8HP70 and 4.0?

[speeding_infraction]

It isn't a matter of opinion. Anyone who has driven one would never make the statement that OD is only good for long downhill stretches of highway. So, either you have never driven a 42RLE for any length of time, of the ones you have driven were not geared properly.

So, that also means that the 8th gear in the 8HP is useful when the gearing is good.

BTW- this all has been discussed and the previous question and concerns were not addressed so maybe someone has some new info that will be useful. Have they figured out a good CAN Bus translator to toss into the controller install? If not, how do they plan to shift it properly in the TJ?

It's a standalone controller. I think similar to the US shift controllers for the ford 6r80

 

[mrblaine]

It's a standalone controller. I think similar to the US shift controllers for the ford 6r80

We are all pretty aware it has to be a stand alone controller, that's nothing new. The question is how does it translate from the Jeep infrastructure to the CAN bus the transmission requires? It matters for shifting.

EDIT- don't misinterpret, I am not against any of this. I want it to work. I just don't want something that is almost good for what this is going to cost.

 

[macleanflood]

Radical solution would be a Haltech to control both the engine and transmission.

-Mac

 

[Woodrow]

The ZF 8HP is probably the best automatic transmission ever made. Very reliable and built to handle quite a bit of power. I didn't see where the controller was coming from.

I had a land rover LR4 with the 8HP and it was honestly perfect.

We have had 2 BMW SUVs with that transmission and I agree it is outstanding. Not the best auto I have experienced though. That would be the Porsche PDK.

 

[JMT]

We have had 2 BMW SUVs with that transmission and I agree it is outstanding. Not the best auto I have experienced though. That would be the Porsche PDK.

Just a bit of German here. PDK is a mouthful but makes sense…

Porsche Doppelkupplungsgetriebe

Double clutch gearbox. Bring it….

 

[MikeE024]

I haven't seen this talked about here yet. American Iron says they are nearing completion of a swap kit to put the 8HP70 behind a 4.0. They mention that it is shorter than a 42RLE and will include a standalone transmission controller. An 8-speed behind a 4.0 could be fun and make the engine feel more powerful and controlled. Of course, you're adding in a lot of complexity to a simple machine, but should be interesting to follow along.

View attachment 698806
https://www.facebook.com/share/185vMGUb4Y/

Here is a modified post I previously made on the subject:

There are other companies who offer it, but American Iron Offroad has been flooding the internet with marketing recently, so it's catching eyes who previously weren't aware.

I've seen multiple "8HP swap" folks warn against running a stand alone TCU in analog mode for engine commands instead of CAN bus since the cuts and blips functions don't work as well for shifting the 8HP.

"cuts" (cuts the throttle for up shifting)
"blips" (blips the throttle for down shifting)

I wouldn't want an 8HP if I couldn't have the shifting inputs working correctly over CAN bus since it's part of what makes the 8HP experience great. The best answer I know of is replacing the ECU and TCU with something like a MaxxECU that controls the engine and transmission using CAN bus. You could also run something like the Holly Terminator and Turbolamik.

99% of TJ owners will probably never consider this experiment once they learn how much effort and cost is involved. Personally speaking, an 8HP would be sweet with the TJ's turbo'd 4.0L, but future 8HP plans will be for the LJ's LS2. Generally speaking, I believe it makes more sense to install the 8HP with a LS/Hemi if you are going to go to all of the effort.

 

[Wildman]

Here's the controller I got for my 8HP70 swap..

https://www.soundgermanautomotive.com/pcs

It's also the kit that Jeep Speed Shop sells with their Hemi swap kits...
You can fun a stock Challenger shifter and if you have your transmission flashed you can have the tap shift ability..

Obviously any trans swap will be expensive, but these are likely going to be north of $5k. The controller alone is 1500, plus transmission, converter, two adapters, crossmember etc. but, it would be sweet. If the 4l60 ever blows in my XJ, there is a very high chance that a zf8 transmission will take its place

You only need the engine to transmission adapter as long as you are using a Dodge/Ram 4WD 8HP transmission for the swap since it's the same 6 bolt 23 spline as the NP231.

