Celica Forums General Discussion Engine and Performance hp loss due to weight

so, im looking around online for the different cars I see around to see what Im dealing with as far as competition, and Im trying to get a better idea of how much horsepower is lost due to weight. Ive heard that for every 10 pounds you (virtually) lose 1 hp about is that true or is there really no way to truly find out? I mean, I know you dont lose hp, but you have more weight to push with that hp. So, if anyone has a better ratio or maybe a way to calculate, let me hear it!

for the celica it's more like 15 pounds per horse..for a gts anyway. most gts dynos go around the 160 whp mark (it's better to use whp than bhp)...and the celica (both gt & gts) weigh about 2,500 pounds. 2,500 divided by 160 = 15.6 pounds per horse that the engine has to push.

so if you lost 15.6 pounds, you would effectively 'gain' a whp unit.

oh yea, you can always add your weight into the equation. im 170 so my car ways about 2670lbs. it doesnt really matter though because 2,500 is just an approximation anyway...it varies up to 100 pounds.

it depends the weight...gt and gts have different weights and it depends if you have a manual or auto..here:

GT/GT Action Package GTS/GTS ActionPackage

Curb weight(manual/automatic)(lbs.) 2,425/2,460 2,500/2,580

This is from the Toyota website! Left numbers are for gt and the 2 right numbers are for GTS

Whoa, terrific link! The heaviest thing is the stock hood, I didn't know it weighs 50lbs! How much does a carbon fiber hood weight?

you have to account for the weight of 14.5 gallons of gasoline and other fluids in your car

the stock hood does not weigh 50 lbs lol.

NICE LINK! weight reduction is the easiest, cheapest way for a slightly faster car. Better for brakes too. I've stripped a lot of my interior, the one problem is most weight reductions are from the rear area of the car. Which promotes understeer. Rotational mass is the best weight reducer (I.E. lightweight rims, flywheel, accessory pullies).

Really? So that info is incorrect..? How much it weighs, anybody know?

i have read other forums aobut this. you can search for more info. prettymuch to get a big difference take every pannel off of yoru car. and strip the interrior down to nothing at all goodluck though. post pics when you start your weighterloss program

no the curb weight is the weight of a car with all fluids full and full tank of gas, dry weight is car bone dry.

I made an estimate awhile back much lower than 50 lbs, think I said 20 and Lucky_317 said it was a bit lower than that. That was in another weight reduction thread. I trust him, but it's definitely not 50 and for those who work out with weights you'd know.

20 pounds for a stock hood? i would have thought it was more (although less than 50). we need someone to actually weigh the thing...i hate trying to make appoximations off of guesses. the innacuracies just get even more blown out

If someone got a carbon fiber hood on there car and perhaps there stock hood laying around in the garage, please go weigh it for us! Its good to get exact figures, like now I know for sure that stock GTS rims weigh about 19lbs, thanks to the other thread.

I'll weigh my old hood when I get home.

scratch 20, I'll go the other direction from Lucky and guess perhaps the hood may be closer to 30 lbs...can't wait to hear the results. I'd weigh mine but it's 350 miles away right now.

does anyone have a batterie in their trunk? that would help with relocating the weight from the front to the back alittle. also lighter weight engine parts dash peices and hood help drop the weight in the front.

Ok, my stock hood weighed in at 26lbs, paint and all.

Whoa cool, thanks man! That's with the stock hood scoop on it still right?

less weight in the back is better since the car is fwd

a lot of the weights listed on that link are bogus.

the stock hood is around 20 lbs NOT 50 for one huge example.

also the seats weigh about 34 lbs not 40+.

they have the right ideas but don't look at the actual weight.

also they do not account for whp only factory rated power.

my car personally is at 12:1 power to weight.

also rotating weight loss such as lighter/smaller rims play a huge role as well.

Yeah, the stock hood scoop was on.

Does anyone know how much the stock battery weights?

about 31 lbs

im thinking of putting my battery in the back but first i need to get a mat that will cover up the back all the way to the back of the front seats. once i get that im going to relocate my battery to the rear

I don't think moving the battery to the rear will make a big difference, and since our cars are FF, it's better to have more with towards the front of the car for traction.

^^ leave the battery in it's stock location if you want to ACCELERATE better (such as in a drag)

it's good from a HANDLING perspective (such as with auto-x) to have as close to 50/50 weight ratio as possible...so relocating the battery to the rear helps out a little because the celica has something like 65/35 weight distribution. putting some weigh in the rear will help you car handle better

the best weight reduction is to do some sit ups

50/50 weight distribution is good for a RWD car, but in a FWD car more weight shift to the rear means less weight on the front. Less weight on the front means less friction the tires can generate, leading to more understeer.

It's true that 50/50 on a FWD would make it feel more balanced, up until you push it to the limit, in which case you'd understeer.

^^ haha guess we can't have it all. the celica already oversteers like a mother

anybody familiar with swinging the celica's rear around?

Really? I don't find my celica oversteer at all!

With Hotchkis Competition Sway Bars and a few other mods (rear strut bar), sure.

With stock suspension, decent tires, and dry pavement...no.