6T75 6 speed conversion
 

We are currently working on fabbing some tranny mounts to market in the future, any ideas, requests or contributions from the community?

Let us have it!!

We need a custom mount for the starter too. LS4s have transmission mounted starters.

We're on track with the starter mount area of the project. (edit) Although, the bell housing can be milled to fit the starter, we are going to fab an adapter plate for a friendly bolt-on conversion....progress, progress.

I think it will be substantial as a simple swap. I've done a little research and it should hold 400-500 whp reliably. My only concern is holding the component substantially with a stiff but comfortable amount of travel. We don't want any broken ears, etc.

We'll probably use some poly and steel and see how it works. We'll be making a mock up for a customer today hopefully, so we'll keep you posted on how progress goes.

If anyone had any under carriage pictures of the starter, tranny, etc. it would help immensely in our R&D!

Bolt in kit for gxps and Chevy's? Interested.

We're working in that direction. Even throwing a nice polish or powder coat on 'em!

This is exciting news!

I guess we'll need to start researching how this swap would work with regards to the PCM, as well as what mods the trans will need to reliable handle 280+ lb-ft of torque at the wheels.

Does anyone know of any shops that mod the 6T75, or what parts are available?

We'll prob be looking at around $300-$400 for the kit as it stands, general consensus on being worth the battle?

-Bell housing adapter plate
-Starter mounting plate
-Transmission bottom side mount (poly bushings)

And other misc. items.

Although the kit is bolt on, we will more than likely have to machine the housing of the tranny itself to accept the starter's location, i.e. hone an area for the flex plate and starter gear to meet. Thus, additional expenses will need to be done.

To compete with that idea, we could have the tranny shipped to us, do the work and mount the plates, starter, etc.

Thoughts?

Shipping a trans back and forth could easily double the cost of the swap, depending upon the location of the owner. And that's not even counting what your shop would (rightfully) charge for the additional machine work. For a money-is-no-object situation, or someone living in the southeast, taking it to your shop is probably a no-brainer. For many of us, it might be cost-prohibitive.

Perhaps you could include very specific machining instructions/specifications so that those of us unable to ship the trans could take it to a local shop for the work.

Just a suggestion.

That said, $300 to $400 for the kit sounds VERY reasonable to me!

Found this on ebay:

http://cgi.ebay.com/ebaymotors/HYDRA...Q5fAccessories

Granted, this is the AWD version, and the non-AWD model may even be cheaper.

This is much less than what I thought the trans would cost, and it will probably only come down more as they become more common.

Now it's a question of software and strengthening upgrades.

This is pretty encouraging, because a decent street trans from TEP is $1650, plus shipping. Add in another $200 for a rebuilt converter, $200-$300 for shipping, then another $400 to install, you're at $2500 and you still have an ancient 4-speed.

If this swap can be put together for comparable money, then the LS4 community will finally have a viable alternative to rebuilding a stocker.

https://ls1tech.com/forums/ls4-front...onversion.html

The title is supposed to be 6T75, some info in there, been lurking for a little while.

Thanks for posting this. As you can see, the interest is definitely there!

To all: Anyone who has been following this section over the past few years would know that I am a big proponent of this swap. In fact, I've been into it the moment I heard GM and Ford were developing this transmission. So much so that I've been all over the map looking for someone to work it out. I still don't understand why GM didn't/doesn't put this transmission in a W-body.

Regardless, I am the customer that he speaks of and I am eager for this to be completed.

Most of the mods I try to get going are for stock cars. So there aren't any guarantees that this will work with the headers' crossover as I don't have headers. This transmission could easily sit higher or lower than the 4T65E-HD. Time will tell.

It should handle it fine. Remember that this transmission sits behind almost 5,000 lbs full-size crossover SUVs. I say build it if anyone's making some serious power (over 500 HP/TQ). Also, our vehicles have ECMs and TCMs versus a single PCM.

The research is pretty much done. A module already exists that will mate the E40 and E67 ECMs to the T43 TCM ([literally] found inside the new clutch-to-clutch 6 speed transmissions: 6T70/75, 6L80/90, etc.).


