Has anyone re-ratio'd a 6.4 F450?

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02Dmax

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I've got an 08 f450. 85k miles. Bone stock everything. I've got friends with stock f250's and f350's that get 15mpg and I've figured it so I know they really are. Mine gets 7.5 and last month I ran $2500 worth of fuel through it. And that cost is going to drown me, lol.

So I'm wondering if it will ever get remotely close to that if I do a tune, egr delete, dpf delete, and re-gear it. I realize its heavier than those lighter trucks but if I could get 12 or 13 with it I'd be tickled pink. I love the truck and really dont want to trade or sell it. Rides and drives great, no problems yet but I can't afford to run it like this. Hell I got rid of a c6500 topkick that got 12mpg to upgrade to this thing.

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A friends 6.4 with 4.88s deleted and tuned gets 14-15 empty and 8.5-9 grossing 30k pounds. I would keep the gears The way they are

His actually gets the same mileage as my 2010 f250 with 3.73s empty or grossing about 20k.
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ClamDigger4 said:
A friends 6.4 with 4.88s deleted and tuned gets 14-15 empty and 8.5-9 grossing 30k pounds. I would keep the gears The way they are

His actually gets the same mileage as my 2010 f250 with 3.73s empty or grossing about 20k.
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I would have to see to believe
 
Forrest Nearing said:
I would have to see to believe
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I didn't believe it. But after watching the engine load and boost numbers and comparing them it made more sense. I probably traveled to 4000 miles worth of events with him last summer. Was always consistent numbers.

phone
 
Ya I'm not holding my breath for 14-15. Definitely would not complain though! I guess it'd make sense to try deletes and tuner first. I'm more interested in the loaded numbers. I only pull about 6,000lbs but that puts my gross at about 18k with the truck also loaded. I just hate to get 5 grand into it and gain 1 mpg loaded. 98% of this trucks life will be loaded.

My inner engineer keeps screaming "5 grand to get it to maybe 12 mpg and an unknown lifespan.......or 7 grand for a nice dt466 swap and known long term life"

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For 18k gross a 12v would be fine and probably easier on the front end.

With a 07.5 6.6 dmax 4500 topkick grossing 30k I'd get 5-5.5. Same load with a 6500 topkick with a C7 Cat I'd get 6-6.5 but it barely gets out of it own way.

I'd try a tune and go from there.
 
estrada5.9 said:
For 18k gross a 12v would be fine and probably easier on the front end.

With a 07.5 6.6 dmax 4500 topkick grossing 30k I'd get 5-5.5. Same load with a 6500 topkick with a C7 Cat I'd get 6-6.5 but it barely gets out of it own way.

I'd try a tune and go from there.
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Man thats horrible. My c6500 has a little 3116 in it, not a race car by any means but it would run 70mph uphill grossing 25ish all day long and get 13mpg on a bad day. Everyone told me I was stupid for having that engine, ran it to 600k and all I did was change oil, change tires, and put a clutch in it. Best service truck I've owned.



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If your 6.4 still has all factory equipped emissions systems, there is where to start. EGR, DPF, PCV reroute-All easily done in the driveway and will be worth it in long run.
 
04jimc said:
If your 6.4 still has all factory equipped emissions systems, there is where to start. EGR, DPF, PCV reroute-All easily done in the driveway and will be worth it in long run.
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Thanks. I know I have to have a tuner to disable the dpf but do I have to have one to delete the EGR? I'm assuming I do to disable the electronic side of it. What's the best way to reroute the PCV?


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ClamDigger4 said:
A friends 6.4 with 4.88s deleted and tuned gets 14-15 empty and 8.5-9 grossing 30k pounds. I would keep the gears The way they are

His actually gets the same mileage as my 2010 f250 with 3.73s empty or grossing about 20k.
phone
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4.88 and 4.30 gear trucks suck. There is no way they get the same. My f450 with 4.30s turns 2500-2600 rpm at around 72mph. Its deleted custom tuned, and has a 71mm atmosphere turbo. It still only gets a max of 10mpg. Hand calculated, not what the dash says. My crew cab short bed with 3.73s turns 2000 rpm at 82mph and gets 17mpg. Same tune and turbo in both trucks.




02Dmax said:
I've got an 08 f450. 85k miles. Bone stock everything. I've got friends with stock f250's and f350's that get 15mpg and I've figured it so I know they really are. Mine gets 7.5 and last month I ran $2500 worth of fuel through it. And that cost is going to drown me, lol.

