Quote: Originally Posted by
Ondonti 
Chuck, isnt the 67mm near choke flow at our altitude? If you think it can go higher then no complaints here! Engineer mike claimed something like only 60lb/min flow potencial at our elevation even though its 75lb/min at sea level.
As intelligent as Mike is (and don't get me wrong, I wouldn't even dream of challenging him to a physics competition), I think sometimes he may read into things a little too much. There is always some variable that may not be taken into account.
With 32 PSI, I'm only using 80 - 82% duty cycle from the boost controller. I would have gone higher on the boost, but I'm already scared enough as it is to continue running it at 32 PSI. I'm certain that I haven't run the turbo out of steam yet, as you can see by the dyno graph, the drop off in power is minimal, at the very worst!
If I were dropping power significantly before redline, I would agree that I was at the limits of the turbo. But being that it is maintaining a steady curve that minimally drops off right at the redline, I'd have to say the turbo has at least another 50 HP in it!
Going from 28 PSI to 32 PSI yielded a 80 HP gain over my last dyno session. That's a gain of 20 HP per PSI. Granted, some of the power could be attributed to the E85. But I have a hard time believing that pushing the turbo another 4 PSI couldn't at least yield another 50 HP or so. That would be a return of 12.5 HP per PSI.
All this is only speculation, and only time will tell. But when it comes right down to it, I'd have to say this setup works VERY well and efficiently, and will be even better when I can extend my redline into the 8k territory. If I'm not satisfied with the turbo alone, there is always the option to top it off with some spray! And if that doesn't do it, it's on to a T4 footprint!
