belt slip

Jason Wild

Registered User
I'm having a big problem with the SC belt sliping on the blower.
I'm running an ESM 5% over drive with a stock jack shaft. I have tryed ever belt out there now i'm running a belt that ends in 93 with a steel tensioner pulley. I have all ready tryed the tensioner arm and still the same problem.

Hope some one has a fix.
 
Always has been a problem when installing a smaller diameter pulley is belt slippage. I have the ESM 10% jackshaft and a SVO 5% (steel) pulley with a K080400 belt (gater belt). No slipping.

My point is overdrive the SC from the jackshaft and leave the stock pulley on the SC. Larger diameter SC pulley reduces the belt slippage.

Rich
 
Jason I have a 10% SCI pulley with stock belt and no slippage, all you do is on the tensioner you will see a tab the only lets it move so far, just bend that tab up so the tensioner clears it and has more travel and problem solved, mine boosts perfect and no hint of slippage or belt wear.

Hope this helps ya

Garett
 
If it's has eaten through the annodize and the ribs are very sharp then it's probably because the pulley is toast. It would need to be recoated with a Hard Coat Anodize.

Jeff
 
Take a close look where the belt rides. 6K is enough to cause this in an AL pulley if it is not properly coated. You shouldn't have any problems with a 5% pulley.

Jeff
 
just a trick for the track there is this stuff you can put on tires to make them grip more i thinks like vht or somethign anyway put a little ont eh belt and you wont get any slip even the guys who already dont get any slip would get a slight boost from it not much but even the stock belt slips a bit
 
I was having the same problem with my 5% and I replaced the tensioner pulley with a larger one. No problems so far and can peg out the boost gauge. The belt dressing stuff only works if you dont plan on flooring it alot.
 
speed95 said:
The belt dressing stuff only works if you dont plan on flooring it alot.

yeah its not a long term fix but in the short run it really does hte job you can get a good six passes or more beofore its starts to loose its affect
 
Jason Wild said:
Paul at btm say it was coated and i know it has been. been used for a year now like 6000mi
If you are running an ESM pulley, it is not coated and I have never stated or advertised that their pulleys are. If the pulley is causing the slippage, it is because it is glazed. There have never been issues with the uncoated aluminum pulleys slipping or knive edging unless the belt was already worn or oil (or other liquids besides water such as antifreeze) got on it. The ridges at the top of the pulley can't knife edge without the ridges of the belt doing the same. In the event though that it has, chuck the pulley in a lathe and hit it with a file gently.

Paul
 
I re-drilled the aluminum bracket where the tensioner bolts on to. The new hole allowed the "stub" from the back of the tensioner to be positioned differently. This allowed me to position it more at an angle towards the blower to give the belt more tension and wrap around the pulley. Simple mod that took 5min and no $
 
Paul
I thought forsure your pulleys were coated with something since you can not polish them unless you sand them.
 
Jason Wild said:
Paul
I thought forsure your pulleys were coated with something since you can not polish them unless you sand them.
ESM pulleys are not coated, BTM pulleys are clear anodized. See pics below:

Paul
 

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I know i'm stealing your thread but: I just dropped in a 94 blower with some 99 gtp rotors, I'm running the 90's stock pulley (%3) and am getting belt slip bad.
Should I drop back to the stock 94 pulley? Any suggestions would be greatly appreciated. I have a raised top and doube ic coming if that helps any.
 
BT Motorsports said:
If you are running an ESM pulley, it is not coated and I have never stated or advertised that their pulleys are. If the pulley is causing the slippage, it is because it is glazed. There have never been issues with the uncoated aluminum pulleys slipping or knive edging unless the belt was already worn or oil (or other liquids besides water such as antifreeze) got on it. The ridges at the top of the pulley can't knife edge without the ridges of the belt doing the same. In the event though that it has, chuck the pulley in a lathe and hit it with a file gently.

Paul

Paul Aluminum knife edges easily. Recently I was out on a service call. The system is a Impeller packer that fills 50-90# bags of cement. The drive system consists of a 30 HP motor that drives a 1.3125" shaft with pulleys about 8" in dia. It has 5 V belts and after about 3 months of use they will knife edge without the belt showing wear. Usually there is about a 1/8" at the peaks between each groove, but the knife edging happens pretty fast. In fact on this system one of the mechanics lost the tip of his middle finger because he wasn't paying attn. and pulled the belt to the pulley and didn't get his finger out of the way. Granted cement is far more abrasive than the environment a car but not by much. The shaft RPM is only about 900.

On the conveyor system I designed use .080 pitch cogged belts 3/8" wide on aluminum sheaves. These are anodized, but not hard coat. Depending on the application some will last about 2 years and others have to be replaced about 4-6 months. Sugar is very bad on them and food products aren't that big of a deal. Speed also makes a big difference. We run top speed of 1600 RPM and everything else is less than that.

Aluminum doesn't glaze it wears and polishes. 6061 is not a suitable material unless it has been hard anodized, it's just too soft. If his pulley is wearing then he could sand blast it with a fine grit and then have it coated. The profile of the ribs and the belt must match perfectly or the surface area is not always in full (and correct) contact with the belt and it will slip.

Tightening the belt further if the proper belt is installed will not "cure" the problem it will only mask it for a short time. He needs to find out what the root cause is. I have run into several pulleys that didn't have the proper spacing/angle/depth for the belt used. Just because the belt seems to fit fine doesn't mean it's the right one for the job. I am not saying that ESM didn't do the job right I am just giving info on pulleys in general.


BTW what spec does ESM use for their pulleys? If you say it's propriety then I have a rather large problem with that.....

Jeff
 
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