Power -vs- Heat

["Mad Max"]

So, what parts have you installed and how hot are you getting?



I thought it might be a good idea to get personal experiences with regards to power verses heat. Most of us have upped the power on our rigs, with bolt-on's and tuning the pumps, timing, etc, some with very impressive gains, and I'd like to know what kind of temps folks are seeing as compared to the modifications and hardware installed?



My personal goal is this - not having to lift to maintain the speed limit, going uphill, while towing. I do not even know it that is achievable, but that is where I want to be... and the hills I'm talking about are also known as the Rocky Mountains.



I am getting ready to load the flatbed and deliver some parts this weekend, about a 3-hour trip, and I am looking forward to seeing what my egt's will be as compared to the mods I have done.

As my sig states, I've got PODs, a PDR HX-35/16, PDR fuel pin, 366 spring, 4" Intake/exhaust, max'd fuel screw, starwheel at the top. I'm at around 270 hp - real good and stable power. I consider my mods to be the 'basic power upgrades'.

What I am wanting to find out is how hot I get under load while towing - pretty much the critical 'knowledge' as compared to the parts I've installed.



We're all concerned about heat, and 1200* is the magic number - under it and you're safe, over it and you're less-than-safe.



I'm hoping my HX-35 can flow enough air to accomplish my goal, but I also know my PODs are pretty hot sticks, so, maybe I'll need different sticks, maybe a different turbo, but I am also planning a Snow water-meth kit, a ported intake ram, and an ATS 3-piece exhaust manifold down the road, so I have to add that to my equation as well because in the future I'll be cooler than I am now.



So, what are your experiences for components and heat?



- M2

 

[cerberusiam]

I have pretty close to the same setup with the addition of lockup TC. Overall, the temps are controllable but it will get toasty when the load is heavy and the grades get long.



Grossing just short of 15k from South Dakota to Idaho with a headwind, the only real problem was 3 sisters east of Evanston Wy. The steeper ones I was in drive, TC unlocked, and down to 50 mph to keep the EGT under 1300 towards the top of the grades. Plenty of power and it would have pulled it at 70 mph locked in OD but the temps would have far exceeded 1500.



Lighter loads at or under 5k are not a problem and very seldom do I need to downshift or throttle down. The modified HX35/16 works good but it is definitely short of air for the fuel I have. A better turbo is definitely needed once the fuel is available.



Have fun and let us know how the trip goes.

 

[MEby]

Max egt's out of my 92' engine was 1250 degrees @ 28 lbs boost truck empty. Wouldnt stay there very long though, couple seconds. mods were maxed fuel screw, custom fuel pin, 21cm turbo, 4" straight pipe, high flow air filter and the high idle screw mia. 0-60 in 10. 5 seconds and a quarter mile @ 85 mph. Roughly guessing my HP was approximately the same as yours. Truck weighs in at 7200 lbs. also see sig.

 

[Greenleaf]

I have a fairly new/modified injection pump via no reverse lever. Fuel screw 1. 5 turns out from run-a-way. Modified throttle linkage(s). POD,s. OEM charge air cooler. Three inch intake pipes. Full-four inch exhaust with striaght through resonator. HTT stage III HX-35 with the fat wheel and 18. 5 housing. OEM auto transmission. AfE filter/modified intake pipe. Ported OEM exhaust casting. Piston lift pump w/bored banjos.



On the flat highway with ambient temps of 80°F I will peg the ISSPRO EGT gauge in a number of seconds when I apply WOT from a rolling start and hold to say 60/70 miles per hour.



I either have a serious air leak or too much fuel. Or not enough air.

 

[cerberusiam]

I either have a serious air leak or too much fuel. Or not enough air.

Too much hot air? :-laf:-laf

 

[DValentine]

Interesting you brought this up. Last weekend I towed a 4x4 backhoe 250 miles. I have never moved anything as heavy. The machine weighed in at 18 K, with the gooseneck and my truck, I figure I was around 30K gross. I didn't weigh it all on the scales. I was in third gear, pyro at 1200 on some hills. 8 miles to the gallon. I wondered how the rest of you, who move such weight, have your trucks set up. Pulling my fifth wheel at 15 K gross, I pull hills like the continental divide, Butte Montana, in 4 th gear, pyro at 1200. I have felt comfortable with my set up for what I move with it. But the backhoe got me thinking about the limitations of my truck as it is set up now. A better intercooler, piston lift pump, better turbo, new radiator might help things... . but I think about Stomp and others who are over 500 horse and wonder if there is a limit on hot rodding in relation to actual work the truck is able to do. I don't mean just hauling a** down the road, or spinning a dyno. I guess my truck is 230 horse. If I was at 350 would I be able to tow the 30K any better, or would the system overload? What I mean is, not be able to rid itself of the heat generated, either through the cooling system or the exhaust.

