ca993twin

Other common failure points on 993s:
leaky steering rack
corroded fan resistor gizmos
broken odometer gear
clutch accumulator (turbo only)

I don't think heater motors are a common failure. Clutches are not common a failure issue but the lightweight flywheel is a common modification. Turbos that are properly cooled and not "flooded" with oil due to the incorrect oil filter can last a very long time. Upgrading is a popular modification.

wsf80

what type of turbos are car used in an upgrade/modification?

ronnie993tt

Make sure you check with Flat Six Innovations before you do any exhaust, flywheel or engine mount mods. You can actually loose quite a bit of power with this stuff says their data. I'm a bit of a purest - oil supply lines with check valves, billet Al diverter valves and Renline pedals. Will eventually do PSS10 when I see a bit of a deal. That's it.

Carrera GT

Aargh, how did I forget divertor valves. Definitely must be done, but just be careful to get a good quality item. Not all the billet valves I've seen are good, some were just plain crap. These things need to be high quality, not just shiny CNC and a poor quality valve seal.

Definitely look at coilovers. Most everyone is happy with the PSS9's now 10's. This alone will transform a 993 to a seemingly impossible balance of ride comfort and superior handling. The crappy $10 Boges and Billi's as factory issue are just horrid junk. I look back at reviews of the 993 and can only imagine (including the 996 GT3) how much better the reviews would be if Porsche just offered a simple $1000 upgrade on the price list to get decent coilovers.

As for losing power, on a turbo, the headers are pretty much perfect and unbeatable, but yes, dicking around can cost power. The flywheel won't cost power if going to the lightweight item, afaik. As for engine mounts, there are some issues with solid mounts in later model 911's, but I'm not aware of any issue in the 993's. It would be great to learn more about this if you care to share.

I run a semi-solid mount, I think from WEVO, but I forget off hand. I had no need for a solid mount, I just wanted to discard the factory hydraulic things. I have a reinforcement plate for the transmission bracket too, but the mount is semi-solid.

nrubenstein

What makes the new diverter valves better? I've seen at least a few reports suggesting that at least some of them also lead to blowing off charge pipes...

Carrera GT

The factory diverter is plastic, and approaching 20 years on the car. It was "okay" at 0.8 bar, but probably tended to leak some pressure. They're in a knuckle-busting position on top and it's just a great, quick update with the engine accessible. As for aluminum billet diverter valve products, it's probably overkill, but why not? The CNC process just means a durable, precise valve. If I was going to swap them out today, I'd probably look and see what Porsche is doing on cars like the 997 GT2 RS and use that part, if applicable. Perhaps there's something on a Cayenne Turbo that would be beefy and durable.

Carrera GT

There's a small selection of ways to go. The most straightforward "settled science" is to retain the K16 factory items and get them rebuilt by a reputable shop. Someone like Kevin can improve the compressor side and there's various stages of upgrades for different levels of performance (and budget) ... just read the sticky "Admin" threads at the top of this forum on turbo fail and turbo removal.

A couple of companies offer aftermarket alternatives using Garrett turbos because ball bearings instead of bushings allow the turbo spindle to spin more freely and spool up pressure more quickly to reduce lag. It will take a few searches, but you'll see some companies and products advocated here.

It's been years since I looked at alternatives, so I don't want to give you stale information. Once you do some research and talk with a few companies mentioned here at Rennlist, I'd suggest coming up with one or more plans and then post here to see what others have done recently and what they'd recommend.

You can certainly take the stock 993 turbo to 500hp/500lbft without overstressing the engine internals, but much beyond about 520hp and things break. AFAIK, there's no way to get up to "serious" horsepower (700+) without serious money and I don't think it's incremental -- you either go whole hog and have the engine fortified for the increased torque, or you have a grenade under your right foot and it's just a matter of time before you kick the pin out.

It would be great to have others comment on local 993 turbo experts in their area. I'd like to find someone local in the San Francisco Bay Area with a solid reputation for building stout 993 turbo engines developing 700+ horsepower.

th20100

concerning The factory diverter is plastic, in France it is quite common to replace them by AUDI S3 diverter

also in platic but stronger and nearly same price than stock one (means lot less expensive aluminum one's), no spring adjustment to check, simply plug & play, to be changed every two year (at that price no problem) before they fail.


anyone can give me the reference for Wevo mount, i know that i have to get longer bolt (as AWD) but i'm not sure about exact reference as on website they stop year model to 1989, when our 993TT start at 1995

Slate993tt

[QUOTE=th20100;11081409]concerning The factory diverter is plastic, in France it is quite common to replace them by AUDI S3 diverter

yep, its a Bosch 710N.