3.6L + 901 transaxle?, Is this a recipe for disaster? Options

[Hydra.]

I'm seriously contemplating going with a 3.6L 964 motor for my 914, but I'd like to keep the existing 901 transaxle. I understand that this doesn't leave much in the way of a safety factor, but what can be done to suitably strengthen the 901? Is it absolutely necessary to lock out 1st gear, or would something like an Albins 2.400 1st gear, along with a billet sideplate help out? I understand the alternative is to go with a 915-based setup, but if a 901 can be made to work satisfactorily then I would rather do that...

[pcar916]

I've been using the 914 transaxle with my 3.6 since 1999. There are many opinions about this and you probably should spend an hour or so going through the threads on transaxle life with big engines. There are several threads in the Paddock that talk a lot about ways to make it last longer. Here's my short version.

1. If it's a street/now and then track car then you'll be fine if you start with a good transaxle. That means good bearings, synchros, R&P etc. If you intend to race you'll be rebuilding/replacing stuff yearly anyway. Race tires aren't going to break away and relieve the stress on the drivetrain like street tires will.

Again read some of these threads including this one that addresses a lot of this. Remember that as you read this, I didn't cool mine until this year. Frankly, in a pure street car I don't think it's needed.

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

http://www.914world.com/bbs2/index.php?showtopic=177277

2. I use 1st gear all the time, but don't overstress it with excessive throttle and/or crappy clutchwork. Smooth is hyper important.

3. Did I say smooth will save your equipment?

4. Controversy alert: I have run synthetic hypoid for the entire life of the box, but most folks will tell you that dino oil is better for the synchros. My thinking is that I'd rather replace a synchro than bearings or the R&P.

I've replaced exactly one synchro in 15 years and that was only because I was installing an LSD diff and had one that was better on the shelf. Your call!

5. The 915 installation is an interesting thing. Expensive as well so make your decision after some reading in the first thread and crunching your cash numbers.

6. I ran the stock CV's/axles for years with no real problems, but they'll wear faster if you're doing a lot of heavy throttlework, so you'll want to keep an eye on them i.e. inspect/repack once every year or two. Then installed 108mm turbo cv's. Now I'm running 100mm 944 CV's because the 108's are so very much heavier.

The 901/914 transaxle is definitely lighter. This was important for me since the 3.6L engine (either 964 or 993) is so much heavier. If I blow up more than three transaxles in a row I'll install a 915 and a cable shifter, eat the weight difference (roughly 35-40 lbs IIRC) and see how that goes. But I think the 914 box will be just fine if I drive smoothly.

If you are one of those folks that shift/clutch fast then none of these boxes will last very long.

Good luck and enjoy the reading.