Launching

[93dxKID]

Ive, bin playing with it every once in awhile...but I was wondering if anyone knows about getting a good launch off the line with a basic modified dx hatchback. thanks

[SleeperZ]

Your best launch in a FWD car is to use reverse gear.

;)

[Canuck]

Originally posted by SleeperZ
You best launch in a FWD car is to use reverse gear.

;)
:rofl:

[WagN2NR]

Wont a stiffer suspension eliminate wheel hop (i.e. Braces and Springs)? No wheel hop means faster Launches.

Bigger tires = More traction = Faster launches. Sticker tires will also improve launches.

Limited Slip Differentials help for the straight shot but make turning more difficult.

AWD also gives more traction if your car comes with that option (I only know of Trucks, SUVs and Subaru’s with that option). RWD is faster then FWD.

Manual Trans are faster then Auto’s.

More Torque means faster launches. (Torque x Engine speed) / 5,252 = Horsepower http://www.howstuffworks.com/question622.htm )

Less Weight means faster launches. (“85% of our gains are from weight loss” -www.xcceleration.com) This is why MiniMonster is so quick. He doesn’t weigh anything (not joking).

Also, if you got all the money in the world, you can tune the gears in some Trans specially for the type of racing your doing. An example would be, if you were racing the ¼ mile, tune the 1st gears low to make it super easy for the engine to get to a higher speed quickly. By doing that, you’ll get to speed quick, but you wont be able to take advantage of your peak power, because the motor will be turning faster then the Trans can go so in effect the Trans slows the engine down at high-end speeds (Like when you drive down a hill in 5th gear if you don’t have Overdrive). Overdrive is a feature that allows the wheels to go faster then the engine (flywheel). Also, when you gear a Trans low, you’ll be shifting like Krazy.

You can do the opposite also, gear the gears High so that you take off slow as hell, but you may never have enough power to use 5th gear (Do this to use all the power an engine has). People do this to determine top speed possible.

Disclaimer: I’ve never raced in my life! I have no idea if what I have said is true, it is only my personal hypthosis. PLEASE CORRECT ME IF I AM WRONG!

[95GSRB18C]

If your gonna end up doing a motor swap in the near future i would recommend gettin a tach whether it be an aftermarket one or the stock EX/Si guage cluster. That way you can see what your RPM's are and do your launchin from there. And like wagn2nr mentioned, i would lower your car to minus the wheel hop. My car was at stock height and i could not get traction worth a shit. I got some coilovers and dropped it quite a bit and now the tires spin freely with no hop at all. Hope this helped.

[02GTI1.8t]

you think you have launching problems. us chipped 1.8t people have 240 ft-lbs of tq a bit below 3000 rpms. its not easy putting that power to the ground in a ff. stiffer (dogbone) mounts eliminated wheel hop and spirngs also made it easier. just practice alot. maybe feather the clutch a bit instead of droping in.

[93dxKID]

Originally posted by B18C1TurboTeg
If your gonna end up doing a motor swap in the near future i would recommend gettin a tach whether it be an aftermarket one or the stock EX/Si guage cluster. That way you can see what your RPM's are and do your launchin from there. And like wagn2nr mentioned, i would lower your car to minus the wheel hop. My car was at stock height and i could not get traction worth a shit. I got some coilovers and dropped it quite a bit and now the tires spin freely with no hop at all. Hope this helped.

I think that my nearly stock dx motor just doesn't have enough power to spin 17in rims....I can do it just find and get a decient launch with the stock 15?...I think they are...rims. About the tach, im planing on getting one by christmas, I found this thing in a sport compact mag. that im thinking about buying....it tells you a great deal about how your car runs including rpms....Similar to the Apexi S-AFC, check it out....http://www.gtechpro.com

[TXKompressor]

whoever came up with double clutching had a lot of common sense to control wheel hop.

It heats up the clutch enough to slip a little so it doesnt just bute real hard... and there is better transfer of HP to the ground on not to the axles.. the bite hurts and transfers too much too soon....

[Canuck]

Beside the obvious (stickier wider tires and stiffer springs), Polyurethane engine and tranny mounts help a lot.

[CSMsi311]

The G-force is not the same (or similar) to a SAFC. the Apexi is a air/fuel controller, you mainly use it to increase or decrease the amount of fuel going to your engine.

The G-force is an accelerometer. It measues acceleration. Newton's law F=ma.

[Talonstylz]

dont redline drop, youll just spin to hell. And the stock DX motor can easily spin 17's. I remember when ViolatorRH00 had his stock D15 in, he would launch at 5000-5500 RPM and wouldnt get too much wheel hop. That was with skunk 2 springs for lowering. A Strut tower bar also helps reduce hop quite a bit.

