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What to do with my Hellcat Gladiator

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Johnny3

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What trans are you running and what controller did they use. My Hemi builds use the 8HP and the controller from Sound German Automotive. Russell makes a plug and play contoller that only needs a signal from the TP sensor...

Best aftermarket 8spd mopar controller there is.... about 1k complete with harness

https://www.soundgermanautomotive.com/pcs/
They installed a brand new crate Hellcat as well as a brand new crate 8HP95. I have no idea what they're controlling it with besides a reprogrammed JT ECU. Even moreso than the engine running rough/etc the trans shift points re off... its not comfortable to drive around town. Like I said, highway is fine but shifting feels like youre driving a pro-stock dragster with a 4000rpm stall converter if youre running around town. No bueno
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Teqsand

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They installed a brand new crate Hellcat as well as a brand new crate 8HP95. I have no idea what they're controlling it with besides a reprogrammed JT ECU. Even moreso than the engine running rough/etc the trans shift points re off... its not comfortable to drive around town. Like I said, highway is fine but shifting feels like youre driving a pro-stock dragster with a 4000rpm stall converter if youre running around town. No bueno

At least call Russell at SGA and talk to him... there is none out there that knows more about the 8HP line of trans's and controlling him than he does... he'll you might have his controller now and it was poorly installed....

Worth asking questions.... if I considered buying your JT, it would be because I know SGA is there ....
I am in no way affiliated with the company or Russell, other than buying for my own projects
 

Randonexplosion

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I was looking at the receipt from the shop and it shows a JL PCM for almost $3k. Maybe they just slapped in a pre-tuned PCM? They're only about $400 new.
 

redriderjf87

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Iā€™ll agree with what others have said. Iā€™d start with a new pcm that is tuned or can be tuned for what is done. Then handle the exhaust issue, and finally tons if youā€™re set on keeping it. Sounds like and Iā€™m not a mechanic but a good chunk of the issue lies in that locked pcm.
This is my vote too
 

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dos0711

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Option 3...because they are in the know.
 

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I find myself in a bit of a situation...

I bought a 2020 Hellcat Gladiator for, what anyone in their right mind would agree is a STUPID good deal. All the pieces are there, asthetically in amazing shape - 13k miles, a really nice truck, no regrets given the price paid. BUT, theres a reason that it was a stupid good deal... it runs like CR4P.

It doesn't start well, it kinda has a mind of its own on throttle, it has huge power delivery problems (under partial throttle acceleration > 3000rpm), the transmission shift points are really inconsistent and terrible for the street. It cruises the highway at 75mph GREAT, but thats not what I bought it for.

The (nationally recognized) shop that did the conversion briefly answered a first email but has failed to respond to follow up emails and several calls. I am still in touch with the seller, he's great, no issues there. He wasn't really up front about how poorly this is running but it was cheap and its not his car anymore - no biggie.

I took the Gladiator to a shop by me, well known for dyno tuning Hellcats, LTA/LT4s... they said they had never seen anything like this. There is no emissions equipment on the car (no cats - I think they were resonators, no oxygen sensors.... etc), the tune on the JT ECU is locked and the fuel system is sort of 'tricked'. The ECU thinks its a 5.7L (according to the tuners) and/or at times a 3.6L; at no time does it think its a supercharged 6.2L.

I had intended to use this Gladiator as a replacement daily driver, trailer hauler and enjoy the utility of the pick up bed. I have a few toys, including a dedicated off-road vehicle, I wasn't looking for this to be another.



My options:

1) Sell the truck as is, with FULL disclosure and let someone else take on the project
Pretty sure I am even money even after shipping the truck and paying the tax to register

2) Try to pursue the original builder further.
I didn't commission the build. Further, it was done almost 3 years ago... I dont really have any recourse; could there be an easy fix I am missing?!

3) Ship it to AMW for a PROPER conversion, including Tons, and enjoy it. I have been in touch with them (Jared has been awesome).
Pretty sure I am IN the money after a proper conversion... thats why someone would buy it from me now. BUT, going this route would mean that this Gladiator is no longer an ideal "daily"

3) ĀÆ\_(惄)_/ĀÆ
"maybe its something really cool that I dont even know about"



All input appreciated
If you can afford that ride you can afford to have it fixed.. I wouldnā€™t expect anyone to touch that thing for 30k in the current state fixed 50k likely. I wouldnā€™t think youā€™d be trashing the company by calling it what it is.. likely no decent aftermarket companies gonna remove all emission controls etc on a motor and jack up a computer that requires it to function properly.
 

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From the auction description, this was a very early transplant for the JT series.
Probably not the best idea to be near the front of that line.

That said, it's worth getting right and finishing right.

Jeep Gladiator What to do with my Hellcat Gladiator Screenshot_20220924-192142
 

NC_Overland

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If you can afford that ride you can afford to have it fixed.. I wouldnā€™t expect anyone to touch that thing for 30k in the current state fixed 50k likely. I wouldnā€™t think youā€™d be trashing the company by calling it what it is.. likely no decent aftermarket companies gonna remove all emission controls etc on a motor and jack up a computer that requires it to function properly.
Why do you say that? The new engine and transmission are installed. Itā€™s wiring/computer/emissions issues. I could see $20k easy or $30k with one tons, but $50k sounds outrageous considering whatā€™s already been done. He said he drives fine at 75 mph, so it canā€™t be that bad of an install drivetrain wise.
 
