In need of taller gears

[CanAm Dave]

Thanks to a break in the weather I got a chance to take the Can-Am for a spin last night. Another enjoyable 70 miles on the clock. It's the first time I've driven the car with the full screen fitted. It was nice not to be eating the local insect population.

Back to the problem. I am still running the engine in and sticking to a rev limit of 4,000rpm. This thing is now so quick I can hardly change gear fast enough. I'm still only using part throttle. The Getrag is just to low geared. At 4,000rpm in sixth I am doing 100mph. Once I have the engine run-in and all the mapping complete I think I will have to search for a solution, be it a lower final drive ratio or a new box. I know others are having the same issue. Hope to discuss the issue on here and at the open day. Maybe a GT3 box is the way forward as it also uses the cable change and alternative ratios are available.

Regards Dave

[dfpat10]

Dave,

I’ve searched seven months to find a 5 speed gear box and it arrives this week, so if I were to make a recommendation, for a six speed transaxle, I would recommend you look at the, 993 Twin Turbo type G64/51 from 1996-1998 (rod shift), 996 Twin Turbo type G96/50 from 2001+ (cable shift) and 996 GT2 type G96/88 from 2001+ (cable shift). The standard gearing in these boxes much taller vs. other gearboxes and the 9 inch rear end can take more power reliably. As for gearing improvements I think you will only need a taller 1st gear beyond 3.82:1. I’m told 3.00:1 works well for first. What does a GT3 box offer compare to a GT2?

David

Edited by dfpat10 on Friday 27th July 02:20

[ultimad]

Dave I'm currently discussing upping my Getrag final drive with Roger Brown from CMS. Once he confirms a 3.1 final is do-able with his manufacturer I will be putting in an order. This would give a top speed of 207 at 7000 and 213 at 7200.

[CanAm Dave]

ultimad said:

Dave I'm currently discussing upping my Getrag final drive with Roger Brown from CMS. Once he confirms a 3.1 final is do-able with his manufacturer I will be putting in an order. This would give a top speed of 207 at 7000 and 213 at 7200.

Hi Andy

Please keep me informed as I would be very interested in ordering the same. Just out of interest my gearcalc gives 218 for 7000 and 224 for 7200.

Regards Dave

[ultimad]

CanAm Dave said:

ultimad said:

Dave I'm currently discussing upping my Getrag final drive with Roger Brown from CMS. Once he confirms a 3.1 final is do-able with his manufacturer I will be putting in an order. This would give a top speed of 207 at 7000 and 213 at 7200.

Hi Andy

Please keep me informed as I would be very interested in ordering the same. Just out of interest my gearcalc gives 218 for 7000 and 224 for 7200.

Regards Dave

YHM

[CanAm Dave]

ultimad said:

CanAm Dave said:

ultimad said:

Dave I'm currently discussing upping my Getrag final drive with Roger Brown from CMS. Once he confirms a 3.1 final is do-able with his manufacturer I will be putting in an order. This would give a top speed of 207 at 7000 and 213 at 7200.

Hi Andy

Please keep me informed as I would be very interested in ordering the same. Just out of interest my gearcalc gives 218 for 7000 and 224 for 7200.

Regards Dave

YHM

My mistake, your figures are correct. I was working something out for a mate earlier and forgot to change the aspect ratio back to 30 from 35. Good to know both systems come up with the same figures. That's if you put the correct info into them!

Regards Dave