alrite guys, with all my mods in my sig i raced my friends s2k that i would always destroy from a roll when he was stock last nite after he got an invidia cat back and a test pipe. he wanted to see how much of a diff. his new parts got him so we went from a 40. i could only pull 1-1.5 cars on him. i would always destroy him before by like 5 cars or more from a roll so now im wondering is there something wrong with my car? ive noticed lately that my boost is only around 14 psi in the high rpm's lately and 15 tops. i can remember it being more than that when i first got all my parts put on so do u think there could be something wrong with my car?
thanks for any help

 

so let me get this straight... you raced a car, beat it. then the car put some performance parts on that give more power. you beat it by less. how is that a problem?

 

sounds like what happens as results of modding...

 

because my boost gauge reads less now and he somehow just gained enough power to cut my 5-6 car win to 1-1.5 with prob. about 10 whp & the whole point of this thread is that my boost reads not as high as it used to and i think i might be losing power, not the race, it just backs up my assumption

 

well for your mods i would say about 14-15 psi is pretty normal actually.

he may have just gotten better as a driver also.

 

o alrite. well i was just thinking i had more boost before but maybe im just imagining it.

 

where are you at in Indiana?

 

What are the supposed gains from the catback and test pipe on the s2k?

 

a stage 2 with 2.9" pulley should see more than 15psi. the regular stage 2 pulley gives me 15psi. i have a 2.9" coming in the mail and am hoping for 16-17psi
you know your car best. if your car feels sluggish and your boost gauge isnt reading what it used to.

here's a thought... was it hot or humid outside? moisture and heat can sap your boost and make the car run like ****.

 

the very southern part close to louisville.

both combined should get him about 10-12 whp i think

yea i think it should be more too.
it was about 85 degrees and a little humid so that could have taken some part i guess.

thanks u guys

 

its bc he has vtec jk those things are pretty quick for n/a with simple mods.

 

I know mine def. boosts less when it is warm out. In the winter I could tell it pulled harder just because it was cold as ***** out. 85° compared to 20-30° plays a big part.

 

I've got 16 from my 2.9" pulley.. in the winter when it was VERY cold out I might have hit 17psi a few times.

i think what happened is that you were racing him during the winter, and now it's warmer.
F/I cars love the cold air.

 

^ Exactly. You should still beat him by more then 1.5 cars though if you beat him by 5 before. Then again maybe you had a bad race and he had his best. Can make a big differance.

 

Hot weather. Catback and test pipe do nearly nothing for an s2k.

 

bump

 

Humidity can have a MILD benefit on forced induction cars while it hurts N/A cars...Assuming your ECU can account for it.

What I'm saying is higher humidity will slow an S2k down more then a SS/SC....

 

When you open up the exhaust you're reducing back pressure which in turn will produce less psi reading on the boost gauge.

 

i did not know that. anyone can confirm this?

 

yep. exhaust can reduce boost.

its actually a good thing your making more power, with less boost.

 

you're judging your boost off an autometer gauge.

need i say more?

 

Its accuracy is questionable.
but its accuracy relative to itself is quite good.
So your point is moot.

 

i might replace my boost gauge sometime anyway so if autometer is not a good gauge, what would u recommend?

 

If I had to choose aftermarket it would still probably be autometer, mechanical but autometer.

 

i used to boost 20-21psi with a 2.5" now i boost like 18-19 with full exhaust