930 failure?

[Ross Nicol]

Sandy
Russ is not a guy to pay Porsche prices, he's the ultimate DIY example. Of course with a lot of unproven parts in a race car he will have an extended development program IMHO. I had a day with Russ in his workshop last september and enjoyed every minute of it.I start racing again next weekend but have been having fun in the Lotus Europa lately.Humbled a 911 and Camaro that ran high 16's at a 1/4 mile sprint last sunday Europa/Toyota 20v- 14.48sec 105mph only 2 sec off the 40.Great fun.
Rossrockonsmile

 

[Russ Noble]

Sandy
Russ is not a guy to pay Porsche prices, he's the ultimate DIY example. Of course with a lot of unproven parts in a race car he will have an extended development program IMHO.
Rossrockonsmile

Ross,
I would tend to agree with you ,except that I am fortunate in having Lim on the team as an absolutely fanatical machinist with extensive materials knowledge and experience. Also Jac Mac is working closely with me on many aspects of the car and has also agreed to be pit crew chief (both these guys getting the usual retainer... 10% of the prize money.... LOL). His knowledge and experience in the racing game is unsurpassed as most will know. The only problem I anticipate is failure of something that has been built too light. But in critical areas I have gone horribly overkill, so don't think there will be a problem. Time will tell, although I am anticipating it will take a season of suspension (and driver!) development to get down to the sort of times I am targetting. So much for the thread drift! Back to the subject in hand.... I expect the 930 will be dead reliable!

Cheers

 

[Ross Nicol]

Russ
you are lucky to have those 2 gentlemen on your team.The only problem is the pressure you must put on yourself to perform for them. Even with Lim's input though I reckon you only get confident with the mechanicals after you've thrashed the car on the track a few times.My personal opinion though is that bad drivers who lack mechanical feel break gearboxes, clutches etc. Why is it you never see Jim Richards with a mechanical problem. Anyway back to the 930, sounds like your onto the area that needed beefing up. When is the expected launch?
Ross

 

[Jac Mac]

Ross, Have you ever seen the Prize Money Schedule for the Southern Festival Of Speed, it would even make an ex-pat Kiwis mouth water, Lim & I are really going to be rolling in $$$$ when Russ brings home the Bacon, Its a long time since I have held that many$00000.00 in my hand, just in case though I dont think I will break all my ties with the TVR just yet. Going by the pic in mondays ChCh Press Russ might have to take some flying lessons just to get past!

cheers
Jac Mac

 

[Jac Mac]

Ross, Have you never seen the Prize Money Schedule for the Southern Festival Of Speed, it would even make an ex-pat Kiwis mouth water, Lim & I are really going to be rolling in $$$$ when Russ brings home the Bacon, Its a long time since I have held that many $00000.00 in my hand, just in case though I dont think I will break all my ties with the TVR just yet. Going by the pic in mondays ChCh Press Russ might have to take some flying lessons just to get past!
Whats all this 'Gentlemen' stuff!

cheers
Jac Mac

See, posting on this site is just like building race cars, do every damn thing twice!

 

[Russ Noble]

Russ My personal opinion though is that bad drivers who lack mechanical feel break gearboxes, clutches etc. Why is it you never see Jim Richards with a mechanical problem. Anyway back to the 930, sounds like your onto the area that needed beefing up. When is the expected launch?
Ross

Ross, you're taking the piss out of me again!!!! Are you a naturalised Ozzie??

"My personal opinion though is that bad drivers who lack mechanical feel break gearboxes, clutches etc".

That's why I've got a strong gearbox and clutch!! Hoping for mid winter (July) fire up. Should be well sorted for SFOS 2008. You bringing your car over to give me a good go?

Jac Mac, stop shouting. I heard you the first time.

Cheers

 

[Paul Bearman]

Thanks Russ, I'd appreciate a dimensional drg.
I would have bought a side plate but I'm in no rush for this & have plenty of Alu billets laying around the workshop & to be honest I'd rather be in the machine shop than at home decorating!
OK, so we've established the 'box needs to be inverted but what about the internals, any mods to be done here?

 

[Russ Noble]

Paul,

I don't think any mods required internally. PM me in a couple of months in case I forget.

Cheers

 

[Ross Nicol]

Russ
No I wasn't taking the piss, I was just making a general statement. Actually you rate highly in my race memory bank because you've been there and done it, not just talked about it.I'll have to be careful not to drift around a topic as that is what happens and I don't read my posts the way you or others may do.Definately not Naturalized I assure you, but NZ accent mostly gone .I hope your going to cost out your build as I think it may be very interesting.That deal you've done with Jac Mac and Lim is superb, wouldn't have thought anyone would fall for the % of prize money anymore :lol: but wonders will never cease.So far I have a 5L of Castrol oil and a certificate to share if anyones interested in that deal for me.How could you resist that .Hope the 930 your strengthening hangs in ok.I always think after doing a mod like this that the next weak link will rear it's ugly head and on it goes.
Ross (Kiwi Forever) Nicol
Pete if you read this please leave our cricket team alone at least they didn't crow about how good they were.Ta!

 

[Dalton Veitch]

Russ, you started this thread with an interesting and practical question on the 930 transaxle. Various members of this forum have tremendous knowledge and first hand experience on these.

Having been associated with old Porsches for 30 years I just wanted to add that Porsche considered their 5 speed 915 transmission couldn't cope with much more than 400 bhp when fitted to race cars. So anticipating race use, when they brought out the turbo road car, they fitted a new four speed gearbox with wider teeth which could take 750 bhp, which meant it could be used in the racing 935's. Porsche had been denied victory at Le Mans in 1974 due to fifth gear failing in a 915 gearbox, and were determined to never let that happen again. This determination to make the turbo's transmission as indestructible as possible has meant that, in Porsches at least, failures are practically unheard of.

