Thread: How much boost with a 3.4 pulley?

about 1 pound of boost per pulley size drop. stock is about 6ish so with a 3.4 you should be around 10 psi. and i cant answer your intercooler question, ive never heard of one being used.

i peak at 11 psi on my 3.4 setup.

all the A2A intercoolers ive seen were on aussie cars. they kept saying they were getting bad lag because of the length of the piping and it being hard to tune because of the MAF location. A2W is just as good for our application, theyve been proven pretty well.

boost changes depending on altitude, barometric pressure, and most importantly, where it has to go. a 3.4 setup on stock exhaust (besides that youll break something) will probabaly creat 12-13lbs of boost. a 3.4 on headers and a catback will creat more like 8-10lbs, which is better.

Wow i see 7psi with a 3.4". how are you guys getting 8+

Originally Posted by Toofastgs

Wow i see 7psi with a 3.4". how are you guys getting 8+

because your car is more modded than ours. silly.

Originally Posted by Bio248

because your car is more modded than ours. silly.

Lest see. 3.4" ZZP pcm, Intake and exhaust.
Unless my exhaust is really that free flowing. Though i saw 10psi with my prix with same mods

hm, weird.

as long as youve got an intake, colder thermostat, and colder plugs i think youd be fine. a downpipe and rockers would be the next step to that progression.

If you plan on modding further then headers is the way to go. If you feel like you are going to stop at the 3.4 then you really wont need it.

I too would recommend the headers as it provides better performance gains and it leaves options for future additions. The only downfall is the price. ZZP has the stainless headers for $700 and the pacesetters for $360. The majority of people on this site have pacesetters or so i have seen. Also [if I'm not mistaking] the stainless headers dyno at 30hp more then the pacesetters.

Aside from boost, has anyone actually documented the HP gain from dropping from the 3.8 to a 3.4? Assuming you dyno'd with all the supporting mods, then after the pulley drop, what sort of gain?

I'm skipping porting the blower and LIM for now. When I go to install a intercooler, I'll just pay core charges on those parts. I am going to get my TB ported by Trannyman, run 1.9s, probably a 3.4 (after I iron out the tune on a 3.8), and eventually switch from my DP/Plog/coated x-over combo to the new ZZP headers.

dont make the mistake of not doing a cam if you have the chance and are willing to work with your car a little more than the normal session. i wish i would have stayed with the TEP i had. thing was mean.

also, the headers really are pretty nice. any of the companies. they each have their downfalls. the best and easiest to install that ive found are s&s. everyone preaches TOGs all day long, but i sold a pair to buy the s&s i have now. they really help with the flow characteristics of the car. headers, rockers, fuel system to keep up, and some for of intercooling (meth/A2W) you can run a rockered car into the 12s with a 3.0/2.8 ish pulley with traction. that's what im doing, but im going to run meth and e85.

Is it a really noticeable gain? Like a lot more pull from stock?

if you tune for it yes. otherwise im still knocking with a 3.4 on my setup.

Originally Posted by Bio248

dont make the mistake of not doing a cam if you have the chance and are willing to work with your car a little more than the normal session. i wish i would have stayed with the TEP i had. thing was mean.

I understand and appreciate the advice. But, this is a big enough project as it is and I'm learning as I go. I will be back in there again some day (installing another LIM that's ported for a IC) and I may take the opportunity and sell my 1.9s. Until then, 1.9s will be good enough. I'm jumping up from a N/A 3800 making maybe 230-235 crank HP. I'll be happy from the start.