Umm,
I was one of the few that stay'd on topic, I think. Ill post it again since it is unclear to me if my post questioning the dyno #'s is off limits or not. I would hope not....Ill tone it down it dowm a "tad".
Im always curious when reading dyno charts. Especially with cars I have some knowledge of.
Upon further review of those dyno charts, I don't believe them.
While Im sure that Ken spent a whole lot o money, the hp numbers and boost levels don't add up, not even close at the "baseline of 7.5psi" levels for sure.
First, 7.5psi makes 565whp Hu, hows that. Are we runing full race cams(1500rpm idle) and 114 octane race fuel.
By pure math, (14.7+7.5)/14.7=1.51 pressure ratio.
So NA hp is 565/1.51 = 374whp.
Next, take that 374 # and apply some more common sense. We know that straight math doesn't work here, as heat and pumping losses take hp away. Lets be super conserative and say 10%. 10% is very conservative even with the best IC in the world, water or not.
374whp *1.10= 411whp.
Were still not home yet. That would pressume that the CR is still 10.5:1. But this engine is not, its 8.7:1. So thats another consertative 10% loss.
So 374*1.20= 448whp. Man, that is one stout S38, even in race build with 114octane.
Next, Duke mentioned a T66 turbo....Mmmmm
If he makes 707whp, that nearly 831hp crank. To make 831crank, the turbo needs to make at least another 8% more air to overcome pumping losses and heat,
831*1.08= 897hp.
Thats ~90lbs/min of air. That compressor map can no way support that much air. Its off scale. If the boost level was higher, again, I could believe it since that changes the operational area of the map. We know that with larger turbines that compressor map will build out to the right to cover higher air flows.
With my limited amount of info, it's not adding up. I may be wrong here. If he said he was runing 20+psi then I can believe it. Otherwise, I need more info.
Umm, as a data point, let us not forget "The Beast". This was Rob Levinsons E28 ///M5 that was purchased from a gent in Canada. This was a "no expense spared, open check" build also. $20k in parts(remember, this was 1990 dollars, inflation adjusted would be well more than $35k now) was spent on the engine alone using all BMW Motorsports parts. Extensive work everywhere. In its orginal form, the engine made between 550-600hp. That was with ~16psi. The turbo was sized down to limit the engine to 500hp to increase reliability. So your telling me Kens engine makes 231hp crank more with less boost then that one with mostly just different intake, turbo, ECU and some other bits?
If so, OK. Id really like to see some more data on the car.
If this post is out of line, PM me and Ill delete it, fall in line with everyone else as say "Great car", which it is.
RussC
