Mike J

Both cars came with dual mass flywheels.

The Turbo engine, while based on the M64/05 engine, had a number of upgrades:

- at the bottom end the rod shanks were stiffened (so yes stronger rods)
- higher volume oil sprayers
- coated skirts on the pistons with lower crowns
- oil pump scavenge side doubled in capacity
- cylinder heads deepened by 5.5mm and hold downs strengthened
- Blower speed increased by 15%
- forged cylinders with machined fins

(from Excellence was expected)

The crankshaft is the same on all the 993's.

Cheers,

Mike

mausone46

I remember the german car magazine AMS back in 1995 Testdrove the 2wd, 4wd and the turbo, they came to the conclusion that the 2wd was the best 993 for the money, not just because of the price difference, but because his lightness compare to the turbo and the fact that beside his mighty power the Turbo doesnt not delivery more porscheness than the 2wd
I hope you understand my english and what I mean

DRPM

thanks Mike.

How do they lower the compression ratio on the TT vs the NA....is it in the heads ?

also worth mentioning there is single plug on TT vs twin plug on NA.

Mike J

Increased room in the combustion chamber - lower crowns on the pistons, and the deepened cylinder heads. Stroke and piston diameter is the same (100mm x 76.4mm)

carguy19

The pistons are dished vs a basically flat top for NA motors, I actually have one in my garage, I will post a pic as soon as I can get there this week.

The dish gives a larger chamber, I did not know that the head side of the chamber was larger, I knew it was different because of the single plug vs dual plug, you learn something new every day.

Leica 993

The 993 Turbo has a direct, bloodline connection to the 959, get the Turbo.

chsu74

How so? Care to elaborate?

LexVan

Yeah, that's a bit of a s t r e t c h.

911PERVY

Yes, crankshaft and con rods are the same for all models

Leica 993

I think it's safe to say the 959 is certainly the father of the 993 turbo. 993 front end design & similarities to the 959 are evident. The AWD system, 6 speed gearbox and bi-turbo, though in different arrangement, all have links to the 959. Peter Schutz, having saved the 911 from extinction, and professor Helmuth Bott collaborated on the AWD system from the beginning of Group B days and in the 993 turbo, went back to the 959 layout instead of the 964 three diff setup. No, they don't have the same parts book but I think the connection is evident, from a design philosophy (especially front end) and a performance benchmark. Internally, if I'm not mistaken, the 959 was given a 911 project code with a special identifier, it wasn't a complete skunkworks operation.

Quadcammer

huh?

One has water cooled heads, sequential turbos, and a three diff setup (from the 964).

the other retains air cooling entirely, non sequential turbos, and a viscous coupling.

Ok, the head lights are similar. Thats about it.

LexVan

I don't know.

chsu74

Hmmm. No

Leica 993

Ok, both are 6 speed, twin turbo all wheel drive Porsches with slightly similar headlights.

MarinS4

Crankshaft yes. Conrods no.

Source? I've been inside of both engines.

Piston/cylinder/head material is the same. Basic "block" is the same.