I learned that the Hellcat has the ZF 8HP90 8-speed transmission.
A friend of mine works at ZF (first time advantage living in germany as a US-Car fan).
The modern HEMI are small blocks, is that right?
Can I somehow fit it on a 400 cui big block. It has really cool gear ratios, so I don't have to change the rear axle ratio soon.

That would be really cool.

I have friends at, ZF and some who could build me a fitting driveshaft.
I just need to know if it could fit to the engine and under the car (space, shifting and mounting).

If I could get this to work... it would be awesome.

You would need an adapter plate as a SB trans will not bolt up to a BB or vice versa.

The ZF trans will be substantially larger so you will have to deal with restructuring your floor pan and torsion bar crossmember.

Final (and most substantial) issue is the ZF is electronically controlled. Unless ZF makes or has some sort of stand alone transmission controller, or unless you're a computer engineer, you're kinda outta luck.

Anything can be made to fit anything else. But it'll boil down to how talented you are, or your friends, to make it work.

I watched a guy build a Yugo with a 460 in it. Pretty sure the 460 weighed more than a stock Yugo did. But he built it right, caged, reinforced, etc.

i am an electric engineer.
the floor wouldn't be a problem.
I have a 74 newport. isn't the torsion bar crossmember wide enough? I think that would be the biggest problem for me.

some time ago I read that some guys already put modern transmissions behind big blocks.
As far as I know modern transmissions have computers for themselves and are not (or not totally) hooked up to the ECU.

I'd really like to make this happen. Of course there would be more intelligent solutions. keeping the 727 would be one

As far as I know modern transmissions have computers for themselves and are not (or not totally) hooked up to the ECU.

The transmission gets a substantial amount of info from the ECU to perform it's own calculations and performance. Better look WAY deep into this before you shell out any money.

Physical fitment issues are basically dependent on how mechanical you are and what equipment/facility you have available.

ZF builds the tranmission for many car manufacturers (chrysler, BMW,..). The german site says that it has an integrated control system.

But that really isn't the problem.

My question is (and was) if it could fit to the engine.

Even if I would need an ECU, I can make that happen.

You would need to make an adapter plate to go from small block to big block bolt pattern ... there is not one available that I have ever seen...

Unless the bellhousing is removable then you could just adapt it to another bellhousing.

okay. I never made an adapter plate. I need to call a specialist for that.

But the 8hp70 has a built in starter generator. Such a starter generator may be modified to act also as an adapter.
I think I have to call some people I know.
If you guys are interested I can write here, what they said.

I know that such a transmission is not really the part to put in an old, cool and original mopar. But I find it quite interesting.
It would bring out the best of the original 400.
With the new heads, pistons and cam (and modification to the subframe and such) it would be really fun to drive.

I would have to import a new rear wheel gear ratio, a new converter and such. with the shipment cost, I could buy just a transmission here in germany. And I have an expert right on my side to help me.

Assuming the trans you want to use has a small block bellhousing bolt pattern, this adapter would likely work for you. http://smrtrans.tripod.com/smrtransmissionsintro/id9.html

Your biggest problem is going to be floor pan and torsion bar xmember clearance. You are almost certainly going to have to do some major fabrication there.

I absolutely LOVE that 8 speed automatic transmission. The wifes 2015 Challenger has is. You have to drive it to gain an appreciation for it. You are rarely ever in the wrong gear. Tap the throttle at any speed and the car just rockets away. I would love to use one in my 70 Charger, but the electrical aspect makes it a no-go for me, plus they are probably $8000 or more.

If trans is made for different cars-engines, I would look at each application for a bell size close to a 400-440 because some type of adapter will be needed. If you get the electronics worked out by all means let me in on it, there a lot of sensors that go with the trans, going thru this with the Nag trans myself. This will be a tough process, Kinda like taking a spaceship and making it into a rowboat.

