Belt slippage?

[BlueThunder90]

Anyone ever have belt problems?

My car runs fantastic, launches hard but at certain times when the revs are up, squeeling from under the hood and a temporary loss of power.

Maybe some better belts?:D

[johnny o]

People have been having problems with SC OD pulleys for the longest time. If this is your problem there a few ways around it but they may not be cheap. Put your stock pulley back on the SC and OD it at the jackshaft with a jackshaft OD pulley or even more extreme switch the pulleys to allow 10 rib belts while you're at it. If it's your other belts.. uhm new goodyear gatorback and make sure your tensioners work. Speaking of which that reminded me some people use a larger diameter tension pulley in place of the smaller stock plasic one that may help.

[BlueThunder90]

I took the car out last night and it's the SC belt for sure. The car drops from 13psi to 8psi and the car just falls on it's face....Will Gatorbacks solve this or should I look to another solution?

[sabbySC]

I had the same problem on my 93 a couple years back. I went with a new tensioner and a shorter belt and all was fixed.

[SeanMatteson]

Steve,

If you're running a 10% OD pulley on your blower, and the stock belt and the stock tensioner pulley, then chances are you've created enough slack to allow the slippage. Most people will start by swapping on a different tensioner pulley. The stock piece is about 2 7/8" in diameter, whereas the other two tensioner pulleys are about 3" in diameter. You can swap one of the 3" pulleys in for the smaller pulley. If that doesn't take up enough of the slack, then you can try the shorter belt. I've heard of people here going all the way down to a 390 belt (which I think means it's exactly 39.0" in length if it were cut and layed out flat).

As the tensioners on our cars get old, then don't place as much tension on the belts. This could also be a part of your problem. There is a little indicator on each tensioner. I suggest you check to make sure that your tensioners are all operating within the allowed tolerances.

Many people have been running the Goodyear Gatorbacks with success. Another cheaper alternative is to run the Dayco PolyCog belts, which look very similar for a slightly lower price. I've got the Dayco's on my car (the previous owner was kind enough to have installed those shortly before he parted with the car). I am also running the 3" Dayco steel tensioner pulleys, and despite running the 10% OD, I haven't had a problem yet with belt slippage.

I hope this helps.

Cheers,

Sean

[tbirdsc357]

I have the same squeeling when I punch it off the line, just started recently.

Might be the tensioner....:confused:

[Jason Wild]

Steve,
My car has done the same thing in the past and still might slip the odd time this is running Goodyear Gatorbacks and a 5% over drive.

[axlr8r]

I happen to have a 3 inch (76mm) Dayco tensioner pulley sitting on my desk, brand new. I think I paid 20 bucks for it.
If you want it, let me know..

[Ryan A Harris]

Buy the larger tensioners 1st off, its the cheapest way around this. Then if you still have the slippage, go to the shorter belt.

Steve, is from the new 15% SC pulley? If so, then I think you may have gone to small. This piont was already said, but by decreasing the SC pulley, you lose a large contact surface for the belt to run on. By doing this it greatly increases the chances of slippage. Also if the pulley is made out Aluminum and not coated with anything, it will be very slippery. The belt will "polish" the pulley over a short amount of time. This "polishing" of the belt surface will make it more slippery, and cause even more slippage.

The next step would be increasing the jackshaft, or going to a 10 rib system. I bet you get rid of the slippage before going to these extremes.

Let me know if I can be of more help to you. Pullies are my specialty now.;)

[tbirdsc357]

Originally posted by axlr8r
I happen to have a 3 inch (76mm) Dayco tensioner pulley sitting on my desk, brand new. I think I paid 20 bucks for it.
If you want it, let me know..

Matt,

If no one has spoken for it, and you don't need it.,...I'll take it.

$20.00??

[Bill McNeil]

Steve,

Start with the larger idler, as others have mentioned. Then move to a 393 belt, because 390 is very short, even with 10% OD.

As a last resort, you could replace the tensioner arm. I just notice last night that mine is getting really bad, so I'll be swapping in one from the parts car.

I was racing one of the new Nissan 350 Z the other day, and I can't figure if my belt slipped, or if the 91 gas was to little for the timing I run, because the car died up top in 4th gear, at less than 4,000 rpm. Still investigating that one.

