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5 or 6-speed automatic transmissions?

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MAP

Member
Joined
May 31, 2001
Messages
127
Greetings,

I thought I'd check back here, as I do from time to time, to learn of any news concerning strong five or six-speed automatic tranny's which can be used or adapted to our cars. I know that 700/200R4's and derivatives have needed many years of development to reach an adequately reliable state for the performance aftermarket, but for street-driven cars, it's probably time to graduate to five or six speeds. The OEM has already done it, after all, but the real question is can they live behind motors making, say, 500-600 rwhp and a like amount of torque, for the entire street-driven life of the car.

Any updates much appreciated.

Best,
MAP
 
Map I just saw this from SEMA:

SEMA 2008 Friday Coverage - Page 3 - Street Legal TV Forums

GMGX Six-Speed Automatic Package

TCI has an answer to a high performance and heavy-duty six speed automatic. If you have a street rod that you want to run a little more rear gear and want the cruising RPM in sixth, then look no further. The six-speed is a few inches longer, but the same width as a Turbo 400. In this package, you get the transmission, controller, converter, (3000 RPM standard, but can change stall), and a trick paddle shifter

TCI - Performance Transmissions and Torque Converters

I don't see it on the TCI site yet but I would expect it soon.


Greetings,

I thought I'd check back here, as I do from time to time, to learn of any news concerning strong five or six-speed automatic tranny's which can be used or adapted to our cars. I know that 700/200R4's and derivatives have needed many years of development to reach an adequately reliable state for the performance aftermarket, but for street-driven cars, it's probably time to graduate to five or six speeds. The OEM has already done it, after all, but the real question is can they live behind motors making, say, 500-600 rwhp and a like amount of torque, for the entire street-driven life of the car.

Any updates much appreciated.

Best,
MAP
 
Thanks, John!

I found the transmission you described on page 4 at that location. I assume that's the 6L80E paddle-shift transmission used in some Corvettes and Cadillacs. GM uses that transmission behind motors rated up to roughly 400hp SAE net.

Any word about how TCI might be beefing-up that transmission?

Also, it's been almost 15 years since I dealt with TCI products, but my recollection is a profoundly unpleasant one. Are they a trustworthy company nowadays? In particular, do they build products that truly live up to claimed hp and torque figures?

Thank you.

Best,
MAP
 
The picture in the link that TCI is calling a 6 speed is clearly a 4L80E. They must consider 3rd/lock up and 4th/lock up extra gears. I have several 6L80E's in the shop right now and a few upgrades and currently working on more. We have a 6L80E's living pretty well in a several corvettes pushing 700RWHP. I believe it will be a while before we see a stand alone harness for the 6L80E/6L90E's to adapt to non-LS based 58 tooth set-ups.
 
Greetings Rusty,

This is helping to pull us forward into the 21st century of drivetrain technology, and this is very good news indeed. (I suspect other vendors here are probably probing this frontier as well, but possibly so as not to tip their hand in a competitive and developing marketplace, we might not be reading much about it here.)

Questions:
1.) Is the 6L80/90E case well adaptable to bolt-up to BOP/C engine blocks dating back as far back as the '60's?

2.) I wasn't aware of a 6L90E - how does it compare to the 80E? In what vehicles are these two tranny's used?

3.) When you say you have some 6L80E's living well in 700rwhp cars, are these bone-stock OEM units? Nowadays, it seems improbable that the factory would design with such a large safety factor over a 400hp target, given that this kind of safety margin is expensive and adds size and weight to the tranny.

4.) How much does the 6L80/90E weigh? W or w/o TC? W or w/o fluid?

5.) Of course, I assume the factory design is with a lock-up TC. Can you estimate factory stall speed, and behind what motor?

Thank you,
MAP
 
Thats funny the pic in the link with the three 6L90E's was taken in my shop. Map I will try and answer your questions Monday when I am in my office.
 
Hi Rustnail,

Interesting - thanks for your help. While this is in progress, I'm trying to come up to speed on these transmissions. The 6L90E is used behind the 550hp (SAE net) Eaton-supercharged Cadillac motor. It's bigger (and probably heavier,) than the 6L80E, which probably accounts for its absence in the C6.

Both of these transmissions, as I understand it, have integral electronics that control all manner of transmission function. These electronics integrate with other electronics in the car, such as the ECU and BCU. Stand-alone adaptation into older vehicles seems to be mostly an electronics hurdle. Speartech may or may not have such a solution for the 6L80/90E.

