Just like it says, I keep hearing they do and really cant think of any reason why they would. I would also like to know how much, like a 3.42 to a 4.10 gear.... I understand why zr1's with their heavier weight would knock off 2 or 3 rwhp but I dunno how gears would change any of that..????

 

I've heard that before too, but I'd need to see several back-to-back dyno comparisons before I'll believe that for sure.

Think about this logically: lower ratio gears (higher numerically) offer better acceleration because of a higher mechanical advantage (like a long lever, having more leverage and making it easier to do work). If it's now easier to get the wheels turning, then I'd assume it also requires less engine power, so I don't see why the HP #'s would be lower.....they should be higher IMO, since there is less power used through the drivetrain?

 

IF there is a loss with gears its very slight...

 

Ive seen people try and use 4.10 gears as an excuse for low dyno numbers or why a certain number is impressive, totally dont understand...

 

With a 4:10 gear the pinion is smaller in diameter than a 3:42. The difference in size reduces the amount of teeth on the 4:10's pinion. To keep the gear set strong the teeth on the pinion need to be longer and pitched deeper which increases the amount of swipe area across each ring tooth. It does require more power to overcome the extra resulting friction but its not a large amount, maybe a few ponies. IMHO dyno #'s dont mean much, its only good for comparing changes. At the track is where you will really see the difference.

Kevin

 

Maybe because the pinion teeth are longer, there is more friction between the two gear faces, but IMO, the increased mechanical advantage should out-weigh the small amount of additional friction.

There is only one "theory" that can almost explain it for me, which is along the lines of increased friction. Since the pinion is spinning so much faster to maintain the same speed, it builds extra heat --- not because there is more friction face-to-face than with higher gears, but because the gears come into contact more times. This additional heat is just wasted energy, and since "energy input" = "energy output", if more of the mechanical energy is being converted into thermal energy, then maybe that's where some power is lost? Also, maybe if the gears get hotter, they expand and run a little tighter?

 

I don't mean to bash you, and you DID say "IMHO" so I respect your opinion...however, my thoughts are that too many people go to the track to test out the gains from their new mods, and then they say "Look I gained 8 tenths from only a K&N filter!", even though they don't account for getting a better 60', better weather, etc. A dyno's results will USUALLY be more repeatable than the track's results. IMHO.

 

He said dyno results are only good in his opinion for comparing changes. I think you misunderstood what he was trying to say. The problem is so many people rely on peak rwhp to show off their cars, but peak rwhp means jack squat. Without a good curve the car isn't going to run good times. Their are too many dyno queens out there that put down 400+rwhp but still run high 12's. I know of lots of local cars that put down more rwhp/rwtq than me but are all about a second slower at the drag strip and trap 4-5mph less than me.