a racing question ..i ned answer and explanation plz

i have raced alot of times but i have nver raced starting from rest ..so i want to ask if i raced starting from rest when starting at the first gear the rpm should be ...:1- maximun -red line-
or 2- average -about 4000 -
or 3- at thet point the car gives maximum tourqe-about 4500 in my car -

some friends calimed that the red line gives max horse power
and some said that starting at red line leeds to loosing few seconds at burn out -tires are spun producing smoke - so i want i detailed answer with explanations plz.....

^okay, what kind of car do you have, and with what engine... we'll start there. Generally cars do make PEAK horsepower around redline if that answers your question.

From his profile:

2003 Daewoo Lanos

:lol:

lanos 2003
5 doors hatchback
94 horse
1.5 litre
4 cylinder

and yes i know it gives max horse around red line but is that the best point to go????plz read the post and i want a detailed answer

From his profile:

2003 Daewoo Lanos

:lol:

:slap:

let the man ask his question

i'd say 4k rpm










but still :evillol:

and why exactly 4k ??

you have to start somewhere...and given the power that your car is making...may have a chance of not losing grip when you go...or you could guess and check...

there was a formula around here that gave you the exact shift points for maximum tq and hp...if you do a search you may find it...it was a while ago

am new here and i guess i wont be able to find it can u give some more help plz???

The only way to find out the EXACT best point to shift would be have your car dynoed. From that you can see where your peak torque and horsepower are. Otherwise you just need to experiment. Each engine/tranny is different we can't just tell you the best RPM to shift at.

not to mention tires and clutch difference. On a Lanos I wouldnt launch from anything more then 3000-3500 rpms. Its high enough to produce torque but low enough not to fry the clutch.
4k will spin the tires too much.

best way is to practice and find out what your best technique is.

You also must consider that dumping the clutch isn't always the greatest way to get a low hp car to go. If you've driven the car at all I'm sure you've found a spot in the rpms where the car starts to make power. You want to rev the car to this spot or higher and slip the clutch so that you have minimal loss of traction (if you even have any). Your car may be so weak that it may not unless you rev it up high like was said. That's why I'm suggesting for you to find that spot where your car actually starts to pull. A dyno is the best way as stated. Your motor has 2 cams right? So it's probably designed to continue making power to redline, but that may not actually be the case. It all depends on how it's tuned to operate.

wait... you mean to tell me that thing can spin the tires?

just kidding.... or am i?

I used to have an auto one that could spin them, but only in the rain. Beleive it or not it was acutally a fun car to drive, but it had a ton of kickback.

meeh. id say just rev it all the way up to rev limiter (if it has one) and dump the clutch. that seemed to work really well on my cuz's stock tercel, but he had no rev limiter. was like 6k maybe?

for a good launch you want the least amount of tire spinning possible so dumping the clutch would be a bad idea, just go somewhere and practice at different rpms, see where u can SLIP the clutch at and just chirp the tires without bogging down, and for shifting, just shift at redline it will keep you in the powerband you need to make good power

You need to launch at whatever RPM your tires allow.

Examples....
With my car, I have to come off the line at idle on a street tire (275/40/17).
With a warm Nitto drag radial I can come outta the hole at around 3400 RPM's....any higher than that and I spin.
With warmed Mickey Thompson drag radials I should be able to come outta the hole from 5500 RPM's. Won't know for sure until I try them out.

yeah, so when u gonna do that?

Couple weeks.
That is if you were refering to me.

i said just dump the clutch since then messin at diff rpms dumping it will allow for him to see where it spins and bogs less than any other place. but w/e. im not the expert here. i just know that in my 2001 sr20de roller cam sentra, that i hold the brake and gas at about 2250 rpms since thats as high as it'll go with the tq converter. i think headers and/or catback would allow me to rev it even higher.

like they've already said, it depends on the car i.e. engine/tranny combo and also the tires. a smaller displacement engine will require more rpms. don't redline and dump the clutch, go for about 3/4 of your redline, that seems to be it usually. no if you had a bigger engine, the rpms would be lower for a launch. go read roadandtrack, or go to their online site, the tell what the best rpm for launch in almost all the cars the test. from there you can get a good idea for what to do. you'll notice, they never to redline launches.