If my memory serves me correctly, I believe that trans has a bolt on bell housing and the actual trans shares a lot of pieces with the AMG/Benz trans. If a unit like the Ultrabell was made for that, it would be a slam dunk. The Kiesler based 4L60E GM based trans uses a bolt on bell for other than GM/Chevy swaps. If you come up with a standalone controller, you may have something!

@ mgoblue9798: thank you very much for the link

I think the hardest part will be the crossmember and, with the electronics, the "kickdown".
I think the transmission needs to know it step on the gas. Or else it would be worse than the old 727.
I have to talk to the guy at ZF.

What their website doesn't tell you clearly, is on your engine block you have to grind off your lower driver side transmission mounting ear. This ear gets in the way of the small block starter mounting location. If you don't do this, you won't be able to mount the starter unless you grind and reweld your SB bellhousing to accommodate the BB starter mounting location.

If the ZF transmission has it's own starter system, you may be saved this headache.

As for the trans controller, at a minimum I would expect the trans controller to want to see throttle position. Trans controller would also want to be tied into a speed sensor and engine RPM. If the ZF trans controller is expecting to receive this information through the OBD-2 CAN bus, I think you are screwed unless you can scrape together a controller to emulate this signal and provide the ZF ecu with a TPS, RPM and VSS signal at a minimum. The ZF controller could conceivably get it's own speed signal from it's speed sensor but I think for rpm and throttle position you would still be stuck. You would have to dive much deeper into this before you would even think about buying a transmission.

You will have to plan to slice and dice your floor pan and torsion bar crossmember to make this fit. The old mopar transmissions were quite skinny compared to modern ones. I applaud your desire to put a modern transmission into your car, IMO it's the way to go to get the most out of your old car!

I have a 5 speed out of an 07 Charger in my GTX behind a 5.7 hemi. What a blast to drive and the mileage is great. MAJOR pain in the ass to get it to work without the stock speed sensors. Finally found a guy who wrote a program to manage this type of swap and that is what made it work. Nothing else we tried got us out of limp mode.
You might want to talk to him. I don't know how much experience, if any, he has with the 8 speeds but it is worth asking.
Russell Drake
www.soundgermanautomotive.com

thanks for all the help, links, contacts and explanations.
That helped a lot.
I also think I have to write a new program or use a dummy ECU.
The real problem is the throttle position. Is there any carburetor with a sensor on it or do I have to switch to an EFI?

EDIT:
I found a video where a guy modified an edelbrock to mount a throttle position sensor.
Also the RPM shouldn't be a real problem. If the normal RPM signal from my distributor won't work I'll get another from msd.
Sure it won't be just plug & play.
But there is a basic transmission and you can add what you (more the car manufacturer) want.

Again, the ZF transmission controller is not going to be looking for a raw RPM input from a coil or MSD unit. It's most likely looking for this info through the CAN bus. Your friend at ZF is going to have to dig up a fair amount of technical info for you.

Adapting a throttle position sensor to your carb is the easiest part of this whole swap. Something like this would work for you...

http://www.hgmelectronics.com/products-t...tion-sensor-kit

The trans talks to the rest of the control modules over CAN C. It gets vehicle speed from the ESC module. Throttle position, Engine RPM and others from the PCM. Your not going to be able to duplicate those signals. It would require a ton of software re-write to get it to work. Unless you get the hardware/software support of ZF it wont work.

Don't forget the electronic shifter as there is no shift cable. The trans valve body assembly also contains the trans controller. That being said you still need other sensor information that is broadcast over the Can C bus as others have said.

the transmission can be shifted mechanical.

what about the edelbrock e-street EFI?
It has a throttle position sensor, needs a RPM signal and much more for it's "ECU". Does it work with can bus?
If so: it does not have any output. That would be an easy one then.
But I don't think so.

EDIT:
the holley terminator EFI has can bus. They have a digital dash to show RPM and such connected with can bus.