Are there any easy choices for upgrading the 4 speed in a 930?

[930cabman]

Our '87 turbo cab had a G50/50 installed when I bought it 10 years ago. Works wonderful, I would highly suggest

[voitureltd]

Originally Posted by lite75

Ruf box uses the stock 78 and up mounts and moves the axles towards the back. The shortened clutch housing makes up for the longer nose cone. Will not work in a 77 or earlier chassis.

Unfortunately I have a 5spd 930 trans in my 77 930. Not a big priority however I always wondered. Someday I will put it up on the hoist next to the stock 77 930 with a 4 spd and see what they did to make it fit as it is obviously a bit longer.

[lite75]

Anthony,
I shouldn’t say it won’t work, but the amount of work needed for the early models is a bit more.

[TurboKraft]

Photos of a Ruf R30 5-speed installed in a (former) Ruf conversion car in our workshop right now.
Yes, the bell housing is a short type like the 1976-77 Turbo 4-speed. When installed in a 1978-88 Turbo chassis, this shifts the transmission aft allowing the longer nose cone to clear.
The axle angle is reduced and becomes more straight.
The transmission mount is unchanged.

[TurboKraft]

We've had the last several Ruf 5-speeds rebuilt. Some observations:
* gearing is remarkably similar to the 3.2 Carrera's G50 5-speed -- so very quick acceleration 1-2-3-4
* many parts are oddballs, with part numbers from 917s, 931s, etc. We have a parts catalog from Ruf and more than half the items has a handwritten "NML" next to it -- Nicht Mehr Lieferbar = No Longer Available
* the release mechanism is a combination of factory 915 & 930 parts
* the release cable is unique Ruf

They're long out of production, and the cost of one makes a SBH G50 conversion look inexpensive.

[ELZ's930]

Ruf box below 79 long bell housing top. Recent upgraded Sachs pressure plate from Chris at TK. The clutch cable is unique other than that it fits like a glove, and I don’t mean one of those OJ Simpson “try-on” type of gloves either.

[Axel84]

I have a real rebuilt RUF BTR 5-speed box. shorter ratios.
but Im not parting with it for below 15k.

[Axel84]

[Axel84]

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[Axel84]

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[David]

Do all the 5 speeds have a shorter 1st gear? I find the stock 1st gear to be just fine for my engine. My Motec data shows a hair less than a second from onset of boost to redline in 1st. The gap to second is too big tho. The Albins gears at less than $1k each are tempting for a 2, 3, 4 change.

[gumba]

I'm happy with the Andial 8:39 r&p and stock gearing in my '79. I find the 911 5 speed with the 8:31 in my bus with similar h.p. too short.

[gumba]

Wevo did both transaxles. I think he calculated the top speed to be about the same, 140mph+.

[MikeD930]

Originally Posted by David

Do all the 5 speeds have a shorter 1st gear? I find the stock 1st gear to be just fine for my engine. My Motec data shows a hair less than a second from onset of boost to redline in 1st. The gap to second is too big tho. The Albins gears at less than $1k each are tempting for a 2, 3, 4 change.

I agree that a stock 930 1st gear is fine. I re-geared my 930 box (used to be non-stock 2nd-4th close ratio) using stock 1st and 4th gears and 2nd gear closer to 1st and 3rd gear spaced between 2nd and 4th. I did this to eliminate a big gap between 1st and 2nd (stock gearing). It's nice not having to rev out as far in 1st gear when shifting to 2nd. As always there's a trade off between close ratio (great for being able to be in a correct gear but top gearing is too low for highway cruising) and wide ratio gearing (great for highway with stock 4th gear but sometimes wishing for close ratio).

[David]

Originally Posted by MikeD930

I agree that a stock 930 1st gear is fine. I re-geared my 930 box (used to be non-stock 2nd-4th close ratio) using stock 1st and 4th gears and 2nd gear closer to 1st and 3rd gear spaced between 2nd and 4th. I did this to eliminate a big gap between 1st and 2nd (stock gearing). It's nice not having to rev out as far in 1st gear when shifting to 2nd. As always there's a trade off between close ratio (great for being able to be in a correct gear but top gearing is too low for highway cruising) and wide ratio gearing (great for highway with stock 4th gear but sometimes wishing for close ratio).

