Do I have a smaller pulley?

[MrMason]

I was driving today after getting my new tires put on, and gave a few WOT runs and noticed that the stock boost gauge goes past the 10psi marker, and also noticed that I hear some belt slip near the top of 3rd and 4th. The pulley cover is still on, I'll take it off tomorrow and give it a look try to get a rough measurement of the pulley size. Stock pulley is something like 3.65" correct? And it should only make 8psi boost correct? I guess it would explain the belt slip since there is no idler pulley.

 

[Jomo1994z71]

Post a pic...you might have a 2.93 where the aux idler aren't required...on a side not...If I'm not mistaken, belt slip can cause your boost gauge to read wacky...

 

[MrMason]

Took some pictures, definitely looks smaller than stock

Anybody know what pulley this is?

 

[03cobra#694]

Not a stocker for sure,maybe a Steeda?

 

[timspony]

...Looks like a 2.93"!

 

[MrMason]

could it be a lightning pulley? Should I get an aux idler for this, or a smaller belt. Need to get rid of the slip

 

[Ls1z28-00]

pretty sure its aftermarket, i would also make sure the car is tuned right, if you didnt even know it had a pulley, chances are the guy you bought it from just stuck it on there without a tune.
EDIT, you cant check the Diameter of the pulley across the face like that, the Dia is measured where the belt makes contact. but being how the outer diameter is still pretty small it could be in the 2.8 range pulley. Since your only seeing 10 pounds id say belt slip is def. a issue.

 

[MrMason]

def not stock, i would also make sure the car is tuned right, if you didnt even know it had a pulley, chances are the guy you bought it from just stuck it on there without a tune.

It's got a tune on it, not sure what tune but I'm going to get it checked out.

 

[Jomo1994z71]

I agree...get it on a dyno to see what the A/F is...

 

[Ls1z28-00]

It's got a tune on it, not sure what tune but I'm going to get it checked out.

that would be my advice, to check the pulley size slip the belt off and get a caliper or mic and measure the diameter where the belt slips around it. then you can find out what size belt you need for sure.

 

[antiv6]

id just ditch the pulley and get a billetflow one with at least a snub idler. That pulley is ugly and looks beat up.

 

[latemodelracer2]

could it be a lightning pulley? Should I get an aux idler for this, or a smaller belt. Need to get rid of the slip

it is a steeda 2.8" pulley....... if you wanna buy a steeda idler lemme know i have one cheap

 

[MBoyle1]

Not stock, stock was a solid wheel looks like a 2.8

 

[CobraBob]

If you need a new belt, check my belt selection guide. It should help you pick the right size belt. Here's the link. Belt Selection Guide

 

[MrMason]

pretty sure its aftermarket, i would also make sure the car is tuned right, if you didnt even know it had a pulley, chances are the guy you bought it from just stuck it on there without a tune.
EDIT, you cant check the Diameter of the pulley across the face like that, the Dia is measured where the belt makes contact. but being how the outer diameter is still pretty small it could be in the 2.8 range pulley. Since your only seeing 10 pounds id say belt slip is def. a issue.

Yea I was just trying to guestimate where the belt was making contact, looked like around a 2.8" to me. It is going past the 10 pounds, but then drops off some when it's in the higher rpm, I can definitely hear it slip though. What should the boost be with this pulley, around like 12-13psi correct?

 

[twhitey]

I have an extra steeda 100mm Idler let me know if your interested. You need a shorter belt. Check your plugs and your a/f