The best/correct gear set for 5 gear in 901 gearbox

[lars1965]

Hi

Can anyone guide me to chose the correct 5 gear set for my 66/67 stock engine with 901 gearbox, I would like the tallest possible , which should be ZD 31:32 also used in 914, but I`m thinking if the fan can cool the engine ok, if the engine only runs 3200 rpm with 80 mph? will a stock 130 Hk engine be strog enough for this gearing?

The Z 29:23 seems perhaps to be the most chosen one?


let me hear your opinion



Lars

[gled49]

Z was stock for 67S, ZA for the later S's and ZD was a 914 only gear.

[beh911]

Here's a reference

[911s55]

Here's a bit more FYI from some past wise guys.

http://forums.pelicanparts.com/porsc...-question.html

[DG58INNM]

For what its worth, I once had a huge selection of gearsets, and liked to play around with various combinations. At some point in time, X, Y, Z, ZA, and ZD have all occupied the 5th slot in my '68 L. I eventually settled on A, GA, O, U, ZA as the nicest all-around combination. Others will have different preferences. Some people advocate just putting in a long 5th for cruising, but I think all five should work together for a proper driving car. I still keep a complete A, F, M, S, X gearbox stashed away in case I ever have a second childhood and feel the need for point and squirt driving.
Dave

[Chris Pomares]

Here is what my car has.
Wavetrac torque bias diff
A,GA,N,U,ZD gears.
My 2.4 POLO has a lot of torque as low as 3000 and spins to 7200.
Now that I have miles on the car I would go to a B or C 1st and a ZA 5th. The ZD gear is a great cross country gear 3200 rpm at 80 but not much use below 65 mph here in the Colorado high country. Probably that number would be 60 at sea level. 130 hp engine and not much torque? I'm 185 hp at the rear wheels and torque in the 150's. My guess you would be better served with a ZA.
Chris

[lars1965]

what is the difference in ratio btw z 29:23 and ZA? rpm with 80mph i 5 gear
how do i put the ZA combination together ?

lars