ltusler

Excellent, thanks!

speed rII

My 3.4 c2 man. had about 17% loss. 255 on the wheels and calculated 300 on the flw.

That 12% seem's optimistic

So flw hp in Hardback's car is some where between 366 and 382.
And the torque that the 3.8 make's, must be fun car to drive

NZ951

Do people bore or stroke the 3.4 motor as a rule? Or just find a 3.6 or 3.8 to start with?

Hardback

LN rebored my 3.6 to a 3.8. They also supply JE pistons and rings with each cylinder upgrade. Go to LNengineering.com, they have plenty of info and explanations on their site. My motor was damaged by a valve seat which resulted in a cracked cylinder. This is why I upgraded.

logray

Yes but you also have the same old tired pistons and cylinders and only a partially rebuilt motor.

Carey's engine is pretty much brand new, cylinders, pistons, and all... I'm betting it's closer to a 12-13% number, or at least maybe once the rings are fully seated.

speed rII

Car was dynoed before rebuild. And the dyno did the calculation's.

logray

I've read from a few dyno shop owners that "tired" C2 996's typically fall in the 16-17% range, and the "fresher" ones do a little better.

speed rII

I think that we are talking about diffrent thing's.

Dyno measures the powerloss that the trasmission and rest of the powertrain causes. It has nothing to do with the engine.

After the dynorun clutch is pressed and dyno measures the drag that is caused by the powertrain. After this flw hp is calculated.
Lot's of different thing's affect's this, tyres, tyrepressure, etc...

sorry OT

logray

Yes I think you are right, we are coming up with the same figures so I think we are saying the same thing, just coming about it in different ways.

Your taking the at the wheels and working backwards (which is how it is actually measured).

I'm quoting average drivetrain loss (negative percent) to calculate FW hp. So flywheel incl condition/running of the engine (compression, etc.) then subtract a percent for drivetrain, tires, etc, etc, etc. These are all just guesses and quoting figuresl, of course the type of dyno used makes a difference.

Carrera 2= subtract 12-14% (new, well tuned/good compression)
Carrera 2= subtract 15-17% (tired, poor tune/poor compression)

Carrera 4= subtract addtl 4-6% unless FWD decoupled
Tiptronic= subtract addtl 2%

seanmcr6

This thread is useless without PICS!!!!

Hardback

Sean... Yeah, Ive been waiting for them myself. Hopefully Ill have some to post for you guys today or tomorrow.

How is your research coming for LSDs? I emailed Guard but no response yet. I'd like to know if the diff in our cars can be rebuilt or do we need to buy a new LSD? Price for either situation etc.

seanmcr6

I've put my quest on hold....new gf....bye bye money xD

jumper5836

Hardback did you stay with the same cam shafts?

Thinking of going the same route this winter while my car is still running but going through a 1l a week in oil.

Hardback

Yes, stock camshafts. The motor is still very potent with a noticeable impovement in torque.