I'd be curious to see the dimensions compared to the current trans options. It would be pretty cool to have an 8 speed but the top ratio is even lower than the 42RLE, so you might still run into the same issues of having to run super short axle ratios to be able to use all the gears, which then also makes trouble with driveshaft speeds. Otherwise you're really going to end up with a 7-speed auto where 8th gear only happens on a long downhill stretch. Looking at the ratios, the 42RLE first gear is between second and third gears in the 8HP, so you'd get an improvement in crawl ratio without having to run lower gears, but you'd likely just be using 7th as your OD and staying out of 8th.

8HP75:View attachment 698833 42RLE: View attachment 698834

Definitely could be useful but maybe something like the ZF 6HP would fit even easier and get you the right number of gears and ratios, if it has the same bellhousing pattern and could be mated to a transfer case.
6HP:View attachment 698835

The 8HP transmission have less parasitic drag than a standard auto transmission which might help the 4.0....

 

[Wildman]

Here is a modified post I previously made on the subject:

There are other companies who offer it, but American Iron Offroad has been flooding the internet with marketing recently, so it's catching eyes who previously weren't aware.

I've seen multiple "8HP swap" folks warn against running a stand alone TCU in analog mode for engine commands instead of CAN bus since doing so causes you to lose the important cuts and blips functions for smoothly shifting the 8HP.

"cuts" (cuts the throttle for up shifting)
"blips" (blips the throttle for down shifting)

I wouldn't want an 8HP if I couldn't have the shifting inputs working correctly over CAN bus since it's part of what makes the 8HP experience great. The best answer I know of is replacing the ECU and TCU with something like a MaxxECU that controls the engine and transmission using CAN bus. You could also run something like the Holly Terminator and Turbolamik.

99% of TJ owners will probably never consider this experiment once they learn how much effort and cost is involved. Personally speaking, an 8HP would be sweet with the TJ's turbo'd 4.0L, but future 8HP plans will be for the LJ's LS2. Generally speaking, I believe it makes more sense to install the 8HP with a LS/Hemi if you are going to go to all of the effort.

Since I don't have my 8HP swapped yet I can't confirm but from what I've been able to understand the cut & blips isn't needed if the transmission is tuned and you're not drag racing or such things with it. But again I'm not 100% sure on this yet and am going off what I've had others tell me.
But there are ways to get it to work without the CAN bus.
Also not sure if Hotwire could add a CAN bus plug into a harness for a TJ/LJ so you could run a newer PCM that had this available.

 

[D's Jeep Wrld]

Radical solution would be a Haltech to control both the engine and transmission.

-Mac

Edit take that back,Id love to use a haltech but they don't have a standalone that'll control it yet,It's MaxxEcu (with gen 1 8hp's) ! Those guys have something that'll control both the engine and the 8hp !!! The options for TCUs is Turbolamik,CANTCU,And a mini MaxxEcu controller that can be ran with the haltech

Yep,That's my plan too! Id love a standalone ecu for my Lj once I go with a turbo but It knocks 2 birds with 1 stone since It'll let me control the 8hp

Can't wait to use the simulated clutch and transbrake,The clutch kick feature seems to work great ! Seen it being used on drift cars so I know it works !

 

[MikeE024]

Here's the controller I got for my 8HP70 swap..

https://www.soundgermanautomotive.com/pcs

It's also the kit that Jeep Speed Shop sells with their Hemi swap kits...
You can fun a stock Challenger shifter and if you have your transmission flashed you can have the tap shift ability..

The challenger shifter option is available from every TCU vendor I've considered. The shifter is ugly, but I could potentially get over it. TurboLamik and others (including SGA) also offer paddle shifters.

Since I don't have my 8HP swapped yet I can't confirm but from what I've been able to understand the cut & blips isn't needed if the transmission is tuned and you're not drag racing or such things with it. But again I'm not 100% sure on this yet and am going off what I've had others tell me.

Dodge didn't make the cuts and blips functions for their truck customers to go drag racing. And the transmission needs to be tuned no matter what. (google why cuts and blips exist in the 8hp transmission...for daily driving).

But there are ways to get it to work without the CAN bus.

Yes, folks reported that the cuts and blips don't work as well with analog inputs instead of CAN bus.

 

[GoldenGorilla]

If I were making purchases today, I'd go with the MaxxECU instead of the TurboLamik route since the TL can't provide cuts and blips via CAN bus with the LS2's E67 PCM.