Actually, they can be had for just over half that price.


Indeed, but there's going to be a little more added to that which hasn't been discussed: module and half shafts.

EDIT: More info on the 6T75 courtesy of FastFieros: http://www.filedropper.com/6t75

FYI: The picture in the document is of the 6T70 and not of the 6T75; the 6T70 will bolt to our engines without an issue.

ECM identification: http://www.lt1swap.com/pcm_identification.htm

This is awesome news. I'd still own my Impala if it had a 6 speed tranny.

6 speed would be sick. anyone know what a total cost would be for EVERYTHING needed to turn an ls4 to 6speed?

mabey we could put a slick on here and not have to worry about it yeah i want one

man i will get on board with this sounds bad a$$

Im deffinetly game for helping out... I was just thinking the other day that this would be a perfect choice for my ls4 fiero mod...
I will try to help out as much as I can from here...

I could definitely get down with this...

I love the interest. Out the door, computer, adapter plates, module, etc. what would everyone be looking to pay. Basically, everything minus the trans.

It says in the thread an adapter plate for the bell housing exists, any info?

looking at the gear ratios, so i take it first gear will be disabled

and will the TAP shift work with the conversion

http://www.fastfieros.com/images/par...r_plate_09.jpg

3/4 of the way down: http://www.fastfieros.com/catalog.htm

I can't speak for anyone else, but if a complete swap package with all of the components you listed above could be had for $800-$1000 or less, I think this becomes the standard upgrade for anyone looking for better performance, or, more likely, replacing a failing 4T65.

Edit: After looking at the cost of the trans module and the bellhousing adapter, I realize that my price suggestion probably isn't reasonable.

Why? Because of the 4.48 first gear ratio?

If you took the time to read the gear ratios, I'm pretty sure you could have read a few lines down:

EDIT: Correct shifter options (from another document) are P, R, N, D, M (DSC+/-) & L (MU/MD).

That means manual mode for DSC (Driver Shift Control) up (+) and down (-) or an "L" gear (like in the Buick Enclave) where the driver can set the highest gear the transmission will use:

http://www.enclaveforum.net/index.php?topic=4722.0

For those without paddle shifters, there is an option:

Shifter from an unknown newer GM vehicle used in a 2007 TrailBlazer RS with the 6L80E:

http://www.tbmsport.com/images/600_I...00611-0856.jpg

http://i55.tinypic.com/51q9te.jpg

Chevrolet Malibu:

https://i54.tinypic.com/2vmhnc7.jpg

https://i56.tinypic.com/29ndn9y.jpg

Buick Enclave:

http://i54.tinypic.com/2n06jk5.jpg

http://i53.tinypic.com/2qb7z2s.jpg

That bellhousing adapter IMO is pretty overpriced. Competition drops prices.

As for the module, that PCS module on that website doesn't talk to the T43.

Everything minus the transmission and the install I figure ~$1,000-$1,100 sounds reasonable.

Is this for a 6 speed Fwd conversion or Awd ? And either way I'm in! :D but Awd would be loved!

LOL...AWD W-bodies. That would take some serious re-engineering!

awd w-body that would be cool with a super charger that would be 4wheels spinning lol

I don't know anything about it.

perhaps i should re phrase can you hold it in a specific gear i know its not the best for the trans but i must say i do love dropping it into first from 3rd

still pissed i have to wait another year for my goat :engarde:

Update:

Confirmed a bell housing adapter plate is not needed. In it's place is the 6T70 bell housing. It will successfully bolt to an LS4 and a 6T75.

We're looking at the following kit:

-6T75 adapter bell housing, machined for the starter's access
-Starter mounting bracket, polished steel
-Poly bottom side brace, polished steel
-Programmed ECU and hand held tuner
-Half shafts (still working on finding specs and adaptability)

Less the half shafts, were looking at around $1200.

Still an interest?

