700r4 vs 4L60e vs 4L65e

[TheSilverBuick]

Assuming I use the MegaSquirt Transmission controller is there survivability advantages to the 4L60e over the 700r4? I'm pretty sure they use the same hard parts internally, but do the electronic controls for line pressure help the survivability of the transmission behind a higher horsepower or torque engine? Like my heavy 455 powered Centurion or turbo L6 build.

What's the availabilty and going rates for a 4L65e? Unfortunately there aren't any junkyards near by so I really don't know what's out there and what it cost.

[squirrel]

In addition to adding electronic controls in 93, the 700 has a long history of yearly upgrades. Generally, the newer, the better. I've noticed that the newer electronic ones shift better, they act more like the old TurboHydro transmissions that have vacuum modulators. The 700 just has a throttle valve, no modulator, so it is tricky getting it to "know" what load is behind it.

The 700 does have a variable vane pump, so it does have line pressure control. It's analog mechanical, instead of digital electronic.

THe newer ones used with the LS might need a spacer to work with the older Chevy engines, which would be pretty complicated with a Buick engine because you might not be able to use the Chevy spacer

Does this help?

[TheSilverBuick]

Okay, additional question. What is required to bolt one of the LS version transmissions to an older engine? Are some of the newer transmission bellhousings bolt on?

[squirrel]

I don't understand all there is to know about it. But from what I can tell, some of the LS engines fit their matching transmissions just fine, but they need spacers for the crankshaft to fit older transmissions. So if you try to put the matching transmission on an older engine, do you need to space the transmission away from the engine? and is the difference in the converter, or the case?

I'm thinking you might look into the 4L80E too....they apparently bolt up to the older engines just fine, so I expect you can use the old style BOP-Chevy adapter without any problem. It's a really heavy transmission, though.

[TC]

I believe the 4L65E has a 5 gear planetary instead of a 4 gear planetary like the 4l60e/700r4's have.......Though you can buy the 5 gear planetary and put it in the 4l60e/700r4..........Basically the 4l65e is just a beefed up version of the 4l60E.......

[TheSilverBuick]

The primary motivation for the question is for the L6 in a '69 Firebird. The current plan is to see about running a switch-pitch TH400 and possibly a gear vendor. But $$$ for $$$, if a 4L60e or 4L65e can be made to work, I already have experience with putting a 700r4 in a '69 Firebird (behind a Pontiac 400), it may be a route to go (I already have a Chevy to BOP adapter). The trans tunnel is already tight for this transmission, the 4L80e would be much worse.

[squirrel]

The only thing I'd be wary of is making the trans last if you put some boost to the motor. The 700 is pretty finicky about TV cable adjustment, and if you're going to use an electronic trans and learn about mapping the controller, then you might have the opportunity to fry the trans while you're getting it figured out.

no that I would know anything about frying a transmission with a boosted engine

[TheSilverBuick]

I believe the 4L65E has a 5 gear planetary instead of a 4 gear planetary like the 4l60e/700r4's have.......Though you can buy the 5 gear planetary and put it in the 4l60e/700r4..........Basically the 4l65e is just a beefed up version of the 4l60E.......

Better input and output shafts I believe too. From what I've read, I agree the 5 gear planetary will drop in a 4L60e/700r4. I'm wondering if because the electronic controls and the popular LS swaps might leave some transmissions behind at a discount price.

[TheSilverBuick]

The only thing I'd be wary of is making the trans last if you put some boost to the motor. The 700 is pretty finicky about TV cable adjustment, and if you're going to use an electronic trans and learn about mapping the controller, then you might have the opportunity to fry the trans while you're getting it figured out.

no that I would know anything about frying a transmission with a boosted engine

I can fry a non-electronic trans just as easy as a full electronic one. I'd have better confidence in the electronic one than a best guestimate of TV cable tension and rate of travel on what will already likely be a rube-goldberg throttle setup on the L6.

[squirrel]

exactly...the 400 is looking pretty good about now, eh? but you then have to deal with diverting boost from the modulator

[TheSilverBuick]

That's got to be a pretty simple, surely you've solved that some how? =P

[squirrel]

Yeah, I do now.

[STINEY]

I always thought the Modulator could be boost referenced with a simple line to the diaphram? Similar to boost referencing a mechanical fuel pump?

[TheSilverBuick]

I've seen mechanical fuel pumps drilled for boost referencing, simple enough concept.

[Bamfster]

With the way you take to the computer/electronics end of things, I'd look to the 4l65e and control it w/MS. They can be built to handle 750ish reliably. As far as the TV cable goes on the 700, it is critical, but only within 1/4 to 3/8 of an inch. You ballpark it at 1/4" and fine tune from there ..... gov plays a big part in fine tuning as well. With that said, that's why I want to eventually upgrade to the electronic controlled trans.

4l80e's are BIG....and heavier, and will the l6 like it's added mass?