Ahhh I can't believe I missed that

 

Just hooked up a boost guage. Still have the 3.12 smooth pulley on, and the belt is super tight. I'm only seeing about 6psi. Is this normal? Next Saturday I'll put the cut pulley on and see what happens. Hard to watch the tach, boost guage, and traffic all at the same time lol. Esp. since the boost guage is sitting on the passenger seat.

 

Ran it again, put the pedal on the carpet till I hit the rev limiter. 6.5psi. Is this normal for 3.12 pulley?

 

depends, what are your breathing mods?
what was the ambient temp and do you by chance know the elevation there?

6.5 psi does sound kinda low though

 

i have never seen 6.5 on a 3.12 pulley, you have an issue for sure...

 

Does the temp really matter that much? I never had a guage on it with the 3.33. But it feels like more than before. I also put HFCs on at the same time. I understand that should lower boost a little , but I'm supposed to be getting 9psi. WTF?

 

Temp is 80. Elev. about 7 or 800.

 

I didn't think the temp or elevation would play a big role being in texas, but just wanted to make sure you weren't like 5000 ft above sea level at 100 degrees outside or something

something is up. If your only breathing mod is high flow cats, you must have a leak of some sort somewhere, or your engine is losing compression somehow, or there's something wrong with your bypass valve

 

Don't think there is any leaks, everything's pretty tight, nothing's rubbing a hole or anything. I thought about the bypass, but how would I check it? I can't hear any hissing.

 

You live in austin? What part? Have we met?

 

Northwest. Don't you remember PMing me about a video(which I'd like to see) of my car racing Evos at San Antonio Raceway? Don't think we've met.

 

I called Vortech, they said the HFCs could lower boost by as much as 2 psi. That's alot. They also said I can temporarily block off the bypass to check that. Belt slip too. I can't hear it, but they said it's not always audible.

 

Have you tried to log a run or two with the R4 software to see what boost the SS box is seeing ? Also ...do you have an aftermarket plenum ?

 

No plenum mods at all. I don't have any software for the SS box. UpRev wants me to take the the box out and get Walbro pump. So I'll be doing that shortly. This Saturday I'll change the pulley, if there's no difference I'll change it back.

 

Of course they want you to take parts out . So they can sell you new ones .

Of course your going to make more boost with a smaller pulley . The problem is that your not making enough boost now . Either you gauge is off or you have a leak some where . It really makes no difference what your gauge reads . Its what the SS box is seeing for boost that you should be concerned about .

 

yeah just going from my crawford high flow cats to AAM 2.5 inch high flow cats lost a little boost pressure. Also going from my previous nismo to my modified APS dual 2.5 exhaust I think lowered my boost reading slightly some too.

When you dyno, you can have the shop log boost pressure and see what that reads

 

I tried every combination of cats and test pipes . The biggest drop in boost was running the test pipes . but I still made 7psi . I tried some high flow cats and made 9psi . The diff. between stock and high flow cats was about .5psi

Again..finding out what boost preasure the SS box is seeing is most important . Its what your tuned off of......not the gauge or a dyno reading of boost . But the SS box!!!!!

 

I'm not buying any parts from them. And I put them on myself. But you're right, they really wanted to sell me these parts and put them on for me$$$$ I do need the injectors. The stock ones are maxed out at 5500 rpms. I'll change the 99$ pump to avoid an extra 350$ tune. Maybe my 15$ Pep boys boost guage is wrong.

 

Well I started changing the pulley and couldn't get the bolt loose on the cog pulley. 'Cause I'm quitting smoking today and it made me stupider. Happy !@#$%^& Cinco de Mayo !@#$%^s. So I put it back together, and found a kink at the back of the guage, made a new connection = 8psi