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8psi with a 3.2 normal???

Justin48

Justin48

New member
Hey so i have a:
02 gtp 54,000miles
xp cam
speed daddy headders
prj intercooler
fwi
3.2 zzp mps
3.5 oversided tensioner pully...

at wot aeroforce says i am only pushing 8psi at sea level, is that normal?

friend of mine has
97 gtp 150,000miles
xp cam
plog
3" catless dp
stainless back cut valves
k&n intake
3.2 press on
and he is running 11psi sea level...
 
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he should have more boost since you are flowing better with your headers, but as far as numbers go someone who is more knowlagable will chime in to help
 
Your intercooler and headers are keeping your boost levels lower...if you want higher boost numbers...put on a smaller pulley and supporting mods...which...with an IC and XP...you should be running at least a 2.8" on there.
 
Headers and Cams will both drop boost levels compared to a car without. I can't say for sure on how much it should have as I don't have a blower car.
 
wow 2.8!!! i was told that a 3.0 was about limited... my total list of mods are
fwi
180*
autolite 104
prj intercooler
zzp stage 3 fmic
bosh ic pump
130#springs
modded retainers
comp cams keepers
double roller chain
machined oil pump cover
42.5 injectors
speed daddy headers
hp tuners
performance shift added
wide band o2
aeroforce
3.2, 3.4 mps

think thats a full list...
 


one with less boost will be faster.

its flowing better.

And I want your PRJ core.... lmao

You should also consider porting your blower or having that done and a larger TB be it a ported stock or say an LS1 or N*.

Might want to also consider a colder plug, those might be too hot for you if you do decide to hit the 2.8-3 region.
 
well i have a set of 304's new in box... sorry i am quite happy with my core... was thinking of doing a port job but would like to see about finding a gen III in a junk yard or something and doing a port job on it... and guess look for a N* while at it... oh the answer to the whos faster did a run from 30-145 and we kinda just keep "nosing* in front of the other... mind you he has a zzp pcm with parameters in it he wanted for his mods.. and my pcm is a "tweaked" tune from paul at prj with a "ballpark" injector correction... i haven't even dialed it in (scared to at the moment but still researching it...) and from a dig we both punched too hard and broke loose but both hooked up right away and STILL ended up at 120 and ended up letting up... he was glad to finally race some one that actually was a "good race" lol...

oh do you need to "shave the snout" for a 2.8? zzp says anything smaller than a 2.8 but didn't know if that ment 2.8 and under...
 
i think reptile has some cores, you could have him port for you and then send him yours.

you can contact him on here
 
Reptile ported my SC and TB and did a wonderful job. Killed my knock on my 3.4 setup too... :D Throttle response really picked up with those mods!
 
And for your throttle body choice...N*'s pedal feel is crap in comparision to a LS1...the N* was too jumpy...I love my LS1...its as smooth as stock was...just some little info for ya.
 


2.8 works fine.

any smaller needs machining, but you should never run a pulley that small. You'd be doing more harm than good.

Basically if you need to go smaller you need a larger/more efficient blower.
 
More timing>then more boost. What kind of timing and knock levels are you seeing on your car? Whats your AFR. If you can run a 11.8ish AFR and 19 wot with no knock then drop lower and see what it does. Id think a 3.0 with 19 wot timing would suit you well.

You should also add a Fuel pump rewire in there to aviod drop off on say a 1/4 mile run. FWIW I was seieng 7 psi on a 3.4 intercooled Header set up. so your 3.2 with your cam Ect seems good. Boost= A mesurement of restriction. The better you flow the less the boost and also the lower the heat.
 
Hey thanks for the word on the LS1 tb... good things to know yeah ill look into reptile on the blower porting.. do people do any port jobs on the ls1 tb's? or is the stock size the limit? right now i dont know what timeing is i am at work but ill look it up but my wb 02 pegs rich at wot around 10.0 dont think it will go any lower lol and i have no kr... hey do 02's have a problem with removal of the tb's "honeycomb" my buddys 97 started throwing codes and haveing issues with it removed.. ill do a few runs and scan it mind you the wb would not be in the scan being i dont have the "pro" hp tuners...
 
01gpgt01 said:
More timing>then more boost... ...Boost= A mesurement of restriction. The better you flow the less the boost and also the lower the heat.
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Alot of people forget or don't understand the principles on boosting cars. High psi figures don't really mean much. What you want to achieve is a high CFM amount going into the intake, which is where the lower pulley comes in. The supporting mods are so the engine can allow it to handle the amount of air coming in, and the flow allows it to be able to escape without building up pressure and launching your heads off the car like a NASA space rocket.
 
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Justin48 said:
Hey thanks for the word on the LS1 tb... good things to know yeah ill look into reptile on the blower porting.. do people do any port jobs on the ls1 tb's? or is the stock size the limit? right now i dont know what timeing is i am at work but ill look it up but my wb 02 pegs rich at wot around 10.0 dont think it will go any lower lol and i have no kr... hey do 02's have a problem with removal of the tb's "honeycomb" my buddys 97 started throwing codes and haveing issues with it removed.. ill do a few runs and scan it mind you the wb would not be in the scan being i dont have the "pro" hp tuners...
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Wow you tune your car and you dont know the Ignition timing and allow it to run on a 10.0 afr? You need to lean that thing out and see what the sparks at. (see what spark is first)You will gain a crap ton from just leaning. Post up some scans.
 
hey well i will do some scans tonight. the "tune" i have is a prj tune and all i changed was the injector size and the shift tables and the fans... i haven't studied enough on how to do a proper spark/fueling tune... i did the install of the parts got it running and drove it back to San Diego from Washington state and just haven't had the time to read on the "major" dial in.. i know its a little lazy but any one know the link some one had running around here for "tapping in" the egr harness to get the wideband to register on vcm scanner? just for temporary for tuning purposes
 
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