red964.com

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cobalt

A 66hp increase at the rear wheels? What amount of increase do you attribute to the cat bypass vs. the remapping? What torque numbers are you seeing?

red964.com

A guestimate would be 350-370Nm. The rolling road printer was broken so we couldnt get a print out. As soon as we get some printer ink we can post the proofs.

s

red964.com

Quick Reply to test sig,

joey bagadonuts

Steve,

Are you using the standard 15% loss factor to determine bhp? i.e. 251 rwhp equals 295 bhp

cobalt

The people I have spoken to insist the 964 turbo drivetrain is more like 18% loss it may be only 15% for the NA cars.

So 295bhp would be approx 360 fwhp using 18% or 347 fwhp using 15% loss. So you are seeing between 66 and 80 hp increase at the flywheel depending on actual drivetrain loss. You are actually seeing numbers that resemble the turbos of the time in Hp.

I am interested in seeing the charts when you get the ink. These are very impressive numbers.

red964.com

Ive interogated Colin (the Ninemeister) and he says our dyno is about 12% on the C2 calculations. The 295bhp is flywheel calculated so 259 at the wheels compared to the std 250 (fw) / 220 wheels - ( ithink )

cobalt

This changes things conciderably. I have always known bhp to mean brake horse power or at the wheels. I think 12% is very low drivetrain loss. When you get the calculations let us know the exact numbers.

joey bagadonuts

Close. Brake horsepower and FLYwheel horsepower are terms used interchangeably. "At the wheels" refer to dyno results measured on a chassis dyno (roller) and usually expressed in rwhp values.

To determine the bhp, you need to pull the engine and measure its output with an engine dyno. I'm not sure Steve has that ability (or wants to go to the trouble) but obtaining results from both dyno types for the same car is the only way to determine drivetrain loss for THAT particular roller.

Due to varying dyno designs, drivetrain loss will vary. Their real value is to measure before and after results for the same car under the same climatic conditions. In an absolute sense, dyno results are not as meaningful as you would hope but they are certainly helpful in confirming performance gains or losses.

So Steve, what were the before and after rwhp numbers?

tonytaylor

Ninemeister answered a lot of this in his repy on this thread here

garrett376

Sorry for the ignorance here, but is "remapping" with regards to a different chip in the DME to manage the fuel and ignition system? Are you selling a chip that does this, or is there more to it?

Impressive gains for a chip replacement, if that's what is going on here!

garrett376

And to beat a dead horse, what's the drivetrain loss average of a C2 versus a C4?

ian c - u.k

he means replacing the chip in the dme with a programable one , then reprogramming the fuel and ignition maps to suit that particular car .
as apposed to buying an off the shelf tuning chip made to suit every 964 , and fitting it to your car

garrett376

got'cha - thanks ian. I am surprised there would be that much variability between one C2 and another, for example.

And about the drivetrain losses, I believe Joey B. said 15% is for a C4 - so 12% is a C2?

Christer

why don't we just talk rwhp? from 220 odd to 250 odd is apretty good gain for a rechip...