The Miata

FDEEZ · Postby **FDEEZ** » Wed Jun 25, 2014 9:14

Nice setup!

The Driver · Postby **The Driver** » Thu Jun 26, 2014 9:14

Saul_Good wrote:I'm a wheel whore. Got new wheels. That is all.

15x9 Advanti Storm1 w/225/45/15 BFG Rivals.

Hehe, those look kinda familiar...

Saul_Good · Postby **Saul_Good** » Mon Jul 07, 2014 9:14

From the SCCA Club Time Trial competition on 5 July. It was a good time. Need more people to show to make it a better series. The way it is now with the low count we kind've just all fit into one class and battle and look at things such as raw score and adjusted score. Raw time I was 5th and adjusted I think 1st (we'll see when they release results).

http://vimeo.com/100082977

Saul_Good · Postby **Saul_Good** » Mon Jul 28, 2014 9:14

Went autoxing this past weekend but due to temps my phone wasn't working so no vids of that. After autox I went to PPIR and ran the CCW configuration. Temps were cooler with overcast so i managed to get some vids.

Best time (not in vids) was 1:12.72

http://youtu.be/ABLGhmcmZyA Chasing a porsche
http://youtu.be/wgikcuwakos playing w/an Audi

coloskydiver · Postby **coloskydiver** » Tue Jul 29, 2014 9:14

It always amazed me how many people under estimate the Miata. That Porsche will pull on you in the straights but it didn't take much to reel him in on the curves. Great driving and looks like you now have a really good feel for the Miata. I truly miss my Miata and am itching to get out on the track. I am looking forward to hitting up PPIR. I have yet to make it out to that track, plus I was born and raised in that part of town. I remember when it was being built and when they had the Indy Cars out there. Your driving skills are impressive and one of these days I will see you at the track.

FDEEZ · Postby **FDEEZ** » Tue Jul 29, 2014 9:14

Ditto on the impressive driving skills!

Saul_Good · Postby **Saul_Good** » Wed Oct 08, 2014 9:14

A lot has happened. I picked up a used Greddy E-Manage Ultimate. Once I figured out how to get it to communicate with my netbook, I started to familiarize myself with it’s functions.

Fast forward to ~3wks ago…. I went to All Performance Garage to tune my car. I was able to get a before run then a tuned run on the same day. I went from 110whp to 116whp (peak HP numbers) and was able to raise the overall powerband throughout the RPM range.
Despite this, I thought my overall HP numbers were low compared to the rest of the Miata world (at least those that have actually dynoed their cars). Wanting to find out more, I asked Dwduc (Jason) to lend me a compression tester. The numbers I got were: 1) 155, 2)156 3)155 4)155-6. Compared to others to my research, that is down from similar miatas that do 185s or better.

Just a note, I didn’t think anything was wrong and would not have started this goose chase had I not dynoed the car. Prior to the dyno nothing was wrong, seemed wrong with the car and I was able to keep up with Dwduc and Spec Miata’s, etc on a big track as well as other NB1 miata’s in STR at autox.
Fast fwd more to yesterday 10/7/14. I called both Coyote Motors and Flyin Miata to tell them of my dyno and compression woes. Both said, my compression #s were fine given the mileage and elevation I’m at. This is a new one for me, but compression is ALSO affected by big elevation changes. I know at higher altitudes there is less air molecules that cause and affects the performance of the car because of that but didn’t know it also changed the compression psi of a motor too. – I wonder if the two are related (altitude causes low comps, less dense air which equates to loss in power) ??? They also told me not to worry so much about the dyno numbers and comparing them exactly with other Miata’s too much. Although a correction factor was used to simulate what I should be making at sea level, that factor is more like a moving target and there’s a fudge factor involved. With that, my numbers are on the lower side, but nothing to be OMGNEEDAREBUILDASAP!!! and that it has more to do with the variation between motors (ie some people have stronger motors than others from the factory). The big takeaway is I did a before/after dynotune on the same machine on the same day that yielded positive results.

TL;DR – I had lower than expected dyno/compression numbers. Called the pros and was told don’t worry your engine is just weaksauce but still healthy.

roninsoldier83 · Postby **roninsoldier83** » Wed Oct 08, 2014 9:14

Decent gains for a naturally aspirated Miata at elevation!

I've put more of my cars on dynos over the years than I care to admit... I've easily put thousands of dollars into tuning time on dynos; especially years ago when I was a much more "active" enthusiast. With that said, I wouldn't sweat your peak numbers in the least. Really the only thing that matters is the delta gains vs your baseline, and it looks like they were pretty solid across the board. Also, your compression numbers are extremely close to each other, so I wouldn't have any concerns at all.

The reality is, your numbers might not even be as "weak" as you think they are. The only real way to know is by comparing other Miata's to yours on the SAME dyno, on the SAME day. Beyond that, even with a correction factor, you can't make a true apples to apples comparison with other cars on other dynos in other parts of the country. There are way too many factors to consider:

-Obviously elevation, barometric pressure, humidity, ect.
-Octane of fuel used.
-Tread on your tires and tire compound- yes, this makes a difference, ESPECIALLY when people use snow tires compounds.
-Size and weight of your wheels/tires.
-The ability of your ECU to adapt for conditions. <-- I can't stress this one enough. Some cars have ECU's that adapt much easier to things like temp, elevation ect, and will increase timing, boost (if boosted obviously), ect in order to maintain power levels. My old BMW actually had targeted torque loads that it tried to hit regardless of conditions.
-Software/firmware the dyno was running on. Condition the dyno was in. Specific model of dyno.
-Dirty air filters, fouled MAF sensors, "clogged" cats, fouled spark plugs, "dirty" fuel lines, ect- they all make a difference.
-Viscosity and condition of the oil you're running.
-The air flow of the fan being used on the dyno. This can make a VERY large difference, especially in the cases of turbocharged cars that have intercoolers that heat soak easily without pressurized air flowing over them.

