1/4 mile gearbox setup

[speed_devil]

Hi everyone
I have Cammed s1 16v with the original saxo vts gearbox - 3.93 diff.
My question is - is it possyible to improve my times with shorter diff like 4.09 or 4.29 and exactly which one ? My best so far 1/4 mile is 14.6

[MiniGibbo]

s1 rallye box iirc has shorter ratios and is recomended for acceration.

[Toad]

I don't think it will make a big difference in straight line acceleration. There's the extra shift(s) you've got to take into consideration with higher FD's.

[Harv]

Sequential Box? :P

[speed_devil]

there will be no extra shift because i finish in 4-th gear and with slightly shorter box i'll finish in 4-th again

[Toad]

Fair enough. I've got an S1 Rallye box, and 1st gear is almost unusable, no traction... What's your red line? You might need to go into 5th with the likes of a S1 Rallye box. (4.54 FD)

[bytor]

whats your terminal speed if your in 4th for a 14.6? :S

[olee]

iirc using a rallye box, youl need to change just before the line, so you actually have to come off the throttle giving up valuable time.

1.4xsi box is best...... or so I have been told.

[speed_devil]

97 miles is my terminal speed

[bytor]

VTS 7250RPM limiter S1 Rallye box will do 99MPH in 4TH, so assuming you are going faster due to a shorter box you may need another change hard to tell.

S2 Rallye box 4th will be 110mph (hardly seems worth it)

1.4 XSI will be 104mph :y:

All on VTS 7250 limiter

[menmen]

Optimal (budget) 1/4 mile setup is 59/13 (S1) final drive with rev limter set to 7800. The 59/13 Crown/Pinion can be cheaply sourced from a Peugeot Partner/Citroen Berlingo. Lots of other Pugs also use this ratio

[speed_devil]

sorry but what diff it that 59/13 ? And exactly from what car i can take it ?

[Andyracer]

For the money and effort there will be better mods... lighter flywheel maybe and lose some weight out of the carpets etc...

[Toad]

sorry but what diff it that 59/13 ? And exactly from what car i can take it ?

I think he's referring to the FD found in the series 1 106 Rallyes.

[scot-ish]

personally i'd recomend the xsi box for the 1/4 mile, as stated. the s1 rallye box is nearly useless in first due to traction probs, if youve got dencent money to spend, look as lsd or the likes and havong an xsi box rebuilt

[menmen]

the s1 rallye box is nearly useless in first due to traction probs

Not true. Just buy some good tyres and the S1 ratio is optimal - if you can do a proper launch. Best budget tyre for 1/4 would be Toyo R888.
When it comes to performace, nothing is more important than right rubber

[dj_russell]

Not true. Just buy some good tyres and the S1 ratio is optimal - if you can do a proper launch. Best budget tyre for 1/4 would be Toyo R888.
When it comes to performace, nothing is more important than right rubber

the toyo is only budget???? i was buying r888s because i thought they were one of the best tyres you can get for the road???

[Toad]

Nah, they're cheap. But decent... :) Yoko's are twice the price...

[Steve]

I don't think it will make a big difference in straight line acceleration. There's the extra shift(s) you've got to take into consideration with higher FD's.

agree...
s2rallye box actually slowed williams down, as it was hitting the limiter not much before the line.
Or he had to change gear.

Where as the VTS box you could just keep it in 3rd.

[Toad]

Hmm. The S2 Rallye box is almost idential to the VTS box...

[Steve]

Hmm. The S2 Rallye box is almost idential to the VTS box...

fractionally shorter.

Barely notice the difference tbh....
In a drag race rolling start in 5th at 30mph against a VTS with VTS box, you pwn them.
But if in 2nd you dont notice the difference :afro: