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What diff ratio are you running? it seems like a 4.44 would be about perfect for there if you are running the 4.10 now.
His hp looks really good on the top end. Dyno chart ends at 7,600rpm, but hp is still way up at ~425rwhp if I am reading it right.
What I am getting at is he could increase the rev limit to 9,000rpm and go to 4.77 rear gear and still have the same top mph per gear as 8,000rpm rev limit on 4.1 gears.
Doing that with JDM 0.806 5th gear would get you screaming to ~140mph and then trail off acceleration in top gear to 174mph. Good for medium straights under 1 mile.
I have a 4:10 rear, and a short 5th. The 4.3 rear would be nice in some places, but I wouldn't do it without a 6th gear for street use.
For the 2:02 laps, I found that not shifting into 5th on the front straight as soon, and spinning 4th to 8k and saving the shift delay until after I crossed the line produced a time savings without penalizing the following lap.
Update, the mighty RX7 broke the transmission at Watkins Glen. Upshifting at 8k from third to fourth. Awaiting diagnosis at IRP, but I suspect main shaft broke. If that's the case, it'll be rebuilt with a liberty main shaft, a B2A trans pan, and eventually a dedicated pump/cooler. Also having them look at a turbo spool delay that is (thankfully) not the motor/low compression.
I was running 2:03s right out of the box, so that's the new baseline. Only got a session and a half, so the 2s were coming.
Let me know what Liberty says on the trans please. I called them to see if they’d sell the hardened main shaft separate which they will but said all of their current trans parts are for a Turbo II transmission and couldn’t guarantee it’d work in a FD.
So, I may have mentioned my use of Stage8 locking hardware on my Manifold to Turbo combination that makes it impossible to come loose, but isn't as tedious to undo as safety wire. My combo for that connection is, inconel studs, inconel gasket, and stage8 nuts. I wanted to bring that same level of security to the engine to manifold connection (which already uses inconel OE studs and gaskets), but there was noting for the Stage8 nuts to lock against easily. Here's the solution:
A 321 stainless flange that goes on like a washer, but has tabs on the end to bend up for the Stage8 to lock against. I'm working on making these (and a few other things I've cooked up) available for a reasonable price.
then went with an integrated filler neck/AST setup.
So @ptrhahn about that integrated filler neck / AST thingy... Is it working well for you? Do you fill it up to the top with coolant? I'm curious how that thing works. Also, where to get one...
I had a low compression motor (RxParts seals warped) going into Watkins Glen 2018, and broke the transmission in the first couple laps. Since I was down and awaiting parts, I decided it was time to uprade all the control and monitoring systems from tuner grade to motorsports grade. I wanted EVERYTHING running and monitored through the ECU, and a clean single monitoring source and not a bunch of disparate controllers, gauges, and circuits. So, the mother of all harnesses would be built.
The final setup took some troubleshooting, and we still need to figure out an inconsistent fuel gauge, but the end result runs amazing, and provides a lot more data. It made nearly 500hp at the wheels (dynojet equiv) at 20psi on the hottest day of the year in a sweltering dyno room, and I’ve got a nice safe 11.5psi setting for the track that still rips.
I’ll update with more details, but BIG, BIG thanks to Ihor, Paul, Brian at IRP for pulling this together, and John Renna for tuning:
IRP Stage 4 ported motor
Scalloped, balanced, lightened rotating assembly
Race bearings and oil pressure regulator
iRacing apex seals
B2A oil pan
Rebuilt Trans
Liberty main shaft
B2A oil pan
Radium Surge Tank, Walbro 450s
Updated Fuel system with larger feed and 1000cc primaries
Haltech Elite 2500 (needed more inputs than the 1500 had)
Haltech IC-7 dash w/ Drakes hood
Ludwig Harness w/ milspec firewall connector & running EVERYTHING through the Haltech:
Diff Temp (with pump trigger wiring not yet utilized)
Trans Temp (with pump trigger wiring not yet utilized)
Dual EGTs
Oil Temp
Fuel Pressure
Water Injection, Sakebomb tank/pump mount
IGN-1A Ignition coils
High-res trigger wheel, Hall sensor
