EGT Towing Survey

[Skipjack24]

Hello All,



I have a 1995 3/4 ton x-cab 4X4 w/ 3. 54's turning 285/75's. Currently running a BD 300/3000 pump with 215 injectors. The trans has BD converter and VB set up to match the motors grunt - Mystery switch allows me to enjoy the exhaust brake.



I pull a boat that weighs in at 10,000lbs and have stayed conservative by towing only in 3rd gear. The truck will pull the boat in O/D, but the egt climbs into 700's with boost (probe in post turbo) in the high teens low 20's while pulling on the flats. Is this about what other auto drivers are finding or are you seeing better performance in 4th gear??



Thanks for your help!

 

[BPINE]

The sweet spot for towing to get the best EGT is about 2100 RPM. Mine runs about 750 to 850 at 10# of boost on level ground with a CGVWR of 23k. Pyro in manifold where it should be.

 

[Skipjack24]

Thanks for you reply. I see you have 4. 10's, a 5spd transmission, and a splitter. So I'm guessing that means at 23,000 GCWR that you must be in approx. 4th over? I realize that 2100 - 2250 seem to be ideal towing rpm for the 12 valve, but those rpm's are governed by gearing. At those rpm's in 4th gear (auto transmission towing 23,000 GCWR), the boost would be pegged at 37 and egt's would be well on thier way to melting a piston. Those rpm's in 3rd are ideal for the motor but a bit slow on the freeway. Hence, I was wondering what kind of O/D performance people were seeing on the freeway pulling 10,000lbs of trailer weight with auto trans. Thanks for your advice on the pyro probe location!



Devon

 

[BPINE]

Skipjack24, I run in 5th at 2100 at 63 mph. You might need a splitter and run in third over for about the same speed. I'm not sure if you have a 4wd or not but maybe a gear change is in order, but you will need an aux overdrive for sure if you do that. I think 3rd at 63 is about 2500 am I right?

 

[The patriot]

I dont see a problem with 700 post turbo. How far are you towing the boat? I wouldnt want to go cross country like that, but 100-200 miles shouldnt be a problem.

If youre worried, buy a BHAF, and maybe exhaust mods? Maybe a 16cm2 housing?

BPine, you must have big tires. My truck is very close to yours RPM wise, and I have 3. 54's.

Eric

 

[Skipjack24]

BPINE,



Thanks for the further info. At 63mph I'm turning 2300 rpm with the 3. 54's and 33's. The splitter would be the ultimate addition! It's just a bit spendy right now and with 150,000 on the odometer it may wait till the next truck. It sounds like 3rd gear and a little slower mph is just where I'm going to reside!



Devon

 

[Turbo Thom]

Skyjack24:

I too run the US Gear overdrive but with a 3. 55 rear gear. I tow 14,000 lbs in fifth gear, 2000 rpm at 67 mph. I have noticed when I run over 2000 the mpg really seems to suffer. My temps at that speed , on level ground runs 1050. The only time I have ever had the temps over 1200 was in the mountians. Since then I have learned to drive . I have gotten to where I can't drive without the OD unit. Our Dodge trannys gears are just to far spaced.



. . Preston. .

 

[Champane Flight]

Me worry?

I would not worry with post temps of 700'. We did our own little study on pre and post probe locations. We did both on my friends 96. Temps flucuated terrible between both pre and post until engine warmed up to operating temp under heavy pull. Then settled out with 200'difference. Of course under intial acceleration and deceleration they do flucuate. If your post probe is in the usual place (dimple in down flange). I would add 200 to 250' to your EGT and you will be in the 900 to 950 range. Plenty safe. Wouldn't worry until you get to 1350.