Is this what you are getting at?


** On edit... . I forgot to mention that the air temps were 65 to 90, boost 24, and water temps would sky rocket when pulling a good hill 240 degrees.

Dave

 

["Mad Max"]

yup, that's exactly what I'm curious about. All the power in the world is kind of moot if it can't really be used under big load, and so my curiosity got piqued about what a real good proven towing set up is for really big weight, and how it was done. With so many available sets of sticks and turbo's it's interesting to see what combo's produce what kinds of results.



My intent is to get towing (loaded down) results and the combo's used to move them. I'm real curious how my rig works this weekend now that it's got the mods.



My last rig (RIP) was set up very similar to my current one except for the fuel pin and exhaust, and the fuel screw was unturned. I had the HX-35 and PODs and diaphram at max, but no other pump mods. Pulling a grade for almost an hour w/ 18,000 gross I was at 1200*, 60 mph in overdrive, 10 lbs of boost, engine temp at 225*, transmission at 235*. That was the hottest it had ever got. The new rig has the same turbo, but with more available fuel and a bigger exhaust. It'll be interesting to see the difference.



Keep the real-world intel coming- this is good stuff.

- M2

 

[glhs]

The hottest I've had mine steady was about 1300-1350 for about 40 miles pulling the 8k 5th wheel camper about 75 mph into a headwind last year. The coolant temp gauge was at the second to last line. Just an increase of 50* on the pyro was making the coolant gauge move up very quickly.

Elevation will play a part too. This was done at 5500 ft.

 

[bgilbert]

I ran my auto truck down the 1/8th mile drag strip the other night and the pyro was pegged right off the line, then for 9. 64 seconds afterwords. It would need some airflow improvements to tow.

 

[Jgolden]

My motorhome, 12,000 lb plus a 3,500lb car behind with a 4 speed allison(no overdrive) will climb a steep hill on an interstate at 60mph 1150*, 4th gear. Real long climb heat goes up.

On secondary roads a good grade will bring me down to 50mph. I can hold 50 in this situation in forth gear but egt will hang too high. Drop to 3rd I can still turn 50 but the higer rpms (I guess) will bring the temps down to 1000*or less. Trans temps remain low. Non I/C

This all requires that other vehicles drive only in a manner that will please me.

I removed my muffler for my last test drive and the improvement was pretty impressive, but the noise level is a little high.

Anybody that tows use a water/meth? I need I/C or water/meth or both before I add more fuel I think.

 

["Mad Max"]

Just got back from a good 4-hour trip, got some good info. 1100* is my new magic number Oo. - never really went much past that at the worst climb. Boost is higher than the last truck - averaged around 15-25 on the big hills. I was only pulling about 4000 lbs so not much weight, but I was trying to accellerate going up hill, etc. Maintained 75-80 mph no sweat. Pyro got to around *1200 during hardest pull maintaining 70 mph, boost got to around 23-25. Under load it made more boost, and under a hard pull the boost really climbed and seemed to do a very good job of evening out the fuel load, and I think that's why my pyro never went over *1200.

Overall I am very happy with my set up - don't see much need to do much more, but with more load I may need to adjust something.



The only recent adjustment was I brought the starwheel all the way flush with the top, and it seemed to bring down the fuel a bit and cooled things off just a bit - seemed to work out just right.



- M2

 

[dpuckett]

If your pyro only got up to 1200 maintaining 70mph up a hill, you did pretty well, IMO, even though the load wasnt much. I have to babysit my pyro here at sea level with a load on the flat (18K behind truck), but that is exactly why I have it. It'll be nice to upgrade the turbo someday.



DP

 

["Mad Max"]

it definitely got my attention, because I'd watch the pyro coming up, thinking 'oh boy, there it goes... ', ... then it'd pretty much just hover at 1100*-1200*... as the boost kept rising... essentially maintaining the pyro where it was. I mean, the pyro didn't just stop moving, it hovered there and rose just a bit as the boost climbed from say 15 up to 23 psi - it was very interesting to watch. Needless to say I was pretty happy, and a little surprised, to see how the boost could keep rising after the pyro was seemingly nice and stable. I guess I got the fuel/air ratio pretty close to allow the turbo to continue to spool up which, I guess, increased the airflow enough to keep things from getting hotter.

I think the two big upgrades from the other truck are the 366 governor spring and the 4" exhaust with the tapered downpipe. Maybe the taper smoothes out the exiting exhaust gas flow and keeps it from cavitating just past the collar outlet, almost like how a 3-stage tri-y header pipe on a gasser scavenges out exhaust. Don't know for sure, but I'll take it.

- M2