if i took an honest 400 pounds out of a high ten second car, how would that affect the 60', e.t., AND trap speed?

 

I was always under the impression that 125lb = .1 et, Im not sure how well it translates at that level but it definitely was true when I tested it going 13.0-12.90

 

Ive heard every 100 lbs will improve et by a tenth but its not exact ofcourse. It will depend alot on where you take the weight out of too that will affect the launch, et and trap.

 

As it goes every 100lbs = 10 hp (metaphorically speaking)

 

Hi,
the aforementioned post are correct. Roughly 100# per tenth. Weight reduction is cheap horsepower gain. Less mass- faster et.- provided all is equal on
comparison factors.good luck and have a blessed weekend.......jim

 

That is probably a truer formula than 100lbs = 1/10, since on a 13.00 car it will equal 1/10 gain, but on a 10.90 car, 100 lbs or 10 HP wont gain a full 1/10, maybe only .06. The faster you are, the more HP it takes to go faster!

Al

 

+1 Thats a generic equation for much slower cars.

 

yeah but you have to think the lighter your car is the better it will respond to weight reductions.....say you have a 200lb car and u remove 10lbs, thats 5% of the cars weight....then lets say u have a 100lb car and u remove 10lbs thats 10% of the cars weight....so the more weight reduction you do the more every bit effects it in my opinion

 

General rule has been stated. 100/.1

Lighter is faster but lighter can mean less traction. That can hurt you when taking off weight. I would say in the right conditions it is safe to say the weight you took out is good for .2-.5 in the 1/4. If you took all of it off the nose you could easily gain .5 due to weight transfer, less resistance on the front tires, ext. Since you probably took it out of the passenger compartment it won't have as big off an effect.

 

op,
decisions can only be as good as the information one has. having said that, please think about what information one would need to form an accurate assessment. if you provide the information i am looking for i will answer your question. the dynamics of this subject is why it is easier to use guidelines or just go get the results. if you get results be mindful of all the variables involved so you can better extrapolate which variable was worth what.


tires have a maximum grip potential, both heavy and light cars are both governed by this. the forces required to achieve this "maximum rate of acceleration" is proportional to the weight of the vehicle. i.e. a lighter car needs less force when compared to a heavier car but both are still limited by the tires. so as long as both platforms can keep the necessary forces onto the tires to achieve that maximum grip, they should be very similar; edge to lighter car in short and long term results; ability to remain consistent longer (the increased forces of the heavier car will wear out the tires quicker)

 

also I think your stall/converter responds to weight. Some are made for lighter/heavier cars. SO depending on what you got, maybe your fitting your stalls ideal weight better. might be a bit extra et.

 

the weight loss came from everywhere...some of it isnt done yet like k member and rack, but thats on the list.
i removed the hvac completley, rear and passenger seat, manual brake conversion, light weight carpet, switched from mild steel bolt in to a cromoly 8 point, trimmed inner fenders, trimmed cowl, kirkey seat, cut all unnecessary brackets from inside and underneath car, true duals(short & sweet), removed a 'ton' of unneeded wiring, removed air bags, removed front sway bar, removed horn, removed door bars, removed complete stereo system and replaced it with basic 2 speakers and head unit, removed all seat belts(except 5 point), drag wheels and skinnies, and I made a custom removable tubular front end out of cromoly. the entire core support has been removed... the frame rails have been cut a few inches behind it and bulk headed, and the new cromoly front end bolts up to to the plates.

i just wanted to get a general idea how much difference this stuff would change my e.t. thanks
Nick

 

thank you, can you share your increments (i.e. 60',330',660',1000',1320' mph/e.t.) with us or post time slip? if possible share the date and time at the track so we can convert results to sea level.

im trying to provide a little more detailed response; i.e. 60' improvement as well as mph and e.t.

the advise others have offered above will get you close, and may satisfy your requirement for information.

 

You will see an incrase in speed/reduction in ET... how much depends on wether you disturbed the balance of the car.

It sounds like the weight came out from all over.. I'd guess, that you should see a 3 mph gain, .3 reduction. Providing you didn't throw the converter off disturb the balance of the car.

 

FWIW, a few weeks ago we took my gf's car out, which is a high 10 sec car, and I was at least a tenth slower and 1 mph off her times. I'm about 100lbs heavier than she is.

 

^^What was the difference in density altitude from the two days though?

Al

 

The runs were made on the same day within a couple of hours of each other.

 

It seems like when I take weight off the front end, I get more than the 100 lbs = 1 tenth rule. Maybe more like 100 lbs = .12 or .15. Because it pushes the instant center back. And these fbodys are front end heavy anyway, so weight off the front end usually tends to bring better results than from other areas of the car. Rotating weight also (in theory) makes a big difference.

 

weight/hp ratio...It really depends on the weight you are going from...

drop 100lbs of a 5k weight car and you will not see much at all but drop the same 100lbs off a 2k car and the gains will be alot greater

do yourself a favor and get a MOROSO POWER CALCULATOR 89650 it is worth its weight in gold to get you in the ballpark...