DavidM

Something s2k2fast4me said in the racing forum that got me thinking. He was saying how the S2000 would do better if if it had a shorter 2nd gear .... initially I was thinking how much shorter do you want it - it's damn short already. Though, then it got me thinking that the 2nd gear drops the revs down to 5.9k (when changing from 1st to 2nd) and that there is 'only' 117kW (156hp) avaliable there. I started thinking what 'if' the 2nd gear did not drop the revs that low but to a more respectable 6.5k revs where there's nice 143kW (190hp) available. Though, that would make the 3rd gear too tall and so on. So I re-calculated the gears so that they don't drop bellow 6.5k revs and this is what I came up with:

Speeds at 9k rpm:
1st = 69kph (43mph) - same as stanndard.
2nd = 95kph (59mph) - 6.5k rpm on the change up = 144kW (190hp).
3rd = 131kph (82mph) - 6.5k rpm on the change up = 144kW (190hp)
4th = 173kph (108mph) - 6.8k rpm on the change up = 151kW (201hp)
5th = 219kph (130mph) - 7.1k rpm on the change up = 156kW (208hp)
6th = 263kph (164mph) - 7.5k rpm on change up = 167kW (223hp)

Compare it to standard gearing (speeds at 9k rpm):
1st = 69kph (43mph)
2nd = 105kph (66mph) - 5.9k (117kW/156hp)
3rd = 144kph (90mph) - 6.6k (145kW/194hp)
4th = 186kph (116mph) - 7.0k (154kW/206hp)
5th = 232kph (145mph) - 7.2k (160kW/213hp)
6th = 266kph (166mph) - 7.8k (172kW/230hp)

As you can see the top final gear (6th) does not change much so the top speed of the car/economy will not be effected. Though, the car will always be in it's 'powerband' which really begins at 6.5k rpm. In the 1st to 2nd change the car would have 22% more power when the 2nd gear engages (ie. 1st to 2nd change). You do drop a little bit of power in the changes to higher gears ... a few kW but that's a very small percentage so I don't think it would slow the car down much there.

I'm wondering how much faster would an S2000 with these gear-ratios be than standard? Maybe Sev can puch these numbers into his car-simulator and see what it sais? I know that the 0-100kph time would probably suffer a bit because it will need 2 gear changes instead of 1, though the 0-60mph time could be better as this gearing would allow the S2000 to reach just over 60mph (61.3 to be exact) in the 2nd. Though, the 400m (1/4mile) time should be better as the gearing would be shorter and it would still need 3 gearchanges (as standard).

I'm not sure what would such short gearing be like to drive .... but I'm thinking that this could be a mod that could make some significant gains and cost a lot less that what people are doing to their engines/exhausts.

Sev

Here are the gear ratios i used. These specs come from estimated times for my car inputed from my dyno run and with optimal 0.15 shift time and 0.15 clutch engament time so they won't be easy to reproduce under normal conditions. Basically it's what a strong s2k will run with strong driver in perfect conditions and perfect shifting, launch etc....

Yours:--------Normal:
3.13------------3.13
2.35------------2.05
1.70------------1.48
1.26------------1.16
1.05------------0.97
0.84------------0.81

0-60 5.1-------4.9
0-100 12.1-----12.3
0-140 37.45----34.65
1/4: 13.56------13.66
Top
Speed: 148 MPH---150 MPH


So basically it will be slightly faster at low speeds and a slower at high speeds.

Sev

Another thing you should consider that would be better is changing the final drive. It is available and doable too, i believe it's ATS who makes it... It raises the final drive to 4.5 from 4.1. Performance is optimized everywhere except top speed which is slightly lower.

0-60 4.6
0-100 11.9
0-140 33.14
1/4 mile 13.47
Top speed 149 MPH

Not to mention the added torque through every gear. I would think this is the best mod out there for the s2k. Price/performance wise and not only does it make the car easier to drive/faster it also doesn't affect reliability...

I would reccomend this mod to anyone...

Moneeb

Sev, this statement of yours has me really interested - I did not know (neanderthal that I am), that this could be done.

Could you please post more details (i.e. cost, amount of work involved etc). Can you really shave 0.5s off the 0-60 times with this mod??

Thanks

Sev

[QUOTE]Originally posted by Moneeb
[B]

Sev

One more thing, you can acheive almost the same thing by reducing your tire size to 225 40 16 and 205 45 16. However you would also need to lower the car otherwise it would look goofy.

Red_s2k

does'nt Randy or reverend have both the ats mod and the final drive change??

Sev

Yes, Randy does.

DavidM

--------------------------
Yours:--------Normal:
3.13------------3.13
2.35------------2.05
1.70------------1.48
1.26------------1.16
1.05------------0.97
0.84------------0.81

0-60 5.1-------4.9
0-100 12.1-----12.3
0-140 37.45----34.65
1/4: 13.56------13.66
Top
Speed: 148 MPH---150 MPH
--------------------------

Thanks Sev, though can you explain why 'my' is slower over 0-60mph (5.1 vs 4.9) - I would have though that this IS exactly where it would be quicker as it gains most in the 1st to 2nd change. Do you account for 2 gearchanges instead of one for the 60mph sprint (it should do 61mph in 2nd before cut-out)?

Also, about the 'final drive reduction' totally agree that this is probably the most usefull mod as far as performance goes ... especially for the money (after all it's only one cog replaced). Though, correct me if I'm wrong, but lowring the final drive will not close the 1st and 2nd gear ratio and therefore still leave the 'hole' in the power when shifting from 1st to 2nd.

ps. If someone with the reduced final drive reads this, can you post your findings and how much it costs?

pps. What speeds does the reduced final drive S2000 reach in each gear?

Sev

[QUOTE]Originally posted by DavidM
[B]--------------------------
Yours:--------Normal: