6.4 Hemi No Power high altitude

[ptrgrg]

Would adding a 6.0 PSI supercharger help ?

 

[mtnrider]

Any kind of forced induction would help. If you are at altitude often and are towing your money would be much better spent on a diesel though

 

[ptrgrg]

Thx - stuck with the 6.4 for now, so any advise on Minimum Supercharging (6.0 PSI Max) greatly appreciated. Thx

 

[mtnrider]

Thx - stuck with the 6.4 for now, so any advise on Minimum Supercharging (6.0 PSI Max) greatly appreciated. Thx

I mean, your looking at $8-10K+ easily so that's a Lot of money to invest in that truck that will likely give you no return on investment at the end of the day. Trade that truck and add that $10K in a diesel and you would be better off all the way around.

.

 

[Bearcatrp]

How high are you? Was at 9000 feet in wyoming with my 6.4 with zero issues last month.

 

[Wild one]

Would adding a 6.0 PSI supercharger help ?

If you're towing with it at high altitude,the last thing you want to add is forced induction to it,not unless you like putting pistons in it after every tow.As stated either learn to live with it,or spring for a Diesal.6.4's at the best of times don't like boost,throw a load behind it,and pull that load up the side of a mountain,is pretty well gonna put enough heat into the cylinder to expand the rings to where they butt together,and then it's pretty well instant broken piston

 

[crash68]

If you venture into a supercharger, a twin screw type produces more low end torque vs. a centrifugal style. For towing your looking to add torque lower in the rpm band rather than adding HP in higher rpms.

 

[Mister Luck]

No one needs an excuse to install forced induction, unless they’re married.
Wild One is correct ring gaps need adjusting before hand but if anything else to address the issue in a more timely manner, check your engines advance function and use higher octane fuel.

Maybe your vacuum system is leaking somewhere?

 

[crash68]

to address the issue in a more timely manner, check your engines advance function and use higher octane fuel.

Given a naturally aspirated engine loses about 3% for every 1000 ft above sea level. So at at 8K ft the 6.4 Hemi could be down almost 100 hp.
As for higher octane fuel in higher altitude, the lack of oxygen sorta negates the need for it.

 

[Travelin Ram]

Can’t afford to trade, but willing to trash the warranty, spend big $$$$ on mods, then spend $$$$ on a replacement engine after towing heavy boosted?

This will not end well.

Just how much weight is being towed, at what altitude, and who are you trying to keep up with?

 

[2003F350]

Can’t afford to trade, but willing to trash the warranty, spend big $$$$ on mods, then spend $$$$ on a replacement engine after towing heavy boosted?

This will not end well.

Just how much weight is being towed, at what altitude, and who are you trying to keep up with?

Everyone is in such a hurry to get anywhere. A 6.4 tows great, you're just not gonna win any races or pass many gas stations with it.

OP is in Texas - which from what I recall seems to be pretty flat. Maybe the far western portion has some mountains. But his location says he's near Dallas. Tallest thing around him is likely going to be a parking ramp. So unless he's MOVING to the mountains I really don't see where adding boost would help him much.

 

[Mister Luck]

Given a naturally aspirated engine loses about 3% for every 1000 ft above sea level. So at at 8K ft the 6.4 Hemi could be down almost 100 hp.
As for higher octane fuel in higher altitude, the lack of oxygen sorta negates the need for it.

Short version

Fuel has a cooling affect on cylinder head temperatures higher octane fuel has greater capacity for cooling adding it is not necessary for your engine fuel map to advance timing to counter cylinder pre-detonations and cylinder head temperatures will be lower at advanced ignition timing altitudes

 

[Zoe Saldana]

Would adding a 6.0 PSI supercharger help ?

What do you mean by "NO POWER"?

I'm in Leadville, Co 9K FT., towing a 8K trailer - no issues.

What gears do you have?

 

[ptrgrg]

3.83 gears towing a 30 foot fifth wheel. 8 Speed Transmission spends most of the time in 6th gear and will not hold the speed limit, any small incline and it will jump down to 5th or 4th (Average elevation 6000 ft). This a Stock 2022 6.4 with 14K miles on it. Engine is in perfect running order (empty this truck is almost like a hot rod)

 

[Wild one]

3.83 gears towing a 30 foot fifth wheel. 8 Speed Transmission spends most of the time in 6th gear and will not hold the speed limit, any small incline and it will jump down to 5th or 4th (Average elevation 6000 ft). This a Stock 2022 6.4 with 14K miles on it. Engine is in perfect running order (empty this truck is almost like a hot rod)

For what it'll cost you to put pistons and rods in it,so it'll handle high loads under boost,you could buy a Cummins.You hit a mile long grade and you're using boost to compensate for the power loss,and you'll be putting pistons in anyways,lol.
You're listening to guys who are running boost at the track,where the engine might see 6lbs for 11 seconds at a time,not for a minute or several minutes at a time,the cylinder heat after a mile is going break the top ringland of your pistons.

 

[Alex Ortiz]

I've towed at 11k feet through the Eisenhower Tunnel here in Colorado and never felt like it was struggling. Sure it doesn't have the power as it does down in Denver but it doesn't struggle

 

[OC455]

3.83 gears towing a 30 foot fifth wheel. 8 Speed Transmission spends most of the time in 6th gear and will not hold the speed limit, any small incline and it will jump down to 5th or 4th (Average elevation 6000 ft). This a Stock 2022 6.4 with 14K miles on it. Engine is in perfect running order (empty this truck is almost like a hot rod)

You are not going to get into the 7th of 8th gear towing that much with a 5'ver behind you, or a regular bumper pull camper for that matter. Depending on how fast you are traveling in tow/haul mode, it's going to stay in 6th gear and inclines it's going to shift down, it's the nature of the beast at this point.

I just bought a 5'ver and found that keeping in the 65MPH range (thruway/interstate), with tow/haul engaged and the cruise control on, it does what it is meant to do and sings happily along.

Honestly if you are looking to get more out of the Hemi, I would look at the camshaft that MMX offers: https://www.modernmusclextreme.com/...-mds-camshaft-na-no-tune-required-by-mmx.aspx

The 3.73 gears are good for what you have going, and with the 8 speed make a very good combo. My 5'ver is just shy of 30ft and is 7600 lbs., dry weight.

 

[joesstripclub]

Just towed my new 30ft almost 10k lb toy hauler up cottonwood pass to Taylor reservoir about a month ago with a power wagon. Definitely down on power by the top but never had any issues. Taking the truck empty to that high of altitude would have the same result. You have to just get used to the truck running a lot of revs or get a diesel if it bothers you. The beauty of the 8 speed is you can go over a grade in 4th or 5th not 2nd in an older truck.

 

[Mister Luck]

Check your Cats …

 

[JCE]

How high are you? Was at 9000 feet in wyoming with my 6.4 with zero issues last month.

^ This. Zero trouble 5,000-9,000ft up for me. The only thing that is a letdown are the brakes. Gonna get some heavy duty brakes on next spring.