help with breaking blower belts !

probably been hashed to death but im at my wits end with this :
used air throttle with two step for years no problem but it had a internal crank support
switched to open throttle with fuel bypass and two step at same rpm ( 4200-4500 )
bearing went bad in crwnk support so I took it out
somewhere along the way it started breaking belts at 3-8 passes is this normal ?
can I go back to the air throttle and help it ?
its a brad 8 with a fresh r980 fuel done by Rage recent, ignition done by spud this year, new crank ,new hub, different pullies all this is in a promod we are turning the blower 58% its a 14mm belt # 1750
it seems to do it when I let off the button to leave and not so much during the two step

 

What's fuel flow on the 2 step. Sounds like bad detonation.

 

Try no fuel bypass

 

It started breaking belts after removal of the crank support?

 

maybe you oughts to check da crank for brokeness

 

I have been running my a980 at 72% over for 5 years and on number 69 run/pass now with the 1750 14MM belt. I have never heard of anyone having belt problems with a Whipple. I make 52#s of boost on the 2 step (3000rpm) and 62#s at the shift and at the stripe. DO NOT RUN any lean outs on the 2-step, you will break belts due to so much volume of boost/lean fuel mixture. You need plenty of fuel on the 2 step to keep things smooth. Contact me and I can help you with any Whipple tuning at no cost. I just like to run them and save money by not spending money on blower belts. Contact me at 931-580-8804 or csmjimbkyle@bellsouth.net-THANKS, Jim
PS-and like above, you probably have other problems---

 

I put in a new crank every year so its had three in it while having this issue............. 5402 do u run open throttle or air valve ?

 

I have a spare internal support bearing I will send you if you are still set-up it use it let me know.

 

WOT on the 2-step with a carbon blue lined belt-1750 14MM---

 

That's interesting to know. Gates Tech steered me away from the Carbon blue, but if it works great! An off the shelf local belt. What are your top and bottom pulley diameters out of curiosity? How much RPM do you pull?

 

Try a Star Racer belt

 

TOL, I run a 28 tooth 14MM on the top and a 48 tooth 14MM pulley on the bottom, and leave at 3000rpm on the 2-step and shift at 9600rpm and go through the lights over 9000rpm and have run a 3.88 at 196mph at 2550#s with a a980 Whipple on a 438ci Hemi. Just align the belts good, run the correct tension and never any blower belt problems. I do run a lot of boost, but very, very fat on the tune-up and a max of 24 degrees timing, just to be SAFE! I hope that helps! Jim

 

Thanks Jim, good to know. Does the A980 have a quill type shaft in the blower drive like a PSI does, or is it direct/rigid ?

 

They do have a quill type shaft, but 4 times heavier, and stronger, but have never seen one break. The early models have a male spline and coupler that joins the 2 piece drive shaft to the main rotor. The later models had a 1 piece drive shaft that took a lot of slop from the splines out. For old technology and the price compared to a PSI C, they are a good substitute, just about 38#s heavier and it hurts on an Outlaw ProMod with no weight rules. Classes that have to weigh a certain weight, they are a great way to go-THANKS, Jim

 

How tight are you running your belts?

 

1" slack, play both ways on the long pull side-

 

never messed with a r980 , does it have heavy rotors like a PSI screw ? if so a 2 step is hard on the belt , bouncing the belt against the blower.
the things I had in the past to fix belt problem's were , run the belt tighter than you normally would, if that helps check the alignment first , and when the belt stretches on the 2 step or acceleration it will ride up the idler pulley lip and try to jump the edge that will brake it every time , taller lips on the idler can help, we made one and fixed 1 combo, and the blue carbon belt is the strongest one BUT it is the least forgiving if you have a issue because it will not stretch without breaking, the purple gray belt seems to be most forgiving. I watched a blue belt through chunks on video with a C screw on the 2 step , changed to a purple belt and A to B , just my experience

 

We ran my TA/FC and Dan Nickelson's promod car with the belts as tight as guitar strings. After doing some dyno pulls with a PSI D at 92% and hearing the belt jump teeth (popping) through the window of the dyno room at Mandolini's while the engine was idling through the mufflers up that back of the building with what we thought was tight on the belts we started running them very tight with good success.

 

has anyone tried the little extra idler pulley on the blower like some of the fuel cars are doing ?