I am planning on doing the 8HP70 swap into my 2003 Aristo over the winter. I'll be using the HTG GCU, wiring kit and transmission adapter. I am currently collecting parts for the swap. I will document the
entire process.

 

I am planning on doing the 8HP70 swap into my 2003 Aristo over the winter. I'll be using the HTG GCU, wiring kit and transmission adapter. I am currently collecting parts for the swap. I will document the
entire process.
[/引用]
Are you using the factory ECU?

 

That would be amazing, where are you going to get the adapter for the trans? what trans are you using the BMW 8hp70?

 

HTG has the Adapter and Flywheel. I'll be using a a 8hp70 from a BMW as that's what the HTG Adapter fits. Also the BMW transmissions are easier and cheaper to source than the Dodge ones.

 

I'm really curious to see how that transmission would compare to the built 6R80 options that exist with PHR adapters. The 6R80 is so easy to reinforce to support 1500+whp, I wonder if 8 speeds vs 6 is really an advantage. I expect an 8HP transmission would be superior if the shift mapping was all dialed in and it could hold the HP, but it's that second part that makes me curious.

Anyone know how much HP they've supported in other conversions?

 

I'm really curious to see how that transmission would compare to the built 6R80 options that exist with PHR adapters. The 6R80 is so easy to reinforce to support 1500+whp, I wonder if 8 speeds vs 6 is really an advantage. I expect an 8HP transmission would be superior if the shift mapping was all dialed in and it could hold the HP, but it's that second part that makes me curious.

Anyone know how much HP they've supported in other conversions?

I think it'll be pretty application specific. The 6R is easy to make handle a lot of power like you said. I picked up a $600CAD junkyard trans, completely rebuilt it and added a circle D converter all in for under $3500 CAD or so for a built trans rate to handle double the power and torque my car makes. Converter options and clutches for the 8HP able to handle that much power and allow you to build boos ton the line may be limiting factors that could be overcome. The 8HP looks to be better from a dynamic driving perspective.

I have heard and seen very mixed reviews with the practical use of the HTG GCU and I ultimately steered clear of the unit. There were too many reported issues for the price point when I investigated it. I would advise you to really research its real-world capabilities, drivability and ability to deliver on your goals for the specific setup you are looking to run. Just because something works well for an 8-second 1/4 mile pass does not mean it will have good low-speed or street manners, or dynamic response to different driving conditions.

 

Subscribed.
I've also spent hours researching this same thing. 8HP70 and 6R80. There's also Sound German Automotive that have 8HP TCUs and adaptors, some other stuff not listed on their website. And check out PMC Motorsports for some other 2jz adapter plates and torque convertors adapters. Shops are starting to sell pcbs (printed circuit boards) that makes soldering the 8HP mechatronics super easy. Caveman easy.

The supply of junkyard 8HPs and price difference between a 70 and 90 are pretty significant. I don't think I'd need a 90.

I too am interested in any mods required to the MKIV trans tunnel and driveshaft length required.

As far as gearing, I could imagine we could still run a low-rpm torque converter, a larger frame turbo and not worry about lag!!!!! Even program the TCU to start in 2nd or 3rd gear. I got behind a Jeep SRT at a red light and that beast shifted through 3d before it cleared the intersection.

I really want to try it!!!! Even with a BPU on stock twins, I think the car would be a totally different monster with a 8HP or 6R.

 

Subscribed.
I've also spent hours researching this same thing. 8HP70 and 6R80. There's also Sound German Automotive that have 8HP TCUs and adaptors, some other stuff not listed on their website. And check out PMC Motorsports for some other 2jz adapter plates and torque convertors adapters. Shops are starting to sell pcbs (printed circuit boards) that makes soldering the 8HP mechatronics super easy. Caveman easy.

The supply of junkyard 8HPs and price difference between a 70 and 90 are pretty significant. I don't think I'd need a 90.