No, but let's hope it moves the earth's rotation on launch...:nod:

Just an FYI, some of the other cool projects were working on:

World's fastest 2.8L 12V Audi A4 Quattro - Projected completion -End of 2011

The 12V 2.8L was only for 1996, therefore a performance market was never established. The kraut's love for the 1.8T drowns out the 2.8L's displacement potential. It being 10:5:1 compression shoots down boost ideology. Superchargers were sold years ago for 7K and increase HP by about 110WHP, bringing finished product to around 280-300WHP.

In the works is a 3.5L 9:1 stroker kit, producing closer to 350WHP, with a boost acceptable bottom end.

Get this, the world's fastest 12V A4 has never been recorded. The fastest B5 A4/S4 that I've heard of is a mid 10 sec car. I'm shooting to chase down both records, in full trim. In addition, I am shooting for a road race capability in case the record breaking gets to bland. Chassis has 200,000 miles on it, and weighs in at 2992lbs.

Project: Violent - Projected Completion - 2012

80mm single turbo 355 + 2 stages of bottle fed + <2000lb. curb weight = Violent

Thanks for your support!

If I can get everything sans transmission for $1500 I would be interested.

I spoke with Jesse at True Blue. We compiled ideas for a few and came to a couple of conclusions. As it stands, there are a few roadblocks on the ECU and TCM. Using EFI live for tuning is a definite necessity we both agree on, but isn't a total solution.

The problems are:

1. The program for the factory trans. is set for a sparse amount of engine types, i.e. ecotechs
2. We would need an aftermarket ECM
3. Programming the 6T would require accessing the trans. programs and matching the links with the donor vehicles ECU, ECM, etc. We would need to access the programs via EFI live and through Delco's access limits. A dealer would more than likely be needed to help us gain access.
4. We would need to match the links and run multiple programs and fight a good amount of trial and error before the bugs are worked out.
5. A harness adapter would need to be incorporated, Current Performance Wiring would need to be consulted for the project.

I'll do my best to get some answers and solutions, however this will put us way above budget for an affordable kit.

Hit me up with some ideas on it still being worth while. I want to help the community, but don't want to market an ill thought project.

OMG... somebody pinch me, I must be dreaming....

The dark side must really be that strong.

Still chopping away. Talking with GM today about the trans. programming access codes, etc. Will update soon!

We appreciate the efforts. I'm looking forward to seeing this.

Awesome! I'd purchase this kit without thinking as a replacement for a failing 4T65 or just as a mod/preventative maintenance. The price would have to be similar.

I've spoke with TCI, they want an outrageous amount to make any units for the application. Something around 6-7K for R&D. I've got a good programmer with AcDelco here in FL locating some files and solutions.

We'll have to wait and see what he comes up with. I'm all set for making the bell housing and starter bracket work, however would like the other issues to be clarified before I market the machined parts. A lot of times, large companies like TCI will buy the parts I make and add the programs and sell the kit. I'd like to keep this affordable enough for our community and not have a need to deal with severe inflation.

Still no luck for the programming.

As I said, making it all fit properly and flush is done, computer driven speed bumps are the only slow down at this point. If anyone has any solutions, send them over and we'll get this thing figured out!

Seems like a well needed adjustment for the community.

I wish i had some input :l
Appreciate the effort man.
Hopefully someone will be able to help.

Do you guys already have it wired up and connected?

No, I'm looking into shipping our kit and a car to someone to program. Interested?

:pics:
J/K... They would be nice though.

Oh, you guys are so close! I'm kinda on the opposite side as you (Orlando) are. I have been looking around for months planning a project of pretty high ambition. There are just a few little roadblocks. I can swap any boltable thing together (I've built one car out of two), but I don't have any skills or resources for tasks that require custom fabrication. I am however very good with electronics.

The short story is this: I believe I can get an ECU to operate the LS4 with the 6T70 transmission. There are already existing combinations of the E67 and the 6T70 (wth internal T43 controller), and HP Tuners has a huge amount of access to E67 parameters. I have in fact become convinced that I can drive almost any NA or supercharged late model non-DI and non-Turbo engine using that computer because of the high degree of configurability available.

So I can get an ECU+transmission combination from, for example, an Equinox with the LY7 and then reprogram the E67 with the parameter values straight out of the tune for the LS4 engine. In theory the controller should then be able to run the LS4 no problem.

