Engine/Transmission (1998.5 - 2002) PDR Dyno & Drag Comp Wierdness...

[DEZLPWR]

After my PDR dyno run, I was puzzled as were others, that my peak HP dropped off after 2500rpm. This should not have happened as I have a Drag Comp. First thought was that my Drag Comp was not working properly, but after further investigation and a few phone calls today, I am thinking that somehow, the way my truck was dynoed had something to do with it. I was told to find out whether or not it was working correctly, that I should be on 5-5 in 4th @ approx. 2200rpm's and mash the throttle till redline. I did that, and besides almost giving myself whiplash, (hehehehe)it pulled HARD all the way to redline, which was almost instantaneous... I felt NO defueling whatsoever! Fuel psi did not drop below 12psi, boost was 40psi, EGT's went to 1300* in a hurry, but not past because I was at redline and 100mph and had to back off.

While some members (Diesel Freak & Racer57) had "normal" Drag Comp looking graphs that were flat from peak HP to redline, mine was not... . Apparently Edge had some other calls from those who dynoed @ PDR who were questioning the effectiveness of their Drag Comps because they also had graphs like mine.

Anybody wanna comment on what may have been causing some of the graphs to show HP dropping with the Drag Comps????



I am keeping my Drag Comp because it is definitely not defueling on the road. On the dyno, well, who knows what was going on!



Please note: This is DEFINITELY NOT BY ANY MEANS a slam on PDR or Jason Burton (who drove my truck on the dyno), as I have the utmost respect for both Jason and the whole crew at PDR. They, in my mind, are simply the best there is!!

Just hoping that I can get some feedback as to what may have went on... .



Thanks!

 

[willyslover]

maybe they selected the lower RPM in error on the print out as the operator selects the paramiters for the graph as to the RPM... . ??? does your print out go farther than 2500 RPM or just a straight line down ?