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6.4 with hemifever tuneing

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50K views 30 replies 17 participants last post by  daveski  
#1 ·
Hey is anyone running the hemi fever tune on there truck and how do you like it. Any mpg improvement and does it help the shift points. Also what tune are you running mpg booster or 87 performance. Any insight would be great
 
#2 ·
I'm running the HF 93 tune and the trans tuning is terrific. Probably the best part of the tune. I haven't seen any noticeable mileage improvement but in fairness the truck is leveled with 35x12.5 tires. None of which is helping the mileage any and I never tried to reinstall the stock tune to verify.
 
#5 ·
HF 92 with custom shift points on mine. Sean did a great job with the overall tune and the shifting is superb. He recently sent me an update to cover some CROM file upgrades provided to him by Diablosport.


Mileage improvement was small and I have yet to take a road trip with the new tune installed and without having to use winter blend fuel.
 
#10 ·
You get a tune for each power level, plus whatever else you specifically ask for. Typically they only charge extra if you need a tune for sometime very specific like a cam change or FI.
 
#11 ·
You can notice a difference throughout the curve, but it's still a Hemi and likes to make its power up top. I installed a 2600rpm Edge converter which made a huge difference getting the truck off the line. One of my favorite mods. Obviously this doesn't help much towing or hauling, but definitely makes the truck much more enjoyable to drive.
 
#14 ·
Hemifever is just the name of a popular tuner for the Hemi motors. He does a lot of tuning with the Diablosport stuff.
 
#15 ·
The 87 performance tune never did anything for my 6.4L HEMI. I couldn't tell I had a tune on the truck.


And I have to say that the 92 canned performance tune was felt but it still wasn't optimum.


When HF does a tune for your truck it is based on performance logs taken from your truck. That's why the custom tunes work so well. You can get a programmer and tunes as a package.


One thing many folks think happens with tuners is that you get this gazillion HP and torque lb/ft increase. Well, you don't. What you get is an increase in HP and torque that comes on lower in the RPM band and is sustained all the way to the shift points.


A good tune will optimize WOT shift points (HF does a good job on this), it optimizes the air/fuel ratio to remove a lean or rich condition - which can help with mileage - so you aren't burning valves or constantly in a knock retard situation and losing power or adding too much carbon to the combustion chamber which carbons up plugs, you can turn off MDS if you want, and it will firm up the shifts, reducing slip and that helps with lowering heat in the transmission.


The throttle boost settings are a nice touch. It definitely helps with throttle response off idle or for a kickdown on the highway. You don't have to wait for it, that's for sure.


All in all I've always considered a tuner one of the best bang for the buck mods you can do. That's my story and I'm stickin' to it. :)
 
#19 ·
You'll need the tuner and an unlocked PCM. HF has a deal going with a tuner, unlocked PCM, custom tune and either a core exchange for a reduced price or you keep your stock PCM to swap back into the truck when going in for service.


Get in touch with Hemifever for specifics. You can't go wrong having Sean do the deal.
 
#20 ·
What does it do for shifting on the 66rfe behind the 6.4? firmer shifts"? quicker? less throttle input before downshift ECT? I'm thinking I may throw one at it and see if it resolves my "issue". I came out of a CTD and understand the HP gains are minimal what I'm really after is drivability. Why they want a 7k lbs truck to shift like a Jetta is beyond me.
 
#21 ·
IMO, slightly quicker shifts and definitely holds the gears longer with better downshifts. I forget how much I like it until switching to the the stock PCM for whatever reason. Then I'm reminded of how much I hated to stock trans programming.
 
#24 ·
Just had my 15 PW in for service and service writer asked if I had done a tune yet or if they should reflash the pcm. I said no tune but please don't flash. He didn't have any issue whether it had a tune or not. Said anything they found would be covered under warranty. They didn't find anything and did a full 20 and 30k service on the truck. Not cheap, but now I have peace of mind that everything is proper on my new (for me) truck.
Let the mods begin!
 
#25 ·
glad I'm not the only 1 pushing in the 60's and modding Power wagons :doh:
 
#28 ·
have they unlocked the stock pcm for plug and play tuners or do you have to order an unlocked pcm and then tune it?

If they have not cracked the rolling encryption on the stock pcm any word on when they will have it unlocked?
 
#30 ·
Order an unlocked PCM with the tuner. Literally 3 10mm bolts and two connectors to swap them out. Keep the stock one if you're worried about warranty issues - swap the stock one back in prior to taking it to the dealership, or if you ever suspect the unlocked PCM has developed an issue.
 
#29 ·
Running the 91 Octane tune from Hemifever. Love the way it runs. Only issue I've had is when I stomp on the throttle it seems a little weak when it hits second gear and takes a bit to spin up. The rest runs great, with a slight improvement in MPG.
 
#31 ·
Trying to understand why you all buy a truck with such mass and want to try to beef up the HP rating and give it more of a jump. Isn't the reason for buying a truck such as the 2500 like have for doing things the smaller ones are not able to?