Duel Angled Idler Assembly for a screw 8mm

Is there any feed back on the RCD Duel Angled Idlers Assembly if it helps with Belt life? I run 90% with a 84 bottom and a 44 Top. Looking for some feed back to get some more belt life out of 8mm Blet or if it worth the money.

Thanks
Ray

 

Are you seeing belt breakage with the big 44 up top?

 

It isn't that bad i get about 15 to 18 runs on a belt. But seeing if i can get any more life out of the belt.

 

You can make big gains looking at your own program as they are very finicky. Most of the drive technology comes from top fuel which is obviously a different animal. We saw improvement moving the idler to a higher location and we run 11mm which produces a large top pulley even at 129%. High belt tension is critical on ours but not as high as 8mm.We run used belts from a px team and get a lot of runs mostly due to the air throttle and 2 step. 18psi vs 55psi on the limiter saves money but has plenty of drawbacks.
The whole setup is far outside gates engineering specs. I've seen outboard idlers fix a car that was eating a belt on the two step every time they launched. We questioned if it was a bad batch of belts but they just switched to efi so who knows if something changed elsewhere.

 

What are the drawbacks of the air throttle?

 

Just wondering, has anyone tried 14mm belts with a screw?....

 

Anybody with a two step and converter leaving at full timing and screaming RPM? Why would full boost matter?

I would think the outboard idlers would be the best bet. Dual tensioners would help the belt from going slack on either side of the pulley during times of engine decel, but may actually take away some of the tooth contact on the top pulley. Outboard idlers try to push more of the belt onto the pulley which would better distribute the load you're asking of the belt while keeping consistent tension.

 

Dumb question, but has anyone sent a belt back to Gates for post failure analysis and maybe a determination of how or why it failed? Maybe if the actual failure mechanism was known, then a good solution might emerge?

 

Has anyone tryed a 84mm wide belt to see if they last any longer.

 

From what I heard Gates engineering attitude was about like GMC's attitude on what we do with roots blowers...
They dont like the belt width, tension or surface speed on the pulleys.
I'm pretty sure back bending the belt with outside idlers was frowned on also but it seems to be helping some cars.

11mm and 14mm no doubt will take more abuse. The huge pulley required on the bottom has plenty of engineering problems itself.
Its all a bunch of compromise.

We can run mid 3.70's at 2550lbs and 129% od with a C rotor. There is no way I will tolerate less than 10 runs out of an 11mm belt in my program.

 

Does anyone have a picture of this?.......

 

Crappy screen grabs:

Force's car on the line with belt.

Force's car in the pits, no pulley.

One of the Lucas dragsters with pulley.

It looks like the idler does not put any additional tension on the belt, but provides a backer so when the belt is wagging around it doesn't jump teeth.

Chris Saulnier - Team Tigges
Mechanic Falls, Maine

 

Thanks !.......

 

http://beltguy.com/National Dragster Project Article.pdf

Here's a kind of neat older belt drive article from ND. At the root I am sure it covers all the basics Thanks to all who have replied to this thread...........