Little boost help please

[Outkasted]

First let me say i have searched and i can't find my answer.

Let me start with my car is a basically stock 02 s4 with about 70k. I just installed an autothority chip which i know is not popular but it was free so i guess you get what you pay for and an autometer boost gauge also free.

I used autozone tubing measuring 1/8" to instal the boost gauge. Is this a problem should i have found a larger tubing?

My guage reads 10 vac on idle. I read it should be around 20-22. Is this a sign of a boost leak or the wrong tubing size.

Lastly in 3rd gear my boost tops out on the gauge at 10 from about 3k rpm until 6k. That is as far as i have tested. After a little research i found it should be at 15. Is this the wrong gear to do this test or once again boost leak. Opinions please and thanks for your help in advance.

[Outkasted]

26 views and no responses.

[Mantis]

dont know much about your chip, do know that 3rd will peak the highest, usually at around 15 psi (depending on the chip), did you notice any throttle cut or lurching, when I tore myt TBB, I could boost fine up to 9psi before suffering any bad effects, beyond 10psi and the car bucked

[highPSI-S4]

First let me say i have searched and i can't find my answer.

Let me start with my car is a basically stock 02 s4 with about 70k. I just installed an autothority chip which i know is not popular but it was free so i guess you get what you pay for and an autometer boost gauge also free.

I used autozone tubing measuring 1/8" to instal the boost gauge. Is this a problem should i have found a larger tubing?

My guage reads 10 vac on idle. I read it should be around 20-22. Is this a sign of a boost leak or the wrong tubing size.

Lastly in 3rd gear my boost tops out on the gauge at 10 from about 3k rpm until 6k. That is as far as i have tested. After a little research i found it should be at 15. Is this the wrong gear to do this test or once again boost leak. Opinions please and thanks for your help in advance.

Autometer gauges are alittle cheaper than most but are very good. reading
10hg vaccum on the gauge does sound like a boost leak to me, does it idle weird or real choppy. last time my vac. was that low i had some bent valves. also you need to do a pressure test. try reading some of the fAQ thread in the forum. as well there are other thread about boost leaks. Is there a stock mode on your software? 10psi is close to stock and is what i was running before i got my gIAC software.

[The_Jerbel]

6th gear will give you the highest boost spike. It's called boost creep. I would pressure test your car if I was you.

[1997gtx]

I have never heard of the chip. Just because other chips boost to 15 or 16, doesn't mean yours does. Do you know what the chip is programmed for?

Log block 115 (boost) and pressure test.
--Adam

[Outkasted]

Thanks i was really just trying to rule out the hose size i used for the boost gauge. I must be leaking somewhere. My trusted mecanic who i got the chip from says i should be hitting 15 psi. There is no bucking, cutting out, strange idle or hesitation at all it just doesn't go past 10 psi. Doesn't even pull that hard to be chipped. I will check my work installing the boost gauge and go from there. Thanks for your help.

[highPSI-S4]

Did your trusted mech give you a ecu with the software on it/how was it up loaded?

I don't know anyone with there software but there are a known shop around here in virginia/ more so for there BMW work.

If you can restore the program back to stock and then check your boost gauge.

and deff. get a pressure tester you don't have to have noises or choppy idle to have a boost leak. Like the others said pressure test it.

[obijohn22]

my car runs about 16 vac at idle. goes to around 20-22 while coasting in gear. spikes to 19psi and holds at 15psi on boost.