Another question...Apparently you can retrofit your III with all the components from a VI so that the 6l80 will see it as a VI. What all needs to be done to do this to a lq9? Sorry for all the basic questions, but I'm no Einstein at this

 

What shops are doing a 4l80 6 speed?

 

I've been looking into various trans options myself and have pretty much decided on a 6 speed 4L80E for many of the reasons mentioned in this thread. I figured I'd register and join in the conversation.

If you have the unique parts, any shop can build a 6 speed 4L80, it's just like a regular 4L80, just with a different valve body and optionally different planetary sets. PATC has a kit that includes all the unique parts for $2K including a stand alone controller. All the parts (except the 2.97 planetary) are PCS parts. Kit includes the planetary, valve body, harness and controller, the rest of the trans can be built like any other 4L80 with beefed up aftermarket parts or GM OEM parts, what ever you need.

I'm building a vehicle, pretty much from the ground up, it's a 1970 GMC Jimmy turned rally car of which I've kept the body and frame rails and ditched the rest. There is nothing "LS" about it so sorry for that, I'll be using a 4.2 liter DOHC 24 Valve 2008 Trailblazer straight 6 with Weber DCOE pattern ITBs and on the other side of the trans a Moser Ford 9" with a Wavetrac.

As it stands right now, a 6L80/90E would be an option for me as my engine has a 58x trigger and can run on an E65 PCM, which is what you need to run a 6L trans. This combination also requires working MAP and an electronic pedal, so it's a no go with ITBs as that has neither of these. The electronic pedal is important because one of the issues as I understand it is the need to starve on shift for torque management on a 6L trans. Doing this on a non-electronic pedal car will cause a lean mix and that's bad. Also ITBs don't have reliable vacuum without a common plenum which kind of defeats the purpose of ITBs, so no MAP either (and no vacuum assist on the brakes either, a whole other costly issue).

A 6L to me does not have enough of a coolness factor to trump ITBs and as others have pointed out it kind of reiterates the same kind of 1st -> 2nd
hole that the original trans that is mated to this engine has the 4L60/65/70E. When I ran the numbers on the 6L ratios they seemed kind of unnessisarily wide, for my project anyway, I'd end up with a vehicle that had the equivelent of a 4.56 rear end ratio and a practically unusable 6th gear that would be into Veyron territory by the time I hit my peak Torque/HP. I figure a Jimmy is aerodynamically capable of about 150 before it's brick like profile hits a, well brick wall.

I also looked into creating an 8 speed by merging a 4L70E with a Gear Vendors and doing the gear splits in the TCU. But there are several issues with that, to make the shifts feel consistant you have to jack the pressure up in the 4L70 to make it's shifts feel similar to the GV shifts, and there probably isn't the kind of predictable control nessisary to to complex shift event very efficiently, as each shift requires a clutch in and a clutch out event in two devices that have different requirements for timing. Also the whole deal ends up with another crazy gear spread that ultimately lands me in a 0.55 ratio of questionable use with a drive shaft spinning at 11,000 rpm at peak HP.

I knew about the 6x TCI all along and originally dismissed it because it had 2 big issues, a cast on bell housing (the 4.2 has a unique bell housing pattern) and the ridiculous pricetag from TCI. Also the TCI had no split gear engine braking only full gear engine braking, and I didn't care for the Outlaw shifter and thought it was silliness to have a paddle shifter that doesn't engine brake at all (even whole gear engine braking requires a detent shift on the 6x, not the electronic event the paddle shifter provides.

So I studied all these options again and again, and finally decided that maybe the best bet for my project would be the 6x 4l80 anyway and I'd change my plans to work within its pitfalls. My plan was to use the HGM Compushift II, a B&M quick silver shifter and just accept the fact that manual shifting would be a wide ratio 4L80 4 speed, and I'd get 6 auto shifted gears when I let it shift itself.

I knew a 6 speed valve body was available from PCS and I assumed it was what TCI was using and the planetaries are available directly from TCI. They make a universal version of the 6x to stick behind non-GM engines with the bellhousing cut off and a ring to mount a Reid bellhousing. Turns out the pump diameter of the Reid bellhousings is 9.3" and the 4.2s 4L70 bell housing is 9.0" which could easily lose 0.3" without really coming close to any of the bolt holes or having much effect on the structure of it. I'd just need to redrill and tap one of TCIs pump plates.

