How much boost should one expect from there pulley?

15% - ????
17% - ????
19% - ????

For that matter what about crank pulley

2% - ???
3% - ???
4% - ???

If you have a boost gauge and the above mods tell us your results. None of theat theoretical stuff just hard true numbers.

 

Anyone with a supercharger pulley of 15-19% usually has a crank pulley of 2-4% so they would come together to make a boost pressue.

My car running a 15% pushes 16-17psi.

 

Stock its about 10psi.

 

Same thing here.

Mods that affect boost : 15% pulley, Alta CAI, Detroit Tuned bypass valve and Andy's VGS

 

I am running am ALTA 17% with a stock air box and an ITG Filter and I produce 16 psi of boost. It has never gone above that.

 

and what about the 19% pully?

 

do you have a psi guage? if so how hard was it to install? (if you did it yourself)

 

I got 18, it's hard to really tell somtimes b/c when your getting that much boost you really need to keep your eyes on the road. I have a warning light set at 18lbs. I might set it at 19 and see if it goes off, i'll keep you updated -- Johan

 

More than 18psi & you run the risk of squirting the headgasket out. Be careful, as the dealers are looking for overboosted cars when they come in with blown headgaskets. Ask me how I know...

 

Very easy to do.

Look at the How-To I wrote a little while ago

Boost Gauge How-To

 

i have a 17%, intake, exhaust, and AFC select. i'm running 19lbs of boost.

 

Thanks!

 

No problem! Feel free to post any questions you might have on the How-To thread!

 

What's a boost pressue?
Hahaha, nice. BTW, Welcome back to the forums ApexinM3.

 

this is absolutly incorrect....
I am not saying the dealer won't try to blame boost for this...but it is near impossible...I am currently running 28 lbs of boost...every day...my motor is stock other than pistons...but pistons are not nessisary if you want to run 28 lbs...but race gas is....

also we have run 40+ lbs before and never "squrited" out a head gasket...this happens from two things...head bolts that are improperly TQed or overheating and lifting the head...THEN boosting on a lifted or poorly TQed head...

 

I have a question, I'm running a 15% pulley now and am considering a 19%. From what I understand by doing so, it causes the stock supercharger to spin beyond spec. Is this true and am I in danger of hurting anything. Second question is how much real gain could I expect from changing the pulley to a 19%?

 

My boost guage reads around 10psi on a stock pulley. 15% you still see around 15 or 16 psi. That is a nice increase in pressure for a simple mod!

Garrett

 

17% and the list of stuff in my sig and I am pushing 1.3 bar

1.3 bar = 18.8549059 PSI



Defi Gauge controller, rec/playback/peak

 

Engine can handle high boost, this we know. But can the SC handle more then 21% reduction before running into problems?

If you had a 21% SC pulley and 4% crank (math isnt hard people...) 25% reduction. Is THIS dangerous?

more specific to my needs, i have a 19, and wonder if i can have a 4% crank

 

I say do it. What the hell, it's only money, right? I don't get where you're getting 21%? You say you have a 19%.

 

One thing not mentioned is the LOSS of boost with a larger intercooler

I am running a 15% Sc and was thinking about a crank pulley
In vegas 2 or 3 vendors had crank pilleys for sale but 1 said "NO WAY ... DO NOT DO A CRANK PULLEY"

I was going to do a crank to overcome a larger intercooler but now am thinking about 17 or 19 on the SC

 

i say 21 because thats the largest heavily supported/manufactured SC pulley size. In theory, you could to 21 + 4

 

I didn't know that anybody sold 21% reduction pulleys. Website?

 

I thought 15% was the "largest heavily supported/manufactured SC pulley size"?

On the pulley reduction...isn't there also a problem with heat? I have read that the supercharger starts to become ineffective at the very top end of its capacity to spin due to a huge pulley reduction.

 

Hello, this is my first post about this new car I own. I am a V8 guy, but I love this little booger! Ive had it a week and dumped about 3k in it already, ( I got the car at an unbelievable price). High boost is great and all, but has anyone had any problems with belt wrap with such small pulleys? Belt slippage? A sign of this would be black dust around the area. Just curiuos. Corners are my new best friend!