Definitely, that tensioner is way low. What size pulleys are you using, which size belt, and do you know what position the idler was on the bracket?

 

Well first off I think it does this bracket A LOT of justice. You can see how much the belt is stretching and if it was a manual tensioner, it wouldn't be able to take the slack out of it. Its a 7.25 crank with a 3.85 blower. 51" belt, and the idler is in the middle position I believe. I'm going to look up belt sizes right now. I think I need 3/4th to 1" smaller?

 

You might be able to just move the idler to the far position (away from the blower) and that will tighten it up a little, but if that doesn't get the resting position on the tensioner between those upper marks, then you should look at a 50.5" belt.

Yeah it isn't until you put one of these on that you get to see just how much your belt stretches during a pull. That is why it is important to get the tensioner as tight/high as possible at rest. It looks like yours was bottoming out there at the end.

 

Wow! That video is scary for those of us with manual tensioners!

 

Those belts stretch A LOT. I just got a 50 1/8th" belt. This one should do a little better lol. I really wanted to see what it would do on 15psi. Last time I changed the belt I got 15-16psi out of it. This time on the dyno I could only get 11....My buddy said on the way home it went to 13 on the highway. Could the load of the dyno also have something to do with it? I know superchargers are obviously rpm based but I know load will also have some play in it. I also want to look into getting the Gates racing belts. I was on there site and couldn't find sizes or anything like that.

 

Cool. Let us know how it looks once you get it on. Might be too short, but you can move the idler to the close postion on the bracket if you need to.

 

Which do you suggest trying first? Moving the idler or the belt? The only PITA is I need to get back on the dyno and see if its completely fixed. I guess I'll be able to tell a little bit on the street if she makes more psi. I just need to get a real crank pulley lol

 

I'd try the belt first, since you have to take the blower down to move the idler anyway, and the shorter belt will be tighter.

 

Ok. I'll reset the idler to the "near" position and try the new belt. Maybe heating the belt up will help. I hope this one doesn't stretch as far. Maybe I'll get back on the dyno early next week and see what it does.

 

So I decided I might as well just put the 3.70 pulley on that I have sitting here. It should only make a couple more lbs and the tune will accommodate it for sure. It made 11 on the dyno (down from 13psi last dyno) and made 13 on the street on the way home. I've seen it make 15-16 with a new belt so we'll see what she does. Maybe 16psi@ 6500. All I know is it should be around/over 700 wheel lol

 

Ok so the 3.70 pulley is on and the belt fit, I did need to move the idler to the "close" position but the tension marks are all the way at the top. Its hitting on the power steering pulley at the moment. Not quite sure what to do.

 

I sent you a PM, give me a call. We'll get it sorted.

 

Hey chris shoot me a text in the morning. I figured a couple other things out. Belt is on with the 3.70 blower pulley. Putting belts on a couple times sucks by your self lol. I'll take her for a ride in the morning and see what she makes for boost.

 

Well I took her to the track on saturday. Only got to make 3 passes and decided not to make any more since they should have kicked me for my last 2 lol. Only a 1/8th but a good time none the less. I was running M/T 26x10.50 ET Streets. She was spinning the tires and the clutch so its time to put the twin disc in. I also need more suspension parts seeing as how their all stock and blown out. Its a good start! lol



Ok so I know its rotated all retarted...I rotated it upright, saved it then uploaded it and this is what I get. Once again I know its not that fast but I had to start somewhere...lol

 

Well I got her retuned today. Not bad for 13psi on a 9.5:1 370ci

 

Which one was your time? really hoping it was the 6.8x

 

I fixed it for you. Congratulations on the time! Bob

 

I ran 6.9s on my 10.8 pass just for comparison

 

What kind of power and trap speed? My trap speed with my old combo was 125ish This thing pulls way harder up top. Thanks for the fix bob! lol I figure she's good for mid 10's somewhere. It was still losing traction too.

 

I would say so. Those are some good numbers. I can't wait to see what it makes when you really crank it up.