924Board.org

[dreamgts]

Have a question regarding gearboxs. I intend to buy a Porsche 924 which is already carburetted with 40's webbers.

http://www.maltapark.com/item.asp?ItemID=797021

http://www.youtube.com/watch?v=hisSqbuvnRo&feature=related

It feels strong and pulls well. yet the car has a 4 speed gearbox which Im not sure about.

In the meantime I have a spare 5 speed gearbox which was donated to me by a friend . This box came out of a 1981 924. I was wondering would it be worth the trouble of exchanging the 4 speed with the 5 speed. I was also thinking about how much power both boxes can handle since I intend to modify the head a bit maybe with a race cam and/or big valves. I do have a 944 box which will though go on the turbo engine of my other 924 project, should I steal this box from the project and place it on the webber versioned engine, would this be worth the trouble?

Im not sure my wife is happy about it either. (I mean buying the car)

Comments please.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[Rasta Monsta]

What does your wife look like? Is she fit? What would you say are her redeeming qualities?
_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[dreamgts]

[Rasta Monsta]

[dreamgts]

[Rasta Monsta]

I dunno, mine's with the program:


_________________
Toofah King Bad

• WeiBe (1987 924S 2.5t) - 931 S3

[dreamgts]

[ideola]

To answer the original question, the box to swap in is the one you have from the 81 NA. The 944 box won't work without modifications somewhere along the driveline due to the difference in diameter & spline count of the driveshaft. The 81 NA box will be a direct swap. However, you will also need the shift rod, as I believe the one for the 5 speed is a tad shorter than the 4 speed's.
_________________
erstwhile owner of just about every 924 variant ever made

[dreamgts]

Ok, so the 81na fits directly, Shall i extract it completly from the clutch housing to the rear since I have all components for this including the gear lever rod too .

What would I need more for the 944 box to fit, the torque tube/drive shaft ???? will I experience difficulty here fitting this.

I ask once again what difference should I expect to see between the 4 and 5 speed (924) box?? Also is the 944 box regarded to be better than a 924- 5 speed box, my intention is to fit the 944 in the turbo version, should I look for another 924 na box for the turbo as well.
My aim is around 220- 240 bhp for the turbo. The webbered car bhp is not known yet this might go up a bit if i decide to fiddle with the head.

Information appreciated.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]

I don't think there's much difference in terms of strength between the 944 NA box and the 81 924 NA box. The gearing might be slightly different, but they're essentially identical in terms of components and strength. To swap in the 81 924 NA box, don't bother with the torque tube unless you really feel like dropping two torsion carriers (major PITA). Just swap in the box and be done with it.

As I noted before, you can't easily use the 944 box because the input shaft is not only larger in diameter with more splines, but it sticks out further. The only way to use the 944 box in a 924 NA is to swap in the torque tube from the 944 as well (which, again, requires dropping both torsion carriers...the one from the donor car and the one on the recipient). If you did decide to do this, I think there is a Ford Bronco or Mustang clutch that will work for the NA that also has the correct diameter and spline count for the 931/944 torque tube, but you'll have to do some searching to figure this out. IMO, it's not worth the hassle. The 81 924 NA box should be plenty capable of 220-240 BHP.

If you're really insistent on the 944 gearbox, the one to get is the 944S2 with LSD. Strongest Audi-based gearbox made.
_________________
erstwhile owner of just about every 924 variant ever made

[dreamgts]

Shit.. I thought the 944 box would work well on the turbo. So as you are stating I might as well save the 5 speed box for the turbo version, since the webbered car will only be partially modified for now.

So lets say the webbered version car is partially modified with lets say big valves and race cam, will the 4 speed box be able to cope with it ;
I reckon I can get 150/160 bhp out of it easily. I used to get that power from a similar modified Ford 2 lit engine so I dont think achieving this with a webbered conversion should be dificult.

What about gear ratios i need low 2nd and 3rd gears mainly which of the 2 boxs has the lowest ratio, If I figured it out correctly the 4 speed might have the low 2nd and 3rd gear needed but im not sure about its reliability.

While considering ideola.s comments and seeing what I got in place and on the floor it might turn out that extracting the 4 speed box from the webbered version might be a waste of time since there might be a possibilty that no difference will be achieved, yet I would like to be directed to any gear ratios for these 2 gearboxs as i said I need low 2nd and 3rd mainly. I must add that i have no experience with 924 gearbox ratios so any comments would be appreciated.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO

[ideola]

Check my downloads page. There is a spreadsheet there with gearing ratios as well as an excellent writeup by Pete Tinucci on the various gearboxes.

http://garage.ideola.com/downloads.html
_________________
erstwhile owner of just about every 924 variant ever made

[dreamgts]

[dreamgts]

Ok this is what I assume is right if I made my calculations right.

There is no gear ratio difference between the first 4 gears of a 5 speed (016/9) and the 4 speed (code VR).

The article written by Peter Tinucci though describes the 5 speed box as quite undestructable while giving praise to the 20mm tube as well. Both of these seem to be used on replicas using V8 power.

Mr. Tinucci though does not give out detailed info about the 4 speed gearbox although the final axle ratio of 3.4 was confirmed.

Mr.Tinucci though mentions a 'gearbox' used for racing purposes having a 3.4 final axle ratio.

I am sure or else suspect that he is not reffering to the 4 speed unit, though it seems that this 4 speed unit gives out more sprint speed in short distances due to its low final axle ratio and although I stand to be corrected , this is what I need.

Although these ratios are available on the 5 speed (016/9) gearbox if one forgets the 5th gear which might give more top speed on long roads.

Therefore by putting aside any strenght differences between the 4 speed and 5 speed boxs mentioned, I am convinced that both gearboxs have the same axle ratio in 1st 2nd 3rd and 4 th gear.

It might be in this case that putting pen to paper and doing some research has saved me some time and work shifting the gearboxs which might have given the same result except maybe top speed.

The car/s are to be raced in short distances, a video of the track can been seen here-

http://www.youtube.com/watch?v=kLL_YMFYoQw

http://www.youtube.com/watch?v=BERDAgS1bcY&feature=related

A look at these will show what I mean when I say I need bursts of speed in short distances.

dreamgts
_________________
2 PORSCHE 924 (CURRENT PROJECTS)
2 CLASSIC CORTINAS (FINISHED)
1 CLASSIC FIAT(FINISHED)
1 CLASSIC FIAT 132 2000CC(JUST PURCHASED)
4 SUV'S
2 SEDANS
1 OPEL PANEL VAN
WIFES SUZUKI ALTO