Drag launch question

[m1tch]

Hi everyone, as most of your know my FC has OEM suspension all round and as they are old they are now classed as \'comedy suspension\' due to the amount of roll that can be created by pushed the car :rollin

Basically the shocks are old and worn etc etc, but they do give me a really good drag launch, which is why I havn\'t changed them or the springs and am currently running at OEM ride height.

Here is a photo blagged off Blackett\'s of one of my launches (white smoke is the clutch imploding under the power lol):







You get the idea, the nose goes skywards a awful lot and the rear end digs in meaning I never get wheel spin (at the moment)

I have a set of new alloy wheels (17" OZ racing Futuras) to put onto the car soon, they are 265 on the rear, 245 on the front, the wheel sizes I believe are about 1% different from OEM ie thinner tyres, bigger rim etc etc.

Basically I am thinking of bolting them onto the OEM setup with possibly spacers - need to check clearance as they don\'t need spacers or body mods on an FD. My main issue/ question is - should I be worried about the level of travel of the rear end when I launch fouling the tyres on the arches?

I could change the springs to lowering springs that are stiffer meaning that I get a different ride height (I know it will probably look like a 4X4 if I fit these rims onto OEM suspension ) I am just worried that if I change the springs I won\'t get the best launches *sigh*

What does everyone think on the matter?

[clive]

You get the idea, the nose goes skywards a awful lot and the rear end digs in meaning I never get wheel spin (at the moment)

You have answered your own question, lots would love to have no wheelspin,

Stay away from the harder springs as these are helping your grip levels

[Prof]

With Clive on this one - most lowering springs will stiffen the suspension, a little or a lot - but with less spring length it\'s kind of inevitable.
 
You could go for drag suspension.
 
Even adjustable suspension is stiffer on the softer setting from my experience.

[m1tch]

Im just worried about bottoming out the suspension on the new rims, I am guessing the car will look really odd with the lower profile tyres on OEM suspension

[SiH]

Jack the car up, put it on stands, then remove the rear shock, and jack the wheel up so it moves through its travel. Check clearance. Simples

[Naughty colin]

How to get a good launch.
1: fit smaller drive wheels for better xceleration but go as wide as you can with the tyre.
2: lower the drive wheels tyre pressure to about 18psi for a bigger contact patch
3: try to eliminate as much squat and body movement as possible as this eats power transfer,you may have to fit harder springs but dont worry as you have already let air out of the tyres for more grip.
4: always remember its a street car not a drag car so dont drop the clutch at high revs,find the max torque point in the revs and balance the clutch out to throttle down its takes practise but its well worth it.
 
Hope this helps and good luck.

[m1tch]

How to get a good launch.
1: fit smaller drive wheels for better xceleration but go as wide as you can with the tyre.
2: lower the drive wheels tyre pressure to about 18psi for a bigger contact patch
3: try to eliminate as much squat and body movement as possible as this eats power transfer,you may have to fit harder springs but dont worry as you have already let air out of the tyres for more grip.
4: always remember its a street car not a drag car so dont drop the clutch at high revs,find the max torque point in the revs and balance the clutch out to throttle down its takes practise but its well worth it.
 
Hope this helps and good luck.

Hey mate, I am still running on the stock 16s for this very reason, although its quite hard to find wide 16s and tyres cheapish, so the new wheels are 17s but have the same wheel and tyre diameter but add on another 12cms of rubber on the rear.

Yeah I dropped my tyre pressures to about 20ish for santapod, it does make a difference

I have been told to fit/keep a soft setup so that instead of the wheels bouncing and spinning the energy when you launch it cushions the drivetrain meaning a smoother launch, Tiddles\' FC can\'t get a better time now he has coilovers compaired to his time when he had the OEM suspension.

Yeah, after trying different launches from different RPM I actually now launch at about 1,500rpm, when the light goes green I go the full throttle whilst bringing in the clutch, the clutch bites and has taken hold by the time I am at full throttle, basically like if you were pulling away fast from a set of traffic lights, I tried dropping it in at like 3k, got loads of wheel spin and a rubbish time. My EBC I can set to allow different boost in each gear and at each RPM, so in first its dialed down for the launch then the boost is full in 2nd etc. I will be fitting a T88 to the car in the next few years, for drag racing for me the lag (although probably not much on a extended streetport) will allow a better launch as it means it won\'t be running on full boost when I launch, but full boost up when I have launched

[Naughty colin]

you defo know what your doing then
sounds like you have your technique down to a fine art
maybe i should take some notes off your reply lol

[m1tch]

you defo know what your doing then
sounds like you have your technique down to a fine art
maybe i should take some notes off your reply lol

The only issue is the clutch and wastegate actuator lol its running a 14.2 on stock boost, im currently beating prof with his extra 100bhp :Giggle

[Naughty colin]

now your showing off lol

[Prof]

The only issue is the clutch and wastegate actuator lol its running a 14.2 on stock boost, im currently beating prof with his extra 100bhp :Giggle

And now I can\'t see if I can get better times in your car as you\'ve cunningly put a bucket seat in it that the more portly gent can\'t get into - :p

[m1tch]

And now I can\'t see if I can get better times in your car as you\'ve cunningly put a bucket seat in it that the more portly gent can\'t get into - :p

Im sorry its a jap spec Bride seat lol its for jap spec people it seems :rollin

Correction, you can get into it, just hard to get out of it :yes