Cheers,
Dalton

 

[Russ Noble]

Dalton,

Thanks for that bit of history. Porsche must have done it right coz no-one has yet been able to point to a trashed 930 under any application.

Cheers

 

[Russ Noble]

And still no 930 failures notified......

Have just got back onto stripping my 930 and sussing out how I'm going to do the spraybar. Apart from a handful of dodgy bearings and the 3/4 slider, all's well. Got to tighten up the LSD though. Haven't pulled that to bits yet to figure it out.Any pointers appreciated before I start in on it.

I took the opportunity to measure up a few things for Rambo's comparisons.

Gear widths

4/3 (as posted by Sandy) 24mm
2nd 23mm
1st 21mm


Shaft sizes at midpoint between bearings

Pinion
Major diam. 40mm
Minor diam 36mm

Mainshaft
Major 35mm
Minor 33mm

Distance between bearings 190mm

Strange how after months both the 930 and ZF "failure" threads have resurfaced at the same time.....

Cheers,

 

[Bill Musarra]

Russ,
I turned the spray bar project over to the shop forman at my local Porsche dealer. He has set them up before including his own. I chose to spray 2nd, 3rd, 4th, and the R/P since 1st is of little use. He also fabed the clutch lever from a 996 since the crossover bar was in the way. Setup the drain line to incorporate the temp sender as well.

Bill

 

[Russ Noble]

That's interesting Bill.

Thanks for posting the photos. I spent yesterday studying my setup in great detail. I'm looking at trying to fit an internal spray bar.

Do you know if there is a tube or jet inside the housing directing the oil onto the gears? If it just feeds straight in, the second and third gear feed placements look as though they will just miss the gears. Too far forward for 3rd and too far back for 2nd. Unless the jet disperses a wide spray?

Do you know what size the orifices are on the jets?

Cheers,

 

greetings all. on the subject of clutch arms -- my g50 arrived from states less arm or cross bar. its the smaller shaft size bushes so whats the best solution ( from scratch ) mtr. is std ls1 wth headers. steve . thanks.

 

[Russ Noble]

Steve,

Probably a hydraulic release bearing. I got a couple off Ebay for about US$80 each and have chopped one around to use with my 930.

You can have a look when you're down next month, but I'll have photos on my build thread shortly.

The other one is for Lim's G50 which because it's slightly different is going to require a slightly different adaption. Nothing you couldn't handle.

Cheers

 

[Russ Noble]

Guys

I've just been surfing looking for info on doing my LSD and stumbled across this magazine article on the 930 for off roaders. I wasn't sure if I was allowed to copy it to here so this is the link instead. Well worth a read.

Porsche 930 4-Speed Transmission For Sand Rails By MecTech Motorsports

Besides mentioning the usual upgrades, although strangely enough not the spraybar, it does list an upgrade for the steel bearing support that I have never heard of before.

The more I read about these trans, the more I'm convinced they are the best compromise of weight/cost/strength. All the upgrades can be done reasonably cheaply and with those in place, I believe that in a '40 they will be totally bulletproof. I have just been pricing a few parts for the rebuild and have been pleasantly surprised also!

Still waiting for someone to photos of a destroyed 930!

I have decided to run an internal spray bar fed from the rear of the case. I have got the bar installed and the jets drilled. When I get it completely finished I will post pictures on my build thread. Building and fitting the spraybar itself is very simple, almost in the home handyman category. The biggest problem was deciding the best way to route it and feed it. I am spraying all the gears plus the pinion and the ring gear.

Can anyone point me to any tech on setting up an LSD? Otherwise I'll just have to pull it to bits and figure it out for myself. I'd prefer to know in advance what I'm doing.

Cheers,

 

[Sandy]

Russ -

Put up some pics of the hydraulic throwout bearing. Very interested in seeing what you did.

Sandy

 

[Bill Musarra]

Russ,
I defer to my source on 930s,David Craig who sold me my 930 and is a master mechanic with Porshe and other exotic trans. David was on the forum for a while and I think you had some correspondence with him about transmissions. I think he left a bad taste in some, but I will ell you this, he is one of the most knowledgeable people around when it comes to Porshe products. I think him honest too as well. Some may remember the 930saga that I went through. I asked him once about the spray bars and from what he told me, you don't really need a spray bar. Even for off roading. He knew several of the 935 and rally guys and said to effect that the ones with internal oilers(stock setups) were all that was needed and it was really fairly redundant. I could be wrong but I don't think they(935s) had any external setupss. I am adding it to mine for 2 reasons. One is peace of mind. They aren't cheap, and there are only a limited number of them out there, and second is the bling factor. I have two panels open in the back with the oil cooler in one, so it balances it out.
David and I get together every once in a while and talk cars. He is on vacation now if memory serves me. I will forward this thread and ask his opinion, or I will send you his email and you can get the straight skinny form him yourself.

Bill

 

[Russ Noble]

Thanks Bill,

I agree with you about David. It's a great pity we have lost his tech from this site, he only made a few posts and most of them were very informative. To me the tech is the important part, the way it is delivered or the guys personality or business dealings are irrelevant to the tech. Mind you I can understand the reason for banning him, but it's our loss....

WRT the spray bar, if you're going to run a cooler and pump then it's going to cost very little more and take very little effort to feed the oil back in via a spraybar. Mightn't do any good, but certainly won't do any harm.

I lost David's and all my other email addresses when I had a computer glitch some months ago so it would be good to get it again.

Thanks,

Russ