harmsway22

So do you think this transmission will make it into the C6, makes sense to me since it was designed for performance and handling more HP.


2004 Cadillac XLR and SRX to Showcase GM's Most Technologically Advanced Transmission

WARREN, Mich. - GM Powertrain's new Hydra-Matic 5L50-E 5-speed automatic transmission, developed to manage the high torque and horsepower of the next-generation Northstar 4.6-liter V8 in the 2004 Cadillac XLR and SRX, is one of the most technologically advanced transmissions on any highway or autobahn in the industry.

"The Hydra-Matic 5L50-E is the first transmission to integrate three performance features found individually on various high-performance American and European luxury sport sedans but never as a total package," according to Rich Mardeusz, GM Powertrain Hydra-Matic 5L50-E assistant chief engineer. The features include:

Driver Shift Control (DSC) - Lets the driver switch from automatic to a clutchless five-speed high-performance manual transmission. Once the driver moves the gearshift lever into DSC mode, a quick tap is all that is required for smooth, crisp upshifts or downshifts within a selected range. Available on various European sport sedans, this is the first GM application of DSC. The transmission control module (TCM) protects the powertrain when in DSC mode by monitoring vehicle speed, engine torque and the gear being used to determine if it should upshift automatically to assure the engine doesn't over-rev and damage the transmission. It also has coast clutches in every gear, which provide engine braking in all five gears so the vehicle doesn't free wheel if the driver removes their foot off the accelerator.
Performance Algorithm Liftfoot (PAL) - PAL prevents upshifts while maintaining engine braking following continuous performance driving. The TCM monitors driver behavior to determine whether or not to enable this feature. If the system detects a drop in vehicle speed prior to entering a turn, up to two downshifts can occur to provide the driver with maximum vehicle performance.
Performance Algorithm Shifting (PAS) - The transmission controller modifies the automatic gear selection during closed throttle high lateral acceleration maneuvers, downshifting with nearly synchronous matching engine speed control for quick power up when the throttle is reopened. This feature is enabled instantaneously once the TCM recognizes a high lateral g input.
The 5L50-E transmission is a modification of the Hydra-Matic 5L40-E transmission used in Cadillac CTS.

"The 5L50-E was designed specifically to manage the high torque and horsepower of the next generation Northstar 4.6-liter V8, while combining the convenience of an automatic transmission with the feel of a high-performance manual transmission," said Mardeusz. "And it does it in the same size package as the 5L40-E."

To meet the performance demands of the new Northstar, the 5L50-E was designed to manage at least a 25 percent increase in horsepower and torque over the existing 5L40-E. Among its host of performance features, the 5L50-E gives drivers the ability to partially override the normal automatic gear selection for greater control when more aggressive driving performance is desired.

Gear
Gear Ratios

1st
3.42

2nd
2.215

3rd
1.60

4th
1.00

5th
0.76

Reverse
3.02


GM Powertrain is a global producer of engines, transmissions, castings and components for GM vehicles and other automotive, marine, and industrial OEMs. Headquartered in Pontiac, Mich., GM Powertrain has operating and coordinating responsibility for GM's powertrain manufacturing plants and engineering centers in North America, South America, Europe, and the Asia-Pacific region.
http://www.gminsidenews.com/cgi-bin/...c;f=8;t=000014

:confused: :confused: :confused:

C5Fun

It sounds like what a car like the Corvette should have. How many XLR drivers are going to use it's features? But, something does not compute. GM Powertrain lists the maximum torque rating of the 5L40-E as 221 lb-ft. a 25% increase in torque rating would only be 276 lb-ft. The current North* is rated at about 300 lb-ft. Hopefully it's a typo, because it wouldn't handle a 5.7L engine producing at least 350 lb-ft. Does anyone have t he actual specs on the 5L50-E? I think I'd like a 5L80-E :D

C5Fun

Just found this in the Detroit Free Press.

"The C5's six-speed manual and four-speed automatics should be carried over to the new model, at least initially. A Cadillac five-speed automatic destined for the XLR roadster can't handle the Corvette's massive torque, Hill said. " :cry :cry :cry :cry

Jinx

Consider that the press release says the tranny is designed specifically to handle the high torque of the Northstar -- which we know to be significantly less than the Chevy LS1 -- and it's clear to me GM isn't giving this transmission to C6. After all, if this tranny could take LS1 loads, the press release probably would have stopped short of calling out the Northstar. That doesn't mean they won't still develop a higher-torque version, but don't hold your breath.

Consider that C6 should have even more torque than the LS1, perhaps as much as the LS6, and it could be 2008 before you see a five-speed auto.

Heck, GM's gotta beef up the 4-speed, since it's already at the limit of what they'll support at 360lbft. After all, if it could safely (i.e. to GM warranty standards) take more torque, why would the auto-equipped LS1 be limited to 360lbft when the manual LS1 gets 375?

I wonder if their target for the 5-speed was the Corvette but they just couldn't get there...

.Jinx
Come on baby, let's do the twist.

Wadoka

It sounds like a good development issue. General Motors, you would think, would have far more development money available than anyone else in the industry. They just can't concentrate on a few good ideas.

