Time to bring this thread up to speed, since it really is the place where I document the car...
Since we last spoke, first this happened:
Dropped valve thread
and while I was repairing that, I started a thread on Accusumps here:
Accusump Plumbing
and during this time a few other things changed too. Below are the highlights of the new engine combination:
- LS7 Block, honed to 4.127"
- Callies Dragonslayer 4.000" Stroke crank (from the 402)
- Callies Compstar 6.125" Rods with 2.0" journals (from the 402)
- Wiseco pistons with 4cc reliefs (~12:1 CR)
- TFS GenX LS3 heads, custom ported by Frankenstein Racing Heads
- Custom cam by EPS (238/248, .629/.604, 114)
- Morel 5315 lifters
- Edelbrock Victor Jr. L92 intake, ported by FRH (plenum and port match)
- Rocker arms upgraded with Harland Sharp trunions
Those were the big changes, lots of other little things in there too. And while I had it apart, I replaced the clutch also with a Monster LT1-S, their custom-flywheel which uses the new LT1 twin-disk clutch pack on an LS engine.
As noted in the thread above, it was a session of thrashing to get everything together and back into the car and get her ready for the Spring GG event in Fort Worth. I was bolting on parts until late the night before I drove up. But the drive went well, and TOW performed excellently! I finished 3rd in the Street Machine class. The newfound power definitely helped. The driver needs more work though.
This past week has been another thrash session to get the car ready for my first USCA event this weekend. One of the things I have been wanting and needing to do is to have the car dynoed and then tuned. I've had trouble finding anyone who seems to specialize in the Holley HP EFI systems, but I did locate someone about 2 hours from me last week. Turns out he had a slot available on Thursday, which fit perfectly into my schedule as well. So I drove over to his shop and spent about 4 hours between the dyno and street tuning.
Jumping straight to the good stuff, since everyone loves pictures and results:
Ignore the red line, that was a timing experiment. The blue line was our final result: 541 HP and 502 ft-lb of torque. Those numbers are through my T56 Magnum and a set of 3.89 Ford 9" gears, which apparently cost a little power. Also this wasn't a DynoJet, but instead a load-bearing DynoCom setup. What I do know is that on this run, she actually laid down 568 HP, but the SAE correction factor brought her back down to the 541 number. Stout!
What I am really enamored with though is that torque curve! It's almost exactly what I had asked for when I had discussions with the various people that contributed to my parts selections. It's broad and consistent, and you can feel it in how the car pulls through the gears.
He attempted to pull all the way to 7k RPM, but for whatever reason the dyno wasn't correctly capturing those last few hundred rpm. You can see how the curve doesn't roll over immediately, but instead carries the power. It's great!
Before taking the car to him, I have done a lot of reading and research on tuning the Holley. I've also worked hard to try and set my fuel and timing tables. Interestingly, he reloaded my tune at the end and did a pull to see how it compared. I was at 532 HP and similar torque to the final runs, meaning my tune was pretty close to his final result. That was pretty cool.
After we dynoed, we drove on the streets for about 45 minutes with him dialing in different areas in the tune. He leans the car out quite a bit, added some part throttle timing, and cleaned up a few other things. I kind of expected him to do work on some other areas of the setup, but he didn't think it was necessary. I do still have some cold and hot start work to do, she doesn't always start right up like she used to with the 402 for some reason.
I drove back up to Fort Worth today with the new tune. The engine definitely felt smoother during the drive with the timing and leaner tune. I also picked up some mileage, a little over 2 MPG vs. where I was. I still don't think I'm optimal there yet, so I'll work on that some more. But that's no small improvement in its own right.
More to tell, but I need sleep now for tomorrow. Just wanted to get these out there to share.