VaSteve

You know...for every X pounds shed, it's like X HP. Is it the same for all cars, or does it depend on the car itself?

SundayDriver

There is not really a formula but for any car you can figure the weight/power ratio. Then you can see what the equivalent change is. For example, you have a 1000 lb car with 200 hp which is 5 lbs/hp. Any weight reduction will improve that ratio and you can then figure the HP needed to get the same answer. Drop 100 lbs and get 4.5 lbs/hp. That is the same as adding 22.2 HP.

But in reality, it is far from that simple. In most cases, reduced weight will offer many more benefits - better braking, better handling and any downforce will work better (but lift will hurt more). If you are running a track with very high top speed, then maybe more HP will get better lap times than lower weight at the same power to weight ratio.

VaSteve

I'm running a low HP car (944) in modified street trim. I'll have to figure out what the car weighs. The weight reduction is from the driver.

DJF1

Do a search, there are many good threads on the same issue. Here are a couple:
https://rennlist.com/forums/showthre...eduction+ratio
https://rennlist.com/forums/showthre...eduction+ratio

VaSteve

Thanks, I better get gastric bypass, I'm not going to be able to add much HP.

Z-man

The rule of thumb I've heard is that every 10 lbs in weight loss equates to 1 hp.

Man, I gotta drop those twenty/thirty pounds before the season starts...
- Z-man.