Belt tensioner set point question

[2004cobra615]

So I have a stock tensioner with metco brace in place currently. I'm looking to upgrade the belt to gates new RPM but either I go 4mm shorter or 11mm longer than current belt.


Can any one tell me if my tensioner is set at 20 or 80% tension?

I believe you pull tensioner toward ground to loosen... It's been awhile.... it so I'm at 80% tension correct.
Will 11mm larger than current set up be to loose?

Thanks
Joe

2004 Cobra 2.9 Whipple

 

[P49Y-CY]

Yes that is about 80 "percent" tight. You push arm towards the floor.

 

[c6zhombre]

Thats going to be tricky with the RPM belt.....as far as choosing between the 11mm longer or 4mm shorter belt. One thing is for sure....you cannot use too much tension on the tensile cord RPM belt or it will snap in half. It's designed for failry low tension levels because it does not stretch like a traditional belt. But having said that....it can't lay limp either, there needs to be some level of wrap.

What you really need to give yourself much more set points is a whipple sliding adjustable tensioner (if you can find one). That would be the ticket to properly set an RPM belt. I think you're only choice without one is to try the 11mm larger belt and see if it works. I'm afraid the 4mm shorter belt is going to snap

 

[TP 112]

Looks like the 2 top spacers need to swap spots on the metco plate. On some tensioner’s the fat spacer will make contact with the tensioner not letting you get full range of motion when trying to put on a shorter belt. The thinnest spacer of the 3 clears with no issues and you can get full range of motion to put the tightest belt on.

Just something to look at and could be helpful.


Sent from my iPhone using svtperformance.com

 

[2004cobra615]

Thats going to be tricky with the RPM belt.....as far as choosing between the 11mm longer or 4mm shorter belt. One thing is for sure....you cannot use too much tension on the tensile cord RPM belt or it will snap in half. It's designed for failry low tension levels because it does not stretch like a traditional belt. But having said that....it can't lay limp either, there needs to be some level of wrap.

What you really need to give yourself much more set points is a whipple sliding adjustable tensioner (if you can find one). That would be the ticket to properly set an RPM belt. I think you're only choice without one is to try the 11mm larger belt and see if it works. I'm afraid the 4mm shorter belt is going to snap

My gut says the 11mm will be to long it's almost a 1/2 inch....
I also agree the 4mm shorter is not an option now that I know I'm at 80% for sure.

According to gates they say rpm will work with greater than 20% tension but factory postion would be nice.

They don't make the Whipple tensioner anymore....

2004 Cobra 2.9 Whipple

 

[2004cobra615]

Looks like the 2 top spacers need to swap spots on the metco plate. On some tensioner’s the fat spacer will make contact with the tensioner not letting you get full range of motion when trying to put on a shorter belt. The thinnest spacer of the 3 clears with no issues and you can get full range of motion to put the tightest belt on.

Just something to look at and could be helpful.


Sent from my iPhone using svtperformance.com

I'll look at it. Thanks

2004 Cobra 2.9 Whipple

 

[c6zhombre]

My gut says the 11mm will be to long it's almost a 1/2 inch....
I also agree the 4mm shorter is not an option now that I know I'm at 80% for sure.

According to gates they say rpm will work with greater than 20% tension but factory postion would be nice.

They don't make the Whipple tensioner anymore....

2004 Cobra 2.9 Whipple

Not sure what your idler combination is....maybe you could swap out a 100mm for a 90mm or vice versa somewhere in the combo and get either the 11mm longer or 4mm shorter belt to work

 

[2004cobra615]

Not sure what your idler combination is....maybe you could swap out a 100mm for a 90mm or vice versa somewhere in the combo and get either the 11mm longer or 4mm shorter belt to work

I'm thinking about switching to e85 soon... So I might have a smaller supercharger pulley

2004 Cobra 2.9 Whipple

 

[c6zhombre]

I'm thinking about switching to e85 soon... So I might have a smaller supercharger pulley

2004 Cobra 2.9 Whipple

Nice! I approve of this message lol. You and the motor will love that.