My problem is that I cannot green-light the LS4 in my project unless I know I can get the starter on it with the 6T70. If you've figured that part out, please by all means let me know how. That is really and truly the only barrier to the LS4 project.

BTW, if you are worried about the torque capacity of the 6T70 I think the 6T75 internals will swap right in. While that may sound horrendous it's probably easier than finding an E67 combination with the 6T75 (I don't think there are any; all 6T75 uses that I know of are SIDI engines).

Also, I have to note that the ultimate goal of my project is an all-wheel-drive performance Epsilon car. I've been dreaming of this for probably a year or more and recently discovered that most of the parts will plug and play. In fact I could take a G6 or Malibu with the LY7 and 6T70 and create the all wheel drive car using the LY7. I'm just used to more power seeing as I currently drive a very modified LSJ powered Cobalt SS exceeding 300 HP (probably closer to 340-350 HP).

Anyway, the point is I am super super close to having all the techincal challengs answered, and then all I would need is to save the money to get the car and parts and make it happen. I hope people are still watching this thread; this is the closest I have seen to a solution that would meet my HP requirements! Thanks!

Funny...just last week or so I was telling GXP25 the same theory. Just need someone willing to pay for the parts

Since the 6T75 is physically similar in shape/format to a FWD manual transmission (differential output on passenger side is flush with the bellhousing), then you can probably adapt an Archie LS1 adapter/starter setup (by drilling/tapping and using the RWD bolt pattern on the back of the LS4) to keep the starter on the engine side (it is about 1 1/2" thick and uses a 168 tooth flywheel). My starter solution for the LS4/F40 6 speed (or the LS4 starter location in general) will not work due to the transmission front cover/ being right where the LS4 starter normally goes.

http://www.fastfieros.com/projects/l...1/my9_6T75.jpg

Here is the LS4 starter location... notice the back side of the starter will be well into the area occupied on the 6T75 valve body/front cover housing.
http://i152.photobucket.com/albums/s...4/IMG_7081.jpg
http://i152.photobucket.com/albums/s...4/IMG_7273.jpg

The other starter option would be to place a starter under the oil pan either using the prototype LS4 pan (or a modified LS4 or LS2 GTO pan - but both of these will require modification). Here is the LS4 prototype pan:
http://i152.photobucket.com/albums/s...u/LS4/ls1_.jpg
http://i152.photobucket.com/albums/s...S4/gtpls12.jpg

GTO oil pan:
http://i152.photobucket.com/albums/s...S4/GTOside.jpg

LS4 oil pan:
http://i152.photobucket.com/albums/s...4/IMG_7482.jpg[/QUOTE]

A engineer for Powertrain Control Solutions is working on a LS2/6T75 swap and developing the transmission control system for it as well... it is already a very interesting thread:

http://www.fiero.nl/forum/Forum2/HTML/119430.html

Its going to be nice

Is that "pocket" on the 6T75 in the OEM starter location of the LS4 or is it simply an ideal location should someone want to relocate the LS4 starter?

EDIT: Or does it not matter since the starter could be moved to this new location? The only issue with moving the starter could be the cover over pipe (cheap and easy to replace).

Also, TrueBlueGTO envisioned the starter idea that Dan86GT is using in his post here: https://ls1tech.com/forums/13410905-post14.html

Here are Dan86GT's pictures:

https://i1129.photobucket.com/albums.../DSCF2563w.jpg

https://i1129.photobucket.com/albums.../DSCF2564w.jpg

There shouldn't be any room issue against the block (new starter location circled in red - approximate):

http://i40.tinypic.com/4tr3tz.jpg

EDIT: Larger image: http://i43.tinypic.com/206zix1.png

And another image:

http://i43.tinypic.com/303es89.jpg

fieroguru, could you ask Dan86GT if his proposed module would be able to communicate with the E40 ECM?

So no T42-T43 adapter/converter involved, provided that the E67 ECM is used?

