mazdaspeed boost control/fuel cut

p-dub · May 6, 2003

whut up y'all?

i'm new to this forum, but it looks pretty tight so far.

i'm not sure if this issue has come up before, but if someone could give some guidance it would be great.

i've read up on the t-25 turbo and most sources said the max you should run the urbo at is 10 psi, because it can't sustain more than that at high RPM.

i've had my mazdaspeed for about 4 months now, and i've put a few trix in it, one of them being a manual boost controller.

the thing is, when i put the boost at about 9.5 psi, the fuel cut kicks in, so when i'm gunnin' the throttle my car stutters like as if i'm pulling off the gas abruptly, but i want to get maximum output from my little t-25 turbo.

anyone know how to trick the computer to think that the boost is at a lower psi setting when in fact it's actually higher??? or any other way of getting around this??? if you know any links or have info yourself it would be greatly appreciated.

peace.

I-Am-Chris · May 7, 2003

ummm no fuel cut and if it is its at like 13 psi or above.
the t25 is good till about 13 psi. the ECU doesnt read boost.

Logan · May 7, 2003

What you are feeling isn't the "fuel cut". It's a wonderful MSP quirk.

bcbadboy · May 7, 2003

UUUMMM
I am boosting 14 PSI's and my car hasen't shut off or felt like it was. I punch my car all the time and nothing feels like it is going to stall or shut down. Computer has nothing to do with boost control.
Do you have a boost gauge?
Is it showing 9.5 psi's?
How about your VAC? What does that read? Are you running rich or lean when you step on it?

By the way
Welcome to the forum.
Hope you enjoy it here.

perfworks · May 7, 2003

alright let the flames begin

i dont think you have a boost cut off or fuel cut off. i will confirm this BTW today when i speak to a rep that actually knows how it was designed.

anyway your meter will ""bottom out"" and the PCM will shut down the injectors. it measures air flow but most important AIR DENSITY. bcbadboy you live in south florida. and the other guy lives in toronto.
think about the air density. dont confuse what im saying with ALTITUDE. thats not where i am going with this.
bc im interested to know how long you have been running 14 psi and if you do it daily. HONESTLY!

bcbadboy · May 7, 2003

I have had it about 1 week 1/2 now and yes I drive it at 14 daily. I only drive my car about 50 - 100 miles a day. I get the 14 on 4th gear every time I punch it on the highway. I wouldn't lie about my boost. I have people here in Miami working on my car and whatever they tell me is safe to do, I'll do it. I am going to setup my Greddy Profec E-01 and E-Manange soon. I should be able see what is really going on in my engine.

perfworks · May 7, 2003

dont take it the wrong way . i wasnt saying you were lying at all. just asking without exageration.

bcbadboy · May 7, 2003

perfworks said:
dont take it the wrong way . i wasnt saying you were lying at all. just asking without exageration.

LOL I know

kwiktsi · May 7, 2003

As I have discussed with a couple of you- you cannot put a "psi" on the fuel cut. It is AIRFLOW based.. You can run 12 psi on a hot day, 9 on a cold due to the denser air. This guy gets away with 14, you can only run 10.. It is not PSI based. I can run 13 psi no problem on hotter days, once it cools off, I can only run about 9.5. It was 10.5 until I put the K&N on the car and inccreased my AIRFLOW and had to drop the boost 1 psi.. I am trying to work this out- I will get back to you guys when I do it.
Joe

Apexi · May 7, 2003

bcbadboy said:
UUUMMM
I am boosting 14 PSI's and my car hasen't shut off or felt like it was. I punch my car all the time and nothing feels like it is going to stall or shut down. Computer has nothing to do with boost control.
Do you have a boost gauge?
Is it showing 9.5 psi's?
How about your VAC? What does that read? Are you running rich or lean when you step on it?

By the way
Welcome to the forum.
Hope you enjoy it here.

you are a moron. wouldnt be suprised if you blew your head gasket, warped your head, hell.....your motor prolly hates you and will blow any day....your cars have 280cc injectors..its not good to run them @ their max duty cycle...my 97 eclipse gsx has 450cc injectors from the factory....and runs @about 13psi from the factory on the t25....do you get what im saying?

bcbadboy · May 7, 2003

Apexi said:
you are a moron. wouldnt be suprised if you blew your head gasket, warped your head, hell.....your motor prolly hates you and will blow any day....your cars have 280cc injectors..its not good to run them @ their max duty cycle...my 97 eclipse gsx has 450cc injectors from the factory....and runs @about 13psi from the factory on the t25....do you get what im saying?