I could go on and on and on... but the truth is, there are way too many factors to consider and unless you had an identically modded car in the same dyno, at the same time, that was making substantially more power than you, I wouldn't sweat it in the least.

That's just my $.02

Saul_Good · Postby **Saul_Good** » Wed Oct 08, 2014 9:14

To further support that compression psi goes down with elevation, Mortose (BIG THANKS TO MORTOSE for coming straight after work looking sexy in his AF ABUs) came by and let me compression test his car. He also has a 99 Miata with the BP4W motor.

So same place, same tool, similar car/motor.
157, 157, 158, 159
His numbers are similar to mine albeit a couple psi better and also consistent.

Postby **RX-7 Chris** » Thu Oct 09, 2014 9:14

Well that ends the debate. Your motor is fine.

The other possibility for the lower numbers is the compression tester itself.

lOOkatme · Postby **lOOkatme** » Sun Oct 12, 2014 9:14

Saul_Good wrote:To further support that compression psi goes down with elevation, Mortose (BIG THANKS TO MORTOSE for coming straight after work looking sexy in his AF ABUs) came by and let me compression test his car. He also has a 99 Miata with the BP4W motor.

So same place, same tool, similar car/motor.
157, 157, 158, 159
His numbers are similar to mine albeit a couple psi better and also consistent.

not trying to be mean or anything but isn't it obvious that elevation makes lower compression? I mean if we lose 25% power at this elevation because of lower atmospheric pressure, is MUST come up on compression. This is also why they sell lower 85 octane fuel here (lower compression, lower heat, need less octane).

anyway, at sea level compression would be around 188.4 to 196.25 PSI at sea level using those numbers.

The bad part of running a turbo at these elevation is you lose 25-35% (depending on elevation) cooling capacity due to loss of mass air flow over the heat exchangers, and you run a higher pressure ratio on the turbo which means it runs less efficient and hotter. so not only do you push the turbo harder and hotter needing more cooling capacity, you lose 25-35% of your cooling capacity to cool with.

ducting, larger radiators, oil coolers, etc, etc, etc are all important when you run a turbo.

stay N/A lots cheaper, plus making less power will result in less stress on other components.

Also, dyno, weight of wheels/tires make a difference, but heavier wider stronger and wider/heavier tires lead to lower lap times, inspite of lower WHP on a dyno.

Saul_Good · Postby **Saul_Good** » Mon Oct 13, 2014 9:14

lOOkatme wrote:not trying to be mean or anything but isn't it obvious that elevation makes lower compression? I mean if we lose 25% power at this elevation because of lower atmospheric pressure, is MUST come up on compression. This is also why they sell lower 85 octane fuel here (lower compression, lower heat, need less octane).

anyway, at sea level compression would be around 188.4 to 196.25 PSI at sea level using those numbers.

Nope. I had no idea, i'm a business maj that's what engineers are for....lol but it totally makes sense. I'm guessing that compression loss was the last puzzle piece that I wasn't tracking when it comes to power loss at elevation.

lOOkatme wrote:
Also, dyno, weight of wheels/tires make a difference, but heavier wider stronger and wider/heavier tires lead to lower lap times, inspite of lower WHP on a dyno.

I know but when I put this stuff up to help other Miata guys outside of Colorado, they still expect to see similar numbers with the correction factor. They don't seem to understand altitude and don't think it's too much difference from sea level. I had one guy compare his 'altitude' of 650ft to my 6500, lol.

But yea, i got my before and after, same day same dyno and it really does drive/feel quicker than the numbers imply. Can't wait to test it out on the 31st.

So trackday on Halloween for $75?

lOOkatme · Postby **lOOkatme** » Mon Oct 13, 2014 9:14

Saul_Good wrote:Nope. I had no idea, i'm a business maj that's what engineers are for....lol but it totally makes sense. I'm guessing that compression loss was the last puzzle piece that I wasn't tracking when it comes to power loss at elevation.

I know but when I put this stuff up to help other Miata guys outside of Colorado, they still expect to see similar numbers with the correction factor. They don't seem to understand altitude and don't think it's too much difference from sea level. I had one guy compare his 'altitude' of 650ft to my 6500, lol.

But yea, i got my before and after, same day same dyno and it really does drive/feel quicker than the numbers imply. Can't wait to test it out on the 31st.

So trackday on Halloween for $75?

Remember that when you go to sea level, you will need to tune the last row or two of cells at the higher loads;)

Saul_Good · Postby **Saul_Good** » Thu Oct 16, 2014 9:14

So I rebroke my lip at autox this past weekend as you can see below. A replacement was $250-300bux!!!

Instead I ordered a RX7 R1 lip and custom fit it to my bumper.

Lots of cutting. But here's the 95% finished product. Just need to drill a few more holes and should be ready to put everything back on the car.

Website · Postby **Shadowden** » Fri Oct 17, 2014 9:14

That came together nicely so far!

Since you have the bumper off are you going to add ducting out of the fog lights to the brakes?

The Miata

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