Ratios for track day

[SilverBullet]

What would be a good set of gear ratios for track days? Looking at Sepang international race track in Malaysia.

[-Alex-]

Purely for track driven car? 4 or 5-speed? VW box?

My 5-speed trans will get these ratios with about 640mm height tires ( 265/35R18).

Speed it at 3000rpm wit 4.13 r+p

1. 3.44= 25.5 km/h

2. 1.93 = 45.5 km/h

3. 1.3 = 67.7 km/h

4. 1.00 = 88 km/h

5. 0.77 = 114.2 km/h

But this is too long for track, i would chosen for track only with a quick think: 1st 3.44, 2nd 2.06, 3rd 1.48, 4th 1.21, 5th 1.00.

I would suggest shorter ratios, so that top speed would around 200-215Km/h, it would give better acceleration.

[SilverBullet]

Thanks Alex for your reply, its for occasional normal driving and mainly to see track action. Looking at 4 speed but 5 speed is an option. Dont know if berg still produces their 5 speed.

[-Alex-]

Berg have still 5-speed kits available for type 1, maybe type 2 too.

For a type 1 trackday only transaxle i would choose these ratios:

3.88 r+p

1st 3.78

2nd 2.25

3rd 1.65

4th 1.26

5th 1.04 or 1.00



trackday and street transaxle maybe these



3.88 r+p

1st 3.78

2nd 2.06

3rd 1.48

4th 1.14

5th 0.93

And autobahn ratios here what i would choose



3.88 r+p

1st 3.78

2nd 2.06

3rd 1.42

4th 1.04

5th 0.82



Four speed with 3.88 r+p and stock 1-2 gear ratios, only 3 and 4 ratios would be needed to change, maybe 3rd between 1.40-1.48 and 4th between 1.00 - 1.12. Depends about the engine max rpm and torque.

[SilverBullet]

Thanks Alex, most likely go with the 5 speed part track and road.

[Oval]

That depends on your speeds: are you under 80MPH? My 'best' track (hillclimb) box is a 3.8 box with a lowered 3rd gear. However, it's a long step up to 4th gear...

[SilverBullet]

I think getting to 180km/h would be quite fast, on stock 03 box now.
its a T4 2666, 332 sch cam.
A friend of mine in a 997 turbo reached 250km/h on the longest straight at Sepang race track before slowing for the corner.
I know I cant reach that but would try to get the most out of the gearbox.

[Oval]

yeah 250km/h in a Porsche is easy, we all do that, but what do you need your Bug to do? Sorry, not sure what Sepang track is: Hill climb? Quarter mile? Low-speed twisty corners?

[SilverBullet]

Sepang international race track, one of the F1 race track in Malaysia. Nothing here in Singapore, so most car enthusiast drive up.

[70Turbobug]

Originally Posted by SilverBullet

I think getting to 180km/h would be quite fast, on stock 03 box now.
its a T4 2666, 332 sch cam.
A friend of mine in a 997 turbo reached 250km/h on the longest straight at Sepang race track before slowing for the corner.
I know I cant reach that but would try to get the most out of the gearbox.

That engine lives from torque,you wouldn´t be happy with a short ratio box imho.Much different than most type 1s.Sepang is a very fast track,you will lose time with a short box.
If a 5 speed is what you want I would go with a 915/03 box ratios:
1.) 3,181
2.) 1,833
3.) 1,261
4.) 0,961
5.) 0,758
R+P: 4,42

You could go with a 245/30 18 tire and be plenty fast enough to leave the Porsches behind you.

As a 4 speed a stock ratio trans with 3.44 R+P works really well on the track.The Rancho pro street 3.88 and 0.89 4th works really well also.

[SilverBullet]

Thanks for the input 70Turbobug, yes Sepang is a fast track, would be nice to leave them behind .
Today is the F1 practice session in Singapore, the night race! Sunday race day.

[Oval]

70Turbobug, that mention of a 3.44 R&P is interesting (and sensible),that would be strong but would require big power to work

[70Turbobug]

With a 2.6L Type 4 he should have enough power and torque.

[Oval]

Oh yes indeed!