26 replies to this topic

[MAXR]

After reading this thread & the one on type116.com I’m not at all sure that I have made the right decision in having a 4.17 ratio Zafira gearbox fitted to my S/C Na at Courtenay’s soon. I’m not interested in 0-??? times just in gear acceleration times above 60mph. I’m especially worried about loss of speed in especially 3rd but also in 4th gear. Top speed is not an issue. The benefits of quicker in gear acceleration will be outweighed by having to change up & then down again nearing a fast corner just because I’ve run out of revs. Courtenay’s have not yet tried a 4.17 ratio in a S/C Na; So they can’t comment. I guess I will be the guinea pig again. Somehow, I think I may be disappointed with the results. I will let you know.

[techieboy]

But without the equivalent of a CVT gearbox, isn't any fixed ratio going to be a trade off? What suits one track isn't necessarily going to suit a different track (or series of straights and/or corners on the same track). Even the same section of track may or may not work with a given ratio, depending on how well you've gone through the preceding section?

[Guy182]

After reading this thread & the one on type116.com I’m not at all sure that I have made the right decision in having a 4.17 ratio Zafira gearbox fitted to my S/C Na at Courtenay’s soon. I’m not interested in 0-??? times just in gear acceleration times above 60mph. I’m especially worried about loss of speed in especially 3rd but also in 4th gear. Top speed is not an issue. The benefits of quicker in gear acceleration will be outweighed by having to change up & then down again nearing a fast corner just because I’ve run out of revs.
Courtenay’s have not yet tried a 4.17 ratio in a S/C Na; So they can’t comment. I guess I will be the guinea pig again. Somehow, I think I may be disappointed with the results. I will let you know.

put your torque curve in that website

seeing vix's graph its flat torque curve too so may be pointless like it is on the turbo.

[Lou1s Cyphre]

If anyone is interested in purchasing my brand new, freshly imported from Germany 4.17 Final drive. PM me an offer; it cost me about 1k from Courtenays.

[MEAGY]

Meagy - did you go for the regal IC in the end? Just wondered if you had measured any temps?

hi no i never, i couldnt be sure it would keep it cool enough on the stage 4 i want as its not been tested really so i sent it back. Im going for a small CC after the intercooler to give it a bit extra cooling. would have loved to see if it would have of worked as im a great fan of intercoolers but i didnt want to stick £600 down the bog!

[MEAGY]

Meagy - did you go for the regal IC in the end? Just wondered if you had measured any temps?

hi no i never, i couldnt be sure it would keep it cool enough on the stage 4 i want as its not been tested really so i sent it back. Im going for a small CC after the intercooler to give it a bit extra cooling. would have loved to see if it would have of worked as im a great fan of intercoolers but i didnt want to stick £600 down the bog!

[MEAGY]

I still think it might work ok on the track, som corners i would have to drop to 2nd for then ned to change up before full exit of the corner so now i would just be in 3rd all the way round then into 4th after exit. Also some straights i would only just gt in 5th before i would need to brake for the next corner but not i will be in 5th say half way doen the straight (in theory anyway).... guess i will just have to wait & see how it pans out, but if i dont like it i will prob rrefit the old FD.....