Then I talked to PCS, how interesting. Turns out the PCS valve body has nothing to do with the TCI one, other than PCS worked with TCI in the development of their valve body. The PCS valve body has all kinds of features the TCI one does not. First off engine braking on electronic as well as physical events, that's a big deal, secondly addressible indents, in other words any of the 4 mechanical shift events in the 4L80e physical shift mechanisum can be mapped to any defined gear change. So in manual mode you can pick the 4 gears you want to be able to shift with any off the shelf shifter designed for a 4L80, another big deal. I also assume this to mean that these gear changes can be forward or reverse pattern.

PCS also, though not something I'm particularly interested in, offers a electronic to mechanical push button shifter, which when used along with a paddle eliminates the need for a seperate P-R-N-D which is usually a paddle shift requirement. Their TCU-2000 also seems to offer the same leval of programming ability as the HGM Compushift II which surprised me as well. Selectable multi-map, CAN output with current in-use gear info available and trans statistics including temperature and with a sender, pressure, definable I/O for ECU triggering, and acceleration rate decision capabilty (shifts different when you are on it than when you aren't).

All very exciting, to me anyway, and IMHO all things more useful than any promise a stand alone controller for a 6L would offer. All this info has kind of come together very recently and now I'm sorry I didn't err on the more conservitive side for my diff gear which I already have as a 3.89 when I was leaning towards the 4L70/GV combo, which if I'd known what I know now I would have ordered a 3.70 instead anyway $200 not that big a deal in the grand scheme of things. In the end the 6 speed 4L80 is cheaper, stronger and more usable in my opinion.

 

WOW! Thanks for the post man; more than I understand, but I'm sure it will help others who are in the know. I still haven't made my mind up on a manny to slam those gears or a 6x4l80 to get the peddle shifting. I still have a good bit of time before I need to make a final decision, but it's nice to know my options are there

 

A correction to my earlier post, apparently the mechanical detents on the PCS valve body are assignable within limits, however reverse pattern is not within those limits.

 

This thread is full of win. Very imformative!

Now days people be pushing these 6l80e transmissions very far without any fails.

 

I'm sure if programmed right the 6l80/90 could live just fine behind my little 4.2 I6 project. My general abuse of the drive train would be more my concern than the HP the engine puts out and the fact that there is mysterious GM voodoo going on in there. My goal on my build is create something fairly bulletproof, that can be driven daily like it's a rental, and most importantly that in the end I know how 100% of it works. A 6l80/90 divorced from OEM electronics may very well happen, and may not be all that far away, but for the aftermarket to really make these transmissions hold up well under such conditions probably is quite a ways away. The basic 4l80 design is meant to hold up pushing 7 or 8 tons of combined vehicle weight around so pushing 2 tons around should be like pushing around a toy and that is not true of the basic 6l90 design.

 

All you ever wanted to know about tuning the A6.......and then some......

http://www.hptuners.com/forum/showth...rs-walkthrough

 

So if I'm reading this right, I can convert my LQ4 to a 58x reluctor, 4x cam sensor in the front and run it with the E38 along with a DBW intake setup and pedal? I have a rebuilt LQ4 in the garage and can easily convert it over to 58X to work with an E38 or E67 PCM. Reason I ask is bc I found a 6L80E that I'd like to use and really don't want to buy a $2000+ used motor if I have a rebuilt motor in the garage. Plus everyone tosses AFM and VVT out when they get them anyway.

 

Yes you can

 

Yes sirrr!

 

Whats the latest on stand alone controllers for 6L80.

The only one I could find is the TCM-2600 , but cant find any reviews or user experience , any one ?

 

got a ls3 need a ecm and for 6L80e

can somebody post parts number all I see poster talking about the ecm and tcm but they never post part number any help

 

this ^

and this ^

 

Along with the TCM-2600 we are can set them up for any 58x controller also. The TCM-2600 will let you put the 6L and 6t transmission behind any engine.

 

What about the PATC 6L80E / 6L90E stand alone controller?

 

They are just reselling the same PCS controller as everyone else. Calling a Stand alone is not correct.

 

So all I need is a TCM-2600 and I can run it behind my LQ9 with a 24 reluctor wheel and my OEM 01 Trans Am harness and ECU?

 

It get the transmission to function . You still need a calibration in the internal Transmission controller and also may have to modify it.

 

Well how do you do that?

I need to know if I CAN or CAN NOT successfully run a 6l80/90 in my 01 Trans AM and if so HOW?