Meatball25

Ok I swapped my stock pulley on my supercharger about 2 months ago, to a NST 9.5 PSI about a week ago it started screamming, especially when I punch the gas. At first I thought it was the belt, but the belt is good, only seems to screech when i hit the gas, not when i am idling or turning. Went to a test andtune up at track in my state, still getting the same boost, just with a horrible scream from my pulley 2-4 second into launch or street driving. Any ideas?

Blue_TC_Man

belt slip get a gator back itll help a good bit

Meatball25

I have a gator back on there now, i thought that i didnt have enough tension either, checked that, and thats ok. im wondering if it is the shaft to my supercharger...

imsonofagun

I've heard from several people that a gator-back belt isn't recommended with the supercharger.

Gates is the way to go and www.RockAuto.com is one of the best places to get them. There is also a certain size that is recommended for s/c setups, depending on the pulleys being used. NST is pretty quick to reply to questions and will recommend belt sizes to suit the need of each individual setup.

Another thing to look at is the alignment of the belt. There are shims where the s/c pulley goes and need to be shimmed whenever the pulley is changed. I've had this issue when the NST pulley was put on and the shop that did the work didn't change the shims. The belt was screeching and getting shredded, covering the engine bay with black particles.

Easiest way to check if the belt is aligned properly is to see if it is centered on all of the pulleys, esp the tensioner pulleys.

NurSpec

what size belt do you have?

Blue_TC_Man

got ya

but tension doesn't necessarily mean no belt slip especially with a smaller pulley belt slipping is pretty common. since your not seeing the amount of boost you should the belt is probably just over spinning the pulley and not able to keep up
like imsono___un said make sure the grovves on the pulley are clean and defined and make sure they line up. try even going to a belt thats just a tad shorter

BuddhasTC

if it's a screeching sound, it's definitely the belt...when it's the shaft goin out, you will hear it more in idle than in driving and it is screeching and clunking and makes a sound like when you put a big boot in the dryer

NurSpec

I found this on another site. I hope it helps

"3. Belt Issues

I have experimented with a lot of different belts out there. When upping the boost, BELT SLIPPAGE IS ALWAYS A PROBLEM with certain belts. Here's the general rule of thumb - ALWAYS use a belt with a "solid" design (i.e. the 7 ribs of the serpentine are straight through and don't look like "dotted lines" like Dayco/Davis belts or Good year
Gatorbacks). The more boost & supporting mods, the more risk of slippage. The less rubber on the belt in the form of those "incomplete" ribs, the less contact with your pulleys, and the more chances of slippage - and so on and so on. GET A GATES BELT. THEY ARE ALL STRAIGHT THROUGH BELTS and don't do any of that silly "gatorback" stuff to cut costs. If you compare a Gates belt to another aftermarket belt, the difference in quality is simply amazing.

Recommended lengths and part numbers:

NST 12lb pulley: 7PK2234, aka Gates K070880, effective INSIDE length, 2235mm. The Gates K07882 may also work at a 2242mm inner circumference, but try to get the K070880 if at all possible, especially if you have the 20% alternator overdrive pulley. NOTE: Do NOT use the 12lb pulley with the TRD A/F map. You will run very lean and do some very real damage to your motor. You must use engine management to use this pulley. Also, make sure you upgrade your injectors. the 410's that come with the TRD kit are NOT enough to hit 300whp, and you will lean out!

NST 9.5lb pulley: 7pk2250 (K070882) or 7pk2260 (K070886) - both will work, however opt for the SMALLER one if you have a 20% Alternator Overdrive pulley."

imsonofagun

Careful of those belt sizes though. There are size differences between the 2005-2006 superchargers and the 2007+ superchargers.

paulky_2000

It's definately the belt slipping on the smaller pulley. Not sure of the fix, but I'd bet money that's what it is.

Meatball25

alright so i brought the tC tonight into my buddies garage, took the belt off and was going to swap it with a Gates brand (I have a gatorback on there now), little smaller in size, thinking it would stop the squeeling. Go and pull on the tensioner to put the belt on... no dice... it barely moved... I mean I leaned into it as much as I could, and wouldnt budge! I cant even put the old belt on if i tried.... It was fine 2 weeks ago, I dont know what could have happened... any ideas?? As of right now my tC is out of comission till i get this fixed!