Carrera GT

That's a good "while you're in there" list. Well worth searching here and checking with a master tech with a lot of 993 turbo experience. Power steering belt, some o-rings and gaskets, numerous screws tend to be corroded, wear and tear items, vent pipes, test power clutch accumulator, hoses, cables, connectors, wiring ... then things like sound insulation on the firewall, cross member bushings, bolts, engine mounts, trans mount, AWD vicous coupling ... all of these are dead at 50K miles. A great opportunity while doing the RS clutch and flywheel to talk with Guard about an LSD, maybe upgrades to a twisted (whining) 1st gear, steel synchros, check for worn gear teeth, there's a pivot pin in the box that tends to fail, shifter linkage can be converted to short throw, etc.

If the owner is wanting a 993 turbo reborn to its former glory (and more) then definitely look at Garretts or rebuilds with hand finished compressor side, etc.

I wonder if someone knows of off the shelf flexible oil lines to replace the insufferable hard oil lines to the turbos.

I chose to do things like replacing frozen exhaust hardware, studs, bolts ... all easily handled while the engine is on a stand. I removed heat and put in headers.

Alternator bearing, RS pulley. Maybe go to serpentine belt? (the old V belt is a source of parasitic horsepower loss.)

Pressure test the IC? New hard pipes?

The start motor is huge and insanely heavy, but I've not found any of the "lightweight" starter companies making a 993 or 993 turbo fitment. If someone has found a lightweight starter, that would be great.

I've never done it, but I'm told that the old factory battery cables are insanely heavy and produce excessive resistance compared to new products that are lighter and far better conductors. Since last century, I've had a "one of these days" project idea to put a flat battery under the passenger seat or in the passenger foot well and shorten the cables.

Anyway, there's any number of ways to give the 993 turbo another 50K miles of high performance, reliable super car motoring. I'd certainly be talking with a master tech and searching here for threads back to at least 2005 or so. My primary question would be to ask what has happened in the last ten years to apply state of the art technology to this old Mezger. It's such a brilliant engine, easily capable of 500hp, and readily capable of 700hp (with sufficient funds) that's it's just a matter of desire and determination.

nrubenstein

In reality, beyond the clutch, we are not really interested in upgrades for this car. The cost/performance ratio is too high and there are too many other projects. With even mild turbo upgrades costing thousands (tuning really inflates that cost impressively), it's just not that interesting. I'd much rather explore the forced induction options for my E46 M3, where engines are relatively cheap and plentiful and power limits are getting pretty stupid.

nrubenstein

I've been distracted by travel and other projects (like repairing the cracked rear subframe mount on the E46 M3), but finally got around to doing my basic engine due diligence.

Net-net, the right side turbo is like the Valdez. Even with the oil drained, I still ended up getting something like a quart out of it when I popped the charge hose off. That pretty conclusively explains the smoking, I'd think. Given how ****ty the turbos look, we are debating rebuilding vs. replacing.

As for the engine itself, we did a leakdown and the results are pretty good. Cylinders 1, 2, 4, and 5 are all between 2-3% leakdown, and cylinders 3 and 6 are at about 6%. Not bad for 100k and a **** ton of track use. (K tells me that my estimate of 40-50 days is implausibly low.) Is it significant that the front cylinders are marginally weaker?

Has anyone found any replacement catalytic converter options that don't suck and don't cost ~$2k? It's hard to imagine that old cats with this much oil in them are going to be that great, especially given that the car has had a fair number of catalyst insufficiency code issues.

993Porsche

Subscribed.


Ken

nrubenstein

We decided to go with new stock turbos.

At this point, the quick parts list stands at:
New stock turbos (BuyAutoParts.com via eBay - $2,250 shipped, no core! Sourced via WorldPAC from BW. I would swear that it was a pricing error, but the auction is still up.)
UMW Stage 1 Clutch
UMW Check Valve Kit
Kuehl Serpentine Evaporator (Pelican)
Bilstein B8 (Gert)
RoW Turbo Springs (Gert)
Front Protection Bar (Gert)
Reinforced Intercooler Tubes (Gert)
New Engine Wiring Harness - Kevin advises changing every ten years or so. It's cheap and the engine is out, so why not?
MPL Tuning Slave Cylinder - we are converting to an unboosted clutch as K *hates* the boosted setup with fiery passion, so hopefully this will improve the feel.
Wrightwood Racing VC Gaskets
And, well, a *very* large collection of ancillary parts from Pelican, Gaudin and RM European.

It's really amazing how much the "while I'm in there" bill adds up to.

nrubenstein

Now *that* is shiny.



It's pretty safe to say that the old one was done:



Now if I can just get that ****ing oil filter off so that I can get the wiring harness out, that would be peachy. It's stuck on there and shredding instead of coming off.

ronnie993tt

Maybe dumb question but if there are guys on this forum approaching 300K miles without replacing any of this stuff, isn't it a bit over-kill doing it at 50K miles?

nrubenstein

To be quite frank, there is very little on that list that wasn't needed.

The turbos were trashed, and rebuild quotes ranged from half to more than the cost of this set of new ones. Why bother at that point? There is a collapsed lifter that might or might not come back with the car running for an extended period of time, but why would I not spend the $400 now and do it while it's easy? The stock evaporator has a massive leak - charge the A/C and it blows freon in your face for about ten minutes. The intercooler hoses have holes where the clamps crushed them. And as you can see, the clutch was trashed.

The biggest "why not, I'm in there anyway" item is the wiring harness. Thanks to the recall, that's $120-130. I mean, the suspension bits are not *technically* necessary, but they will be nice to have.

Also, the car has nearly 100,000 miles, has been topped out at the salt flats, and done a baseline minimum of 50 track days. K thinks the total is actually a fair bit higher.

Quadcammer

a ton of this depends on use and to be clear, the member with the 300k mile turbo had his engine replaced at 250k.

I believe he also uses it as a daily driver, which is likely easier on it then doing a bunch of track days.

nrubenstein

And isn't his second engine trashed?

nrubenstein

Changed out the lifters and reinstalled the intake manifold today. Surprisingly, none of the lifters were actually collapsed. Instead, all but two had completely destroyed o-rings. More interestingly, two lifters were completely missing their o-rings. Does that ever happen?

Tomorrow, I'll probably spend some quality time working on the shell. Rear shocks looks a fair bit easier to do with the engine out and the foam also needs changing.

chsu74

Contact FD Motorsports for 200 cell CATs. I have them and its great.

nrubenstein

FDM no longer is selling cats.

Right now, the least expensive good option is HJS 100 cell inserts from Gert. Given that the (parts only) spend for this job is $12-13k, we've decided to leave the cats alone and see how they are - I scoped them out and they aren't blocked at least. Changing them afterwards is pretty easy with fresh fasteners all around. I give it maybe a 50/50 chance that they get changed inside a year, but there isn't any harm in trying.

nrubenstein

A few pics...

Very clean inside the cam boxes:


Torx T-45. When you have a stripped 6mm hex head (this one was holding a turbo oil sump on), hammer this in instead. I've used it twice now on completely stripped bolts and it solves the problem handily.



New foam! (The glue is drying in this shot.)


Sadly, the rear shock mounts were cracked, so I couldn't reuse them. Once I have those, plus a few odds and ends like new wastegate actuator hose, the engine can go back in. On the plus side, I'll actually have the injectors back from the rebuilder, so I won't have to reinstall them from the top.

ronnie993tt

OK, I get it. Heavy use. Thanks. I think the 260k miler was California car and slight issue with cylinder 2 resulted in failed emission. As I recall, move to Nevada where it would not have been an issue was out of the question.