901 VS 915 TRANSMISSION, 450 HP V8 901 OR 915 Options

[boxstr]

Holy crap this is the way to go,they even have a sequential box, only $10k. I am going out the tommorrow and check it out. http://www.markssandtrans.com/
CCLINSHIFTYGUY

[Type 4]

That box has 4.57 R&P. Off road gearboxes have gearing for Big diameter tires.

[boxstr]

I have a feeling they can custom gear to my specs and or intended usage. At least they had better be able to for those prices.
CCLINGEARINGUP

[andys]

450HP narrows your transaxle choices severely. If it's a track car you're mostly considering, then the transaxles with the straight cut gears would not be an issue. For the street; forget it......way too noisey. For your kind of power, the two reasonably priced choises are the 930 (which can be run up-side-down to save on costs), or for a few more $$ go with the ZF (like used in the Pantera). Both of these will already have ratio's suitable for a V8.

Andy

[Brett W]

Here is my major dilemma with the V8 conversions, I don't want to baby it and wait for the next shoe to drop. If I have a T56 6 speed tranny behind a V8 I don't have to be careful what gear I start off in. I drop the hammer and go. That is what a V8 teener should do. In the spirit of Porsche it should be able to handle a little abuse. I can't stand cars that I can't hammer every now and then. Not all the time but when I want to run it better be able to keep up.

Mendeola does a sequential box that seems like a nice box. I would just rather have a good standard gear box that can take the power. Why bother putting a V8 in a teener if you can't take advantage of the power capabilities. I know the car weighs 2600lbs, but if you got 247+ cubic inches then why not make use of it.

The cost of a 930 box is close to 10K, the same goes for the Pantera box. Mendeola can get you a box for 6-8K$ that will be able to handle the power and the parts will be easy to find. Plus you get an over drive or a very tight ratio box for your street terror.

[Aaron Cox]

ZF transaxle out of a pantera - PROBLEM SOLVED

[Sammy]

Ben, absolutely right.
I drove the car for about a year and a half, prolly around 4000 hard miles.
After that it was shifting better thasn when I put it in. How long would it last? Who knows. Maybe 5 years, maybe more.
I paid $75 for the tranny and $50 rebuilding it (gasket set, had all the spare parts necessary).

Many years ago Brad and I had a conversation about an Audi turbo 5000 automatic transmission.

He said it would work and would be tough enough (it uses some of the same internals as a ford C4), I never got any farther than taking some measurements.

That may be the answer. Those trannys are available in the pick a parts occasionally.

[Brett W]

The Audi 5000 tranny is worth a look. It supposedly can handle 450 but there are dissenting opinions on whether or not it can handle any power. Some say yes others say nay. They will allow you to run 930 CVs and different axels. You will have to do a different shifter as the mechanism is on top of the tranny. The gear ratios aren't bad for a V8. The turbo box is a little better as far as ratios. There is a lot of info out there about them.

The G50 is a better choice. They are getting pretty easy to find although price is quiet a bit more than a 915 they are strong boxes.

[BIGKAT_83]

When I did my 914/350 sbc conversion I'd heard all of the stories about 914/901 transaxles and was very worried about this. I managed to buy 4 extra sideshifts at a steal and figured this would take care of the problem.

I've driven my car ~10k miles and I'm still on the first Transaxle and I don't baby it. I'm able to spin the 255/40 tires at will and do almost every time I drive the car. The 914/901 has really surprized me on how tuff it is. I think the secret is to start with a GOOD transaxle and not a 30 year old POS.
I do recommend that you use the larger 86mm 911 cv joints and axles.

Bob

[Sammy]

With my V8 914 I only used 1st for creeping into the garage or on a trailer to go racing, but on many, many occasions I lit up the tires in second gear because someone wanted to see it or whatever.
I had victoracers on it (205-50-15) so they were plenty sticky. I didn't have an LSD but could leave two nearly identical marks on the pavement for as long as I wanted to rev the engine.

One time at Irwindale a guy came up to me and asked, "how can you post such fast times with your clutch slipping so badly?"
I said "clutch, my clutch isn't slipping."
He commented that he can hear my engine rev up to redline out of every corner like the clutch is slipping.
I told him that wasn't the clutch, it was the back tires (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)
I swear I could steer that car with my right foot. Almost felt like a rally car.

On the right track, I could and did shift from 2nd to 3rd without even using the clutch and never damaged anything.

[Steve]

Before you guys jump onto the Pantera ZF bandwagen I would check with the Pantera club and some Pantera owners.
It might have the gear ratios for a V8, but according to the Pantera club and Pantera owners that I have talked to the trans blows up if you modify the Ford 351 cleveland to much over stock.
They didn't give me any HP rule of thumb numbers.
They just said beware and leave the engine stock.
I wonder what a stock 351 cleveland puts out??

