The current engine is an RPB with unknown hours. I've got an RPA on the shelf in the same boat (gonna refresh it in 2021 then swap it over).
Your TMT idea occurred to me as well. The current gearbox in the car is the older Quaife Q58, and I've got a Hewland JFR201 on the shelf as a backup. But that TMT can handle the RPx engine with no trouble at all. Might pay a slight hp-loss penalty, but I think it would be worth it.
The new valve block is a Geartronics unit, along with matching actuator, compressor, and accumulator. I'll post some pics later today.
The Geartronics’s stuff works great 👍 And the support is great too. I’m also running a geartronics valve block but with the blip valve as I’m still running a cable throttle, but controlled by life ecu. Radical’s valve block can’t cope with the same pressure this one can.
Are you having to send your engine to radical uk or is there an agent who can rebuild them in the states?
If there was a hp loss with the tmt, which I would have thought would be negligible, you would gain by the fact that it has a plate diff instead of the quaife atb, the car would handle better.
Right: the valve block failed due to a leak. The Geartronics valve block is rated at much higher pressure, and so we can now run the whole system at higher pressure which will increase its reliability and reduce shift times. I'll be on track next weekend to try it out.
Spring Mountain Racing (near Las Vegas) is an accredited PowerTec supplier, and they can do V8 engine refreshes.
The main problem with the TMT swap will be the bolt pattern, I think. I doubt there is a native TMT bell that will bolt to an RPx engine.
Great, I’m sure the shifting will be better 👍
That’s handy you don’t have to send your engine back to the uk.
Yes it doesn’t look as easy to mount the tmt as the jfr with sandwich plate. And there’s a bit of a hollow at the front which the jfr doesn’t have, so will sit further back. Would probably have to have a new bell housing and separate oil tank to make it work.
All the wiring and plumbing is done, testing looks good. Sebring on Saturday!
Looks good John. What have you raised the pressure up to?
I’ve just realised your chassis, or rather the frames that bolt to the chassis are different to the later SR8’s. Radical added a 5th mounting point on the rear frame to join to the top frame that bolts on inline with the rockers. I didn’t realise they ever had it like your car is. Not sure how necessary it is tbh, I think Radical were just trying anything and everything to try and stiffen the chassis up.
Have fun at Sebring
Current working pressures are between 8.27 and 10.69bar. The North American MoTeC/Geartronics engineer is off doing double top-secret updates to the shifting setup, so it might change. 🤔 🤔
The car is chassis #87, and it has more tubes in the back than my older SR8 (#42). Seems Radical kept adding tubes as the years went by.
That’s more like it 👍 I think the min pressure you now have is more than the max pressure the Radical valve block can take 🤣
Double top secret? I expect super fast shift times then!!
Your old chassis must have the rectangular bolt on top bracket between the rockers. Presumably your current chassis is also low hoop?
Yes -- the old chassis has the rectangular bolt on top bracket. And both are low hoop. (I've still got the old chassis -- I can't bring myself to throw it away)
About the pressures, I was running the Radical gear with the same pressures, and that's why the valve block failed (@ turn 15). Now it's all upgraded to Geartronics spec hardware.
Haha yeah the old valve block wouldn’t have liked 10.69 bar 🙈 Surprised it lasted as long as it did tbh.
I found an interesting picture from a very early SR8, with a different chassis set up again (which I’ve been told you could only drop the engine out the bottom), and an FTR with the bell housing machined off.
Nice photo! That must be one of the very first few built.
As far as dropping out the bottom, I find the engine surprisingly difficult to R&R. I unbolt everything, get the engine chained to a hoist, move it back a few inches, then wiggle in and remove the front mount "frame", and then I can get the engine out. Maybe going out the bottom is easier?
This past weekend was spent at Sebring, and I can report overall success with the car. I finally have the closed loop flawless shifting car I've been searching for.
I had one issue with my ECUMaster PMU (power management unit): I tripped the inertia switch twice. The inertia switch is a built-in accelerometer designed to detect a vehicle crash and turn off all electrical power. Luckily I was able to figure that out, and changed the limit from 6g to 12g.
Apparently, exiting turn 7 on the exit curb and shifting to 3rd gear generates nearly 7g (combined in all 3 planes). Sebring prides itself on its bumps. 🙁
That’s Great news the shift system is working perfectly 👌
Good idea having the inertia cut off, I guess you can lower the limit back down for less bumpy circuits?
I'm learning how to read the ECUMaster logs, and I'll be able to set the parameter to a smaller value once I gather more data about "typical values".
Yes, the new shift system is damned amazing. Expensive, since I'm working directly with Geartronics Engineering, but worth it, I hope. The shifting should result in lower wear rates and less expensive gearbox refreshes... but I won't really know that until the summer teardown.
