Hi guys

In the last rally 2 other Porsche's (911's) went out because their CVs failed. My standard 914-4 ones have now lasted me the past 3 years, but I think I'm on borrowed time. Also, I checked the play and they're excessive, so they're on their way out that's for sure. I was wondering if anyone has experience of these:

http://www.pelicanparts.com/cgi-bin/smart/...36%29%2C%20Each



I need them to put up with 200bhp/lbft engine and a whole load of abuse I think these will do nicely but thought I'd get a second opinion from here from anyone that's tried them.

Cheers

Moggy

My brand new ones only lasted 3 events, but we do excessive things at launch for sure.

I went with the 944 turbo CV, but you need to change the output shaft on the 901 and a few other bits, but these will not break. Andy had a great posting going through the numbers of what you to do to swap them over. Just search for CV's and I think you will find the link.

If I remember right the output shaft is one from a old 911 (901) that has a different spline to match 944 turbo CV's. It also seems like I only changed the output shaft and the CV's, didn't have to change anything else, but maybe had to do a bit of machining on the stock drive shaft.

Here is the link: http://www.914world.com/bbs2/index.php?sho...=turbo+CV's

Thanks Randal. Fantastic feedback and info. I'll investigate this option with the 944 CVs.

Cheers

Moggy

I am running the 944 Turbo CV set-up with over 300hp and 12" slicks...no problem.

-Britain

I don't like running new "tight" CV joints on a race car, unless it is an AX car and only runs for a minute at a time. They tend to build a lot of heat since they are tight. I always ran good used ones on my race car. You could always get the new ones REM'ed. This would loosen them up some.

Quick question about that: it looks like you should be able to swap the output flanges w/o opening up the box - true? I figured it would at least need to be drained of oil, but I don't really see any seals in the PET. Should/can the taper bearing (part 8, page 132) also be replaced at that time? Or at least checked and repacked...?


The thread you linked to mentions the 4mm of machining on each end of the drive shaft - and that thread or this one talk about the Sway-A-Way floating drive shafts. There's a list of output flanges, CV joints, stub axles, and wheel hub part numbers on this here wiki if you're going crazy looking for which parts ought to fit together.

Changing the output shaft on the 901 is really easy. Just be sure you have the correct torque specs. I drained a bit of oil, later to be reused, then changed the shafts and didn't spill any oil.

Thanks for all the great info guys.

I have all the parts on order now, however I have a question. Do I really need to get the 911 hubs? I have 4 stud 914 ones on at the moment that have been converted to 5 stud. Will these fit the 911 stub axles?

Also a word on the drive shafts themselves. I found that my splines were worn enough to allow the inner part of the CV to move slightly in the splines. So looks like I need to source a decent set of axles too.

Finally, I completely agree to the comments above regarding not using new CVs for race use. I have always gone for good used units or new ones that I have run in at least 500 miles on. The 911 guys that went out in the last rally because of their CVs blowing up used brand new CVs, straight out of the box. One guy had two failures on consecutive days because of this.

Cheers

Moggy

Yes you need 911 hubs. They will not fit 914/4 stubs. Sell your old hubs. Someone else was recently looking for axles. Parts Heaven in Hayward were out. High Performance House in Redwood City. Maybe Otto's in Venice Beach, both California. You could get some new Sway-Away that have the correct spline. IIRC 20 1/4" is about the right length. They would float in the CV joints-no locking snap rings and would not need machining to fit. I saw someone on the world site do this...

Eric Shea did a write up on this in his 5 lug conversion thread. Its what I'm using for my 3.2 on a 914 trans. Hubs, stubs and cv's from a '70 911 were $300 and then the sway a way axles ~300. Might be a good racing set up since the parts are reasonably priced, fairly common and don't require any machining to fit.

If those sway away axles are available with the 911 spline count you have yet another option. The 911 100mm cv may be cheaper? 914 and 944 have the same spline count.

Moggy,

I like this one best because of the free floating Sway-a-Way axles. They will handle the torque much better. Offroad guys have been using these for some time now. Perfect for your situation.

http://www.914world.com/bbs2/index.php?showtopic=91963

Give me a PM and I'll hook you up. This is what I'm running on my car.

E.

I have stripped the driveshafts down to their constituent parts now and am now left with a mystery. One driveshaft has 33splines which I am pretty sure is the standard 914-4 one, the other has 25 splines on. WTF? Looks like I am going to need to get another standard 914-4 driveshaft so I can go this 944CV route but I'm intrigued to find out what and where my mystery driveshaft comes from. Any ideas? There's no markings on it of any kind.

Hi Eric - I'm not really keen on going down the custom driveshaft route for a number of reasons. Historic regulations and ease for spare parts. Although I have used sway away shafts before on some of my old offload racers and can vouch for them being as strong as people say. Almost as strong as your strengthened rear arms despite side swiping a few banks over in Ireland a few weeks ago they're still as straight as they were when I got them from you. Don't know what it takes to bend ones of these but I can't manage to do it, despite trying my damd'est. Good product mate.

Figured it out. It's a 914-6 driveshaft anyone wanna swap for a 33 spline 914-4 one? I want a pair of 33 spline driveshafts to fit the 944 cvs I am gonna upgrade to.