Just as the topic says, all of you Mazdaspeed guys, how many of you have boost gauges? If you have one, how much boost are you pushing? Are any of your experiencing fuel/boost cut? If so, at what psi?


I just talked to Jake, apparently his car is spiking to 16-17psi of boost and holding 15psi of boost... and it doesn't look like he's hitting fuel cut. He's on the stock ECU, no EM, and no boost controller. His high(er) boost levels are probably just from the fact he has a full downpipe/race pipe combo, but the fact he's not hitting fuel cut is what interests me. My car would hit fuel cut right around 15psi or so, sometimes lower (14psi), just trying to see if the fuel cut point for Speed3's & Speed6's is the same.

Boost is relative to the air density, so I don't see why would the EMS would cut off the fuel depending of the boost level.
All the EMS/ECU I have seen cut the fuel based on RPM levels.

When I was stock b4 the EMU I never hit the cut... prob goin back to non-Emu soon.

<div class='quotetop'>QUOTE (arctic_blue83 @ Oct 21 2007, 04:49 PM) [url=index.php?act=findpost&pid=7054]<{POST_SNAPBACK}>[/url]</div>

Just as the topic says, all of you Mazdaspeed guys, how many of you have boost gauges? If you have one, how much boost are you pushing? Are any of your experiencing fuel/boost cut? If so, at what psi?
I just talked to Jake, apparently his car is spiking to 16-17psi of boost and holding 15psi of boost... and it doesn't look like he's hitting fuel cut. He's on the stock ECU, no EM, and no boost controller. His high(er) boost levels are probably just from the fact he has a full downpipe/race pipe combo, but the fact he's not hitting fuel cut is what interests me. My car would hit fuel cut right around 15psi or so, sometimes lower (14psi), just trying to see if the fuel cut point for Speed3's & Speed6's is the same.[/b]

highest ive seen on mine is 16, most of the time it holds at 11 or so while accelerating through the rpms, sometimes 10, and i had fuel cut only two times so far.

<div class='quotetop'>QUOTE (Anh Bi @ Oct 21 2007, 04:54 PM) [url=index.php?act=findpost&pid=7055]<{POST_SNAPBACK}>[/url]</div>

Boost is relative to the air density, so I don't see why would the EMS would cut off the fuel depending of the boost level.
All the EMS/ECU I have seen cut the fuel based on RPM levels.[/b]

Actually, on the Speed cars, as well as various other factory turbo cars, boost induced fuel cut is based on the MAP sensor, this is been proven, and as a matter of fact, I later went to using TurboXS' FCD (when I had my Speed6), which is just an adjustable MAP clamp, and I was able to tune out fuel cut completely. Although some cars have fuel cut based on MAF sensor voltages ect. You're thinking about a fuel cut induced rev limiter, not a preventative over-boost control method.

It's also been proven our ECU's have the ability to compensate for altitude and form their own algorithm to induce fuel cut, as several Speed cars up here have experienced fuel cut at boost pressures below that of what they should be seeing stock at sea level. Most of the Speed cars at sea level don't hit fuel cut until around 18psi, whereas up here a couple guys have hit fuel cut as low as 13-14psi, when they're supposed to be pushing 15-16psi stock at sea level.

My gauge spikes around 15psi and holds at 11-14psi through the paces. I have never hit fuel cut yet but probably because I only have a testpipe for exhaust mod. Be interested to see what the others out there are running for boost. Still waiting for my ETS Top Mount.....I wonder if the guys running the upgrade intercooler are having more stable boost ranges. It seems mine is all over the place. 2nd 13-14psi, 3rd 11-14psi, 4th 11-13psi...... I am thinking it could be my gauge????

<div class='quotetop'>QUOTE (arctic_blue83 @ Oct 21 2007, 04:49 PM) [url=index.php?act=findpost&pid=7054]<{POST_SNAPBACK}>[/url]</div>

Just as the topic says, all of you Mazdaspeed guys, how many of you have boost gauges? If you have one, how much boost are you pushing? Are any of your experiencing fuel/boost cut? If so, at what psi?
I just talked to Jake, apparently his car is spiking to 16-17psi of boost and holding 15psi of boost... and it doesn't look like he's hitting fuel cut. He's on the stock ECU, no EM, and no boost controller. His high(er) boost levels are probably just from the fact he has a full downpipe/race pipe combo, but the fact he's not hitting fuel cut is what interests me. My car would hit fuel cut right around 15psi or so, sometimes lower (14psi), just trying to see if the fuel cut point for Speed3's & Speed6's is the same.[/b]

Yes I never hit fuel cut and I know this because I had to ask Brandon what the car would feel like when I would hit fuel cut. After he told me how i was, lets just say I would have know that was going on.