318ti.org forum - 10psi Pulley Help

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10psi Pulley Help

As you guys know i got the stg 3 software done. When putting in the ECU back we also put the smaller pulley in.

So stock pulley is at 7.5 pounds and the smaller pulley should be at 9.5 pounds.

Well, my gauge/boost isnt showing 9-10psi but at most 8. Why is this? Could it be the belt at all? Can a Vacuum leak cause this? My Vacuum idle is at 17-19. Or what else could it be that it isnt boosting at 10?

Could it be that as i am revving into the higher RPMS the boost goes up little by little? Ive tried doing this and taking a quick glance before i have to shift, and i still dont see it at 10.

From what i remember, you could hear the whining spool at around 4k rpms. Ever since the software upgrade i start to hear it around 3,600k RPMS. Could it be that i am running at 9.5psi but the gauge isnt showing it?

I was planning on buying the other smaller pulley "11.5-12psi pulley" hoping that from that pulley it will read 10.5 I say this because the "9.5-10 pulley" isnt reading at that boost. But i dont want to put this one on, and this one actually does works/read at 12psi, and hits 12 pounds then my motor blows up.

BTW, i searched the forum, and there is NOTHING on this question. So yea the "search the forums" or posting the "advanced search link" is out of the question.

Thanks for the help.

Did you put on a shorter belt at the same time? Maybe you're getting some belt slip. When I went from my 6 psi pulley to 9, I had to put on a belt 1/2" shorter or the tension was nil. It all depends on where your tensioner is in its range of motion.

Quote:

Originally Posted by ClubSport (Post 134981)

That's one of the things that came in my mind. But when i measured the pulleys together it almost seemed like there was no difference. The tension was still tight, so i didnt think it might be the belt. 6 to 9 is a lot.

BUT, i think i might need a new belt soon since it makes noise when i first start the car (not to loud). When i do get a new belt, ill proably get a little bit smaller.

Any help for a 318ti.org member on www.318ti.org?

Ive done my share of helping when ppl PM me or i PM them.

:help:

Kool thanks 318ti.org members and site supporters...

Quote:

Originally Posted by HuGo (Post 135069)

If you measured the size of the pulleys and there's almost no difference, then that's the problem right there.

The sound of belt slip reinforces my previous idea.

Quote:

Originally Posted by ClubSport (Post 135337)

If you measured the size of the pulleys and there's almost no difference, then that's the problem right there.

The sound of belt slip reinforces my previous idea.

I put them together and i would say the difference was maybe like 1/7 of an inch smaller.

Hugo check with DustenT he was experiencing some similar issue with not getting the psi he was setup for.

Quote:

Originally Posted by el pollo loco (Post 136055)

Hugo check with DustenT he was experiencing some similar issue with not getting the psi he was setup for.

Im not even going to attempt to ask him. He aint going to help me.