overhead. Many tuners don't want to go over let's say 85% IDC peak, so if your car is seeing 90% peak IDC (injector duty cycle) at 17psi with your targeted AFR's, your tuner will likely turn down the boost to avoid running over a certain duty cycle. Some will tune at higher IDC's than others.
When tuning, depending on how many of these parameters need to be changed, and to what degree, this can take anywhere from 1-4 hours. Commonly, most dynos tunes on stock cars I know of take around 2-3 hours. This is usually done all in one day with you there, unless something goes wrong, or you specify otherwise (like you want to drop your car off for the day or something).
- During the "tune", are they constantly making aggressive pulls? Or is it more computer-type management than actual spirited driving?
When tuning for WOT (wide open throttle), yes, they make multiple full throttle pulls. Usually, after tuning partial throttle maps/scaling MAF/injectors (no WOT), they will make a WOT pull while datalogging, then after the pull, examine the log (load/boost/MAF gs, AFR, knock retard/knock if any ect), make corrections needed (this takes a few minutes typically), then make another pull and repeat this process over and over until you're finished. Now, even though they're making WOT pulls, that does NOT necessarily mean it's really that hard on your car. If they're doing their job correctly, they're trying to AVOID knock, and make your car's tune be able to take abuse without damaging your motor. Most tuners if they see a large knock count during a pull, will cut the pull short rather than risk damaging a motor, and will only make another pull when they've made changes that should hopefully result in reducing/eliminating the knock you're experiencing. That's the point, the make your car run at an optimum level SAFELY!
- Any ideas what a shop would charge for such work?
Depending on the shop. Most charge anywhere from $150-$175/hr, and an average tune takes about 2-3 hours. Some shorter, some longer. Some offer flat rate deals, like MAC offers $350 flat rate on AP or OpenECU tune. Revolutions Performance offers a very similar deal. It's really just depending.
I know this all really long winded and probably confusing, but I hope it helps! Have a good one buddy!
-Brandon
AKA- [color="Blue"]arctic_blue83[/color]
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Wow, thanks Brandon. I realize you invested some time to answer my questions, and more so, to put it into simplistec terms for me too. I really appreciate it. I'll definitely flag this message and keep it for valuable reference material:)
I'll need to read it over a few more times though, lol. My brain's only absorbed roughly 5% of the info so far...
- Nate
I'll need to read it over a few more times though, lol. My brain's only absorbed roughly 5% of the info so far...
- Nate
one and one makes two, together we are free
-
roninsoldier83
- Posts: 664
- Joined: Wed Sep 24, 2008 9:14
- Location: Lakewood, CO
- Contact:
kingtut wrote:So, once your car is tuned- Is that something that is permenant? Or can you switch back to the stock tune?
Depending on what you're using... in most cases, no it's not permanent. If you're using an Accessport for instance, you have to "marry" it to the car, meaning sync it to your ECU (this is just so you can't use it to flash multiple cars/so Cobb can make more money). From there you load a map into your ECU, whether it be one of Cobb's maps (that they made at their location to send out, aka OTS Off-The-Shelf) maps, or a custom map a tuner has made for you.
An AP stores multiple maps... you can either load a "stock" map from the AP, OR you can unmarry the AP from your car which will result in it flashing back to your stock map, aka, going back to stock.
If you use a Standback, it's a piggyback, you're actually not "changing" any ECU parameters AT ALL. Instead, you are intercepting signals BEFORE they go into the ECU and modifying/manipulating their values. In other words, if your MAF is showing 3.1 volts, and you want to add more fuel, you are "tricking" the ECU by adding extra voltage, let's say you're telling it that it's seeing 3.3 volts, when it's only sending 3.1, in order to get the desired effect. If you bought the plug-n-play wiring harness, technically, you could remove the Standback at any time, and there would be no trace of it ever being modified as you actually never reprogrammed the ECU, you just manipulated values going into it.
So yes, you can revert back to stock with those 2 tuning options.
kingtut wrote:I asssume a tune would be looked at poorly from the dealership's standpoint? How would such a thing effect warranty work?
IMO, yes a tune would be frowned upon by a dealership as they have just about no way of checking all the parameters you might have changed, and no way of knowing how aggressively you might have tuned it. So yes, if you tuned the car too aggressively, and blew the motor or something, they would not want to honor your warranty. I don't blame them. If I ran a business like that, neither would I. Now, with that said, unless you somehow brick your ECU (hard to do unless you unplug the AP while it's writing changes), you can always just go back to stock if warranty work is needed. Back to stock=no one the wiser. Well, unless you decide to run a Standback without the PnP wiring harness, and you've cut up/soldered your stock wiring harness, in that case, if anyone looked, it would be pretty evident haha. With a PnP wiring harness though, I see no reason for the dealer to ever know unless you have them take a look while the Standback is connected. The AP on the other hand... after you flash whatever map you're running, you don't even have to have it in the car (although I would recommend it just in case).
The problem with the AP though is finding someone who has Protuner software for the MS3/MS6. You see, if someone wants to become a Cobb Protuner for their Mazda product line, they have to BUY the Protuner software from Cobb (Cobb charges everyone haha), and considering the high price of entry, for a tuner to buy the Mazda specific or 2.3 DISI specific software (not sure how they have it setup), they have to be able to see a profit later on. Meaning, if a tuner has to tune at least 10 cars in order to make a dime after purchasing the software (it's expensive from what I understand), they're going to have to see a customer base prior to buying it from a good business point of view.
Tuners at locations like MAC, Super Rupair, Revolutions Performance ect, they've all probably tuned 500+ Subaru's a piece. There's a huge customer base, and a TON of them have their cars professionally tuned. Whereas for more low production cars like the MS3/MS6, the tuner customer base isn't so big, as there's just not as many of them out there.
What I would do if I still owned my MS6, would be to try and get a list of local AP owners/potential AP owners and present that to a tuner to spark a tuner's interest into buying AP Protuner software to tune that product line. As it stands, I don't know any Protuners locally who tune AP's for MS3/MS6 cars, but I haven't checked in a while....
Which is why I think many people will still with the Standback, as anyone can tune it. Which is sad IMO, as I prefer flash based tuning over a piggyback anyday, but that's the way of the world. Although before buying either, I would call around to local tuners, and just make sure someone you trust is WILLING to tune either one of those devices. Hope that helps!
AKA- [color="Blue"]arctic_blue83[/color]
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
Mine: 2015 Subaru WRX
Hers: 2013 Subaru WRX
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