Does anyone know of a good shop that i can get 4.56 gears installed at? located in South Carolina or North Carolina? i have 37" tires with 3.73 gears and pulling a 8,000 pound trailer i am pushing 1100 degree's EGT. need to get them RPM's up to drop them EGT's. Or i guess is it bad to run with the overdrive off for 12hrs strait hauling about 800 miles weekly?

 

I would not worry about 1100 degrees. You can do that all day and not hurt a thing.

 

Turn the overdrive off and lock the t/c in 3rd you'll be fine for as long as you want.. Those 37's and 6" lift aint helping ya either but I'm sure you already knew that

 

just got me a little scared when i looked up that alluminium starts melting around 1400 degree's and i think thats what i pistons are made of.

 

My EGTs are proportional to the RPMs. The higher the RPMs, the higher the EGTs. I can't even get above 1200° unless I'm right near red-line (3100 RPM). Coincidentally, that's where I hit max boost too (32 psi).

If you want lower EGTs, back out of the skinny pedal a bit, or upgrade your intake and exhaust to something that flows better.

 

Your SO and not having a programmer helps keep you egts in check..

 

I would put the 4.56s in.

It would make a nice difference.

My 35s and 3.73s put me at 1800 RPM at 70.

Your probably down around 1600 at 70?

4.56s will put you at about 2000 RPM at 70. Which should be about perfect.

My highest are egts are when the RPM is low, at around 1400-1600 RPM.

 

I don't really see why you'd spend your money on gears. Like Cincy said, drop it out of O/D, make sure the converter is locked and be on your way.

I would be more concerned about trans temp. 1400 degrees is where you want to draw the line on EGTs.

garrett

 

Actually that's not usually true. 9 times out of 10 grabbing a lower gear and upping the RPM's will lower the temps. If you're right at redline and max boost, I'm guessing you're wide open throttle. Temps are always hottest at the end of wide open pull, because the heat continues to build up. Consistent speeds are a whole different ball game.

Shawn

 

I guess I don't understand how upping the RPMs can lower EGTS. My experience is exactly the opposite. High RPMs = high EGTs. Of course this is while towing heavy, which I do a couple of times per month through out the warmer time of the year.

The more fuel you put on the fire, the hotter it is. Are you guys getting proportionally more air at higher RPMs, thus cooling the EGTs? That's the only explanation I can think of....

 

Not bogging down the engine is what keeps my egt's in check

 

I agree with cincy!

 

Hit the nail on the head here. These engines will get flooded with fuel if you lug the engine, and with a heavy enough load and/or grade you get REAL toasty.

 

You cannot "bog" a diesel like that, there is no way to "flood" with fuel unless one is way over fueled to begin with.

Unless one is trying to tow on a race tune with TM disabled you can mash the go pedal all you want and it won't give anymore fuel than the fueling tables will let it. It won't flood, it just won't go.

You have less problems with EGT at 1800 rpm's than at 2500 rpm's as long as the turbo can maintain boost. Messing up the boost and the fueling curves will cause major issues.

 

I also agree with cincy.

When I am towing and the EGT's start to get a little too high I downshift.

EGT's are about the fuel supply and it's burn. When you increase the skinny pedal the EGTs rise. If under load your RPM's start dropping and your speed drops you naturally increase the skinny pedal, this increases the fuel supply and your EGT's rise accordingly. You continue to increase the fuel supply to keep your speed up all the while your RPM's keep dropping and you lug the engine in the process. It take more fuel to maintain your speed at a lower speed and lower RPM's.

By dropping the RATIO of your drive gear (increasing the thrust) it takes less fuel to maintain your speed, the EGT's come down accordingly.

With a standard tranny, the recommended towing gear is actually 5th, and that is more or less relative to flat towing in it's recommendation. Overdrive or 6th gear is not recommended when towing, even though our trucks are more than capable in 6th gear towing 18K on the flat. The EGT's ARE higher than if we downshift TO the correct towing gear.

Basically the same applies to an auto tranny, for it not to HUNT or LUG you have to lock out the overdrive to maiintain the correct constant FOR towing.

CD