Gus

Link??

kos11-12

This is Kaib's gearbox , saved the info to compare, I try to post you the big chart Bill has done with 5 & 6 boxes , I saved it somewhere .


First: The stock 3.50 (12/42) 43mph
Second: 2.25 (16/36)
66mph
Third: 1.684 (19/32)
89mph
Fourth: 1.286 (21/27)
117mph
Fifth: 1.04 (25/26)
146mph
Final drive 3,333

porsche mania

I saved this way back when I was planning in fitting a set of roller throttle bodies. The YouTube vid of his car looks great. The only downside to kai's box is that to make it useful you needed his 8000rpm redline!
I found a ratio calculator with rpm drops on line and plan to have another play after work. So far I've struggled to find anything that works while still keeping the stock first gear. Better get the wallet out! I'll post a pic of the best I can come up with later.
Kos, if you could find the info Bill has posted before I'd be very grateful.
Many thanks, Jim.

Captain Ahab Jr.

interesting thread, I have both a 5 speed and I'm about to fit a G50/21.

I'm not sure which way to go at the moment, sell the 5-speed and spend the money on ratio changes on the 6-speed or go the other way.

My driving will be getting to the Alps and going up and down mountain passes so I'm not sure if a well spaced 5 speed would be more fun than a well spaced 6 speed. More gear changes with a 6 speed on twisty slowish roads might be upset the flow of driving corners than the 5 speed. Or is a close ratio 5-speed in the 6 speed with a tall autobahn gear the ideal.

Before making a choice I'll fit the 6-speed and spend a week this year in Pyrenees to see how I get on.

I know the gear linkage is different with the 6-speed but I don't think the drive shafts are any different, maybe on a C4 they are but the output flanges on both gearboxes look very similar in length and diameter

Matt, where are you?? This thread needs you!

kos11-12

Hi Captain ,
I guess 6 speed is better, you could set 6 th for motorway Eco cruse, the only thing is the brass synchros but is it a real problem for road use, apparently they wear quicker compare to the steel in the 5 box, not sure why they fit brass on the 6 speed, the 6 speed Cup G50/31 has the steel,
Do you guys know how much each ratio cost .
Marrel & Pelin in France have quoted me 650 € +vat for each set bespoke of ratios.
I will ask them a quote for 1st,

kos11-12

Hi Captain ,
I guess 6 speed is better, you could set 6 th for motorway Eco cruse, the only thing is the brass synchros but is it a real problem for road use, apparently they wear quicker compare to the steel in the 5 speed box, not sure why they fit brass on the 6 speed, the 6 speed Cup G50/30 has the steel, Do you guys know how much each ratio cost ?
Marrel & Pelin in France have quoted me 650 € +vat for bespoke ratios. I will ask them a quote for 1st,

Mania I am out, but will try to post the chart I saved from Bill posts in a few hours.

porsche mania

If I had been able to source a 6spd I'd gear the first five as I would a 5spd and have 6th as a motorway gear!
Don't think I'd gear a 6spd close ratio, your almost garunteed to need to do shifts at awkward times. Your car is very light and I'd think the standard ratios in the g50/21 would work very well in your car!
As for your 6spd fitting I'm sure it's the length of the drive shafts that differs not the bolt pattern on the output flanges. could be wrong though.
I can provide a sucure loving home for your g50/21 should you choose to sell!

kos11-12

I hope it's the wright one , can't see well on my I pad

kos11-12

6 speed

kos11-12

5 speed
03 , 05 and the c4 ( excluded Swiss)

kos11-12

All this work prepared by Bill Verburg
Thanks To Bill !!

Spyerx

Hey guys Bill posted a bunch of charts and some graphs of ratios in my build thread, check it out here:

https://rennlist.com/forums/964-foru...l#post12870577

porsche mania

I thought I'd read something Bill had posted recently but couldn't think where I'd seen it. Thanks for the heads up, I'll get reading!

GTgears

Point of clarity... Both 5spd and 6spd have brass synchros stock but you can put steel in either. Only RS variants of the early cars got steel.

kos11-12

Thank you ,
good to know , in your opinion what was the idea of fitting brass, on road transitions compare to steel on the RS ones ?