Jared's 2015 Challenger Hellcat Build

[covidcommander]

It's been a wild couple weeks.

Due to time constraints and the fact that my buddy had a brand new Trackhawk 8HP95 kicking around we decided what we would do is gut the HP95 and put everything in my HP90 case. Easy enough, right? Wrong. There are case differences, and the the front pump/housing/clutch assembly (I'm not a trans guy, I'm not sure what it's called) doesn't fit as it's just a touch larger than the HP90 assembly and gets hung up on the case.

At that point, we had ten days to get the TH400 in and make the event. That day we test fit the trans, found out we had the wrong bellhousing, and got all the parts we needed ordered rush delivery. A few days later, we got back to it with all the parts, decided to go the David Freiburger motto of "don't get it right, just get it running" for the event, and swapped in a Hellcrate harness and PCM.

My tuner was on Vacation so with hours left before we had to leave for the event I just copied my tune over from my pcm to the hellcrate PCM and we got the car up and running. Went out to try the transbrake and bump box and under full throttle the car just closes the throttle blade to 17% and opens up the supercharger bypass.

We ended up deciding to leave the car at the shop and go out and support our friends in the drag and drive, as opposed to bring the car and start fighting with it. I think that was the right call and allowed us to enjoy the event and just hang with friends.

I'll have to figure out what's going on with the car, I'm sure copying the tune right to the hellcrate PCM probably wasn't the best way to go but I didn't have a ton of options at the time. We are swapping manual harnesses into the car and I'll have to get my PCM bench flashed to a manual OS. Eventually I still want to go with a Holley dominator setup but I'm having a hard time opening my wallet for it knowing just how much other stuff the car needs as well. I am definitely playing with fire with the stock bottom end and I don't feel great about it.

Sucks it didn't fit inside the case

 

[Unholy707]

Awesome! Thanks Jon! Can’t wait to hear more about this, pretty stoked

 

[covidcommander]

Yeah we have all that stuff on the way. Actually, swapping every single harness on the car over to new harnesses. I bought the car already modified and while we were working on it we kept finding wires and stuff cut everywhere we looked, behind every interior panel with other wiring spliced in like shit. The original shop that built the car for the previous owner was a complete hack job, hell the added PWM for the second fuel pump was wrapped in bubble wrap and thrown in a trunk cavity, and all the wiring they did was a mess.

No wonder I've been fighting with this car the past 2 years.

Why you can't trust any shop you don't know personally. Some people just shouldn't work on cars. Sucks they cut all the harnesses. Hack job.

 

[jonx96]

Alright so one is in the wild right now. They have the boxes made they are just waiting on the wiring harness a quick summary from what Rick said
You simpley plug in and run wires to aftermarket shifter for reverse switch and park safety switch.
When it does not see either switch it says drive. When in reverse it goes into reverse on dash . And when in park it says park.
That last parts pretty cool to keep the gear indicator!! 900 is the cost of the box
ETA about 3 weeks

 

[Unholy707]

The magic of can bus. Very nice, pretty excited about this. Great work on their part, I know what goes into figuring this out. Wonder if wire harness will have a connection for the engine harness transmission connector and get its power from there since you have can bus, park signal, 5 volt signal and bcm signal all right there.

 

[Jroc]

Alright so one is in the wild right now. They have the boxes made they are just waiting on the wiring harness a quick summary from what Rick said
You simpley plug in and run wires to aftermarket shifter for reverse switch and park safety switch.
When it does not see either switch it says drive. When in reverse it goes into reverse on dash . And when in park it says park.
That last parts pretty cool to keep the gear indicator!! 900 is the cost of the box
ETA about 3 weeks

I appreciate you looking into it. This might be the way to go.

 

[Unholy707]

I appreciate you looking into it. This might be the way to go.

100% the way to go, by the sound of it. wish I could find some videos or something about the car in the wild

 

[Jroc]

Why you can't trust any shop you don't know personally. Some people just shouldn't work on cars. Sucks they cut all the harnesses. Hack job.

Exactly. Well at least I can get everything completely sorted out and hopefully stop fighting with the car this way. It has definitely been a case of buying someone else's project or buying someone else's problem lol.

 

[Jroc]

100% the way to go, by the sound of it. wish I could find some videos or something about the car in the wild

Sounds like it's a can box like we were thinking of making. I'll likely pick one up and do a big write up and video on it when they're available. I bet these will sell like crazy for people doing TH400 swaps and will encourage more people to do them that want one, but don't want to deal with all the computer BS of putting a "dumb" transmission in a "smart" car.