Kevlar timing belts vs OEM timing belts... thoughts?

**92RT-TT** · 12-13-2011, 03:12 PM

I'm just trying to get people opinions on the pros and cons of running an OE belt vs a Kevlar belt? The only negative things I've heard about the Kevlar belts are that they are rather unforgiving if you have a solid tensioner.

What are people's experiences with them?

**AdamVR4** · 12-13-2011, 04:44 PM

I've had nothing but good luck with mine, but I have a stock valve train and only spin it up to 8030 RPM.

As far as I know, until Ray had a random failure with an OEM belt, it was widely thought that there was no reason to use the kevlar belt.

This is the next belt I'll be using: Gates Racing Timing Belt Mitsubishi 3000GT - T195RB

Are you going to use aftermarket valve springs?

**vr4tune** · 12-13-2011, 04:53 PM

coopkill changed kevlar to OEM his because it made noise. I think that it may be a isolated incident not sure I have no experience other than OEM.

**AdamVR4** · 12-13-2011, 04:55 PM

Originally Posted by vr4tune

coopkill changed kevlar to OEM his because it made noise. I think that it may be a isolated incident not sure I have no experience other than OEM.

And yes, some people complain about squeaking and the blue rubbing off on pulleys. That issues seems to be hit or miss. With the cost of the kevlar belts today, I'd go with the gates belt... That's assuming you're going to run aftermarket valve springs/cams/rev past 7K.

**vr4tune** · 12-13-2011, 04:57 PM

I spin 8200 on a OEM belt and 3sx valve springs on a DD for a year now.

**AdamVR4** · 12-13-2011, 05:00 PM

Originally Posted by vr4tune

I spin 8200 on a OEM belt and 3sx valve springs on a DD for a year now.

And there's nothing wrong with OEM, either

All we've got is very limited anecdotal evidence. It would be great to see some tension test and CMM (or however the heck you would accurately measure a belt) comparisons.

**green-lantern** · 12-13-2011, 05:07 PM

Aaron works for a belt company so he knows a good bit about it. He will probably chime in.

**UTRacerX9** · 12-13-2011, 05:42 PM

I think it's practically a moot point. Most people who have modified their car to the point where they might actually NEED a kevlar belt usually blow up their engine/tranny long before needing to change belts, whether it's an OEM one or not, and then they replace it for the rebuild.

**stealthee** · 12-13-2011, 05:57 PM

99.999% of the time the belt isn't the failure point in the timing system. A tensioner fails, water pump seizes, etc and causes catastrophic failure that even a kevalr belt won't stop. No point in spending the extra coin on kevlar.