Originally posted by SgtPappy
Woops. My bad, I meant that I once heard a rumour that the P-38 could hit 444 mph in level flight. Benny once told me that the P-38L's engines were once tweaked to give off about 2,000 hp each... this output was not made by higher grade fuel I think... but just some clarification if that mod ever made the 38L go 444.
Not really the place for this, so I'll keep it brief. If you want more, search the forums, this has been discussed at length repeatedly.
The P-38L was rated by Lockheed at around 442MPH, verified by Lockheed test pilots and logs. The P-38L was equipped with -30 Allison engines with considerably more HP that the engines in the P-38J, however they did NOT make close to 2000HP each. The engines in the P-38L were capable of sustained operation at over 3200RPM, and at MAP of above 75".
However, the USAAF did not accept the Lockheed/Allison ratings, and in effect rated the P-38L at its military power level only, resulting in a rated top speed about equal to that of the P-38J-20-Lo at WEP, about 425MPH.
There is evidence that Lockheed and Allison engineers and representatives in the field showed 8th AF crew chiefs how to rig the P-38L for the full power rating, however, HTC does not model field modifications, for various good reasons.
The P-38J and P-38L were run on 150 octane fuel, but again, the USAAF did not allow the power ratings that the P-38 could have produced by taking advantage of the high octane fuel. At least not officially. The official ratings were 64" and 3000RPM.