Hello Everyone.

I am new to this forum as I recently got my hands on a 73 914.. (originally a 2.0 car, but currently has a 1.7 in it which does not run) I fiugred since the 2.0 originality is gone.. i could do a v8 conversion. I was wondering how much power can the stock 5sp. side shift transmission hold up to. I read around the forum and the only thing i could find was that 1st gear burn outs is a nono... but nothing on how much power they could hold.....any knowledge would be greatly appreciated.

some say 300hp max but this is half the story. many have been driving their sbc with stock trans for years - but they don't beat the shit out of it. if you will be running fat grippy tires and blasting off like you stole it, on a regular basis, you might want to consider a 930 trans. BUT this alternate option will cause a cost increase of thousands of dollars. might want to start off with a mild v8 and stock rebuilt trans and see how it goes, and take it from there.

The power capabilities vary with which gear you're in but as long as you stay around 200-300hp and the associated torque, and wait to tromp on it until after the clutch is out all the way your good. In a race car you'll be rebuilding more often to inspect everything.

I'm currently running 270hp, about the same in torque with a very light flywheel, and have been since 1999. Before that I ran about 220hp with a strong 2.7L engine. Ya gotta be smooth to keep that transaxle healthy.

Consistent with another thread in the Paddock,

http://www.914world.com/bbs2/index.php?showtopic=161520

if you run a big hp engine then cooling and filtering the oil will substantially increase the life of the box.

I run a stock 901 behind my 3.6L motor. The engine was dynoed (is that a word?) at ~300HP.
It's been a few years, so far, so good.

However, i don't use 1st gear anymore, so for daily driving it's effectively a 4-speed.
I take off in 2nd. I can lay down 30 feet of rubber taking off on 9" racing slicks.

901's are still pretty cheap and plentiful. I have a 915 ready and waiting for the day the 901 breaks.

Much appreciated everyone. I just want bigger balls than the 4cyl.. but dont need to go over board. sounds like a mild built v8 (250Hp) is the way to go. Thanks everyone!!

Hi Enhoover,

When I was starting my V8 conversion, I got a ride with a friend with a 300 HP Chevy smallblock and he romped through the gears with sloppy shifts with partial open throttle. In my mind, he was very abusive to the trans but it TOOK it. When I commented on the shifts, he just smiled and said "I have 2 other 901s under the house." His point that 901s are CHEAPER to replace than going to a BIG TRANS.

I've been following V8 conversions for some 10 years now and find a general consensus that 300 - 350 HP will allow the 901 to live. Of course the TRUE issue
is that torque that breaks trannies. An engineer bud advised me that the transitory SHOCK loads from sloppy shifts far exceed the load by simply applying engine torque when in a gear. So the bottom line is: run a "mild V8" and shift like a road racer, not a drag racer.

My car has a built 383 SBC and I knew that neither the 901 nor the 915 could take the torque. I HAD to cough the $$ for a 930 (4-spd). While it can take all the torque, the gear ratios SUCK: 1st- a bit low, 2nd- ok, 3rd-great shift from 2nd, 4th- is a very tall 5th with a .65 overdrive ratio. The box desperately needs 5 gears and Porsche corrected the issue with the G-50. 930s are scarce and run $2500 - $3500, G-50s run $3500 and up.

So there it is, now you get to make the choice. If a 300 HP Chevy works for you, I'd suggest staying with the 901. However, if you GOTTA' go big, you'll have to spend BIG...it's all about $$
Enjoy,
Terry

HP is just half the issue mentioned above.... That is that torque times RPM = HP So 300 hp at 4000 is much different than 300 hp at 6000 RPM. I've driven a 901 behind a 330 hp SBC for 25 years and the only time I had a problem was sidestepping the clutch in second for a big burn out. The ring and pinon won't take that kind of driving.

You can build a SBC with the proper choice of heads, cam, headers and exhaust set up to not allow the torque to build too rapidly below 2000 RPM and you'll have a nice driving machine. You won't need first, it's just too low and the normal second gear is perfect for the V8.

I've driven in the mountains of colorado and done some auto cross.... it's a fun machine and the box is very reliable if not abused.

B

I always recommend locking out 1st and changing a few gears to better match the low RPM of the V8. I have yet to have a V8 customer with an issue