To sum up all of the posts here and to make a long story short, the 3.9 has no potential.
I wrote about four !@#$#@! paragraphs last night to answer this post and the next several below it and the damn site sneezed and burped and it all went to the internet limbo in the sky. So here goes one more time:
If you look at my thread in the HP section, ( 'Land Speed LS') you'll discover that I used an NX Pro 400 'spray-and-Methanol' system to set three records in E/F CC and one more in E/F SS at Maxton NC in ECTA competition. It took me all one season of driving the 760 miles each way each month to finally get it done. (We did trailer it after the first two trips.) I discovered that setting records is not simply a matter of bolt-on-and-go.
I flogged it unmercifully, trying to get past fuel pressure and ignition problems and went three months while never making a clean-running pass down the mile. I'd started with a mish-mash of parts I had on hand and ultimately had to start again with all new components. My thanks to Sponsor NX.
During the time I was 'playing' I tried as much as a set of 175 HP jets in an attempt to clean out and run smoothly. I ultimately set up a dedicated methanol system with a fuel cell in the trunk complete with its own pump and filters and a pressure regulator on the firewall in the engine compartment.
When I first set the record, I was running a pair of pills in the range that should be producing about 125 HP. I set the record, came back around and changed the methanol pill and raised the record a bit. I did the same thing again and raised it further. But at that point I ran out of alcohol pills---the next one I had was 8 steps richer and I didn't try it.
Instead, I drained the methanol and rejetted the fuel side for 116 race gas. I set that record---E/F SS---as well and then ran out of time. Since ECTA racing has now moved to Ohio, the Maxton records have been frozen And I'll hold them forevermore. And nobody's gone faster in Ohio---at least yet. All this was done with production 3.9 internals.
The car was bought new and now has a little better than 150K miles on it. Even with all the flogging I have given it, it doesn't burn oil between changes. Not too long ago I got 26 MPG on a road trip.
I have a 4 litre Jag engine being readied, very slowly, to go in the car, with internals spec'd for the pair of turbos in a box on the shelf. Parts include Ross pistons, GRP aluminium rods, and a Moldex crank. The combo is intended to make it possible to use the turbos along with the NX spray/methanol and set a new record in the blown version of the class in ECTA competition in Ohio. And continue to use the car as a DD.
KS