I too am interested in any mods required to the MKIV trans tunnel and driveshaft length required.

As far as gearing, I could imagine we could still run a low-rpm torque converter, a larger frame turbo and not worry about lag!!!!! Even program the TCU to start in 2nd or 3rd gear. I got behind a Jeep SRT at a red light and that beast shifted through 3d before it cleared the intersection.

I really want to try it!!!! Even with a BPU on stock twins, I think the car would be a totally different monster with a 8HP or 6R.

Unless the 8HP can offer a more refined ride when built (the 6R80 has a bit of a clunk in 1st and 2nd, at least mine does fully built with converter, billet shaft, and clutches) the 6R really gets the job done. double overdrive and lockup converter that can withstand over 1300HP locked up, those extra two gears are likely only going t really make a difference in really specific circumstances.

Driveshaft is dead easy - any competent aftermarket driveshaft shop can make one to length with the correct flanges.

The key components after having done this are the TCU, how much torque the trans can carry through the shift, shift speed, and integration with the EMS (e.g. if you need/want auto-blip downshift, torque reduction on upshifts).

 

G Mash, you are certainly an MKIV pioneer posting all of your dealings with the 6R80 trans. I think I've read all of your threads and vids. Thanks for contributing. I think there is one other MKIV with this trans, but only a couple vids on UTooob.

I was hoping US Shift would have all the bugs worked out of their software. Their product looks like it has potential, but waaaaay to expensive, IMHO. I haven't seen any other alternatives to US Shift, although some high-end ECUs are now able to control the 6R80 (MoTec.)

The price-point for the 8HP seems to be about the same, but 2 or so more TCU options. I haven't encountered any 8HP people talking about clunky shifting. The 8HP seems to be the bees-knees.

As far as gearing, 1st gear in the A340 = 2.8, 6r80 = 4.2, 8HP = 4.7. So, with double the 1st gear ratio, I would think a high-stall torque converter wouldn't be required for a big turbo. It seems some of the Chrysler guys (SRT) are running 2800-ish stall torque converters for street/occasional strip. Perfect!

To dig further into the weeds, plotting the gearing ratios vs. torque/HP curves would tell us a lot about potential speed vs. RPM-loss for the entire rev-range. And, this may even show if raising the RPM redline would be beneficial. Fun with numbers!

 

Here's another topic for discussion: I was reading on another forum about a gearing debate for turbocharged motors. It seemed to make sense to me. Turbochargers need engine load to create boost, i.e., power. That is why the A340, TH400, and other automatics with a 2.xx first gear ratio is a great match for the 2JZ. Having a very aggressive 1st gear wouldn't load the engine enough to create high boost, thus a low 1st and 2nd gear ratio are more fitting for NA or supercharged engines. My argument is: Ford 6/8/10 speed transmissions are used in the small-ish Ecoboost engines, and they seem to be super quick.

SRD Tuning offers a bellhousing plate and flex plate adapter for the AA80 and CompuShift website says they may have a controller for it! I think those trans are rated at 450-ish ft lbs.

In 2021, there seems to be a lot of options to try, not just the auto-to-6 speed manual conversions! Most autos will require DBW conversions and a controller with lots of tuning. I just don't want to cut/massage the tunnel and spend 5 figures doing it.

 

Hi everyone! Started my swap. ProEFI + HTG-GCU. Here the comparison of A340E and 8HP70 size

BMW coupler will not fit aristo driveshaft. Not surprized.

 

Those appear damn close in size from this angle, sub'd.

 

they have almost equal length, but 8hp much more beefy

 

I'd be interested to see it next to a factory manual W, R or V trans, I bet they're pretty similar. Have you tried tucking it up against the trans tunnel to see what fits or needs adjustment?

 

Garage Whifbits mentioned in instagram comments that no tunnel modification needed. Will see when I put my in place. I got my trans for $120 so i firslty need to open it for the review.

