Proline clutch ?

[SledFreak]

Maybe or your belt is slipping a bit. Clean your clutche faces and try a another run and see if you run that high. My sled pulls 10,900 as well without a clutch kit. Also, if that RAM air kit you put in helps provide hp, then will need to change your clutching to some degree. I'm getting a Proline, so I will let you know it works out.

 

[MrSled]

Mighty maybe you have more belt slipage?

 

[Mighty]

It's running really strong (ask JTS 8) ), I find it hard to believe there's any slipping going on.......

 

[Apex Gt Rick]

Mighty there was a couple of times I hit 11k with my stock clutching too. Infact last time it happen I was with a friend with a cpr kit and he hit 11k that day too. I think it was conditions for us.
Rick

 

[byoffcr]

Something ain't right :itchy: My stock clutched Attak is hitting 11k and I only have about 300 miles on the sled. Do I simply have a stronger motor??

You cant relate your kit to proline as far as RPM.. Different weights, helux and springs.. If your pulling 11000 its running hard at 300 miles

 

[yammiman]

Someone needs to clear something up for me - all of the dyno sheets I've seen on a stock Apex show the maximum HP in the 10500 to 10700 range - now we have all of these guys on here telling how they are reving them to 11000 + - are all of the dyno runs I've seen been on sleds that were not broken in? - does the peak HP@RPM change once they are broken in?

 

[jimmie d]

Yes, engine loosens up and RPM gains a few hundred on a 4 stroke, that is why adjustable weights are so important.

Jim

 

[Reaper]

Several GT's up here pull 11,000 with stock clutching

 

[yammiman]

So does the peak HP extend along with the additional RPM? - in other words, peak HP is at 10700 on stock non-broken in motor - is peak HP at 11000 on motors with 500 + miles on them? - are you getting what I'm asking?

 

[kviper]

On real good hard pack my GT with CPR kit will pull to 10,800. On any thing short of good hard pack it will get closer to 11,000, I think it is track slip as i will notice a 100 to 200 RPM variance while running full tilt across a lake and running on and off good hard pack. Jeff Simon told me that the guy's wile testing are finding that they like to run at 11,000 on top for best result's. Mine with 1,300 MI CPR kit and one tooth smaller top gear will be run where it is at. (All is good). kviper

 

[kviper]

yammiman i understand exactly what you are saying and not sure if any one has dynoed one with over 1,000 MI but if the HP hold's close the higher RPM will generate more force and shift out farther.

On another note what MrSled said about belt slip is a real factor. If you didn't wash and brake your belt in properly these 8DN's will glaze easily and cause slipage and higher WOT shift RPM. Wash your belt and run 20 MI minimum with out WOT run's. I couldn't resist WOT with mine when it was new and glazed the original belt as well, Been there. kviper

 

[Turk]

My rpm,s totally changed in my Attak overnite. With my home meade clutching I was 10,200 rpm max. Next day odometer hit 200 miles & rpm,s went up over 600 rpm,s at the same spot same temperature, same barometric pressure. I had to add more weight to the primary at 200 & 300 miles to get rpm,s in the sweet spot.

 

[87gtNOS]

Several GT's up here pull 11,000 with stock clutching

You must have a black primary..stock clutching is spinning the belt.

 

[Riceburner]

What is a black primary? Dirty ????

Lots of sleds had extra grease on the secondary shaft when delivered. Some of that could have made its way to the belts of these 11,000 rpm stockers.

 

[87gtNOS]

What is a black primary? Dirty ????

Lots of sleds had extra grease on the secondary shaft when delivered. Some of that could have made its way to the belts of these 11,000 rpm stockers.

yes, rubber on your primary, causing your belt to slip even more.