So you just changed 2nd and 3rd? Is 3rd lower than stock?

[quattrorunner]

I really like 1-3 but the stock gap between 3-4 is big.

[MikeD930]

Originally Posted by David

So you just changed 2nd and 3rd? Is 3rd lower than stock?

Yes...I changed 2nd & 3rd. 3rd gear is lower than stock. 2nd gear ratio is 1.444 and 3rd gear ratio is .928. Here's a snap shot of my gearing thrust (based on my rwhp dyno chart). The top is with stock gearing (note a big drop in thrust between 1st and 2nd) and the middle chart has lower 2nd & 3rd gearing (note less drop between 1st and 2nd) and the bottom chart is with previous short gearing (I loved it except for lack of gearing for highway cruising).

Stock gearing




Re-geared 2nd & 3rd




Short 2nd-4th gearing

Originally Posted by quattrorunner

I really like 1-3 but the stock gap between 3-4 is big.

I'm surprised you like a big gap between 1-2...I suppose your engine is able to handle that gap.

[David]

I've finally started my transmission project so of course I have to consult Pelican

I was originally planning to change 2nd, 3rd and 4th to 1.444, .963, and .667

This would put my speed at 7,000 rpm in each gear at: 56, 88, 132, 190 vs stock of 56, 97, 142, 202 (of course the car won't go 202 or even 190)

But now I'm leaning toward changing the R&P to 4.625 (8:37) and changing first gear to a 1.833
This would put speed at 7,000 rpm at 63, 89, 130, 185. So quite a bit taller 1st but right now I rev through 1st so fast that a bit taller should help and then a much tighter gap to 2nd so it should still be well into the boost after the 1-2 shift.

RPM at 75 mph would increase from 2,590 to 2,835 but that seems bearable.

Thoughts?

[Maxx1]

Originally Posted by David

I've finally started my transmission project so of course I have to consult Pelican

I was originally planning to change 2nd, 3rd and 4th to 1.444, .963, and .667

This would put my speed at 7,000 rpm in each gear at: 56, 88, 132, 190 vs stock of 56, 97, 142, 202 (of course the car won't go 202 or even 190)

But now I'm leaning toward changing the R&P to 4.625 (8:37) and changing first gear to a 1.833
This would put speed at 7,000 rpm at 63, 89, 130, 185. So quite a bit taller 1st but right now I rev through 1st so fast that a bit taller should help and then a much tighter gap to 2nd so it should still be well into the boost after the 1-2 shift.

RPM at 75 mph would increase from 2,590 to 2,835 but that seems bearable.

Thoughts?

I didn't know the car was geared that tall. I'm sure there were final drive ratio options, but my car did redline near 60 mph, so it sounds about what you listed there. I like your idea, 185 is fast enough for an old car.

[jcw000]

Hi Mike,

Thanks for all of the info. I am looking now at either a 1.444 (Albins) or 1.471 (Guard) 2nd and a .963 (Albins) 3rd. Just wondering how you picked the 1.444 2nd and .928 3rd and whether your are happy with them or have any regrets. Did you go with Guard, Albins, or other? Do you find the new gears any louder than OEM? Sorry if you've discussed elsewhere; I looked but couldn't find your comments on these items.

Best,

Josh

Originally Posted by MikeD930

Yes...I changed 2nd & 3rd. 3rd gear is lower than stock. 2nd gear ratio is 1.444 and 3rd gear ratio is .928. Here's a snap shot of my gearing thrust (based on my rwhp dyno chart). The top is with stock gearing (note a big drop in thrust between 1st and 2nd) and the middle chart has lower 2nd & 3rd gearing (note less drop between 1st and 2nd) and the bottom chart is with previous short gearing (I loved it except for lack of gearing for highway cruising).

Stock gearing




Re-geared 2nd & 3rd




Short 2nd-4th gearing






I'm surprised you like a big gap between 1-2...I suppose your engine is able to handle that gap.