[TravisNeff]

The pantera owners will also say the weak link in the whole car is the ZF transaxle. When it goes it takes cubic dollars to repair it.

[andys]

QUOTE (BIGKAT_83 @ Mar 2 2005, 06:48 AM)

When I did my 914/350 sbc conversion I'd heard all of the stories about 914/901 transaxles and was very worried about this. I managed to buy 4 extra sideshifts at a steal and figured this would take care of the problem. I've driven my car ~10k miles and I'm still on the first Transaxle and I don't baby it. I'm able to spin the 255/40 tires at will and do almost every time I drive the car. The 914/901 has really surprized me on how tuff it is. I think the secret is to start with a GOOD transaxle and not a 30 year old POS. I do recommend that you use the larger 86mm 911 cv joints and axles. Bob

Ahhhh, the magical and intangeable ingrediant............It's all how you drive 'em. Some can and do have the ability to drive them kindly, yet aggressively. Others' can and do destroy just about anything they drive, and blame the trans. Some people just don't have the feel for it....Not trying to offfend anyone, it's simply a hard learned reality. Of course there is a power threshold that when crossed, will break things irregardless.

When I was looking to buy a 914 about 1 1/2 years ago, I ran across a guy that had an 8 or 10 y/o conversion with the 330HP crate motor (I don't remember the designation, but I believe it's the iron head version of the earlier ZZ3). Beautiful car done in white, 911 brakes, Fuchs, etc. Anyway, he never had a trans let go since he did the conversion, and admitted that he drives it real hard.

Andy

[Type 4]

Jeff at Transaxle Eng. builds the Fortin gearbox for the Offroad guys it uses Audi guts in a cases built for use as a north south transaxle.

http://www.fortinracing.com/transaxles.html

There are some use Fortin's available for sale If you would like to buy one send me an email.

[jd74914]

QUOTE (Brett W @ Mar 2 2005, 06:20 AM)

The Audi 5000 tranny is worth a look. It supposedly can handle 450 but there are dissenting opinions on whether or not it can handle any power. Some say yes others say nay. They will allow you to run 930 CVs and different axels. You will have to do a different shifter as the mechanism is on top of the tranny. The gear ratios aren't bad for a V8. The turbo box is a little better as far as ratios. There is a lot of info out there about them.

My friend retrofited it to his old audi drag car and it handles about 350hp with lots of drag lauches. He's been launching it with a new, and larger, turbo with more boost and its been fine.

How about the manuals out of the newer mustangs. My friends uncle has one that puts 450hp onto the pavement, and he doesn't hesitate to drag. It hasn't broken yet.

Lastly, the same guy has a '74 Pantera with a totally rebuilt and bored out 351C. He doesn't baby his tranny and it hasn't blown up yet (I don't know if it has been beefed up though. I know the mustang tranny hasn't).

[neo914-6]

QUOTE

The G50 is a better choice. They are getting pretty easy to find although price is quiet a bit more than a 915 they are strong boxes.

All true but they are heavy and long enough to stick out...

[marks914]

450 HP? Tell us about the engine, thats pretty potent, virtually undrivable for the street. Has it been dynoed? I do not think you can just simpy flip the gear, there is some machine work ...
_Mark

[redshift]

For 17k, you get a 6 speed ZF, that won't break when you hand it 1000bhp, all at once.

For around 10k, you get a 5 speed ZF that won't break when you hand it 1000bhp, all at once.

For around 7k, you get a ZF that you can throw 500bhp at, and that's NOS, without mods.


M

[Brett W]

http://www.quaife.co.uk/catalogue/page11.htm

Nice 6 speed box with a lot of options. Price is nice too. As much as a 930 box with better features. You can even go sequential for a few bucks more. It looks like the Quaife gearbox will be around awhile.

http://www.gt40s.com/ubbthreads/showflat.p...page=vc&fpart=1
Read what these guys have to say about the ZF box.

Too bad we can't fit a Corvette box in out cars. They are all shaped the wrong way, but they are stout enough for 700+. It is the same box that is in the Mustangs. Tremec makes nice trannies.

The Fortin gear boxes are 13-15k new and 9K used. The X-trac is, unfortunately 30-35K.

Miles where did you get the specs on the ZF box.

[redshift]

Chatting with a couple Pantera guys, when I was looking at 'em last year. One guy had about 700hp, monster 427, on the 5 speed modded one.

The Pantera I had was not modded at all, and besides the nice Italian driving position (knees in neck, arms outstretched) the thing I remember most about it was the clunky shift gates. (IMG:http://www.914world.com/bbs2/html/emoticons/smile.gif)

http://www.pim.net/expertzf.html

If I were going to throw a new car, at a 914, I'd start right there..

(IMG:http://www.914world.com/bbs2/html/emoticons/wink.gif)

Hey, $1k price drop?!

M