Breaking rear tires loose

Prob no HP gain, but a reduction in rotating mass which makes her rev faster and if you will (easier)....deff noticeable!!

No gain in engine horsepower, but a gain in RWHP. Let me give you an example. I had Chris Jensen up to Bakersfield for a second SCT Tune with the 109 octane fuel. The dyno we used had read 542 RWHP with my stock tires on the truck (325-40-22, about 90lbs each, wheel and tire). When Chris came here I had the truck in race trim, meaning I had the 16x10 Bogarts and M&H Cheater slicks on the truck, with no other changes it read 565 RWHP before the MS109 tune. Granted the dyno was a bit optimistic, but we were just using it as a tuning tool. Same dyno shows a 23 RWHP gain because of the race tires on it (they weigh 43 lbs each compared to 90 lbs each for the stock wheels). So you can see what a difference rotating mass makes(94 lbs total less weight). So you are correct , the engine will rev quicker, and the lighter flywheel takes less horsepower to turn, thus yielding more RWHP.
 
No gain in engine horsepower, but a gain in RWHP. Let me give you an example. I had Chris Jensen up to Bakersfield for a second SCT Tune with the 109 octane fuel. The dyno we used had read 542 RWHP with my stock tires on the truck (325-40-22, about 90lbs each, wheel and tire). When Chris came here I had the truck in race trim, meaning I had the 16x10 Bogarts and M&H Cheater slicks on the truck, with no other changes it read 565 RWHP before the MS109 tune. Granted the dyno was a bit optimistic, but we were just using it as a tuning tool. Same dyno shows a 23 RWHP gain because of the race tires on it (they weigh 43 lbs each compared to 90 lbs each for the stock wheels). So you can see what a difference rotating mass makes(94 lbs total less weight). So you are correct , the engine will rev quicker, and the lighter flywheel takes less horsepower to turn, thus yielding more RWHP.

Well said. :rock:
 
Taller side wall has a big effect, 31.6" Tire vs 32.8". His gear ratio would be around 3.95, that would explain not spinning.

This in turn would make my 10 a tad slower as well. Damn dealership that put the tires on.:banghead:
 
DA here (at the local airport), right now, is 7472 feet. It's amazing how much quicker the truck feels when I get some good air.[/QUOTE]

Damn Chris, my new house sits at just under 500 feet above sea level!!! And I still complain the truck is too slow...
 
Damn Chris, my new house sits at just under 500 feet above sea level!!! And I still complain the truck is too slow...
When we did the shift time measurements last winter, it was interesting to see how much quicker the sea level trucks were than mine. Running even a 13.9x up here would almost be a miracle.


I doubt my truck will ever see good air.
If they have another track day in Phx, or a GTG in Vegas, we'll have to get our trucks out to see what good air feels like.
 
If they have another track day in Phx, or a GTG in Vegas, we'll have to get our trucks out to see what good air feels like.

Your trucks will feel like totally different animals. It might take some time to learn how to drive them with your new found power.
 

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