 

I thought I saw an 8HP-to-Toyota driveshaft yoke adapter in one of the kits. I'll see if I can find it again.

 

Whifbits made their own transmission end, to fit OEM AUTO TT driveshaft.
As i had Aristo trans on my Supra and custom driveshaft,
I have 2 options:
1) make custom billet coupler to apapt Toyota and BMW flanges
2) make hybrid front driveshaft
Price almost the same.

 

PMC Motorsports (Poland) may also have a yoke flange. It's not listed on their website, but I would think they have a prop flange solution for this trans swap. I really like their innovations and parts offered for the 2jz.

What kit (or parts) are you using? Many pics, please!

PMC Motorsport Adapter Kits Toyota JZ 1JZ 2JZ (pmcmotorsport-shop.com)

Also AutosportEngineering.

 

I use parts from these guys: Engineered by DomiWorks - Custom parts for all needs (adapter plate, torque adapter, cooler adapter, board and board cover)
i think I will make custom drive shaft to use with bmw OEM couplers.
more info you could find here : https://www.drive2.com/r/toyota/supra/4062246863888351636/ last 3 posts. use google translate.

 

I use parts from these guys: Engineered by DomiWorks - Custom parts for all needs (adapter plate, torque adapter, cooler adapter, board and board cover)
i think I will make custom drive shaft to use with bmw OEM couplers.
more info you could find here : Toyota Supra LHD 8hp75 Single on DRIVE2 last 3 posts. use google translate.

Stange. I have a 2001 aristo and using the DomiWorks guibo it works with oem driveshaft.

I had an older one which wasn't machined properly. The newer ones also come with a seal in it and a new nut.

 

Sorry my 8HP70 project has been put on hold until the fall. I had a turbo go bad so I had the stock turbos rebuilt with a Hybrid setup and I also purchased one of Stu Hagens Cast Exhaust manifolds to complete the project. I will be going ahead with the transmission swap once I acquire all the parts. Yes I am going with the stock ECU. As a side note Garage Whifbitz out of the UK has a complete 8HP70 Swap Kit for the IV Supra now available.

 

Man, this swap is so interesting to me. I'm leaning towards the 1EA0B (latest/greatest CD009) but with the GR700A kit only $4k ish more and this ZF auto trans being the latest in technology, it's hard to make an official decision. Too many options, such a good problem to have.

 

I bought the GCU and 8HP kit directly from the HTG website.

Do you know how to solve the problem of signal communication between HTC GCU and factory ECU?
factory ECU to HTC GCU

B23	VTA	Throttle Position Sensor (Actual Throttle Position Sensor)
D20	TACH	Tachometer
E9	IGSW	Ignition Switch
D6	STP	Stop Light Switch
B10	VG	Engine Airflow
B22	THA	Air Temperature Sensor

HTG GCU to factory ECU

C4	NCO+	Automatic Transmission Over Drive Direct Clutch Speed Sensor
C5	SP2+	Speed Sensor
C10	NCO-	Automatic Transmission Over Drive Direct Clutch Speed Sensor
C11	SP2-	Speed Sensor
C17	OIL	Automatic Transmission Oil Temperature Sensor

D16	R	Automatic Transmission Reverse Gear Position Indicator
D17	D	Automatic Transmission Drive Gear Position Indicator
D26	P	Automatic Transmission Park Gear Position Indicator
B13	N	Automatic Transmission Neutral Gear Position Indicator

 

Did you also purchase HTG's wiring kit for the stock ECU?

 

Yes! I have purchased HTG's wiring kit.

 

Well as I stated, I have not started the project yet as I was planning to do. I would contact HTG Technical Support and go from there.

 

Ditto, Keith.... you need to make a bee line to HTG. I'm sure some of this has to do with the new shifter that is required for this conversion.

Good luck.

 

May I ask you a question?
What is bee line?

