Short belt mod
02-11-2010, 01:44 PM
#42
The AC pulley is an idler unless the AC is turned on. It has a clutch to engage the compressor. So, I'd be very surprised to see gains from this. The weight reduction from removing the AC would be good though. The PS would be a slight benefit. The improvement is in energy saved to accelerate the pullies. So, on a dyno, look for an under the curve increase w/ peak being equal (once accelerated to max RPM, there is no more benefit).
I have an underdrive pulley, no PS & no AC w/ two idler pullies added to increase crank, alternator & WP wrap angles. The pulley between the crank & alternator is a 2" diameter smooth idler that the back of the belt (flat side) rides on. The idler pulley between the alternator & the WP needs to be a 6 ribbed pulley. I used the same idler pulley from the stock tensioner. Don't recall the actual length of the new belt.....let me go look @ it; be right back.......it's 53.25". It's easy enough to measure w/ a string or small rope. Just measure with the tensioner pulley half way within it's tension travel.
02-11-2010, 06:28 PM
#44
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Picture this: opening day at the track, new track owner, new crew, LOTS of cars racing TNT. Guy drives his TA there. Spends 2 hours getting it ready to race ( crawling under it, getting dirty, etc.), then the timing system takes a ****. Meanwhile everyone was waiting in line and got a couple runs in. He gets pissed and spends another 2 hours getting the car back ready for the drive home, and we all line up and do some arm-drop racing bc the tree is down. I thought to myself, what a waste.
it
04-25-2012, 04:07 AM
#48
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hi there, sounds like the set up im after, do you have pics ? many thanks
Finlay
Finlay
The AC pulley is an idler unless the AC is turned on. It has a clutch to engage the compressor. So, I'd be very surprised to see gains from this. The weight reduction from removing the AC would be good though. The PS would be a slight benefit. The improvement is in energy saved to accelerate the pullies. So, on a dyno, look for an under the curve increase w/ peak being equal (once accelerated to max RPM, there is no more benefit).
I have an underdrive pulley, no PS & no AC w/ two idler pullies added to increase crank, alternator & WP wrap angles. The pulley between the crank & alternator is a 2" diameter smooth idler that the back of the belt (flat side) rides on. The idler pulley between the alternator & the WP needs to be a 6 ribbed pulley. I used the same idler pulley from the stock tensioner. Don't recall the actual length of the new belt.....let me go look @ it; be right back.......it's 53.25". It's easy enough to measure w/ a string or small rope. Just measure with the tensioner pulley half way within it's tension travel.
I have an underdrive pulley, no PS & no AC w/ two idler pullies added to increase crank, alternator & WP wrap angles. The pulley between the crank & alternator is a 2" diameter smooth idler that the back of the belt (flat side) rides on. The idler pulley between the alternator & the WP needs to be a 6 ribbed pulley. I used the same idler pulley from the stock tensioner. Don't recall the actual length of the new belt.....let me go look @ it; be right back.......it's 53.25". It's easy enough to measure w/ a string or small rope. Just measure with the tensioner pulley half way within it's tension travel.
