I've been doing some searches and found one of my first posts and hadn't realized that my TGP has been sitting for a year and a half now. Time flies. :laugh: Anyways, to give a quick recap I picked up a low mileage red '90 TGP with a bad trans that has lost 3rd and OD. I've been going back and forth over doing a 5-speed conversion or stay with an automatic and had a question on the automatics.
I've found a local THM F7 from a late model Cadillac Allante with the 4.5L V8. The F7 is the heavy duty version of the 4T60 that they used up until '93 (when the Northstar V8/4T80E combo became available for that last year). I was wondering if anyone has any experience trying one in TGP. The Allante with the 4.5 was rated at 200 hp, 270 ft-lbs of torque and the car itself was a couple hundred pounds heavier. I'm thinking it might be a good match and from what little I can tell the actual transaxle is somewhat similar to the TGP's HD 4T60.
Also as a side note, it looks like there is at least one aftermarket stand-alone electronic module to control the later electronic versions of the 4T60E/4T65E's now. It would be an expensive combination, but the new Grand Prix GXP with the small block V8 is putting down north of 320 ft-lbs through it's 4T65E. That and I've been curious if any of those new internals are backwards compatible as upgrades to the 4T60. I haven't been able to find any new info and good performance builders for this family of transaxles seems hard to come by.
why? you putting a LG5 in a Lac? or its tranny in a TGP? Either way seems like overkill and uneconomical. I doubt if the lac tranny can shift like the tgp tranny which is built to shift way faster and take way more abuse. cadillac shifts are usually mushy 2-3 seconds between gears. kinda like my buddy mike in his beemer. luxury shifting :icon_lol:
Since I already have a TGP and mentioned I was going to put a new trans in it, I doubt I'm going out and buying a Caddy to pull the engine from the TGP and put in that. ;) As for why I'd consider the F7? Two words: torque capacity. I could care less about how it shifted since shift kits are a lot less expensive than building up a transaxle to handle more power. The options for non-electronically controlled GM automatics that will stand up to the torque of a modified TGP, let alone stock, is very small.
As for the F7 trans, I was able to find some more information on my own. The one I'm looking at is from a '91 and is apparently partially electronically controlled (kind of a hybrid between a 4T60 and a 4T60E with a mix of special HD parts thrown in). The earlier F7's from '87-88 were the only ones that were fully hydraulically controlled but also didn't feature as much revisions (they were used with the smaller 4.1L V8's that produced less power than the 4.5L version in the 89-92 cars).
So while the trans I was looking at won't work, my question still remains. I'd be interested in hearing if anyone has tried an early F7 behind the turbo 3.1 or any other high output engines.
I highly doubt you'll find anyone here or elsewhere that has used the Cadillac Alliante 4T60 in a Turbo GP. By the way, bone stock TGP's make right at the same amount of torque you stated that the Alliante's 4.5 makes, don't be fooled by our "225 ft-lbs" rating(rated at a rediculously low rpm). Throw on a manual boost controller and the peak torque rating will rise significantly even on a stock car due to the computer programmed "lag" that you encounter with using the stock boost control setup.
The TGP tranny's must be pretty good. :icon_wink: I am still using mine as a daily driver and an occasional 13* run at the drags and taking on anybody that wants to. It's like nitrous, you cant keep from stepping on it only no button. It ain't perfect but it is hanging in there. I think it will support 12* runs. The caddy don't even come close to the power and torque that this little motor has. :icon_exclaim:
It's got about 75k since the last rebuild and at least 60 1/4 mile runs and 14 runs on the 1/8 mile in one evening. I am just going to rebuild it again after I have to have it towed home. :laugh:
Jud
Well I'm coming back to trying to find a good rebuilder in southern California again or doing a 5-speed swap. I found a couple W-body 5-speeds in the junk yards this weekend. One was a Getrag 284 car ('91 Grand Prix, 3.4L DOHC), but it had 209k miles! That's one of the higher mileage TDC cars that I've ran across and the shift linkage didn't feel too good. The mileage combined with non-existant parts had me moving on. At another place I found another GP with a Getrag 282 behind a 3.1L, but I couldn't get the mileage off it. If it's there next weekend I might pull everything off it.
It's too bad the 4T80E is so big and has incompatibilities like the starter location, because I'm running across more and more Northstar V8's in the yards now. I wonder if any internals can be used to upgrade the 4T60/65-family? It's expensive but there's aftermarket options to control them now (http://www.powertraincontrolsolutions.com/content-4.html for example), and there should be less expensive options if the Megasquirt do-it-yourself stand alone (http://www.msefi.com/ or http://www.megasquirt.info/) auto trans support comes out in a few revisions. For the price of a good rebuild I wonder if I could track down a new 4T65E behind one of the new V8 W-bodies and pick up an aftermarket controller. Or do the 5-speed swap... So many choices and none of them optimal or cheap. :laugh:
I belive the TGP was the test mule before the f7 came out. Then caddy got wise and made their own box with a anchor :laugh: . F7=4t60 hd.
I've heard that rumor, but the hydraulic version of the F7 came out a couple years before the TGP and the partial electronically controlled version for the Allante came out the same years as the TGP. I bet the Hydramatic division interchanged some parts, but it almost makes me wonder if it was the other way around.