rx7speed

get out you auto guys


just curious how you guys launch

right now I am just dumping at 3000-3500rpms

I get either lots of wheel spin or some spin then a bog

someone else was telling me to slip the clutch a little instead. it seemed like I did a little better trying that but I don't want to wear my clutch like a ***** and also I need to get better at it

so guys what are your tech for launching during a street race.


what rpms, and how?

snjracer

slightly lower tire pressure and dump it pretty hard.. no one can really answer this question about exact RPMS cause every car makes differant power at diferant levels.. i make way less power than you so i dump it at like 3500 or higher (a little) and get slight traction problems when the juice kicks in.. but it is all about practice... go for a drive (when no cops are around obviously..) and practice at lights find the sweat spot where the car doesn't go up in smoke but does not bog.. i JUST found mine this weekend

good luck

rx7speed

what do you mean you make less power then I do??

what the heck are you driving

snjracer

never mind i just read your other post.. i was refering to the times in your signature.. but i see now that is no longer the case

i drive a juiced honda civic

rx7speed

yeah had the turbo motor but blew it.

then a few things I had on the N/A motor I ended up getting rid of so kinda starting over again
sold the cat-back, ported intake, put the timing back to stock,and plus I didn't have those problems when I ran the 14.8 N/A, might be missing a few things, but I'm getting there still

snjracer

what caused the engine failure??

rx7speed

I couldn't get the thing running right

kept on getting boost spikes and me not knowing a whole lot with tuning turbos I just had things freaking out on me.
plus I had damn boost creep


grr


finally it looked like one of the boost spikes just did it in for my motor though and chucked an apex

Jokerman

I remember in my 4spd 78 320i that to launch hard from a stop and get the best run i would run the engine to about 3k and then slam the gas at the green and ride the clutch a bit to keep traction (granted not much of an issue) and to keep the little 4cyl reving towards its power band so i could get out of my attrociously small 1st gear and into 2nd. A good clutch drop would work to if you aren't talking about massive torque and hp numbers, just be ready for that repair bill after to many. I have to say though that i enjoy drag raceing a bit more in my auto camaro than in my bmw, but then again my camaro is a 16second car (slow) compared to my high 18second BMW (really slow, still beat several hondas, especially around corners at speed). Maybe its the fact that i can preload the trans with just two feet and two pedals instead of the 3 pedals 2 feet combo of a stick.

avro206

Your car is a rotary- pretty different power curve then a V8- launching a 5spd is very different for each car- no "one cetain RPM" will apply to all cars. Generally speaking you want a little spin- toget into the powerband quickly- but no too much- that'll hurt your time.

That's whats nice about a V8- lots of torque down low- it's ready to go and fast- down low. Maybe less wear becasue of this.

88IROC350TPI

LOL, slight wheel spin? I'd hate to see you experience MAJOR wheel spin if you consider your traction issues "slight" Its time for an lsd and some drag radials for you.

Anyway, I drive around in a 6-speed '99 Z28 and still can't get it to launch good. The way I usually do it is just easing into the clutch so the car rolls and then just slamming on it. Even easing into it the car still breaks loose sometimes and spins all the way into 2nd. I'd scared to dump the clutch just yet. The tranny mount is already broken (broke it the first night driving the car )

rx7speed

hehe you don't think I know that


just curious what you guys do. I understand the rpms might be different to launch to but just curious as to your ideas...


and hey I like my powerband up in mid to high rpms.... lets me run more gear..... so far works for twisties..... but it sux more then a witches titty in a metal bra for launching

ChillPhatCat

Sounds to me like you're launching at the right RPMs, You need to launch close to your power band to get the right launch, but too much tire spin will lose time. Back when I was running my snow tires after all the snow had subsided, I did a 0-60 run, first with very little tire spin dropping at 1200 RPM... came out to 9.4 seconds (keep in mind my sig). Then I dropped at about 1500 RPM and completely hammer it... spun all the way through first and I got 10.2 seconds.... I'm down in the high 7's most likely now with the Khumos and about 60 lbs less of "required equipment".

The question is where does traction break and where does your power band begin? If the powerband is higher than where you loose traction, my best guess would be to drop right in the middle of those two... slipping the clutch is for fixing mistakes, you launch too hard, only way to regain traction is to feather it.

CrazyHawaiian

Honestly, I refuse to race my 85 SVO (5 speed T5) from a stop. I fear when I dump it, it will all just explode. I do all my racing from a roll and downshift.

giovanhalen

From "shutdown" by the beach boys. To get the traction I'm riding the clutch/ my pressure plates burning this machines too much. Cutches are very strong, you will probably break something else first.

TonyC

iTrader: (1)

I rev it up to 2500 rpm, let the clutch out almost all the way, floor her briskly and let the clutch out all the way. Seems to work really well.

snjracer

well you know.. when you make as much power as i do ina fwd car it is hard to keep from spinning

ATOMonkey

There is no good way to launch a street car. The tires aren't sticky enough to dump it, and the clutch will die if you slip it. I try to launch it so that my tires spin enough that the engine only bogs a little. So I get a little spin it bites then I go. On my turbo couple I launch around 4000, and if it start to spin too much I feather the throttle a little. Like everyone says, you just have to do it enough times that you can feel what the car wants. It sounds like you're doing a pretty good job as is.

Cruz'N Bruz'R

I don't dump, EVER. I'll just blow the tires away, plus destroy the T5.

I start to let the clutch out till she starts to bite and eek the car forward, then I just feather the gas till around 2200 while letting the clutch make contact, but not pull the car forward. From then I can't just dump the clutch and slam the hammer down. No spin, and if tuned right no bog. But launch RPM will always be different on every motor. If you have gobbs of torque, you don't need to launch at a higher rpm.

And sure this way of launching is hard on the clutch, but if you want to play, you have to be willing to pay. I also never decrease my tire pressure. I've tried different tire pressures at the track and it makes no difference. I also don't bother heating street tires up either. there's no point. They will never get hot enough to make a difference in your launch. The rubber compound does not have the same characteristics as soft compound slicks.

snjracer

88IROC350TPI

I do a small burnout before racing to clean the tires off. A lot of people say its pointless but I strongely disagree. It makes a world of difference for me.