Much of the ductwork on the P-47 had more to do with where the turbocharger was located than anything else. You can get away with less or no intercooling with a mechanical crank driven supercharger, depending on how efficient it is. But without an intercooler on a turbocharger you have to reduce boost by about 50%, unless you use chemical cooling (like the methanol injection I use, or the propane injection some use).
If you were to mount the intercooler by the firewall, you'd KILL efficiency. an intercooler really has to have a great deal of air flow to be effective, AT LEAST as much as a radiator. Mounting it behind the engine and between the engine and the firewall would reduce efficiency a great deal.
I don't know how much the cooling system/intercooler change would help the P-38, but it likely wouldn't hurt.
I agree, it wasn't really that the cooling system on the P-51 made it faster, it's just that it created the least amount of net loss.
The last P-38 raced at Reno that I remember is Lefty Gardner's "White Lightning" (since sold to "Red Bull" drink corporation), and it is VERY stock. In fact, it uses, or used, stock surplus engines right out of the crate. The last time I saw it the turbochargers were not mounted, just the shields and covers were there. It also is set up as an early type recon plane with the low drag cowls. From what I understand, the "modification to "White Lightning" is only that it was converted from a late model P-38 recon plane to an early model. That's what I was told and saw evidence of, it may have changed.
IF that is indeed the case, then it cannot have the turbochargers on it, because a late model would not have the ductwork intercoolers in the wings, and the plane cannot have the core type intercoolers in the chins, because it has the early chin which has no room for intercoolers. It also did not have the sound that the turbochargers give, it did not sound anything like "Porky II" or "Glacier Girl". It is my understanding that "Glacier Girl" is the ONLY early model to have flown in several decades that DOES have operational turbochargers.
Best I remember, no one has raced a P-38 seriously with any sort of budget in at least 30 years. They are far too rare and too expensive, and racing one would be very expensive, you need twice the amount of parts. I think Lefty hit 399MPH a few years ago, with a stock, unmodified P-38. It could be done, and made to be very fast, but you need to spend enough you could buy "Dago Red" (was the fastest P-51 at Reno the last few years) and all the spares, plus a complete back up plane that would be fast enough to get to the "Silver" Unlimited race.
Lad Gardner, Lefty's son, put "White Lightning" down in a cotton field in Greenwood Mississippi about 4 years or so ago, maybe more, because of a carburetor fire. It was towed to a hangar and set back on its gear, but they couldn't raise the funds to repair it, so it was sold. That's the only P-38 I've heard of making an emergency landing here in years. The others were all actual crashes. About 15 years ago, both engines on the CAF P-38 quit on takeoff, and it crash landed, both people on board were badly hurt, and the CAF has made no progress in repairing it that I'm aware of.
