Wow

 

It really does make 284hp, however it makes less torque than a authentic 9444 turbo. If this car was priced less and already on the mainland, I'd go for it.

 

i wonder what gearing they're using?

unless my speedo cable is wonky, on my stock-size tires i can do 65 in 2nd gear.

 

And funny as it is, I used IHI KHF5 turbocharger. I have a topic about my car also in that forum, there's dynosheet also.

 

How would you explain the large increase in HP over a stock 951 which has well over 10 PSI boost? (question not directed at anyone in particular)

 

manifold design, turbine design, engine management...

a fully free-flow exhaust would explain the difference in torque

 

Different compression? Probably wouldn't make that large of a difference though, but everything adds up..

 

It says the compression is 8.0 -1 and Isn't the 951 8.6 -1 that may account for the lower torque. Lets not forget if Callaway is doing car he will make the car as fast and efficient as possible. When Porsche makes a car the performance, price etc, needs to fit in with all the stable mates. Think if in 86 they came out with a 300 hp 951, That would have taken sales away from higher priced cars.

 

yea callaway had more money disposable per car because it wasn't a mass production thing.

 

So 24 years ago Callaway had better engine management and better turbo efficency that we are using with all the modern aftermarket stuff we're using today? I don't think so. Were they advancing the timing more to get that much power at 10PSI?

 

compression ratios are the same - both 8.0:1...the cam used in the callaway is the stock 944 N/A cam, also the same cam for the Turbo S, this explains the later torque and partially the higher horsepower. Also, stock 944 Turbo max boost is less than 11 (.75 bar), Turbo S is 12 (.82 Bar). I would say the log manifold partially explains the difference in torque from the callaway to 951. It is not as good a design.

 

It's done with the timing and hence the knock sensor circuitry that NA originally didn't have.

And as for maximum hp, Motronic is almost as good for that as aftermarket ECU, most important thing is tuning it. I'd rather not use Motronic today, but everything can be done.

Callaway installed bigger injectors also, so almost every important aspect of raising power is served.

 

they may also have done some head work, cleaning things up a bit while keeping the same displacement

 

... the other thing to think about is that although HP has been upped substantially and the torque almost as much, this seems to be a STOCK 944 suspension-and-structure-wise. In reading the historical literature attached by aribop, Callaway doesn't appear to have upgraded the undercarriage or brakes the way the 951 was. Not optimal.

 

i also feel fairly confident that callaway was not particularly worried about all 38 cars being independently dynoed by customers. i'm not saying it didn't make 285 horsepower, but it's possible that it was overestimated for impact. keep in mind, if i remember correctly, that porsche also often underrates their cars' output.