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Johnny3

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At least call Russell at SGA and talk to him... there is none out there that knows more about the 8HP line of trans's and controlling him than he does... he'll you might have his controller now and it was poorly installed....

Worth asking questions.... if I considered buying your JT, it would be because I know SGA is there ....
I am in no way affiliated with the company or Russell, other than buying for my own projects
Helpful advice... I will try. My mistake earlier, I believe its an 8HP75 not an 8HP95
 

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Johnny3

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I was looking at the receipt from the shop and it shows a JL PCM for almost $3k. Maybe they just slapped in a pre-tuned PCM? They're only about $400 new.
From what I now understand... The install shop's "special sauce" with their conversions is the custom, pre-tuned PCM. So they take a new one, reprogram it, then put it in the truck. I dont know if this tune was bad from the start (unlikely), has gone bad over time, or if the previous owner (who owns a company that employs heavy machinery mechanics) did something to throw the tuning off. But if its locked how did that happen?? I do a lot of my own wrenching but I am extremely ignorant when it comes to understanding ECU/PCM tuning

My hesitation in dealing with the original installer is a) I truly tried and the response has been extremely disappointing and, b) I would rather re-do the work with all the emissions equipment intact/compliant and the "right" PCM to make it factory reliable.

@Lunentucker makes a good point I never considered... this conversion was VERY early. Im sure the original installer has come a long way in figuring out what works and whats reliable. Perhaps I need to try them one more time (now that the exhaust is all chopped up - ha)
 
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AyeCantSeeYou

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From what I now understand... The install shop's "special sauce" with their conversions is the custom, pre-tuned PCM. So they take a new one, reprogram it, then put it in the truck. I dont know if this tune was bad from the start (unlikely), has gone bad over time, or if the previous owner (who owns a company that employs heavy machinery mechanics) did something to throw the tuning off. But if its locked how did that happen?? I do a lot of my own wrenching but I am extremely ignorant when it comes to understanding ECU/PCM tuning

My hesitation in dealing with the original installer is a) I truly tried and the response has been extremely disappointing and, b) I would rather re-do the work with all the emissions equipment intact/compliant and the "right" PCM to make it factory reliable.

@Lunentucker makes a good point I never considered... this conversion was VERY early. Im sure the original installer has come a long way in figuring out what works and whats reliable. Perhaps I need to try them one more time (now that the exhaust is all chopped up - ha)
You have nothing to lose by talking to the original shop. At the very least, if you don't like what you hear from them, you are free to go elsewhere and get real answers. If it were me, I'd be talking to the shop that made the conversion AND talking to a couple others that specialize in doing that. Take your Gladiator to them and let them give you a detailed plan for what it'll take to get it running right.
 

DAVECS2

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I think I could probably get this running correctly, but I need to do a through exam. My guess is the electronic bypass valve is not connected along with some of the oxygen sensors. The trackhawk, Hellcat, TRX, all use the same GPEC2 as the JT and JL, just they are connected to more pins on the ECM. I would use the stock ECM with the transmission as the integration is pretty decent once it is working.

If you don't want to deal with it anymore, be happy to trade you my truck plus cash. It is a supercharged 3.6L, but it runs very well and has had all the demons excised.
 

Cripton805

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It seems to me, they wanted a custom tune and more power out of it.

I would try to get everything back to stock Hellcat form. Get the sensors back in there, cat, resonators, stock ecu / mapping, & inspect the harness for damage.

With someone very experienced with Hellcat builds in general.
 
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Johnny3

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It seems to me, they wanted a custom tune and more power out of it.

I would try to get everything back to stock Hellcat form. Get the sensors back in there, cat, resonators, stock ecu / mapping, & inspect the harness for damage.

With someone very experienced with Hellcat builds in general.

Yeah... there was a "custom tune" in this one to 750hp instead of 707... perhaps it is just as easy as putting a new ECM, from the original builder, with "stock" Hellcat configuration and a new exhaust? I would love to think so but... (see my response to Dave, below).


I think I could probably get this running correctly, but I need to do a through exam. My guess is the electronic bypass valve is not connected along with some of the oxygen sensors. The trackhawk, Hellcat, TRX, all use the same GPEC2 as the JT and JL, just they are connected to more pins on the ECM. I would use the stock ECM with the transmission as the integration is pretty decent once it is working.

If you don't want to deal with it anymore, be happy to trade you my truck plus cash. It is a supercharged 3.6L, but it runs very well and has had all the demons excised.

Dave, I have been reading a lot on engine/programming issues... you appear to be one of the foremost experts here. Thanks for taking the time to think about my issue(s) and respond. I am not quite ready to throw in the towel yet but I appreciate your offer.

FYI- there were NO oxygen sensors in the exhaust on this truck when I picked it up... AMW told me that the O2 sensors, intercooler and electronic bypass, along with some other fuel related stuff, are the reasons why this doesn't run right... they haven't done an in person diagnosis but suggested they had seen this before.
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