tow rig/ dd questions

[oldestof11]

The only engine i would consider to hit 400 plus and tow would be a commonrail. And them to hit more and still have a single would be the 6.7l.

[rockbuggy4x4]

Thanks for the input guys. I'm trying to research more on a single turbo vs a compound setup. I just don't see how a single would be beneficial for a dd/ tow rig especially with 300-400hp. But I'm new to this so I may be wrong. Is the hx35/hx55 a tried and true setup?

[RCCUMMINS89]

Sutter1stgen would know first hand.

[Sutter1stgen]

Yes it is. With my tight converter auto I put down 330/660 with egts never going past 1k. I still had more in the truck I think. I had a lpplp and ddp3s.

Stackx2 ran them before me and he laid down 337/740 ish. Hottest he could get empty was 1k
Grossing over 24k he managed to hit 1200 one time on his way to Texas from Cali. His truck pulled hard.
Another thing to remember was he was running the terrible, nasty, worthless pods, lol. And he had a diaphragm lift pump. So this should tell you how well they can cool. Th Hx52 with the 72mm wheel may be even better at cooling. I personally think they are a great midrange setup. I wouldn't go any smaller. And this whole towing at 400hp thing is going to heat you cooling system as well. Might be something to think about.

[RCCUMMINS89]

Bring up a good point.

Not that we ever use that much power towing. But once I started making over 325-350 rwhp... but cooling system can't keep up. Meaning by the time I wot it from 20-80 (not very long time wise) my coolant temp will rise from the 2nd mark to passed the 3rd mark. I can reach the hot mark in about 10 - 15 seconds at wot.

[dunes450r]

Bring up a good point.

Not that we ever use that much power towing. But once I started making over 325-350 rwhp... but cooling system can't keep up. Meaning by the time I wot it from 20-80 (not very long time wise) my coolant temp will rise from the 2nd mark to passed the 3rd mark. I can reach the hot mark in about 10 - 15 seconds at wot.

i have a very hard time believing you can heat soak your cooling system in 10-15 seconds. heat won't conduct that fast through the cylinder walls to be absorbed by water and get pumped around in that amount of time.

the factory gauge is not consistent or reliable on temps either. i've seen actual temps fluctuate as much as 30* for the exact same mark on the factory gauge. you need to put in an actual temp gauge and then get back to us.

[rockbuggy4x4]

I know the higher hp is going to take a toll on coolant temps. I was going to get a 2nd or 3rd gen radiator to help keep those temps down. Also was thinking about an electric fan. Has anyone run electric fans? Never did like the stock gauges. They tend to get lazy/ inaccurate over time. So LOTS of gauges are on the "to buy" list. lol lpplp? low pressure piston lift pump? That's the lift pump on the side of the engine correct? or is that an aftermarket one?

[BILTIT]

yes the lpplp is on the side of the engine but the stock one is a weak diaphragm pump, the piston pump is an upgrade (from a 2nd gen but with modified spring pressure).

[RCCUMMINS89]

Bring up a good point.

Not that we ever use that much power towing. But once I started making over 325-350 rwhp... but cooling system can't keep up. Meaning by the time I wot it from 20-80 (not very long time wise) my coolant temp will rise from the 2nd mark to passed the 3rd mark. I can reach the hot mark in about 10 - 15 seconds at wot.

i have a very hard time believing you can heat soak your cooling system in 10-15 seconds. heat won't conduct that fast through the cylinder walls to be absorbed by water and get pumped around in that amount of time.

the factory gauge is not consistent or reliable on temps either. i've seen actual temps fluctuate as much as 30* for the exact same mark on the factory gauge. you need to put in an actual temp gauge and then get back to us.

I'll take a video..... it only does it if one advances timing a lot. I bet David sees the same results.

Remember advancing the timing keeps more temps inside the engine. and less goes into the exhaust.

[RCCUMMINS89]

Scratch that, I can't take a video right now..... my egts go up too fast with these injectors. But trust me, my engine temps went up that fast. IF I had my timing advanced enough to keep my egts at 1250 with my old sticks. Back the timing off, it wouldn't raise it up and I'd have higher egts. Won't move the needle at all unless wot.

People that haven't put that much fuel, timing, and power through an engine don't see how fast our cooling system can be over whelmed. I can't overwhelm it no matter what when my truck is tuned at a 350hp level.

[Sutter1stgen]

John was running conservative timing, pods, and the compounds we discussed. His egts were scary low. But he complained that long grades would heat soak his cooling system no problem. Hell even jqmile mentioned it with his p pumper after he installed twins. Its like you go from worrying about one thing getting hot to the other.
At the end of a quarter mile pass I can bring my temps up pretty quick, and high (14.50 sec). So I can see someone towing, which no doubt applies more of a strain and load on the engine doing the same in less time, possibly even with far more extreme outcomes. I run a teefer advanced so I know it's keeping the heat in there a bit better.

Well enough of the points getting across, compounds are cool, and they make driving a pleasure no matter the conditions and hp range.

[rockbuggy4x4]

yes the lpplp is on the side of the engine but the stock one is a weak diaphragm pump, the piston pump is an upgrade (from a 2nd gen but with modified spring pressure).

Ok. So I would need an upgraded lift pump (one from a 2nd gen). Would an airdog/ fass fuel pump be work too, or would that be too extreme?

[RCCUMMINS89]

http://shop.thehungrydiesel.com/Low-Pre ... t-Pump.htm

This is the one that Biltit was talking about. The one from a 2nd gen by itself is too much psi. One has to regulate it down, or get a diff. regulating spring. Cummins also makes a low pressure piston lift pump, but it has a Cummins price tag on it, not to mention is has a smaller piston and therfore moves less fuel.

An Airdog would work just as well, they are just more money. Now you'll never outgrow an Airdog, where as a Piston Lift pump will have it's limits (over 400hp, as I'm using one at over 400rwhp). So it's up to you if you want the simplicity of a mechanical or the extra fuel capability of the electric.

[RCCUMMINS89]

John was running conservative timing, pods, and the compounds we discussed. His egts were scary low. But he complained that long grades would heat soak his cooling system no problem. Hell even jqmile mentioned it with his p pumper after he installed twins. Its like you go from worrying about one thing getting hot to the other.
At the end of a quarter mile pass I can bring my temps up pretty quick, and high (14.50 sec). So I can see someone towing, which no doubt applies more of a strain and load on the engine doing the same in less time, possibly even with far more extreme outcomes. I run a teefer advanced so I know it's keeping the heat in there a bit better.

Well enough of the points getting across, compounds are cool, and they make driving a pleasure no matter the conditions and hp range.

Come to think about it, I used to have problems with my common rail. I couldn't hold speeds up long grades while towing....egts would be in check but it would over heat. I had my tuner set up to give me the warning at 240 degrees and that thing would beep more often than my 1000 degree egt warning.

[Sutter1stgen]

If I could run a piston lift pump i would. My power goals were not realistic with a mechanical pump though. I like the fact that you can rely on the mechanical lift pump in almost every scenario. Alternator goes out you can still get home. I'd chose mechanical over electric any day.

Huh that's funny Eric. I would have never thought a common rail would do that. And no I'm not kidding.