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C6 Corvette ZR1 & Z06General info about GM’s Corvette Supercar, LS9 Corvette Technical Info, Performance Upgrades, Suspension Setup for Street or Track
So in my quest for more hp I have done something, I run a meziere pump so having the full belt at almost 80" long is somewhat pointless and all that extra wrap could be using a little hp... enter in the short belt mod. The belt in the pics is only about 55" long and only goes from the crank to the ALT to the PS down around the single idler and to the crank. No more waterpump and no more spring tensioner. Overall the engine does feel a little more snappy than before.
I went and bought a couple different belts to find the best fit. There's no way you're stretching it over the alt, so I unbolt the alternator (5min) then slip the belt on. Then maneuver the alt back into its bracket. Then I get the bottom bolt in and using a screw driver line up the top one. Tightening the bolts down bring the alt into alignment and puts tension o the belt. Not too hard at all, first time is more difficult because the belt is new. Now that I've validated it I have dremeled the bracket a little bit to allow the alt to slip in easier
It seems that would put stress on the pulleys and could cause something to fail. Have you ever seen how much a tensioner moves around under a load? Its pretty crazy. Also once the belt stretches a bit there will be nothing to take up that slack. Just my opinion I would stick with the longer belt and tensioner but to each his own.
It seems that would put stress on the pulleys and could cause something to fail. Have you ever seen how much a tensioner moves around under a load? Its pretty crazy. Also once the belt stretches a bit there will be nothing to take up that slack. Just my opinion I would stick with the longer belt and tensioner but to each his own.
The reason the belt stretches so much on normal cars is because of the tensioner bouncing around which is not good. A belt really shouldnt stretch much after initial break in. This did loosen up a tad but it still has a little more tension than the stock tensioner put on it. Any movement of the belt is not good, which is why katech and other companies offer solid tensioners so in essence this is very similar.
As far as loading the pulleys different, the belt still wraps around the pulleys very similar to stock and the ac compressor is also loaded on one side only.
I'm a little unclear on the tension deal? As long as thebhelt is tight, which it is there should be no issues. I've spun this to 7300 many times now without a problem
3 of my other buddies have been running the same setup on their cars camaros and vettes for about 10k miles and no problems. Stretch on the belt comes from the tensioner bouncing around. If anyone has used a solid tensioner like the katech you'll notice the belt never needs to be retensioned as it ages.
Also if you guys notice many new cars don't even use tensioner. They use stretchable belts that are but on with a special belt wrap tool
I'm a little unclear on the tension deal? As long as thebhelt is tight, which it is there should be no issues. I've spun this to 7300 many times now without a problem
Look, I'll give you points for ingenuity. But the fact is this only "works" if ALL the spinning pulleys are running VERY true.
Most stock dampeners do not run perfectly true, so with your set up (and with a fixed tensioner as well), every time there is a "high" spot it goes tight, every "low" spot it goes loose. Now of course, if you are running it on the "loose" side so that the "tight" spots are not problematic, e.g. putting too much load on the balancer, generator, water or power steering pullies, and it's not loose enough to slip or come off, great.
Yes, I see your ATI balancer, and (hopefully) that one runs fairly true.
Just for me personally, I'd want a bit more control over the belt tension than you have with this set up. But as far as this being an "HP increase mod", c'mon man..
Last edited by Dan_the_C5_Man; 01-25-2017 at 02:34 PM.
Just wanted to update here....been on for about 1500 miles since the op. Several hard days shifting at 7200 including some dyno pulls as well everything still tight and good and I haven't thrown any belts like 2 stock tensioner did. Overall great mod
01-24-2017, 06:41 PM
Short belt mod anyone?