The pocket for the starter on the 6T75 is not the stock LS4 location, it is mounted up higher on the bellhousing. If you look closely at the 6T75 with the starter notch, that bellhousing is the high feature V6 bellhousing, not the Metric one used on the LS4. If you use the Metric bellhousing, this starter location will lose the top bellhousing bolt to make room for the starter and the block will need to clearanced slightly for the starter snout to overhang the bellhousing face.

Here is the Metric version:
http://www.fastfieros.com/projects/l...1/my9_6T75.jpg
Here is the one with the starter notch:
https://i1129.photobucket.com/albums.../DSCF2564w.jpg

I posted the question in the thread about the E40 and E67 ecms.

Thanks for the reply. Yes, I understand this. We wouldn't be interested in the metric pattern version since it's the 6T70 and not the 6T75. We'd want the 6T75 since it's higher rated.

An adapter plate would be used to mate the 6T75's high feature bolt pattern to the LS4's metric.

I haven't looked at the LS4's block up close in person (you'd have a better chance and letting me know), but I'm wondering if there's a little more room near that area where the 6T75's "pocket" is facing the LS4 block for that slight overhang of the starter.

Thanks for asking the question about the ECMs.

Why discard the 6T70? The difference is 20 lb-ft. Both transmissions are still exceeded by our motors, but have to be an improvement over what we have.

Besides, the 6T70 is probably more widely available.

I wonder if Dave at TEP has any magic he can sprinkle on these?

From the PFF thread:

Ratings aren't enough.

I think we all know that GM tends to rate their transmissions however they feel like. I tend to look at gear ratios and the vehicle the transmission is originally put behind.

The 6T70 is used in compact to mid-sized vehicles whilst the 6T75 is used in crossover SUVs with the intent of towing.

It also comes down to torque management with these new clutch-to-clutch transmissions (6L80/90, 6T70/75).

For the other LS4 cousins (SS sisters and Super), a more OEM shifting solution arrived courtesy of GM (thanks to BlauGXP for the picture):

http://i43.tinypic.com/k1cl83.jpg

The wheel should be a direct swap and you should be able to keep your airbag. There might be color issues with the Super.

Informative video on how the 6T70/75 works.

http://www.youtube.com/watch?v=X-wWfMnrx-U

Just curious as too how this is going guys , im still all in for a 6 speed swap , specially if it works with tapshift allready.

Any new info here? I am attempting to put a 5.3 Gen IV (58x wheel) with a 6t75 trans into a kit car.

LS4/6T75? What needs to be Solved?
 

How about a Recap?
of All of What is needed,
What has been Solved,
What needs to be Solved?
so we can work on what needs to be worked on,
and not work on something that has been Solved?

Probably never going to happen. Lets put the r&d into a manual swap from a g6!

My Recap
 

I can't speak for anyone else pursing the project. But the summary seems to be:

A) A custom oil pan is necessary to properly relocate the starter
B) A theoretical ECM/TCM solution is a possible solution to the 58x motor working
C) A custom adapter is necessary for the trans and FWD LS4 motor.

Speaking from my end. Making the custom parts is the easy part. But if the CAN bus systems reject one another, then additional programming R&D will be necessary. If someone has the engine and trans I could assist in testing "B" but someone has to take the plunge first to get at least those two.:usa:

I have a better Idea for a transmission, a T56. Now before someone boo hoos about a RWD conversion not being possible (like those with no fab skills always do) watch the videos. In a few years when my car is worn out I will be attempting this....or ruining my car in the process. These cars should have been RWD from GM, a FWD V8 is such a shame.


http://www.youtube.com/watch?v=u3WlHlZfXgw
http://www.youtube.com/watch?v=gv11PVoiL_c

Yeah, it'll happen. See below.

A is not necessary as shown here:

https://i1129.photobucket.com/albums...y-explodew.jpg

View from the transmission toward the engine:

https://i1129.photobucket.com/albums...ro/MPassyw.jpg

View from the engine toward the transmission:

https://i1129.photobucket.com/albums...-trnsstr8w.jpg

https://i1129.photobucket.com/albums.../DSCF2563w.jpg

https://i1129.photobucket.com/albums.../DSCF2564w.jpg

Link

The 6T70/5 have a little pocket on top of the transmission.

