Prey4Me

iTrader: (2)

Just wondering how much rwhp it takes to to overcome 100lbs? From my experiences, it takes an '03 cobra about 50whp to pull an f-body. Now, with the f-body about 3400lbs and the cobra about 3600lbs, that roughly 200lbs. So my guess would be about 25whp for 100lbs, does that seem right? Any opinions welcome.

REDCYCLE13

iTrader: (7)

Although I have no real data. I've been told on multiple occasions that it takes about 10hp per 100lb to travel the same speed.

Prey4Me

iTrader: (2)

I have also heard that. I have also heard that taking away 100lbs. would equal about one tenth at the track, so 10whp = .10 of a second? Anybody else have any info or experience?

25psi

Cobras are faster than ls1's stock.

Tainted

iTrader: (9)

100 lbs = 10hp = .10 off the 1/4

Wants an LS1

SHHH...they dont know that, ALL mustangs are slow.

Phil8616

iTrader: (11)

you also have to think about gearing, drivetrain loss, when a car can make its top hp/tq etc....I think those all have a big part too...correct me if Im wrong

FoxNotch

This is what Ive heard a lot as well.
Its a generalization of course but its good for comparison........I mean bench racing.

95N20FORMULA

iTrader: (3)

ive been told its 100lbs = .10 at the strip but im a firm believer that its 115lbs instead...

Prey4Me

iTrader: (2)

I know that . What I meant was, lets say, a 400whp LS1 vs a 400whp cobra, it would take the cobra about 50whp to pull the LS1 because of the cobra's 200 pound (+/-) disadvantage. Here is an example,
'02 ZO6 (exhaust)
'03 Cobra (pullied,ported,bolt on's) 580-590whp
'02 Firehawk (H/C,bolt on's) 448whp
The ZO6 has about 200lbs on me, I have about 200lbs on the cobra. Using the formula, it should take me about 50whp to counter the ZO6's weight advantage, while the cobra would need about 100whp to make up for 400lbs. Should a stock ZO6 (w/catback & zip-tie mod) keep up with my car and a cobra making 480-490whp? That would equal roughly 25whp per 100lbs, I'm I correct or way off?

sleeperstyle

iTrader: (4)

i always went with the 100lbs= .1 thing, but the 10hp = .1 thing is not at all correct. you can make 10 more PEAK power but the curve be the same, the car won't be much faster at all. hell the curve could be worse chasing that peak power, to the car is, dare i say, slower...

this all applies to 12 and 11 sec cars too. once you get lower than that it takes a little bit more to go faster. hell in a 13 sec. car 100lbs may give you .2 or more! all cars are different.

RED04Z06

If you have 448rwhp and 434rwtq, you should easily beat a C5 Z06 with only ziptie and c/b. But then again, on the streets, anything can happen.

95_formula

no there not I beat them all the time in my lt1 and I get beat by ls1s.

LT1>everything

Sigforty

I would say your numbers left out the driver on weights. Figure in an average 200 lb person and the weight difference is the same unless one car has more people. I have actually used 15 hp per 100lbs and do not count the weight factor as a .1 in the quarter. Due to the quicker you go the more it takes to get that .1

wickedwarlock

iTrader: (4)

I agree, I say the general rule may apply to 11s and up, but after that I don't think so. Same applies going very high up on the scale. IF the truck runs 20s, rofl, 100 pounds less weight might get you 3 tenths, hehe.

100 pounds less or 10 more hp = .1 in the 1/4 as a general rule.

Just as Sigforty says, after you start getting really fast, it's going to take more. A good example is those guys runs these 8s and 9s. Going from 8s to 7s, seems to nearly doubling your horsepower. I don't mean from a 8.1 to a 7.9.

Fastphilly

Drag co-efficientcy is a factor as well. Maybe not at the start of the race, but as you start hitting close to 100 and above it does play a role.

25psi

agreed!

twitch32

I would have to say that your suspension set up would be the biggest deciding factor in the equation...my frined in okc told me about a car that went 12.3 on a stock no mod l89 that had nothing but suspension work done to it.

blackened05

from what i've seen weight becomes less of a factor at higher speeds as well. lighter weight will get you through the 1/8 quicker, more hp/tq will get you through the 1/4 quicker

soulless

iTrader: (3)

I noticed the biggest difference on top end when I put my car on a diet. I think it has something to do with the higher the gear the less torque going to wheels so it is easier to accelerate. What is everyone elses experience?