2.9L Whipple Crusher, belt slippage

[Kwik03DSG]

Ok I have an issue I need help solving, all guys with 2.9L/3.4L whipples feel free to chime in.

My car was in the process of getting tuned and has massive belt slip after 5300-5400 rpm. car noses off from 26.5psi at 5400 to 14psi. (Made 690whp at that point, so much more to be had :banana

The blower is a 2.9L whipple Crusher with a caged 2lb lower and 2.8 Reichard Racing upper pulley. The car also has 3 Billetflow idlers, 2x90mm and 1x100 mm pulley. Belt was a new Gates K080755 belt. Tensioner is a Reichard manual tensioner with spring.

In short, other than going to the K080755 HD version, is their anyway to cure the slipping? Kind of lost on this, as I thought I had taken the necessary precautions to avoid this.


Fire away with any suggestions, thanks (and yes I did search. Saw YZFkid's thread and 2 others, not much info when dealing with belt slip from larger displacement blowers)

 

[Kwik03DSG]

Wow... did I stump and confuse all of SVTP with this question? lol

 

[MyStIcHrOmE 04]

Man I have never had any luck with a 2.75 upper pulley (on my 2.6h KB). I would think your best bet would be to run a 3-3.25 upper and a different crank pulley. The more belt wrap the better. Good luck!

 

[Redfire03]

If you really want suggestions, put a bigger upper lower on. That will solve your belt slip problems.

 

[Kwik03DSG]

Man I have never had any luck with a 2.75 upper pulley (on my 2.6h KB). I would think your best bet would be to run a 3-3.25 upper and a different crank pulley. The more belt wrap the better. Good luck!

Thanks. I tried to avoid that but it looks like it might have to go that route. Ive seen a few guys acquire the 2.9 and have not heard about belt slip issues with a small upper, so i wanted to see what is working for them that I might need to try.

If you really want suggestions, put a bigger upper lower on. That will solve your belt slip problems.

See thats the issue... the 2# lower I have is the custom ones they were doing on here with the caged lower.
To my knowlege they're not making those lowers anymore otherwise Id look for a 4# or try to upgrade it to a 4lb, and Im not really willing to risk potential issues going to an uncaged lower like a Metco with a larger displacement SC for the sake of belt wrap.

Ill try the HD gates belt and hopefully that is the solution.

If anyone has any other ideas, it would be greatly appreciated! :thumbsup:

 

[I8URLS1]

Sell it and buy your CTS-V oke:

 

[Kwik03DSG]

Sell it and buy your CTS-V oke:

LOL Jared.. no not yet. I feel like I have to see this project through first.

 

[I8URLS1]

LOL Jared.. no not yet. I feel like I have to see this project through first.

I know the feeling full well

 

[stangfreak]

You don't need a caged lower with a 2.9 whipple.

 

[Kwik03DSG]

You don't need a caged lower with a 2.9 whipple.

Consider it "avoiding potential risk" as was explained earlier. Better safe than sorry because if this motor does let go before i sell my car (dont intend on that happening) and i do another bottom end build, it doggone sure will not be because of a silly, easily avoided snapped crank snout.


short of finding someone with a caged 4lb lower, I am not getting rid of the 2lb caged lower.

 

[03Cobrra]

Not much you can do but go to larger pulleys. Temporary solution just to get the car tuned is spray some vht on the belt it will work but it doesn't last long.

 

[Kwik03DSG]

Not much you can do but go to larger pulleys. Temporary solution just to get the car tuned is spray some vht on the belt it will work but it doesn't last long.

Thanks. Ive been keeping a close eye on your car, both here and on YouTube. its a heck of a build.

Have you been able to source the 10 rib puleys you needed? I might go that route if its not too difficult.

 

[03Cobrra]

Thanks. Ive been keeping a close eye on your car, both here and on YouTube. its a heck of a build.

Have you been able to source the 10 rib puleys you needed? I might go that route if its not too difficult.

Nope but I haven't pursued it much lately I've been busy with other things. No one I have spoke to wants to make the pulleys for a reasonable price.

 

[stangfreak]

Consider it "avoiding potential risk" as was explained earlier. Better safe than sorry because if this motor does let go before i sell my car (dont intend on that happening) and i do another bottom end build, it doggone sure will not be because of a silly, easily avoided snapped crank snout.


short of finding someone with a caged 4lb lower, I am not getting rid of the 2lb caged lower.

I would be worried about the Manual tensioner instead. I understand what your saying. I have been running a 4 lb lower on my car for 9 years and I have a 2,9 whipple car making 710. Your not going to snap the crank snout. People with the 2.8 kenne bells are running non caged pullies and and they are running 9s all day with no problem abusing the crap out of them. I'm not new to these cars.

or check out the innovators west line. Good luck op.

 

[Kwik03DSG]

Nope but I haven't pursued it much lately I've been busy with other things. No one I have spoke to wants to make the pulleys for a reasonable price.

Thank you for your input! You got my imagination going and I got to thinking... there is a local shop thats pretty darn good at fabrication work. Ill have to give Mike a call and see what he can do if the HD belt solves nothing.

I would be worried about the Manual tensioner instead. I understand what your saying. I have been running a 4 lb lower on my car for 9 years and I have a 2,9 whipple car making 710. Your not going to snap the crank snout. People with the 2.8 kenne bells are running non caged pullies and and they are running 9s all day with no problem abusing the crap out of them. I'm not new to these cars.

or check out the innovators west line. Good luck op.

Thanks for the IW solution, I might do that and go bigger on the upper to keep the blower rpm's down. And over the last 2 days searching I have seen the manual tensioner also being a focal point of issue... Is there a aftermarket tensioner thats design is identical to OEM (as im sure OEM isnt a 'manual' tensioner?)

thanks,
Edmund

 

[stangfreak]

Edmund, not that I know of. I still use the stock tensioner on my car. I would go with the IW products. I personally feel that the 2.9 is perfect for this car, especially if its stock. But anything bigger than a 2.9, yes you will have belt slip issue, the crank's that are breaking, plus your forced to run high boost and race gas all the time, and not to mention the heat created by these big blowers. The whole thing about twinscrews "running cooler" I think is bs. I never believed it even back when they made the 2.2 kb.

so you should be fine with that 2.9. Then if yu want more power, go turbo. No more worries about belt slip, crank issues etc. Im not a fan of going any bigger than that. I went from a 2.2 2.4 2.3 now to a 2.9 whipple lol I achieved nothing. which is why I refuse to buy a 3.4 whipple or a 4.0. Im going in circles. My next setup will be built 4r and twin 62mm. setup. I will have no problems on the streets unless the other car is packing wht I have.

 

[1raresnake]

Did you ever figure out your belt slip?