Here's a video of an LS2 + 6T75 matted together and turning over:


B is possible as you mentioned over the phone. However, like you said, there are issues with the E40 24x cars.

The same guy who put the above stuff together is a PCS (Powertrain Conrol Solutions) engineer working on getting this transmission to talk with ALL of our vehicles (and others). Apparently it's done. It's all a matter of testing and torque management.

C is not a problem and is done as well (yellow and cyan parts in the CAD drawings above).

But yes, it's the electronics which are the hard parts.

I rather spend the money on implementing the 6T75's AWD option instead as there are some serious weight distribution issues with these cars. Also, it'd be cheaper too.

I am nearing the finish line on my LS4/F40 swap:

Custom Flywheel (with cad prints):
http://i152.photobucket.com/albums/s...4/IMG_8004.jpg
http://i152.photobucket.com/albums/s...4/IMG_8003.jpg

10" clutch/pressure plate:
http://i152.photobucket.com/albums/s...4/IMG_8074.jpg
http://i152.photobucket.com/albums/s...4/IMG_8075.jpg

Bolt on Starter Bracket to keep the LS4 starter:
http://i152.photobucket.com/albums/s...4/IMG_9351.jpg

All done but finishing up the wiring harness:
http://i152.photobucket.com/albums/s...4/IMG_9357.jpg
http://i152.photobucket.com/albums/s...4/IMG_9359.jpg

Of course AWD would be awesome but wouldn't it be just as or more difficult than just a straight RWD setup? Also what are you refering to by the "weight distribution"? I don't think adding a little weight to the rear will affect much.

At fieroguru.... Drool!
Are you planing on making a kit for the other fiero guys? (tuning aside)

The way the W-body is setup, as with most FWD setups, the engine sits on or forward of the front wheels. This isn't very ideal in a RWD situation where a near 50/50 (front/rear) weight ratio is desired along with steering rack location et al. Do note that the GXP has a ~65/35 ratio.

Converting to RWD doesn't do much for this.

With money not being much an issue:

For traction purposes, AWD. For RWD "effectiveness" and feel, new car.

Our cars are not even worth expending the mental energy required to speculate on this. I know that this makes me "buzzkillington" but maybe we can collectively work on attainable goals like, stopping the fucking headliner from vibrating...

hhahahahahhahahhaha ^^^^^ love it! i completely agree!

Haha I agree with Texas That shit gets annoying

open up the headliner, i had a small 3inch in diameter, plastic circle that was just in there bouncing around . once i opened the back of the headliner it just fell out and the noise is now gone lol

Thanks, I plan on getting around to that this week. I knew it got bad when I contemplated driving the car into an overpass pillar the next time it happened.

the reason this all stopped is because they couldnt get the computer code written. There was 1000s of lines of code and when they went to programmers they wanted way too much money to write the code. So they stopped working on it.

That's a shame, would have been very cool to see happen...

I don't know where you got your information from, lol.

The swap is on hold. We are waiting on PCS or someone with an E67 wanting to try out what TrueBlueGTO suggested.

So anyone in New Jersey, step right up.

E67 as in from say my 08 GXP? Im in... What do i have to do... As im sick in tired of the trans in my car.

I have someone who is willing and interested in an LS4 for his kit car, hopefully we can justify and fit in the budget a testing of the 6T75 with it.

Get with TrueBlueGTO as I'm sure he'll be able to accommodate you.

I just hope you're close to New Jersey.

I for one am still interested in this, but am looking at the 6T70. Isn't the 6T75 a little bit bigger than the 70 for a W-body???

I would be up for this, but i would need the new trans first, the spacer plate and the starter bracket first wouldn't I??? Would love to get and have something better than the 4T65E in our cars, and hope to avoid having to go the TEP Stage 2 route for what i want to do with mine...

This mod is still plenty doable the best thing is I think the 6t75 is a standard bellhousing pattern which means any LS motor could make its way in a Wbody we all know the 6xx series will work in a Wbody since the 12+ impalas came with them from the factory.

