BB and modern 8 speed Auto transmission ?

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thomaslk

thomaslk

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Hi all,
is there any known conversion kit for modern trannies like ZF8HP in place of the TF727?
Currently these transmissions run in a lot of car/truck applications and can definitely cope with the torque of strong 440s and even stroker derivates.

See wikipedia for detailed info:
ZF 8HP transmission - Wikipedia

Any firsthand info available?

rgds
Thomas
 
Yes - ZF8HP runs with all kind of different stall hydraulic converters - and even (in Gen3) combinations of converter/hybrid electric motors - but this electric stuff is not my focus :)
 
Probably not that useful with a big block in a light car. The first three gears would be useless.
 
thomaslk said:
Hmm - but why is then the Redeye using exact this tranny?
Click to expand...

Well the modern Challengers are just short of 5k pounds so the Redeye isn’t exactly “light”.

The Sprinter ambulances at work are up to 8 speed transmissions. Not the same one I’m sure, but those things are kinda underpowered and definitely not light. But with the 8 speed transmissions they get up and go pretty well when you get them shifting.

I think it’d be impressive to see what they can do with a lighter car and more power. I think they’d make the whole launch traction thing easier to deal with. I love the 6 speed manual in my Duster, 4.30’s and can still do 70 mph at like 2,400 rpm. Gears go by pretty fast, but that’s part of the fun.

I think the biggest issue would be the controller, all of those transmissions use the ECU for control. You’d need a standalone controller to run the electronics on them.
 
What people neglect to realize is all these modern LX cars have 2.6X to 3.0X rear gears.
So low gearing in the 8 speed allows that numerically low rear diff to not hurt performance.

You would be nuts to pair with anything numerically higher than say a 3.23.

A V6 2018 challenger with an 8HP70 will out 60' and out 1/4 mile a 2010 charger with a 5.7 and a old Mercedes derived 5speed.

Same car will then go get 33mpg Hwy.

Gearing is a magical thing if you know how to utilize it.
 
My Hellcat has only 6 gears, as any gentleman's would. lol

I believe the Sprinter does use the same basic 8 speed as many other cars including the Hellcats.

Using an 8 speed with 3.23 gears...that's OK but you're transferring the multiplication from the rear end to the trans. Which is better able to handle the torque of a big block with lots of traction?

Keep in mind most of today's engines - even the Hellcat's - are not super torquey down low.

It'd be cool, for sure, but I'm not convinced you'd actually get anything out of the first 2 or 3 gears on the strip.
 
From what I've read these are solenoid shifted, some Chev guy adapted one into a Chevelle and wrote software for a controller, but I know of no source for this. He gutted the electronics in the trans and connected up direct to the solenoids as I understand. Find yourself a software guru. Should be easy for someone who can write software. A matter of timing/ apply/ release of the various solenoids.
 
It's far easier said than done. The trans is shifted by a computer that takes inputs from a variety of sources. Speed, engine RPM, manifold pressure, throttle position, coolant temp, etc. If it sounds familiar, it should - basically the same parameters as EFI.

You can't gut the electronics in the trans and just use the solenoids...for the most part, the solenoids are the electronics.

Chevy guys are Chevy guys...but one area they beat the Mopar crowd (and always have) is in breaking into factory PCM's and learning how to re-write code.
 
Old Thread I know. Has anyone gotten this up and running? I was going to adapt a A518 behind my 383 in my B Body but given a good used 8HP70 cost about what parts are going to cost to build the 4spd and they both have to have the same adapter it looks promising.
The controller the guy built was just an Arduino, nothing too complicated. His program was simple and he shifted it via button.
 
I looked into this last year and ended up changing plans once I realized the cost.

JVX racing has an adapter to get the trans bolted to the big block and Sound German Automotive has the controller needed to run it. You just need a RPM, speed and throttle position input if I remember correctly. It would work with my FiTech system.

Cleveland power and performance sells trans tunnels from Charger/Challengers for $350 I believe that you could graft in to give you enough room and has the mounts for a modern console of you wanted a Challenger/Charger style one.

You can snag a 2wd Ram 8HP70 for about $1200 online.

Then you are just left with a shifter and a driveshaft and adapter and probably some 2.73 axle gears.

About $5-6k all in depending on which parts you get.
 
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