Pero Posted December 16, 2011 Share Posted December 16, 2011 Does anyone know where I can source kevlar timing/aux belts in the UK? I know Power Enterprise sell these in the US, but I cannot find a dealer for them. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted December 17, 2011 Share Posted December 17, 2011 Whifbitz? Do you really need kevlar belts? Quote Link to comment Share on other sites More sharing options...
Rob_Mitchell Posted December 17, 2011 Share Posted December 17, 2011 Fit a pair of gates racing belts from Whifbitz, plus they look good Quote Link to comment Share on other sites More sharing options...
Pero Posted December 17, 2011 Author Share Posted December 17, 2011 I do need kevlar belts yes. It's actually just the aux belt I need, and it's not for a Supra. It's for a Fiat Coupe. We went to get it remapped on Thursday. It made 570bhp and 450lbft on the dyno, but when the mapper took it on the road to fine tune, the aux belt shredded, took out the cam belt and destroyed the engine. This is a common occurrence and a very expensive one, so I need something that will hold up under the torque. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 There are plenty of none automotive suppliers of ribbed belts in Kevlar reinforced material, just search on Google for them, and hope they do a size that is near enough, length wise. Quote Link to comment Share on other sites More sharing options...
Pero Posted December 17, 2011 Author Share Posted December 17, 2011 There are plenty of none automotive suppliers of ribbed belts in Kevlar reinforced material, just search on Google for them, and hope they do a size that is near enough, length wise. There aren't plenty actually. I'm looking for a 6 rib v-belt, and I cannot find a single supplier anywhere. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 Try using Aramid fibre instead of Kevalr? Gates do some, and there's a UK company I have used for them, and they were 6 rib, but I can't remember the name. An auxiliary belt shouldn't be under much load unless it's running some none stock device, is it not a harmonics issue? Quote Link to comment Share on other sites More sharing options...
Pero Posted December 17, 2011 Author Share Posted December 17, 2011 I think the belt goes when you're giving it beans and then lift off without dipping the clutch. The sudden force of the engine breaking looks like it's too much for the belt. This is the single most common problem on high powered Coupes. There are guard pullies available to help keep the aux belt away from the cam belt when it goes, but sometimes it still makes its way through. Then it's engine rebuild time. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 Yes, it's a harmonics problem, very common when cars are modded, especially with a fierce clutch. A "wave" forms in the belt then an oscillation, it flows around to a pulley and either comes off or starts to fray. Automatic adjusters don't help, either, as they have give in them. I had the exact same problem with the PAS belt on my RB26 engine when I fitted a triple plate clutch and a sequential dog box. I had to make an idler pulley to run on the back of the longest belt run. I have photos. Quote Link to comment Share on other sites More sharing options...
Pero Posted December 17, 2011 Author Share Posted December 17, 2011 Very interesting. Did that sort your problem? I would love to see the photos so we could maybe have a look into something similar to stop this from happening. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 Photo of pulley, it runs on the back of the long run on the none driven side of the belt. It's a cam belt idler pulley on a fabricated bracket. It needs to be pretty strong! Quote Link to comment Share on other sites More sharing options...
Pero Posted December 17, 2011 Author Share Posted December 17, 2011 Thanks for that Chris. Much appreciated! Can I just ask, do you still have to use an uprated belt or will the stock belt hold up with this mod? Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 A stock belt SHOULD be fine, but how is it tensioned, with a spring loaded automatic adjuster or a manually adjusted, fixed one? A manual type is better for engines that see shock loads on gear changes, or that are inertia free enough to be ultra responsive (highly unlikely for a supercharged road car engine). I prefer manually adjusted tensioners for race applications. Quote Link to comment Share on other sites More sharing options...
Swampy442 Posted December 17, 2011 Share Posted December 17, 2011 I was going to suggest a swap to a manually adjusted tensioner but CW beat me to it. Seems like you know what the problem, just have to find a way round it, and a stronger belt may only cause more damage should it go. Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 17, 2011 Share Posted December 17, 2011 The idler pulley needs to just press very lightly against the back of the belt, maybe bowing it in one eighth of an inch maximum. It's to stabilise it, not re route or deflect it. If you post a photo or link showing clearly the stock belt and tensioner set up I can advise, it's a fairly common issue, and why Toyota fit a damper on the adjuster arm on manual TT models. (It's really `cos they know the Yanks can't change gear in a manual without sending shock waves through the drive train, but they are too Japanese and polite to actually say this out loud... ) Quote Link to comment Share on other sites More sharing options...
Pero Posted December 18, 2011 Author Share Posted December 18, 2011 The way the belt is routed, there is not 1 long run of the belt like on the Supe, but two shorter equally spaced runs between two pulleys. I'll see if I can get some pics up. I think another problem is possibly the tensioner pulley is made from plastic and doesn't have a lip, so under extreme conditions it gives ever so slightly and causes the belt to jump off. I'll need to find a solution as my tuner's car had the engine go because of this on Thursday, and I'm running an even bigger turbo than him. Can't have the same happen to me or I'll kill the mapper. Lol Quote Link to comment Share on other sites More sharing options...
Chris Wilson Posted December 18, 2011 Share Posted December 18, 2011 How long is the belt (6PK then some digits after the PK, what are the digits)? You may need an idler both sides, but normally only on the slack side, the side the crank pulley isn't "pulling" the belt on, RH side from the front if the engine rotates clockwise. Is the belt crank pulley guided? Quote Link to comment Share on other sites More sharing options...
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