I cant even imagine how an ls4 would do with a 6 speed. I would die to get one swapped into my gxp! Im sure she would roast the tires even easier than it does already:burn: Especially with shorter gears. Maybe the 3.69s or 3.73s.

I think the programming is the final hurdle to making this swap work, and for the reasons you mention above.

Well the good thing is we already have T42 Trans controllers which also control the 6t75 so some minor wiring and software change and it should work

So there's a certain model 6t70/5 i would need for use in my Impala? And is the T42 controller the same in mine, or is mine in my '07 a different model/number???

Trying to weigh my options, and see which I'd be better off with - a built TEP trans for the 300 whp project i am looking at doing, or trying my luck with the 6T70/5...

This would be really cool if we could ever get it working.
The gains in acceleration and mileage on the highway would be pretty good for a project like this.

I have an Allure (Lacrosse) Super now and I know a new transmission is in my future no matter what; it would be worth paying for a more modern 6-speed over a re-built 4 in my mind..

Thats what I was thinking. The acceleration with shorter gearing would make our cars rockets. A 6 speed with some 373s would be awesome and way more enjoyable to drive:thumb::drive:

I'd run drag radials for summer tires :cheers:

Thats always an option! I just wish it was a manual 6 speed instead of an auto:eyes:

No, the new six speeds have the T43 which is located inside of the transaxle.

Programming for this has already been taken care of and this transaxle can handle an LS2 without issue.

So there shouldn't be any issues with this swap?

Sorry to be a nag, but if there are no programming issues or power handling issues does anyone have any details or links to where we could get what we need?

If there are truly no programming issues all you'd need are mounts, programming, possibly custom axles, and a plate to adapt to the ls4 pattern and house a starter?

Thanks,

Mike

Seems the real barrier is the width - there is very little room left in the LS4 W body engine bay, so adding 2.5" for the trans plus an adapter plate would mean sectioning frame rails and/or strut towers.

Would be cool though..

Here is where a guy working for PCS (Powertrain Contol Systems) did a LS2/6T75 swap in the back of a fiero... He uses a PCS controller for the transmission, not the stock GM ECM.

http://www.fiero.nl/forum/Forum3/HTML/000136.html

Also, the LS4 bolts directly to the 6T75 w/o needing any adapter plate.

Even if you go the same route, the LS4 ecm calibrations are auto only, which means they have to keep their TCM's (or you can try setting the Manual Transmission flag in the calibration and see what it does). This means the P/N start interlock is within the TCM and it communicated that signal to the ECM via the high speed GM LAN wires. Also, the VSS is wired directly to the TCM and it sends the vehicle speed info to the ECM over the GM LAN wires as well. The guy running the 6T75 with the LS2 is using a factory Manual transmission calibration for the LS2 engine, so he can wire the P/N and VSS directly to the ECM

If the Manual transmission flag allows a P/N and VSS signal to be wired direct to the ECM, then that would greatly simplify things. But unfortunately, no one has confirmed what happens with you set this flag on an LS4 calibration (E40 or E67).

If you have to turn off the DTC for the 4T65e-hd, then you will need to find someone with TunerCat as HP Tuners does not have access to most of the Transmission DTCs in the LS4 calibrations.

So I would say it is premature to state that the wiring/programing issues have been figured out for the LS4/6T75 swap.

For my 6 speed manual transmission LS4 swap (also in a Fiero), I kept the TCM and did some hard wiring and resistor work to get as many of the signals as possible to be within the expected range. I still had 2 DTC from the missing transmission, so I had them turned off by a guy with TunerCat.

Thanks for the link!
Read through the whole thing and it looks like doing this swap first would be a long-drawn out process that may not necessarily be successful.

First gear also looks bad enough on a Fiero, can't imagine how it would be in a FWD where the weight squats to the rear pretty good!

If someone had this done/documented I'd be much more willing.

Here's hoping that this does indeed happen one day (hopefully before my 4T45E blows).

Fiero how was it possible a ls2 and ls4 both bolt up to the same 6t75.

Adapter plate on the LS2 to convert from the RWD SBC pattern to the GM Metric pattern:
https://i1129.photobucket.com/albums.../DSCF2571w.jpg