Let's see, I dynoed my GT3 stock right after breakin and it was 348 rwhp on a mustang chassis dyno. Others I have seen have been 350, 352 ect. You get the idea....
With my Europipe/filter I expect 360+ rwhp when I dyno it again 4/16....

 

The Mustang Dyno historically shows 5 - 7 % higher than other dynos. Put a stock 1999 C2 on that dyno and will will show 270 RWHP rather than the normal 253. This in iteself doesn't matter because all dynos are a calculated result. (Some are not SAE numbers) What does matter is that if you are looking to make imrpvements to your car and see accurate results, you must use the same dyno and setup for comparison. It doesn't matter whether the starting power is 800 RWHP or 200. The percentage change matters.


A bench tested engine showing 380 HP that is put in a Porsche will have more than an 8% drivetrain loss. I guess I should have my car dynoed on a Mustang so I can show that I have more than 460 RWHP in my little old 996.

 

Where is the proof for that statment ???

 

What other dynos? Dynojet? It's just the opposite.

A Mustang Dyno requires that you enter a weight for the vehicle and then provides a resistance throughout the entire run, simulating wind resistance. For this reason, it is an excellent tuning device but its no good to put down big numbers. Once a car begins moving, there is less resistance at the wheels when you overcome the polar moment of inertia, but the Mustang Dyno keeps applying this force acting against you. If you were on a Dynojet you would only have to overcome the polar moment of inertia and then you'd have nothing but BIG numbers. The Dynojet will generally put down another 10-15% more whp than a Mustang Dyno.

 

I'm not getting into a pissing match with you. As far as chassis dyno...they are nothing more than a tool for tuning. They do not show accurate WHP and can easily fluctuate by changing various input parameters like pressure, temperature altitude, etc. Some even have a vehicle weight parameter which is aboslutely absurb sicne vehicle weight does not effect HP.

Like I said before, f you want to use a dyno for tuning, it may work fine for you. But unless you are racing someone else on a dyno, they are useless in determining actual power to the wheels. They are an mathematical estimate only.

 

well I disagree with your rwhp assesment of the GT3. Perhaps your figures are closer for the 1999 Mark 1 GT3 variant...anyways, not interested in a pissing match either...What it will do for me is tell me the power increase my car has with the addition of a new exhaust system. I already have a base stock dyno from the same machine at the same place....

 

That's the way to do it. Then compare what happens to the numbers after the mods. Take a close look at the low end torque number after you change exhausts. If you are going with a more free flowing exhaust, you should see the bottom end torque decrease. Also get a printout of all the parameters used when dynoed. I have seen many shops adjust the air temp and pressure inputs just to show bigger numbers.

 

Good info. Thanks

 

My friend is a mechanic at Ferrari (Maranello up here). He has told me the 360's normally put down between 300-320whp depending on the dyno. So maybe its not drivetrain loss, but Ferrari lying about the numbers. Wouldn't be the first time a manufacturer has pumped up the numbers of its cars to sell them. Then again, maybe they just have an extremely parasitic transmission/driveline, who knows.

 

Would you like to put your money where your mouth is? Several people on Fcrap dynoed their CS's, all in that same rwhp catagory.

 

nah, i wouldn't. that would then be a bet on ferrari truthfully reporting their hp. my "mouth" was simply stating there is not a 25%+ drivetrain loss. i probably would bet you wouldn't find that sort of diff between a crank and chassis dyno of the car though.

 

Ferrari overrates their HP, and underrates their weight. As i have said in the past.

 

ya, but youve also said a lot of dumb **** in the past.

 

For the haters...heres the dyno sheet !