[stu]

You DO NOT use double clutch method when launching, it would be stupid. Double clutching is for cars that don't have very advanced synchros (or none at all I guess). It is what you use when you are on a track going into a turn. When you are entering a turn, you downshift to a lower gear since you have slowed down. In order to do this smoothly, you must match the revolutions of the engine to where they would be in the lower gear (ie, higher rpm). Older cars that don't have synchros, or very good ones anyway, are very difficult to just throw into a lower gear. Sooooooo...what you do is double clutch. This is where you let out the clutch halfway after you have revmatched and before you slip it into the next gear. This clears up the synchros, or gears or what ever, and allows you to downshift easier.

So when Dom from "The Fast and The Furious" says his line about double clutching during a drag race, you can just laugh your ass off because you know that shifting up, and double clutching don't go together.

[TXKompressor]

I am with ya but it does work in heating the clutch up.. and allowing it to slide a little better then just raw grip... I remembered the term from growing up around the tracks (stepdad had a Hotrod shop) we would go and watch all the domestics... Stepdad tried explaining it, kind of made since....

yeah, Dom is a tool!
The Rice and the Ridiculous wasn't one of my favs, especially talking about putting SR20's in Honda's WTF...


Originally posted by stu
You DO NOT use double clutch method when launching, it would be stupid. Double clutching is for cars that don't have very advanced synchros (or none at all I guess). It is what you use when you are on a track going into a turn. When you are entering a turn, you downshift to a lower gear since you have slowed down. In order to do this smoothly, you must match the revolutions of the engine to where they would be in the lower gear (ie, higher rpm). Older cars that don't have synchros, or very good ones anyway, are very difficult to just throw into a lower gear. Sooooooo...what you do is double clutch. This is where you let out the clutch halfway after you have revmatched and before you slip it into the next gear. This clears up the synchros, or gears or what ever, and allows you to downshift easier.

So when Dom from "The Fast and The Furious" says his line about double clutching during a drag race, you can just laugh your ass off because you know that shifting up, and double clutching don't go together.

[2000SiVTEC]

That is because a lot of those older hot rods do not have synchros. It does not work in a modern car, period. All you need to do to slp the clutch is modulate how fast you let it out. If you can't do that then come pay me for some driving lessons...........

[TXKompressor]

Originally posted by 2000SiVTEC
All you need to do to slp the clutch is modulate how fast you let it out. If you can't do that then come pay me for some driving lessons...........


LOL....

I dont have any problems just wondered if that worked for moderns, I never have used but I have never had that problem...

[Talus]

When I'm headin into a switch-back at about 20-25, I can't downshift to first until I double clutch to match the higher revs. You may say that modern cars don't need it, but I'd like to see you downshift my 97 5-spd Jetta at high speeds without it.

[Natef82]

Originally posted by 93dxKID
I think that my nearly stock dx motor just doesn't have enough power to spin 17in rims....I can do it just find and get a decient launch with the stock 15?...I think they are...rims. About the tach, im planing on getting one by christmas, I found this thing in a sport compact mag. that im thinking about buying....it tells you a great deal about how your car runs including rpms....Similar to the Apexi S-AFC, check it out....http://www.gtechpro.com

A faster launch is going to be finding the point where you can put as much power to the wheels without allowing too much wheelspin. 17's add a ton to your unsprung weight (unless your rims are worth more than your DX!), not to mention rotational inertia. Put your 15's back on. And then practice till you find the sweet spot. It probably won't feel faster, but it's the same way the butt dyno works. It's impossible to use "seat-of-the-pants" testing to get acurate data.

This is Apexi's version of the gtech...
http://www.apexi-usa.com/meters_revspeedmeter.asp

Another option for a tach is this little doober. I've got one of these on my Chirstmas list!:D :D :D
http://www.rev-lite.com/rev.html

[Brian]

Originally posted by Talus
When I'm headin into a switch-back at about 20-25, I can't downshift to first until I double clutch to match the higher revs. You may say that modern cars don't need it, but I'd like to see you downshift my 97 5-spd Jetta at high speeds without it.

You can rev match without double clutching anyway. Work on giving the throttle a quick blip before you downshift to rev match. Double clutching is really unnecessary.

[95GSRB18C]

and double clutchin just wears your clutch out faster obviously.

[TXKompressor]

Originally posted by B18C1TurboTeg
and double clutchin just wears your clutch out faster obviously.


Well put....

[Talus]

Originally posted by 1EightT
You can rev match without double clutching anyway. Work on giving the throttle a quick blip before you downshift to rev match. Double clutching is really unnecessary.
I'll have to give that a try. Berthoud pass, here I come!!!

[B16crxTurbo]

The best advice I could give for improving your launch would be play around with the revs when you launch. Try higher and lower, and then when you think you have found the sweet spot...
PRACTICE, PRACTICE, PRACTICE... and you WILL get better.