Ok first of all assneck, the injectors on a MSP are 370cc. Second of all I am no where near blowing my engine. I have pros working on my car. 14 PSI is the highest those injectors allow me to go. Now I am changing my injectors to 550cc or 600cc. And I have other mods in store. T25 can hold up to 315HP. I will be changing that soon also. Another thing if I do blow my engine, I have another lined up. Don't be calling me a moron cause I don't disrespect anyone here for doing things to their car. I paid for it and I can do what ever the **** I want to it. Worry about your engine and let me worry about mine.

Laterz

Apexi · May 7, 2003

"Ok first of all assneck, the injectors on a MSP are 370cc."

http://www.mazdamp3.com/vbb225/showthread.php?s=&threadid=18934

and i sure as hell hope your gonna get some sort of fuel management and egt gauge before you put those new injectors on..

bcbadboy · May 7, 2003

Apexi said:
"Ok first of all assneck, the injectors on a MSP are 370cc."

http://www.mazdamp3.com/vbb225/showthread.php?s=&threadid=18934

and i sure as hell hope your gonna get some sort of fuel management and tuning before you put those new injectors on..

I don't care what anyone else says about the the injector sizes.
I pulled one out and had htem checked already.
Yes I bought already the Greddy Profec E-01 boost controller with programmer and a Greddy E-Manage Fuel piggy-back system. I have everything under control. There are alot of info on this forun that are kickass correct, but there are to many guesses and assumptions also. Don't just come here for info only. Talk to people that have been working on cars for years and then put 2&2 together.

Laterz

Apexi · May 7, 2003

i have been tuning cars for awile ty. not gonna try to help ppl who dont wanna listen, so good luck with the car n have fun.

p-dub · May 7, 2003

oh yeah, silly me....

one thing i forgot to mention on my original post is that i don't have any gauges right now because i've been waiting for a triple gauge pillar-mount pod for over a month 'cause it keeps getting back ordered. i've got boost, air/fuel ratio, and EGT gauges but can't use 'em yet.

we've used a temp. boost and air/fuel ratio gauge to try and figure it out, but it still ain't workin'. i'll try some of the tips you guys had. thanx yo.

perfworks: waiting to hear what you can find out.

peace.

Spooled · May 7, 2003

I have a couple questions about what is "safe" for the MSP engine. From what I have gathered, running lean seems to be the most dangerous way to go. So as long as you are running a good A/F ratio, what else would cause engine damage from adding boost? Does anyone have any idea what sort of HP the MSP engine can handle safely, assuming that the A/F ratio is ok? If it is decently high, then it seems like all you'd have to do is get an electronic boost controller and some sort of electronic A/F manager like the Apexi SAFC. Then you could set the EBC to the max boost that your injectors can keep up with and let the AFC do the rest. I am very interested in getting some clear info on this. I really want to kick my boost up without having to worry about adjusting it for the weather and constantly monitoring the A/F mix. I would be lying if is said I wasn't slightly scared after seeing LinuxRacr's engine...

Thanks for any info.

Apexi · May 7, 2003

http://www.i-club.com/forums/showthread.php?threadid=9739
i just hope that doesnt happen to you..

by the way p-dub, and anyone else with an egt gauge, or looking to get one.., for that egt gauge, loook into a tre probe, best of the best..compatable with all of the popular gauges.

http://www.teamrip.com/accessories.html

perfworks · May 7, 2003

Apexi said:
"Ok first of all assneck, the injectors on a MSP are 370cc."

http://www.mazdamp3.com/vbb225/showthread.php?s=&threadid=18934

and i sure as hell hope your gonna get some sort of fuel management and egt gauge before you put those new injectors on..

BC where are you getting your info??
MAZDASPEED already confirmed that the injectors are 280cc's
are they wrong and you are right?
what the **** now im second guessing.
THE GUY CAME ON THE FORUM and confirmed it!!!!!!!!!!!
who flowed the injectors and at what psi
i would like to talk to them. sorry for being skeptical but the company that put there name on YOUR car says something completely different.

unwrittenLaw · May 8, 2003

http://www.i-club.com/forums/showth...p?threadid=9739

That guy blows up his engine and still gets it fixed under warranty, and my dealer won't even replace my fuked up windshield...sucks

I hope he takes better care of his car next time around

Apexi · May 8, 2003

no no no he did not get it replaced

mazdaspeed boost control/fuel cut

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