nihil

You're just nitpicking at this point. Yes there are other brand names, but it's irrelevant to this discussion. "Kevlar" was the first to market and is the common name for this material, along with being the most widely used brand of para-aramid fiber.

As for the timing in regards to its finding its way into the timing belt market, it's not like kevlar/aramid timing belts are new to the world just because they're new to you. Like many other consumer level automotive advances, they trail racing development in the classic "Win on Sunday, sell on Monday" fashion.

951Dreams

Yeah, when chains go it's not pretty. But in my experience, chains last the life of a "normal" American engine. A least before people junk em. Now if you go 200k, yeah, you need to change that thing. Did my Suburban at 180k, it didn't really need it, it was a little loose, but I did it to prevent issues if it went. I know many who are going 250k on their original.

I'm not REALLY serious, the R&D would be cost preventive, and if the design wasn't just right, it could be as serious an issue as the belts.

But wouldn't it be nice to just have to worry about it every 150k? Instead of 30k? Course I guess it's just academic on a 30 year old car anyway.

I never really understood the whole belt thing, sure, they are quieter in most cases, but how many belts have you heard of failing compared to chains in your lifetime, the BMW issues aside?

Pipe dreams.....

Voith

Point is this: How do you know belt manufacturer is not already using equal strength or even better suited material in their belt as is, why must it brandish a other manufacturer marque and blue color in order for you to believe it is worthy of x5 cost factor?

Ferrari, Bugatti, Harley, you name it, all use black belts and moving harley with a fat biker + fat passenger from zero to 100mph at WOT will generate a LOT more torque than few springs countering well oiled lobes of camshaft(s).


I had this exact conversation here about 6 years or so ago with Travis the Rennbay owner who then promoted these. Looking on his page now, it appears he no longer sells them.


I don't care what is in the belt as long as it is doing its job as supposed. All standard belts more than exceed that so paying 5 belts price for one with blue logo and additional other fancy company trade mark that breaks for no apparent reason just the same, is not something I would advise. But to each its own.

Its not such a big issue as is hype surrounding it. Here in europe almost all cars use belts and there is almost no belt failures. The point of eventual failure are the roller bearings and water pumps, but those too fail extremely rarely when maintained and changed at correct intervals.

I had a 944 belt failure and bent valves on mine, but it was due to missjudging of rollers on my part when doing the belt job. Interestingly enough even though it happened at highway speed, damage to belt was not as extreme as I have expected. Standard belts are tough as nails.

The real belt strenght benefit on 8v cars could be obtained by converting to 16V belt which is wider.

marc abrams

With the high rate of water pump, roller, and belt failure's I read about here, I have to believe the belts are being over tighten. Food for thought, I've have seen timing belts on other cars so loose that you can slide them off the pulley with your pinky finger and those cars run without jumping timing.

odonnell

We use Kevlar (aramid fibers) in my industry as high-strength wrapping tape around subsea flexible pipelines that see pressures in excess of 1000 bar in extreme environments, where the tape's job is to keep the armour wrapping wires from laterally bucking under pressure. Not saying a belt made with this stuff isn't insanely stronger (depends on manufacturer implementation of the technology), but it's been proven in countless other industries for decades. I understand about cord being a common failure, but like I said in my last post, I've personally seen failures that involved shearing teeth - not always from a seized roller. I'm curious to see real world failure rate of blue belts, one case on rennlist doesn't say very much.

nihil

Speculate much?

This is the part of the conversation where you offer up some evidence or at least a compelling argument to support your theory.

Do you really think the color of the belt makes a difference?

Yes the name 'Gates' does in fact mean something, as they've been around nearly a century and I've spent a lifetime seeing the logo on various automotive and industrial rubber bits. By your logic, the name 'Porsche' has the same credibility as the name 'Kia'.

Again with the color?


Well I guess if Travis took them off his site, that means your hypothesis is sound?


You obviously care enough to publicly speculate that a well known and established company is blatantly mislabeling their product and overcharging consumers, with no more supporting argument than "the colors are different" and "Travis took them off his site".

Having worked with composites, I know good and well that kevlar is fairly pricey and wears tooling faster than say nylon/polyester. This means it's both more expensive to buy, and more expensive to work with. Factor in that any company producing any belt is obviously doing so for a profit, and the pricing isn't surprising in the least.

Do I wish it were cheaper? Sure, I wish everything were cheaper. Am I going to cry about having to pay to play with newer tech? Nope.

Matt O.

There could be a lot of reasons for that, to include the belt sucks or he couldn't source them. I wouldn't infer the quality of a belt because of that. There is another side to that story.

Matt O.

This whole thread is hilarious. Timing belt fails in part because of it's material, someone makes a stronger belt, we complain because how dare someone make an unproven belt.

I'll take the kevlar, thanks.

nihil

You pretty much nailed it with 'hilarious'.

Not knowing these particular engines very well, I tried -really- hard to be open to the possibility that some quirky Porsche design flaw would make them benefit from a weaker mechanical fuse of a belt. Almost sorry I even questioned it.

blade7

What does the hydraulic tensioner do other than compensate for the expansion of the head and block ? There's a tensioning method for 944 engines that achieves the same thing.

V2Rocket

The block and head expand/contract due to cold/hot temperatures...and so does the belt.

When you set the belt to proper tension during a timing belt job, the belt and engine are cold (room temperature/ambient). But when the engine is up to temperature, the belt will also be warming up too and stretching more. But the engine and belt materials expand/contract at different rates.

So the belt doesn't want to stretch quite as much as the engine will expand at running temperature, but is forced to because of the parts fitment...and eventually the stretch doesn't go back.

All 944 engines have a "manual" or "fixed" belt tensioner. The 87+ "spring style" only sets the initial tension, but you lock it in place and it is the same fixed position forever, until you change it again manually.


The hydraulic 968 tensioner allows for sudden tension load changes due to hard acceleration and high RPM, and also compensates for temperature...the belt itself basically dictates the tension fluctuation.

Matt O.

Dude, get the flipping gates belt if you want. It's what I run, and a lot of people who don't post here. Individual hypothesis on whether or not it's "worth" it aside, it's a few extra bucks and used in racing applications... It certainly isn't weaker.

nihil

I had one in the cart for the 944 before I even responded to this thread, and also have a couple already on the shelf for the 1.8T.

It went from folks saying it simply wasn't worth it, which is fine and dandy, to it could possibly maybe almost damage your engine or be black painted blue or blacks could be blues in disguise. Just giving the naysayers ample opportunity to offer up some sort of tangible argument.

odonnell

It seems like for our cars, there isn't really anything objective when it comes to real world durability. Nobody has done scientific measurements between the two. It's a matter of preference/personal forecast until there is actual proof beyond conjecture.

951Dreams

Things I've discovered not to post about on 944 forums unless you want to start a s*it storm of disagreements.

1) Oil weight/type
2) Oil brand/type
3) Spark Plugs
4) Gates racing belts
5) Tires
6) How to get more HP from a N/A
7) Adding Turbo to a N/A
8) Automatics
9) LSX swaps
10) Whether you HAVE to change your belt every 3/30
11) Aftermarket steering wheels (tho MOMO seems to be pretty safe, mostly)
12) Wheels, offsets, what looks best on what

So, if you want a lively discussion, feel free to bring any of the above up.