 

It's an American slang (idiomatic) term that means to go in straight line from one place to another. In this context it means not to waste time and go right to HGT.

 

OK! Thank you!

 

Since this is still pretty fresh I'm going to ask this. Seeing that this is an 8 speed a bigger first gear than the original 4 speed etc. Do you guys know if a higher stall torque converter or custom built torque converter will still be necessary? And just a couple unimportant questions if you have the answer. Will you need to buy an electronic shifter with this along with a shift boot and will this swap kit fit for an is300 aside from it probably being able to fit the driveshaft cause I'd like to know if I would need a custom transmission mount.

 

Full disclosure: I have not done this conversion, but I've spent a TON of time researching it. I am really interested in it.

Dareman, these are great questions. My theories are:
1) I don't know the physical dimensions of a A340E TC vs. the 8HP TC, but the stock stall speeds should work nicely and I've seen adapters to fit a BMW TCs to a 2JZ. I believe the Hellcat TC stall is around 2K RPM, some BMWs around 2200 and our A340e stall is 2600-ish. Obviously a different torque curves, but the shorter 1st gear should make up for it.
2) BUT... turbos need engine load to create boost (mo' powa) and I am curious how much boost is created, or even needed, with such a short 1st gear.

3) SO... with the modern aftermarket transmission controlling units, I believe it is possible to start the transmission in 2nd gear, instead of 1st. Or start in 1st gear and skip 2nd gear... etc... I think you can program it to do some tricks like that.

You will need an electronic shifter. Sport shifters from late-model Chargers/Challengers work, as well as the Mopar rotary dials, but I believe the preferred shifter is one of the BMW M3 sports-sticks with manual shift-mode, so you can tap up/down for changing gears. I don't know about IS300 shifters, but they may work if they are electronic. That would be ideal, if your platform is the IS300.

And I would 99% assume you'd need a custom transmission mount or a conversion kit.

Hope this sheds some light, and I'm hoping someone can post more info on this swap.

 

Full disclosure: I have not done this conversion, but I've spent a TON of time researching it. I am really interested in it.

Dareman, these are great questions. My theories are:
1) I don't know the physical dimensions of a A340E TC vs. the 8HP TC, but the stock stall speeds should work nicely and I've seen adapters to fit a BMW TCs to a 2JZ. I believe the Hellcat TC stall is around 2K RPM, some BMWs around 2200 and our A340e stall is 2600-ish. Obviously a different torque curves, but the shorter 1st gear should make up for it.
2) BUT... turbos need engine load to create boost (mo' powa) and I am curious how much boost is created, or even needed, with such a short 1st gear.

3) SO... with the modern aftermarket transmission controlling units, I believe it is possible to start the transmission in 2nd gear, instead of 1st. Or start in 1st gear and skip 2nd gear... etc... I think you can program it to do some tricks like that.

You will need an electronic shifter. Sport shifters from late-model Chargers/Challengers work, as well as the Mopar rotary dials, but I believe the preferred shifter is one of the BMW M3 sports-sticks with manual shift-mode, so you can tap up/down for changing gears. I don't know about IS300 shifters, but they may work if they are electronic. That would be ideal, if your platform is the IS300.

And I would 99% assume you'd need a custom transmission mount or a conversion kit.

Hope this sheds some light, and I'm hoping someone can post more info on this swap.

Yeah I've asked people who done this swap on youtube these questions no reply. and it probably doesn't help this only been done in a foreign country. Why not America is weird I guess they only like manuals over here. Seems like mostly everything in the kit would work I just wonder how would a custom transmission mount work and where would you do that at? Yeah No one said anything about the TC in any of the videos I've seen I was hoping to get a decent amount of push and throttle response when I'm coming off stop lights. This will be a street car so. IS300s shifters are definitely not electronic I did like my stock shifter but it is what it is. I guess a shift boot will work to make it look presentable and the BMW shifter lights does match the amber illumation in the car so it'll fit together.