That's what I have at the moment - Rusty (or anyone else too, of course,) if you see anything that needs correction, please feel free to chime-in.

Thanks,
MAP
 
Don't we have a TCI employee on the board?
I can't remember his name, dang I am getting old!
 
Greetings,

Just making a quick post to bump this to the top for any updates.

Thank you,
MAP
 
Hello,

I just received an e-mail from Street Legal TV News, about the current PRI show in Orlando, Fl. This link shows an interview with Tony McCurdy at TCI about their new 6-speed GM automatic transmission:

Street Legal TV : PRI 2008 TCI

(The link might not work directly without first registering at the site.)

Salient features:

1.) Based on the 4L80E transmission, with "two added forward gears." (Rustynail, you were absolutely right for ID'ing the photo as that of a 4L80E.)
2.) Stall speed for converter can be made to anything from 1,800 to 6,000 rpm. Lockup is available.
3.) Compatible to "above 850hp."
4.) Of necessity, Computer-controlled.
5.) Shift points and line pressures are fully programmable, so can shift from soft to hard.
6.) Trans uses a steering-wheel mounted paddle shifter, which communicates wirelessly with electronics in trasnmission.
7.) Uses one OD gear rather than two. (This theoretically means that less power is wasted in turning the driveshaft needlessly fast in relation to the rest of the running gear, since this implies taller gearing for the rear for the same total drive ratio to the tires.)

The transmission, as I understand it, is sold as a complete package with all electronics. Price = not discussed, but likely $$.

Best,
MAP
 
the trans in the video is a 4l80e.from what i have heard they are turning on overdrive before the shift to second and then turning it off on the 2nd shift.then they do it again.overdriving first and then second gives you 6 forward speeds.kind of silly if you ask me
 
I read about doing that in one of the mags several years ago.

I was looking into it for towing. I was having the big jump from second to first kill the rpm and thought another gear in there would be swell.

This was to be an upgrade of my TH400 equipped tow rig at the time. The newer one has a 4L80E and I guess more power as I don't experience the same problem. The new one does have 3.73 as apposed to the 4.10 in the old one. Maybe that was the difference.
 
I spoke with Tony at SEMA; I believe he said the kit price (trans, paddle shifter, TCI control box ect) will be 8-9K :eek:
 
Greetings,

$8k-$9k doesn't make sense - it's hard to justify the ROI with such a steep price of admission. For example - if they're switching OD in and out to get the extra gears, then instead of spreading the total ratio range, then they're actually conserving the existing one and making the ratios generally more closed.

Also, the incentive for a competitor to take the 6L80/90E and make a stand-alone electronics controller for it, which is apparently the only significant hurdle keeping it from the aftermarket, is just too enticing at this price point. Who knows, maybe GM themselves will do it.

As such, the TCI kit would probably have a short market life before becoming swamped by cheaper and probably better alternatives.

And I still have long-standing reservations about TCI as a company.

Rustynail, or anyone else in the know - naturally - could you shed some light here?

Thanks,
MAP
 
Greetings again,

Here are some updates. I called TCI and GM performance parts.

About the TCI 6-speed:

1.) Price has not yet been determined.
2.) Tentative choices (highly subject to change) for forward ratios are: 3.00, 2.34, 1.64, 1.30, 1.00, and 0.75:1. The total ratio range is 4.00:1, so this confirms my suspicion that the primary goal has been to close-up the ratios rather than increase the total range compared to the base 4-speed. Since the 200-4R is already 4.09:1, I see little incentive in my case to switch to the TCI 6-speed transmission (I'm looking for economy and acceleration on the street.)
3.) Target market introduction date is early 2009.

About GM offerings:

1.) The current top-of-the-line offering is the Supermatic 4L85E.
2.) In speaking with GMPP and also a dealer rep with claimed close ties to GM powertrain, I was assured by both that the desire to have a stand-alone 6-speed auto transmission that would be reliable to the 600-700hp range, would be communicated up to key decision makers. The 6L90E transmission is a very promising platform; again, the only barrier for the retrofit market would be the current lack of stand-alone control electronics. But since GM overcame that barrier for the 4-speed market, presumably it's only a matter of time for these newer 6-speed models.

By the way, the total ratio range for the 6L90E is 6.01:1, which models very nicely for acceleration as well as economy with various software I have from Performace Trends.

Best,
MAP
 
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