nathanUK '81 930 G50

It supports over 500bhp. Not sure if that is crank or wheels. Maybe Kevin or Stephen will chime in.

dholling13

They also have a high flow 2 unit that is like the Garrett; my high flow s puts out just over 400 bhp at .9 bar.

PorschePhD

Drop me a call and we can talk about the setups you can go with.

DonE

There's something else going on here. If you don't have enough oil in the feed to provide a GT35r turbo (which needs less than a KKK), then you'll burn anything else. Are you using a stock oil feed line? Those can flow a lot of oil.

I use a GT35r turbo with no center section cooling. I do not use the stock check ball or the stock oil scavenge pump either. It is a straight -3 steel braided line from the stock oil feed location, right to the turbo - no restrictors at the turbo like what was supplied by the retailer. I also use an after-market high volume scavenge pump. So, I am moving a lot of oil through the turbo with no problems at the seals. One other point - the hot side of the turbo is wrapped in insulating turbo wrap and a stainless steel shield.

When the engine is shut down, I hear the turbo spool down for about 20 - 30 seconds, and that's from idle. This turbo has about 25k miles on it.

JBL930

Thanks for the replies, the turbo is now off and on it's way back to the people who rebuilt it, the garage said there doesn't seam to be any problem with oil feed it looks like the bearings have just collapsed, I can only guess as to what has caused it but I'm sure the turbo guys will have an explanation when they have inspected it. Don, my car still uses the standard scavenge pump but has all of the braided lines with no restrictors, I'm told that it is being cooled with oil but I'm afraid I don't have any technical info, I'm also lead to believe that mine isn't a full GT35r, it's a 9m creation that they won't elaborate on, it doesn't have any heat wrap or shields around it, should I think about getting something for it?
Stephen, if it goes again i will be on the phone, thanks again

dholling13

I might consider selling it and moving on. If this is the second time around for a rebuild; what's going to happen next? Parts from the turbo getting in your motor? These High Flow units from IA are worth their weight in gold. The performance seems like it should have come stock on our cars. I have 30 track days on mine this year and there has been zero problems other than spinning tires in certain turns ...

srf506

Bearing collapse? As in a pure mechanical failure of the bearings? That doesn't sound right to me unless it was rebuilt with some cheap bearing set not up to the task, or improperly assembled. I think there's more going on here, but Jonathan, it sounds like your oil set-up is okay to me. So now I'm really confused. But as previously suggested on the board, spend the extra time to clean the oil system really well. You don't need a chunk of metal getting in the wrong place.

JBL930

I'm not sure I could sell a turbo that I don't know the specifics of, the HF2 does look like an option if we can't sort out the problems with this one.
Jim, I thought that bearing collapse sounded a bit drastic too, coked up and seized or dried out and seized would be easier to swallow but the mechanic said the whole internal assembly was so loose the fan/impeller/compressor wheel (not sure of the correct term) was resting against the housing, he said he could move the wheel in all directions! He said luckily there seams to be no debris on the cold side but there was some swarf in the drip tank, they are going to flush the whole system as I need new lines up to the front oil cooler anyway, they are a good bunch at Northway so I’m confident they'll do a thorough job. It's having a full service too, this will be the first time the valve clearances have been done since the rebuild, apparently they were all in need of adjustment so it might feel a bit crisper when she's done, I’ll keep you posted on the news with the turbo, it is certainly a bit suspect for a rebuilt unit to completely fail in under 3000 miles, I’m sure it will all become apparent

Jean

IMO nothing to do with the turbo unless the system is poorly designed (edit: just read that it is a rebuilt turbo, but still unlikely), if you have damaged this one, you will also damage the next, KKK or Garrett as well.

I recommend that you look elsewhere for the problem first to understand what happened, and then decide to change turbos if you still want to. The GT35 is great.

JBL930

Jean thanks for your input, the car had done around 10,000 miles before the first turbo rebuild and then it was the seals that went, most likely down to hot shut downs? The rebuilt unit has been in the car for around 3000 miles, no changes have been made from the original set up and I have been very careful to make sure the car idles for a couple of minutes every time I shut it down, I’ve even had a Clifford alarm fitted that allows me to remote start and shut the car down so I have no excuses.
Do you have any clue as to what we should look for, should I think about fitting a larger scavenge pump, Don mentioned that the Garrett needs less oil than a KKK which would make you think that the standard scavenge pump was more than up to the job? Apart from flushing the system and checking oil pressure etc is there anything else that might be overlooked?
Thanks again for all the input chaps

srf506

Jonathan, one last thing and then I'll shut up. Did you prime the turbo before start-up the first time to ensure oil in the unit? The garage said bearing collapse, were they blued from heat or did the cages mechanically come apart and destroy the bearing w/o indication of excessive temp? If there's evidence of heat damage than I still say the oil system for some reason is inadequate/not working properly. Good luck mate.

Cheers,
Jim

JBL930

Hi Jim
I don't do any mechanical work on my car, I simply wouldn't trust myself, 9m do all that stuff for me so I’m sure that they follow the correct procedures for installation as they certainly fit enough of them!
I spoke to the turbo people today and they said the turbo has been starved of oil and the central cartridge (I think that's the word they used) had got excessively hot and caused the failure, I just don't understand how the original turbo lasted 10,000 miles and the rebuilt one only lasted 3000 miles with the exact same oil supply, it must have been some kind of blockage or air lock, or maybe it was a sub-standard rebuild?

911addict

Jon, interesting that Northway are now servicing your car. Are they knowledgeable on turbos and modded ones at that?

JBL930

Hi Mark
Northway were the chaps I used when I first got the car, they were the ones that informed me that my engine was a bit tired (cams, turbo etc) which prompted me to get the engine work done, they don't really do any tuning as such and that's when I started to do some research and found 9m. I would always get my car serviced at Northway out of convenience as they are only about 30mins from Henley, it just happens that something usually needs a little more attention by the time the service is due and therefore it ends up going the 200 or so miles up to 9m. Why do you say it's interesting that I use Northway?

911addict

I have heard good things about Northway ;-)