My buddy has listened to me praise his trucks' 8HP transmissions for years (e.g., how well they shifted, how cool they run). I consider the 8HP to be a dream upgrade for my rig, and I'm not willing to grossly undermine the enhancement if that opportunity ever presents itself. I'm about to call my buddy right now to tell him how awesome his transmission is because it's that's F good.

How about a turnkey solution
https://blueprintengines.com/engine...t-engines-calibrated-ecu-natural-pulley-kit-3

 

[mrblaine]

How about a turnkey solution
https://blueprintengines.com/engine...t-engines-calibrated-ecu-natural-pulley-kit-3

Iron block, why?

 

[MikeE024]

How about a turnkey solution
https://blueprintengines.com/engine...t-engines-calibrated-ecu-natural-pulley-kit-3

I watched his SEMA video on this last year.
View: %5BURL%5Dhttps://youtu.be/JtrVIIdtYQs?is=gjZtKxyPif4ptcqk[/URL]

 

[ColoJeep]

How about a turnkey solution
https://blueprintengines.com/engine...t-engines-calibrated-ecu-natural-pulley-kit-3

Honestly , that's a great deal . Especially if you value your time at all . If you think of the cost to built a new 530 h.p. V-8 then the ZF-8 is a new transmission not a used unknown . This has 50 more h.p. than the 392 Hemi , plus 25 more lb.ft . What would a new 392 engine and transmission cost from Stellantis ?

 

[D's Jeep Wrld]

If I were making purchases today, I'd go with the MaxxECU instead of the TurboLamik route since the TL can't provide cuts and blips via CAN bus with the LS2's E67 PCM.

My buddy has listened to me praise his trucks' 8HP transmissions for years (e.g., how well they shifted, how cool they run). I consider the 8HP to be a dream upgrade for my rig, and I'm not willing to grossly undermine the enhancement if that opportunity ever presents itself. I'm about to call my buddy right now to tell him how awesome his transmission is because it's that's F good.

Yeah the 8hp In my Diesel gladiator has had me wanting one big-time these few years for the Lj I've been eager for years to go with an 8hp but unfortunately I broke my 42rle too early if I had broken it 3 months ago I would've been able to go with an 8hp....rather than spending 4k towards an Ax15 a little over a year ago (because a built 42rle wasn't ideal for me at all for my driving style so I had to go with an Ax15)

 

[mrblaine]

(because a built 42rle wasn't ideal for me at all for my driving style so I had to go with an Ax15)

There's a pretty goodly sized group of folks on here that can be recognized simply by their most common mottos without ever seeing their names.

Smart phones suck (ring any bells?)
I drive like an ass
Tons and fodeez

Should I keep going?

 

[Strizzo]

It isn't a matter of opinion. Anyone who has driven one would never make the statement that OD is only good for long downhill stretches of highway. So, either you have never driven a 42RLE for any length of time, of the ones you have driven were not geared properly.

So, that also means that the 8th gear in the 8HP is useful when the gearing is good.

I have an 05 so i have driven a 42RLE for enough time i'd say. My point was that if you want to use 8th, you need to regear to 4.88-5.13-5.38 and still have the issues with driveline vibrations due to high driveshaft speeds, plus you don't really need the 4.71 first gear with that low gearing except for improved crawl ratio. If you get the 8HP for the lower first and second (both lower than 42RLE first) gear to turn bigger tires without running very low axle ratios, the 8th gear 0.69 OD is likely too tall.

- example: running 35s and 4.27 axle ratio running in 7th gear 0.84 instead of 8th gear 0.69 and 5.13 axle ratio would get you about the same final drive ratio without spinning driveshafts to the moon.

We have had 2 BMW SUVs with that transmission and I agree it is outstanding. Not the best auto I have experienced though. That would be the Porsche PDK.

I'm talking about torque converter autos, but if it has a clutch, i'm doing the shifting myself tyvm.

 

[ColoJeep]

There's a pretty goodly sized group of folks on here that can be recognized simply by their most common mottos without ever seeing their names.

Smart phones suck (ring any bells?)
I drive like an ass
Tons and fodeez

Should I keep going?

The spectrum is very wide . That's what makes it interesting , Jeep owners are not a Monolith .

 

[mrblaine]

The spectrum is very wide . That's what makes it interesting , Jeep owners are not a Monolith .

I think you got the spectrum part nailed as in on.

 

[mrblaine]

I have an 05 so i have driven a 42RLE for enough time i'd say.

Tire size and gear ratio??