Either way, I still beat him. :p

[BlueThunder90]

Thanks guys...

Ryan, this is with the 10%, not the 15%. I'm getting 13lbs with the 10% now with tuning so I'm just fine with that.

I'll work on the tensioners, anyone have a part number for it? I'm assuming I should replace all 3?

The car is running pretty good other than this problem. the car is doing high 14's in the 1/4 on a Kumho tire which is good considering I thought I'd be in the 15's with the major bog at the 1/8th mile.....there's always next week-end :D

[Bill McNeil]

Steve,

Why don't you post your track results? High 14s in an SC is great, no matter how you look at it. You aren't on the Ontario list, or the Canadian list, so you should really submit your entries. This way, your progress will be even further noticed.

Let me know.

[BlueThunder90]

Bill,

The 14.9 was decent, but would have been much better without this belt problem. It started a few days before and it was pretty bad at the track.

Here's the slip if you wanted to add it to your list.

[Bill McNeil]

Steve,

You just beat out Ryan buy 0.005 of a second, but Sean has you beat by a full 0.012 of a second! It's amazing how many SCs get stuck at 14.9. Take a look at the list now that you took #15 away from Mr. Harris.

#10 14.651 @ 93.91 MPH - Paul Milawski - 1993 SC

#11 14.66 @ 96.31 MPH - Les Borda - 1990 XR7

#12 14.69 @ 93 MPH - Paul Harrison- 1990 SC

#13 14.72 @ 94.39 MPH - Steve Pathay - 1995 SC

#14 14.927 @ 95.92 MPH - Sean Matteson - 1990 SC

#15 14.939 @ 92.05 MPH - Steve Arbuckle - 1990 SC

#16 14.944 @ 95.56 MPH - Ryan Harris - 1995 SC

#17 14.948 @ 92 MPH - Michael Maroschak- 1989 SC

#18 14.982 @ 91.2 MPH - Jamie Fauht - 1991 SC

[Bill McNeil]

Your 60' time is impressive for street tires! You can't blame those. Judging by your MPH, I'd say you are losing power up top, whether it be the belt slipping, or you leaning it out and causing it to pull timing. Time for an EEC tuner I'd say!

You can see the rest of the list here: Canada's Fastest SCs (http://bmcneil2.tripod.com/billmcneils1993tbirdsc/id12.html)

[BlueThunder90]

I'm very impressed with these tires on the track. I'm running Kumho Escta Supra 712's at 23.5psi.

It's odd why the car launches so hard and about 1/2 the way down, she starts slippin.....oh well, going to be fun working on it. I want to get this issue solved before I start using nitrous....especially if I am leaning out, spraying nitrous wouldn't be a great idea :D

[Bill McNeil]

Steve,

Are you coming to our track event on October 11th?

I think it's about time you attended an SC event! ;)

[Bill McNeil]

On another note, I have an aluminum pulleys, and none of them slip. They have not been coated with anything either. I'm inclined to believe that a good belt and the right amount of tension will prevent slippage without having to coat the surface(s).

[BlueThunder90]

Originally posted by Bill McNeil
Steve,

Are you coming to our track event on October 11th?

I think it's about time you attended an SC event! ;)

I was considering it. I want to get some work finished on the car first and I doubt that it will be finished in time......but we'll see :D

[johnny o]

I got this from the SCCOO page. It'll answer your part number questions so here goes:

Steel tensioner idler pulleys. This is a 3 inch steel idler pulley instead of the original 2 7/8 plastic pulley.
Use the old bolt without the old washer. You can replace all 3 tensioner idler pulleys using this part.
Ford part number YS-233. List price: Approximately $20 CAN.

Shorter supercharger belt to help eliminate slippage with 10% overdrive supercharger pulley.
Part number 080390. Available from Gates or Dayco. Gates manufacturers the original belts for Ford. Dayco offers a Poly-Cog type belt which will not show cracks like the Gates belt does. Installing a 3" idler tensioner pulley on the supercharger drive belt should eliminate all slippage. You can buy a new pulley from Ford, part number YS-233, or swap the smaller supercharger tensioner pulley for the larger one used on the accessory drive belt.

[BlueThunder90]

Thanks Johnny!