Does anyone know the specific engine differences between the 91' 965T and the 92'/93' Turbo S? Has anyone performed the mods to their cars in the past? If so, what was a ballpark cost? thank you for any help that might be offered.

 

Why? Cheaper and better mods are available.

 

I was looking for bolt ons that would be CIS friendly. The 1.0 BAR spring is an obvious choice so the specs from the Turbo S would be helpful because thats the spring i believe was used in that motor. Which mods were you speaking of?

 

Search this forum. The differences between S and non S models were far more than bolt ons. If you were going to try to recreate an S it would be cheaper to do EFI and bolt ons instead.

 

Yea, thanks for your help. If anyone would like to answer the original question it would be much appreciated.

 

Basically, heads, cams, boost, intake mods.

 

The Turbo S motor wasn't all that exotic. If I was tearing into my engine I'd go a little farther than Porsche did on the Turbo S.
Cost.
If the plan is to keep CIS, doing the Turbo S mods (964 cams, polished intakes, .9 bar spring; don't know why no one could type that instead of barking "do a search") is far cheaper than an EFI conversion.

 

I believe the clutch was also hybrid 964 turbo/RS.

 

I've personally don't recall seeing that written anywhere but there's so little info out in the public domain about the Turbo S engine anything is possible. For instance, one magazine said the S had a different spark advance scheme. Everything else I've read (and there doesn't seem to be much out there) never mentioned that.

I thing the most important aspect of the S was the chassis and what wasn't on it, making it almost 400 lb. lighter than a Turbo. I keep thinking "some day I'm going to turn my car into a Turbo S replica" but I can't bring myself to start stripping stuff off of my car.

 

FYI, I've never seen a street Turbo running 1 bar from the factory. I'm sure the reason is related to durability and warranty costs.

Absolute best bang for the buck:
*Send your WUR to Brian Leask and have him rebuild it. Do this before you stick that 1 bar spring in your car.
*Buy the upcoming RarlyL8 muffler (I have a prototype and it made a big difference)
* Make sure your recirc valve is operating properly. If it isn't get a new one.
*Lose the air injection (potentially big job but sheds 20 lb. of dead weight)
* If you have and extra $2500 at this point buy headers
The bonus to these mods is you now took 60 lb. off the very rear end of your car when you replaced the factory muffler, air injection and cat (subtract more weight if you do headers).
If the car isn't fast enough for you after these changes start saving for the crazy big HP mods.

 

For motor details see below;

Engine type: M 30 / 69 S
Exclusive Special Option No X33
Output 355 HP @ 5750 rpm
Torque 471 Nm @5000 rpm

Scope of modifications:
- cylinder head, inlet and exhaust ports modified
- inlet manifold modified
- modified camshafts
- valve timing (setting) 0.9 - 1.1.

Modified parts:
930.105.147.50 camshaft left hand
930.105.148.50 camshaft right hand
911.105.171.02 Spacer flange, left hand
911.105.172.02 spacer flange, right hand
900.105.172.02 Bolt, 4
N 010.183.1 Bolt, 1
930.113.025.03 gearwheels
N 013.349.1 roll pin
930.100.908.03 gasket set
930.104.043.14 cylinder head, 6

The cams were SC and boost increased .15 bar to get the ~380 HP over the X33 power.

 

I only say that because there was one having a clutch fitted by the dealer where I bought my 965. He had ordered a standard clutch and it didn't fit - he said it seemed to be a combination of 964 turbo and 964 RS.

 

Tjr, you've added to the knowledge base of the Turbo S

 

Thanks - it's pretty difficult around here as there is so much expertise on here already!

 

I am fortunate enough to own a Turbo S Lightweight. Some of the engine differences are the following, attribution to Mike Connell, although the lsit may not be exhaustive.

Engine
Engine type - M 30/69 SL
Displacement - 3299 cm3 (3.3 L)
Engine power - 280 kW (381 PS) at 6000 rpm
Scope of Modifications
camshafts
injection valves
no servo pump
no A/C compressor - possible with Z order 1555 (A/C system as special equipment)
single fan motor
polished fan ring and fan wheel
air filter housing and intercooler frame painted red
fan tensioner belt coated black

Much of the work went to the body, suspension, brakes - effectively the car is a Turbo 964 RS that is 400 lbs. lighter.