Surveying what's been run successfully before I go to an alternative...

List hp/torque/application(driving style)/length of time (1 day/years)/modified or stock gearbox

i.e.: 240hp/200ft lbs/street/lasted 1 year/stock-lsd

I know the 915, 930, and ZF are better but we can all benefit knowing the capabilities of the less costly 901/914.

Post documented data if you have it.

OTTO - runs 3.0L of race motor through a built 901....

Much depends on your tires in as far as longevity of your 901
is concerned....and , of course, how much you abuse them

I'm running 10 inch Hoosier R35 slicks.....Tho I try to take it easy in 1st gear at AX....the red mist hits and....
One of these days I'm gonna leave drive line parts at the line....but not far behind.
Prior to the slicks, I was running 225 R specs back there.
The 901 *seems* fine after 3-4 years of AX abuse. Traction at our venues is not the greatest, tho.
I'm running prolly 200 hp & 190 ft lbs which is enuff to haze those slicks.

I can buy a lot of 901s for the price of one 915.

I've had zero problems with a stock 901 on a 350 V8 for well over a year now and driven a few thousand miles. 300 HP is conservative estimate considering what's been done to the engine and on how it performs. I have a hell of a lot of fun with it but I don't abuse it by burning up my expensive tires. My opinion the comments about the 901 not handling V8 power/torque generally come from people who've never owned a V8 conversion or have any experience with them.

Xitspd - has a 3.6L race motor running through a 901 also....

I made 374 rear wheel horsepower and 410ftlb of torque on a Dyno this spring with my 914 sbc conversion.
I'm running 255/40 tires and have had the 901 last for almost 3yrs with no problems. I have 911 axles and CV's from a 89 C2.
I've driven the car around 10k miles and don't think I been in it without spinning the tires atleast once or twice.

Bob

QUOTE (J P Stein @ Sep 19 2005, 09:45 AM)

Much depends on your tires in as far as longevity of your 901 is concerned....and , of course, how much you abuse them I can buy a lot of 901s for the price of one 915.

Ok, survey so far:

Bondo: dreamin
Otto: 3.0L -6/?
Xitspd: 3.6L -6/?
John Rogers: ?/195 hp/?/30 min sprints/LSD,cooler
JP Stein: -6/200 hp/190 ft lbs/10" R35 slicks
Andyrew: V8/240 hp/ 320ft lb/1 year
914GT: V8/300 hp / x ft lb/1 year/stock tires
BigKat: V8/374 hp/410ftlb/10k miles/225-40 tires

My LT1 does 275 Hp, 325 ft-lbs.. my driving style is hard but smooth launches.. 901 survival time so far is negative six months to a year.

(In other words, I haven't even finished building the trans yet, and the car is just a shell. But I'll let you know how it works, when it works.)

QUOTE (BIGKAT_83 @ Sep 19 2005, 11:39 AM)

I've driven the car around 10k miles and don't think I been in it without spinning the tires atleast once or twice. Bob

my kind of car guy

My race car has 185HP at the rear wheels and usually does 30 minute sprint races and at places like the CA Speedway will be foot-to-the-floor for probably 25 to 30 seconds. At races like in Mexico I shift from 1st to 5th to 1st twice a lap with a couple of 4th to 3rd shifts thrown in. The races are usually 30 minutes in length. I do not speed shift, do hi RPM starts and now I run a trans cooler and lube pump with a gallon of Swepco for safety. At the race last weekend the trans temps got up to 280 degrees on the temp gauge I have in place of the speedo drive which is about 75 degrees lower than without the cooler (air was 85 degrees). The tranny has a GT limited slip and we replace the CV joints yearly for safety.

240rwh270rwt for bout a year..

Recently bout 50 more tq.. REAL stress on the trani because its off idle. I suspect the trani cant hold it, but its been doing great.

ANdrew

Renegade site quote:

Can I use my stock tranny?
Yes. The stock 914 tranny is good for 300 hp in street applications. However, try to avoid abusing it. The gear ratios are ok in stock form, but, we also offer taller gears that make it better suited for use with most V-8s. You may want to use your tranny in stock form, until you are ready for a rebuild. Then, just send us your tranny for the rebuild and we can replace 3rd, 4th, & 5th with taller gears, at the same time.

Rod Simpson site quote:

TRANSAXLE CHOICE
901: Good choice for basic conversions, engine should be limited to 300 ft lbs of V8 torque or 225 ft lbs of V6 torque in 1st gear and 340 ft lbs of V8 torque or 255 ft lbs of V6 torque in 2nd thru 5th. Top speed will be approx. 148 mph @ 6500 rpm with the stock 31:22 (ZA) 5th gear set. If you want a taller 5th gear, it can be replaced with a 19:32 (H) 2nd gear reversed (32:19), where the driven gear in the set becomes the driving gear. Then 6500 rpm is approx. 179 mph and 55 mph is a comfortable 2000 rpm. The stock 215mm pressure plate with the RSH disk will hold up to 350 ft/lbs of V8 torque. The stock disc will hold up to 260 ft/lbs.