Other than lack of strength to withstand higher-than-factory :D power and torque, the other major issue with the 4L60E is its unusually wide ratio range. The available gears are spaced too far apart. Another ratio in the mix would be great for keeping the engine in its best operating range.

e3pres

Is this "new" transmission the same one that GM has been building for BMW for the last several years?

SWCDuke

A six liter engine will push peak torque on the base engine to about 400 lb-ft. GM says they increased torque capacity of the 5L50 for the new XLR, but that's only a 4.6 liter engine and peak torque is basically a function of displacement and compression ratio, regardless of the number of valves and cams, so the XLR will only have a bit over 300 lb-ft.

It's not clear to me that this transmission is going to have 400 or better lb-ft torque capacity.

The current A4 can't even handle the 375 lb-ft of the current LS1, which is why the electonics closes the throttle a bit in the mid-range to limit torque to 360 lb-ft.

Duke

Zivnuska

Since the C6 wheelbase is going to be longer to handle a five speed auto, I guess it comes down to if you believe the Caddy A5 will be tweaked for the Vette or if you believe that GM is developing a second 5 speed auto? It seems a waste to have two completely different auto trannies on the same basic platform.

peccles

GM should be investing for a 6 speed automatic in their higher end cars
like Jaguar and BMW. They are just about the last car company to start
offering 5 speed automatics (only available in the '02/'03 Saturn VUE, '03
Saturn ION, and '03 Caddy CTS).


Paul
'00 Nassau Blue FRC

SWCDuke

Jaguar and BMW doen't have engines with 400 lb-ft of torque. The higher the peak torque and the broader the torque bandwidth, the less transmission speeds you need.

Duke

hoisin7

I agree that it does not seem likely that GM will have this transmission ready for the c6, especially given the increase in torque that is most likely coming. Hopefully they will be able to upgrade whatever automatic they offer so that it can handle the full torque of the c6 engine. Given that the automatic is purchased by more customers than the manual, one would expect that GM would put at least some work and thought into the automatic transmission they are going to offer with the new vette.

As for 5-speed automatics in the competition, both porsche and jaguar offer 5-speed transmissions that can handle close to (if not over) 400 ft-lbs of torque (XKR for jaguar, 911 turbo for porsche). Of course, these cars are much more expensive--sure, the tiptronic transmission from porsche can handle the output of the 911 turbo, but the transmission is also a $3,000 option. I doubt many corvette buyers would opt for such a price increase just to have 5 forward gears in their automatic.

Regardless, GM has pretty much always packaged competitive technology and performance in the vette at a (comparably) affordable price, so I don't know if one can entirely discount the possibility of this transmission (or one similar to it) finding its way into the c6.

Cheers,

Hoisin

vader86

an A5 is supposed to make it into the C6, just dont know if it will be in the 1st year of production

AP

A5 could ... they can make it stronger than the 5L50 ... if they want to ...

RedDog4

I saw on Hot rod tv last week a white hardtop c5 with a 500hp motor and a 5 speed auto tranny they were testing

I Bin Therbefor

The vehicle you saw was the Corvette 500 Caribbean Cruiser. It was one of the GM R&D vehicles shown at Hot Rod Power Tour.
Basically a Z06 on the outside with mild aero package and vented hood. 6.6L engine driving a 4L60E Automatic and 3.42:1 gears with 335 rubber.

Hot Rod speculates hp at 475 with equal torque.

:yesnod:

ZROne

The only time the tranny would see peak load would be in 1st gear. The other gears peak load will always be less. In fact, you could double the horsepower and torque driven to the tranny at 2nd gear+ and it would still be less than full throttle first gear.

I am interested to find out why they were able to design a 3 speed auto that could handle 500+LB's of torque in the 60's-70's and can't find the parts to make one that can do the same now.

Zivnuska

Can anyone explain why GM would design a transmission for the XLR that has several sporty features and not make it so that it could be used in the C6? I wouldn't think the XLR volume could support the development costs unless a modified version finds its way to the Vette. It makes no sense to have two A5's for the same platform.

SWCDuke

It's been explained above!!! A Corvette engine makes considerably more torque than the Northstar engine, and the current A5 that they are selling to BMW just won't cut it with a Corvette engine, but it can probably be beefed up to meet the torque input of the Northstar, which is over 100 lb-ft shy of new Corvette engines that are in the pipeline for the next few years.

The problem Corvette engineers have always had is finding drivetrain components that are shared with other vehicles. Corvette just doesn't have the volume to shoulder the tooling costs on its own without significantly raising the price. That's why every mid-engine Corvette design has gone down in flames. The Corvette probably won't get an A5 until GM decides that one is necessary for the light duty trucks or can find one somewhere else in the world to buy.

Given the high and broad torque bandwidth of the LS engine its debatable whether an A5 would benefit the performance that much or just be another "gee-whiz" feature. The latter is most likely the only reason to have an A5. Also consider that an A5 will weigh more than an A4.

For you guys who just have to have a five-speed automatic buy an XLR with its puny little 32 valve engine and all the other "high tech" fluff that adds several hundred pounds of weight and leave the big torque Corvettes to the real men who want to shift their own gears.

Duke

vader86

it wont be in the C6 to start, it cant handle the torque output