Tapp blowing belts compared to stock primary

[KillerBee]

18 sidewinder ltx le. 3500+ miles on stock primary and never blew a belt.Many high speed runs, drags etc. Changed belt once as a precaution. Installed Tapp primary last year and with few miles never had a problem. This year I’ve blown two belts in two days last weekend. Both belts broken in, etc. Drag race on both occasions blew belt (snapped), one from a standstill the other from 30 up. Original offset 59. Stock secondary with thunders 33/35 helix and orange spring wrapped at 6-1. Is the suggested 57.5 offset really that big of a difference??
Thanks in advance for any suggestions!

 

[KnappAttack]

Has the stubshaft moved in at all after blowing the belts?

I just installed my TAPP and another TAPP for a friend and set the offset at 59.1 on the stock Winder secondary after checking alignment with Ultimax XS825 belt at full shift. Don't set it up at 57.5 on the TAPP. Friend ran all weekend with no issues using the Ultimax XS825 and it was quick & fast.

What are you using for belts?

 

[KillerBee]

Thanks for the reply. First belt blown was an xs825. Second was an 8jp. Should also mention I was on a 270 tune.
I have never looked at the stub shaft because I have not previously blown a belt.
Can you please explain “after checking the alignment with the xs 825 at full shift”. Doing that visually Or otherwise?

 

[KnappAttack]

Thanks for the reply. First belt blown was an xs825. Second was an 8jp. Should also mention I was on a 270 tune.
I have never looked at the stub shaft because I have not previously blown a belt.
Can you please explain “after checking the alignment with the xs 825 at full shift”. Doing that visually Or otherwise?

Otherwise, doing it visually would not be accurate. You must measure with proper tools and be exact on your measurements to get it perfect.

I built a special bolt that I can thread a clutch Compressor on the primary to the full shift position, then put a wimpy secondary spring in the secondary with the belt under tension in the clutches at full shift, I can then move the secondary in and out and with a straight edge mounted to the secondary, then can measure the alignment to an exact number using any belt, or clutch combo for perfect alignment.

 

[Simplespeed]

How fast is the primary belt trying to go from the bottom to the top to get to full shift out ??? Too fast with too much force ??? Just think of the force it takes to snap a belt ??? Your doing it before it gets moving are you not ??? As soon as clutch starts to close them belts were toast…30 mph is barley off idle …. Soften the shift if you don’t find a flaw causing it . High horsepower has a way of finding the flaws… Mike is right, everything needs to be in perfect alignment and in balance….

 

[Thunder Products]

18 sidewinder ltx le. 3500+ miles on stock primary and never blew a belt.Many high speed runs, drags etc. Changed belt once as a precaution. Installed Tapp primary last year and with few miles never had a problem. This year I’ve blown two belts in two days last weekend. Both belts broken in, etc. Drag race on both occasions blew belt (snapped), one from a standstill the other from 30 up. Original offset 59. Stock secondary with thunders 33/35 helix and orange spring wrapped at 6-1. Is the suggested 57.5 offset really that big of a difference??
Thanks in advance for any suggestions!

The orange spring should be set at 3-1 or 3-2

6-1 is way too much and the clutches are fighting against each other

 

[KillerBee]

Thanks guys! I will check the stub shaft. Sled is up north so it will be a while to check things out.
I will also loosen the secondary but i will mention i had very little back shift when running it loose (3-1 or 3-2).
Forgive my ignorance Mike but when attaching a straight edge to the secondary, what exactly are you then measuring For “perfect alignment”?

 

[KnappAttack]

Thanks guys! I will check the stub shaft. Sled is up north so it will be a while to check things out.
I will also loosen the secondary but i will mention i had very little back shift when running it loose (3-1 or 3-2).
Forgive my ignorance Mike but when attaching a straight edge to the secondary, what exactly are you then measuring For “perfect alignment”?

I align the straight edge to the belt with a caliper when its close to full shift with tension on it in the clutches. So the straight edge is on the same plane as the belt and can be measured properly. I spend a great amount of effort to verify my alignment on my clutches overtime I make a change.

Simple things like belt selection, length & width make small changes to the offset as well. What is not taken into consideration the way I measure is chassis flex and motor mount flex, but the 998 is pretty stout in that regard, so one of those things you can kinda overlook and not worry about.

If you have a straight 35 try that in there with a Dalton B/O set at 90. I had one I setup for my friend last week with a 39-35 also set at 90. I wouldn't be using using that reverse helix like you are trying to do there if your using a Hurricane 270 tune. Use at least a straight helix like the 35 at a min.

 

[KillerBee]

Thank You!

 

[VyperNation]

I was going to ask at some point, might as well be here. I put TAPPs on both my winders (thank you @Thunder Products !!!) and was curious if anyone knows if the hurricane alignment tool works with the TAPP. I haven't had any issues blowing belts so far, but am only just under a thousand miles with them.

 

[KillerBee]

Vypernation i would be interested in your current offset as well as whether you are tuned and are using the stock secondary….?

 

[KnappAttack]

I was going to ask at some point, might as well be here. I put TAPPs on both my winders (thank you @Thunder Products !!!) and was curious if anyone knows if the hurricane alignment tool works with the TAPP. I haven't had any issues blowing belts so far, but am only just under a thousand miles with them.

The Hurricane bar is NOT accurate for use on the the TAPP.

 

[VyperNation]

Vypernation i would be interested in your current offset as well as whether you are tuned and are using the stock secondary….?

Ill get back to you on the offsets. They are both stock secondary with Thunder springs and rollers. the 146 is tuned 270hp and the 137 is 280ish.

 

[VyperNation]

Finally got around to checking the offset on both sleds since installing the TAPPs. Offset on both is sitting at 60 even. While I have had no issues, in the off season I plan to reduce that to the 59.1 number. I have been replacing the belts now at the end of a trip where I roll the belt over 1k miles just to be safe so I don't have to deal the shaft pushing in....again....if we blow a belt.

 

[putz21]

I checked my offset with my TAPP as well and am sitting right at 60 even and have been running TD Max 17 with 1,000 miles this year thus far. 2,000 miles last year with TD SM tunes. I have the Dalton B/O set to 80 I believe, but may try 90 in a couple of weekends. No blown belts yet.