QUOTE (Neo914-6 @ Sep 20 2005, 04:28 PM)

Rod Simpson site quote: ...148 mph @ 6500 rpm with the stock 31:22 (ZA) 5th gear set. ...

ZA is the stock top gear for a 914.6 box; the 914/4 top gear is an even taller ZD (31:22)

KEP site info:

KEP 228mm PORSCHE PRESSURE PLATES (9")

Fits all 914 and pre 1970 911 transaxles using the KEP 9" flywheel and special KEP Porsche release bearing. Torque capacities using a stock disc are shown below.

9" STOCK
200 ft. lb.
Stock 228mm VW Bus pressure plate. Suitable for engines under 3 liter for street use.

9" STAGE I
223 ft. lb.
This pressure plate works well in Porsche 911 powered 914's or V6 camper vans. Enjoy good holding power and easy pedal effort.

9" STAGE II
273 ft. lb.
This is the one used by winning unlimited class offroad racers. Also very popular for use in V8 powered 914's under 400 HP.

9" STAGE III
378 ft. lb.
This pressure plate is designed to handle 500 HP on an organic disc. Good for street or race applications with lots of power.


KEP 215mm PORSCHE PRESSURE PLATES

Porsche 215mm pressure plate for 914's and '65-69 Porsche 911 features stronger diaphragm and a full circle torque link system to prevent failure due to excessive torque.

Stock - (for comparison). Holds 180 ft. lbs. of torque.

Stage I - 215mm Pressure Plate. Holds 230 ft. lbs. of torque.

Stage II - 215mm pressure Plate. Holds 270 ft. lbs. of torque.

Dave Ferguson would only quote "over 300 HP" from his Jerry Woods-tuned 2.8 liter (max class limit) race-only Six motor. Unknown torque rating; I assume it was between 250 and 300 lb-ft. I don't recall how many events per year he ran, but he was not overly kind to the equipment. He would shear the teeth off of the pinion gear every few years, and rebuild the transmission (in large part to swap gear ratios for different tracks) several times per season. Not sure exactly what got replaced in those rebuilds. He ran Goodyear cantilever slicks, I think a clutch-type LSD. He had a transmission cooler, but I think he wasn't using it when I talked to him.

--DD

Bondo: dreamin
Otto: 3.0L -6/?
Xitspd: 3.6L -6/?
John Rogers: ?/195 hp/?/30 min sprints/LSD,cooler
JP Stein: -6/200 hp/190 ft lbs/10" R35 slicks
Dave Feruson: -6/300 hp/~300 ft lb/slicks/LSD, cooler
Andyrew: V8/275 hp/ 315ft lb/1 year
914GT: V8/300 hp / x ft lb/1 year/stock tires
Renegade: V8/300 hp/? ft lb
Simpson: V8/? hp/340 ft lb
BigKat: V8/374 hp/410ft lb/10k miles/225-40 tires
KEP stage II: V8/400 HP/273 ft. lb./unlimited class offroad racers.

I drove my v8 (383/425) for about 8 months. Was built 8k miles before I bought it, and I put maybe 12k on it. You could spin the tires (9's) and slip the clutch simultaneously in all gears but 5th. 1st was unused.

The clutch that came in it, and 2 replacements.

Transaxle was stock, odo said just under 40k when I bought it. I don't know the tq numbers.

M

bumped for Brian

Thanks for the bumpin.... good data..would be cool to check in with all the above in a year and see how've they faired.

Chuck Beck was kind enough to host some Porsche and Kit guys at his home last month and on the discussion of Transmissions he said that the 901 (or in the case of kit cars , a VW box) will live longer with more than a 4 cylinder engine. Seems a 6 or 8 cylinder with more impulses per 360 degrees is smoother on the internal parts. This may be why the VW and 914 box are so strong. Al

I want to also mention that my numbers (240rwhp and 275rwtq) where at the wheels...

And thus at the trani it was 275hp, and 315tq...

forgot to add DH recommendations:

Unless you are installing an engine with a 400 SBC crankshaft or equivalent - which will normally produce well over 400 ft-lbs of torque, our recommendation is that you stick with the 901 transaxle. It is quite expensive to do the 915, especially if you will be paying someone to do the machine work, assembly, and such. You will also need an electric speedometer if you happen to use the later aluminum case 915. The adapter kit is more expensive, and you will need 915 shift linkage, cv/axle spacers, clutch cable mount, etc. The only reason to use a 915 is if you are using a stroker motor, ie. 377, 383, 406 where the 901 simply will not handle the torque. Even for a 400HP 350, the 901 is fine. In fact, we personally much prefer the 901 to the 915 due to the better stock gear ratios, better shifting, easier clutch pedal, and ease of installation.