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Hennessey Tune

NoCoHC

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#1
There is a guy with a used 15 Challenger Hellcat near me. It's got low mileage and he's selling it for a decent price. It has the Hennessee 850 HP package on it and is running a 93 octane tune. The problem is we only have 91 octane available in Colorado. He said the altitude compensates for that so you are fine running 91. That may be true if Hennessee isn't overly aggressive on the tune. Just wondering if anyone knows much about their tunes? I've read some of the threads about their terrible customer service, but since I wouldn't be dealing with them I'm not as concerned with that. I would probably get the car retuned but wondering what the potential is that the engine is already hurt.
 


MiHiHemi

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#2
Take it to Glenn Rains at RPM in Littleton. He’s a MOPAR whisperer with a Mustang chassis dyno. No doubt he can dial it in for our altitude and fuel if need be. He also does pre-purchase inspections.

https://www.rpmdenver.net
 


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Mean Cat

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#3
Take it to Glenn Rains at RPM in Littleton. He’s a MOPAR whisperer with a Mustang chassis dyno. No doubt he can dial it in for our altitude and fuel if need be. He also does pre-purchase inspections.
That's good advice right there ^^^ , take it somewhere to have it checked out & defiantly have it retuned for altitude & 91 if you buy it.
 


BULL

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#4
There is a guy with a used 15 Challenger Hellcat near me. It's got low mileage and he's selling it for a decent price. It has the Hennessee 850 HP package on it and is running a 93 octane tune. The problem is we only have 91 octane available in Colorado. He said the altitude compensates for that so you are fine running 91. That may be true if Hennessee isn't overly aggressive on the tune. Just wondering if anyone knows much about their tunes? I've read some of the threads about their terrible customer service, but since I wouldn't be dealing with them I'm not as concerned with that. I would probably get the car retuned but wondering what the potential is that the engine is already hurt.

Find out what the hardware is, pull some plugs, maybe run a data log and where stuff is at.

( I said all of that instead of just something useful like I hate H.)

:unsure:

;)
 


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#5
Find out what the hardware is, pull some plugs, maybe run a data log and where stuff is at.

( I said all of that instead of just something useful like I hate H.)

:unsure:

;)
I agree to that , don't trust him.
 


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MiHiHemi

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Glenn built my 426 last winter and is building another one for me this winter. Stroking an aluminum 426 race (Hellephant) block with Thitek heads and custom CNC hi-ram intake of his own design. He’s done tons of Hellcat mods/builds over the years.
 


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GT Momentum intake
 


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NoCoHC

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Thread Starter #9
I definitely wouldn't have gone with them or paid their crazy prices for the mods. The guy seems motivated to sell the car but not sure how excited I am about it running on 91 octane with a 93 octane tune even though we are at altitude. Unfortunately I think we will be seeing lots of distress sales of Hellcats and a lot of other toys in the coming months.
 


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#10
There isn't that much difference between 93 and 91 octane to worry. I always recommend someone have a Hellcat checked by a qualified shop when buying one previously modified, but if you're at higher altitude, you should have nothing to worry about.
 


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I put an Magnuson kit on my '09 a few years back. It was a complete kit with a pre-made tune for the setup. The car ran fine, but I just could not trust "the black box magic" in a can because I wasn't sure of the altitude and fuel it was made with compared to where I am on Long Island, so I brought it to True Street performance (luckily local) and had it re- tuned by AJ (aka. Hemituner on this site). The car ran/runs like a top and he was able to pull another 38HP with NO other mods. If you can get it retuned to your daily local environment (i.e. altitude and fuel) even if you pull more or less horsepower it's worth it to be right.
 


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#12
I would say if the work was done by Hennesey, you could always call them and ask if the tune is going to be safe if you're in doubt. Or you could always have one of the top Hellcat tuners retune it.
 


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#13
A different gat or aid from minus seal level here in Florida, but to make a great change in altitude upp erds,, bad news. We will just keep hitting gators. Use to do a lot of Harley riding through many demographic areas and better have a bag full of jets.
 




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