NeilW

I can understand the belt structure being kevlar-reinforced but what about the teeth themselves? A common mode of failure on older belts is simply the teeth being sheared off. Would the kevlar belt help with this?

Helstrm

I would be in. I think changing belts every 35k or so is insane. However changing them every 3 years does not sound so bad. In my case I would put 35k on a daily driver per year and changing the belts every year is just too much. I would still pull the inspection covers and check tension as well as other components. Most cars that I have owned run 60k before they recommend changing the belts and even then you could run them much longer without issue. (I don't) I would love to be able to get 60k out of these belts before tearing the front end down again. I am in.

njwilser

I think what some are missing here is that the tioming belt is really part of a system that is only as strong as its weakest link. I would assume, on a reasonably well maintained car, belt failure is most likely prompted by another component( rollers, w/p, contamination, tension etc., etc,).
My guess is that the new belts are pretty damn tuff, and no belt can withstand the stress of an adjacent failure.

Legoland951

I still have some of my 944s with the ORIGINAL working water pumps so they do last much longer than the belts from my experience. I have never had a problem with a stock conti belt (not just rubber-they contain some kind of fiberglass or some kind of fiber already) for $7 each and I have never replaced a belt before 60k miles unless to replace some other part like seals. I thought I had my first pre 60k mile self installed timing belt failure last week, but it was from a BROKEN CAMSHAFT (you see everything after you change about 100 timing belts). When properly installed, the balance shaft/crank seals last a long time too. I think its a great idea for a kevlar belt, but what are the stock belt made of already? I know its not all rubber for sure. Also, I order belts 20 at a time and $7 compared to $100 is a huge difference. I would take deposits before I make a huge amount of belts expecting to get $100 a piece.

Yabo

As far as I know, rollers/waterpump should last about 2 belt changes, so it would be worth it, especially if you could reuse the belt, it would still be better!

theedge

Thats a GOOD point actually.

MoonBoy

I thought that the belt was intended to strech along with th block, head, etc, when the engine was going through thermal cycles?

Jakerx

i would definitely want a kevlar belt.

Matt H

They did, however, go to talk to a Porsche tech and I bet 9 out of 10 tell you they dont even own a 9201 tool. That is marketing hype. Kevlar was not common in 1986.
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88BlueTSiQuest

It was even less common in 1982, not to mention the 70's for the 924 and 928's.

Bill

Moon hit the nail on the head.

There are several reasons the Porsche engineers used a belt over say gear drive or chain drive. Belts are quieter. Belts are cheaper. But I believe the main reason is, aluminum expands at twice the rate of cast iron. As the 944 engine heat up, it grows and the belt needs to grow or stretch with it. Especially since there is no automatic belt tensioner on these engines. I have taken readings on a hot engine belt with the 9201 gauge, and the belts are over double the cold tension. If a kevlar belt does not stretch, will the tension become way too tight as the engine grows? Or lower the tension and will it be too loose when cold?

Prove to me that kevlar will perform with the engine's expansion rate, and I would be interested.

Yabo

I have never felt a belt that even when the engine was hot was TIGHT, I think there's room for error in the tightness side, most importantly is that when it is cool it won't be loose enough to slip or hit things it should not... For the looseness of these belts, I don't think the aluminum expands by inches or anything, so I don't think it is that important, as long as there is some slack to accomodate for it. Do the stock timing belts actually stretch, or do they just get less slack in them when the engine expands? Seems if it was actually stretching the belt much, it would cause a lot more snapped belts.

superman90

I'm in ..

eman930

The trick is not to find the best T-belt, The trick is making some kinda auto tensioner for the 944/951. This way the belt will always be in spec. Now if some one where to make a auto tensioner kit that had a better belt, Even if it only doubled the maintenance periods on the belt then I would go for it

RMills944

i know my water pump is at least 70,000 miles old. I believe it's even original (135000 miles) The only reason to change it is in case the bearings wear and need replaced. I''m going to change it out this year, but I'm not going to start changing it with every belt. Hell, the VW has an 80,000 mile belt change on rubber belts and the water pump is part of htat service.