So I'm wondering if it will ever get remotely close to that if I do a tune, egr delete, dpf delete, and re-gear it. I realize its heavier than those lighter trucks but if I could get 12 or 13 with it I'd be tickled pink. I love the truck and really dont want to trade or sell it. Rides and drives great, no problems yet but I can't afford to run it like this. Hell I got rid of a c6500 topkick that got 12mpg to upgrade to this thing.

Sent from my SPH-L710 using Tapatalk 2
Click to expand...

I would tune it definitely. But also look into regearing it. I've done a few trucks and works really well. I actually have a set of 3.73 sitting here to go in mine as well.
 
97singlecab said:
4.88 and 4.30 gear trucks suck. There is no way they get the same. My f450 with 4.30s turns 2500-2600 rpm at around 72mph. Its deleted custom tuned, and has a 71mm atmosphere turbo. It still only gets a max of 10mpg. Hand calculated, not what the dash says. My crew cab short bed with 3.73s turns 2000 rpm at 82mph and gets 17mpg. Same tune and turbo in both trucks.






I would tune it definitely. But also look into regearing it. I've done a few trucks and works really well. I actually have a set of 3.73 sitting here to go in mine as well.
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Now put 20k pounds behind it and see the difference in mileage. No way I would regear to 3.73s if towing. I hated towing with that that ratio

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Engine load was always 20%ish higher and boost was 5-10 higher with the 3.73 meaning more fuel consumed. I don't care. What rpm it was

Edit -while towing

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02Dmax said:
Thanks. I know I have to have a tuner to disable the dpf but do I have to have one to delete the EGR? I'm assuming I do to disable the electronic side of it. What's the best way to reroute the PCV?


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Yes, the truck will go into limp mode if the EGR isn't functioning correctly
 
ClamDigger4 said:
Now put 20k pounds behind it and see the difference in mileage. No way I would regear to 3.73s if towing. I hated towing with that that ratio

phone
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It regularly pulls much more than that and hasn't been an issue in any other truck we've regeared. The other reason for wanting the gear change is the problem the 450-550 trucks have with the water pump. Due to the high rpm they constantly turn, they cavitate badly and will eventually cut through the timing cover dumping all the coolant in the oil.
 
97singlecab said:
It regularly pulls much more than that and hasn't been an issue in any other truck we've regeared. The other reason for wanting the gear change is the problem the 450-550 trucks have with the water pump. Due to the high rpm they constantly turn, they cavitate badly and will eventually cut through the timing cover dumping all the coolant in the oil.
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Where do you tow, the flat lands at 80mph? Did you change any transmission tuning? Lower stall converter? There are nothing but hills around here. The truck lives in 4th gear. Even on the highway in 5th on any slight grade it wants to make 35lbs of boost at 1500-1600rpm which is harder on an engine then just running it in 4th gear.

edit-truck has 33inch tires which doesn't help at all.

phone
 
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ClamDigger4 said:
Where do you tow, the flat lands at 80mph? Did you change any transmission tuning? Lower stall converter? There are nothing but hills around here. The truck lives in 4th gear. Even on the highway in 5th on any slight grade it wants to make 35lbs of boost at 1500-1600rpm which is harder on an engine then just running it in 4th gear.

edit-truck has 33inch tires which doesn't help at all.

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It is relatively flat out here, compared to back east, but the hills out here can top 8k feet and the constant high elevation, definitely makes pulling hard. And most the time the truck is rolling 80mph. My 450 has a 6 speed manual. The last 550 we regeared was an auto though. I tuned the engine and trans in it with a 71mm atmosphere charger. It pulls great pulling a 25k pound trailer and boat combo to Canada every year. The bottom ends in a 6.4 are very stout, making 35lbs of boost at low rpm isn't going to hurt them. What I have found is the closer you run to 2k rpm or slightly under is where you will get the best mileage.
 
04jimc said:
I just get a plug from plumbing store the size of the tubing connecting intake tube to oil fill and then route some heater hose from the oil fill outlet down past framerail.

Edit: Just googled it and found this- http://www.powerstroke.org/forum/6-4l-performance-parts-discussion/215591-ccv-re-route.html
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Thanks.

In other news.......the station I have always bought fuel from has had their diesel pumps shut down for tank replacement so I've been filling at a different station. 10 tanks now from that station and my mpg has gone from 7.6 to 8.8. Lol. Looks like I found a new home to buy fuel.

I agree totally with the "keep it around 2k rpms for best efficiency" statement. I always run mine just below 2k which is about 60mph, which sucks but when I first got the truck I ran 80 everywhere but my mileage was getting clear down around 6.4.


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