Just like the title says.

 

the larger the wheel ( diamater ) the higer the final drive = less torque = less hp = slower car. Weight, no. That just kills your handeling.

 

Maybe I should re-phrase, do dimension/weight show up on the dyno charts? Will I get more TQ if I had a smaller diameter wheel. I know a similiar thread was opened a few days ago but it was about a tranny (short or long gears).

 

good question, it might, check with the dyno in the area, they probably know or will be curious enough to find out now
and bigger wheels do affect horsepower/torque man, rotational mass. look it up.


[Modified by KAMiN, 1:50 AM 4/25/2002]

 

yes.
just like a light flywheel but not as direct an effect

 

yes heavier wheels will knock a lil off the measured dyno power. As far as diff sized wheel/tire combos that arent stock diameter, I think the dyno computer should be able to correct for it right? Isn't it possible to enter the gear ratios and wheel/tire size so that the computer recalculates the actual torque/HP figures?

 

Yeah, I imagine the dyno would take that into account. Gear ratios don't affect horsepower.

 

wut gear should one dyno in?

one to one?

whats the formula



[Modified by comptechgsr, 1:51 AM 4/26/2002]

 

Not at the engine, but it does affect it at the wheels. I thought most dynos measure the ability of the car to spin the roller thing, which I'm sure you'll agree that it'd be easier to spin up the rollers in 1st compared to 5th gear.

 

I'm not sure how dynos exactly work, so I guess I'm not sure what they measure.

Either way, horsepower at the wheels is not affected. A transmission and wheel sizes trade torque for rpms, but the product of the two (power) should remain unaffected. As such, I'd imagine a dyno should simply measure how hard and how fast the rollers get spun. If it couldn't account for gear and wheel sizes, then something would be terribly wrong.

 

its true its true... .smaller wheels will give you slightly higher dyno numbers