260DET

Newb to this 'grate sight' but I've been around if that excuses me lol, car is a circuit race Datsun 280ZX equipped with a LS3 4L85E combo, Nissan 300ZX replacement project is in progreess. The 85 is good but too heavy so I'm looking at a GV 'glide setup which is much lighter and more efficient, I've already found that with the right low stall high efficiency converter a lockup clutch is not beneficial over all and heat is not a problem so in total I'm happy with an auto.

The only possible problem is 1st gear will be 1.76 with the glide which I'm thinking may be problematical at low off track speeds including trailer loading, particularly with a low stall converter. So any torque converter related comments are welcome, I'm not going to disappear once I have your info but am happy to stick around to report on how it all goes eventually.

In car video with the 4L85E setup.

wht/73

While it probably will be a few pounds lighter, I don't think it will be more efficient then a lock up converter with .70
How could it be, viscous vs locked up?
Then as you mentioned is the 1st gear ratio diff, 2.48 vs 1.76
Too me, it wouldn't be worth $ or the time.
I'm sure the pro's will post one way or the other.

What's up with your steering wheel?
It's on the wrong side!

forcd ind

iTrader: (7)

With the 85, are you getting into 4th, and are you able to lock up at speeds.
Are you doing paddle shifting.
Not sure what a glide and GV's together would weigh, I think the 85 is around 177 lbs minus the conv.
Looks like a cool race, what speeds do you hit.

wht/73

I would keep the 85 just for the paddle shifting as forcd mentioned.
Especially on a track like that.
I wouldn't lock it at WOT with a stock or single aftermarket converter.

260DET

For those interested in this setup, the weight saving is around 50kg (110lbs) plus it's more efficient internally so less parasitic loss. For my purposes 2nd gear ratio is more usable too. Shifting is yet to be sorted, I'm waiting on GV to advise on that. I prefer a floor sequential shifter which the 85 has and am thinking that it may be possible to use a modified aftermarket mechanical shifter that switches electrically for 2nd and 4th.

In theory lockup is better, the 85 has it but it's not used partly because I don't get around to switching it But it does add weight particularly parasitically, the 85's converter is efficient enough that the transmission can run for 20 minutes without getting very hot at all. So overall I doubt that the TCC is of much benefit to me, assuming that the right replacement converter is available.

Re the video, the car was getting aero lift at about 250kph so rather than make like a plane I was backing off.

260DET

The situation now is that after more research a bare lever bump shift setup solution has not been found and that's about it. Anyone with knowledge able to suggest something with engine braking too but other than a lever operated Powerglide with buttons for the Gear Vendors? That's way too complicated and mistake prone in the heat of racing. The 85 has a electronic TCI and it's bare bump shifter works a treat.

Other than that it's all looking pretty promising. TCI seem to specialise in the requirements of Circle Track racing Powerglides which sounds similar to my requirements. They offer CT converters with a claimed efficiency of 98%, hmmm, who needs a lock up. My builder will be referred to what TCI offer although the 85's converter is a damn good unit.

260DET

No GV knowledge around here? And GV are not responding to my shift question, I guess that it's a problem that they have not sorted. They do have some sort of control system but there are no details on their web site, guess I'll have to stay up late one night and phone the slackers.

Options seem to be, one, get the Powerglide converted to electronic shifting or, two, shift it using a solenoid setup. Not sure if one can be done, two can be. Basically it's about being able to get one controller to activate the GV and glide shifts sequentially.

SHARKBITEATTACK

260DET

The idea has been dropped, it could be made to work but there are a couple of uncertainties involved. Both involve downshifting, both fast downshifts and engine braking are required but I could not find conclusive info on the operation of the GV at those times.