Hit 1200* while towing

[JStraw]

I took a friends 34' Carraige Excel to a new campground 350 miles away. I normally pull my 36' Fifth Avenue with no problems. His is a double axle compared to my triple. Man, I could really feel his rig behind me like it was a lead sled. It had constant push/pull effect whereas mine glkides like its not even hooked up. To top it off, on a incline North of Birmingham, my EGTs spiked and I had to slow. This is the first time I've had this happen. Has anyone pulled different trailers and noticed similar effect? The only constant was a steady 10mpg.

 

[RustyJC]

1200 degF pre-turbo or post-turbo? If it's 1200 degF pre-turbo, that's no big thing. My truck (admittedly a 2nd gen, but with an HX35W-12 turbo) would hit 1300 degF pre-turbo EGT when it was absolutely stock except for the Jacobs e-brake.



To your question, yes, I've pulled a friend's 33' Hitchhiker II with this truck, and it pulled much harder than a 36' Jayco Designer XL we had at the time!



Rusty

 

[MMiller]

1200* is no problem! Yes I have pulled trailers with bigger differnces then that. A past girlfriend had a small 2 horse trailer that was bumper pull. It pulled harder then my 32' flatbed does. The horse trailer pulled the same weather it was full or empty. Some trailers I think are just poorly set up. My trailer has oil bath hubs and I have been told they pull better then greased wheel bearings. There is alot of variables between differnt trailers.



Michael



Didn't think about where the pyro was at. I routinly run mine up to 1300* if I know the truck will be coasting soon. I won't run it very long at 1300 if load is not going to change soon.

 

[JStraw]

Thanks guys. It is pre-tubo temp. 1200* just seemed high to me. I guess if I keep my panic mode set to the 1200* mark I shouldn't experience any damage to the motor. I 'm still using the 18. 5 cm2 exhaust housing as when I had swapped in a 14cm2, my superslab performance seemed to be downgraded. But... would it be better to sacrifice top-end for the extra spool-up speed? Would it help with hill climbs or is that a gearing area I may have to address on the old '93?

 

[MMiller]

14cm2, my superslab performance seemed to be downgraded.

This midwesterner does not understand that statement.



The 14 should have gained you better throttle response, faster spoolup. But like you said it would loose some top end. Now in my opinion this is bad if you are doing lots of towing at highway speeds. I am still using the stock turbo, and just adding fuel down low to spool up the turbo. Fill in your truck specs a little more in your sig. Are you 4. 10 or 3. 55? Not saying the 14 wouldn't work, some guys round here use them.



Michael

 

[Larv]

Is 1300* pre-turbo where a driver should get out of the throttle a bit? Is 1200* ok? Trying to think ahead to our trip this summer in the Canadian Rockies.



Thanks in advance!



Larv

 

[JStraw]

So far, the majority has been towing on Interstate. I've got the 3. 55s in the rear.

 

[MMiller]

Everyone around here will agree that the cummins will run 1250* all day long with no problems with the pyro in the exhaust manifold. I would not recommend pulling a 5 mile grade at 1300* the whole way up, but here in Iowa with our rolling hills, occasionally my truck will see 1300-1350 nearing the top of the hill, and I know it will have a chance to cool down on the down hill side. One thing with my 93 I have to also keep an eye on coolant temp on hot days. It has never gotton past 2/3 on the factory gauge, but I keep an eye on it none the less. It runs hotter now then when it was stock, when pulling hard.



With the 355's the smaller housings can be used more because you will not be running against the governor on interstate trips. Unless you are running tall tires(over33's) then gearing should not be a problem. If you don't like the way it pulls the hills, and you have some room left on the pyro, a little more fuel will help on the hill climbs. Opening up the exhaust and the air intake will help too. Really IMHO the size of the stock exhaust housing will be fine for towing and highway speeds. They will help with off idle response and acceleration.



Michael

 

[RustyJC]

Is 1300* pre-turbo where a driver should get out of the throttle a bit? Is 1200* ok?

I understand the 3rd gen HO's with the HY35 turbos run hotter than my 2nd gen, but as I said, mine ran 1300 degF pre-turbo EGT stock when towing our 5th wheel. With my bombs, it can get hotter now if I don't watch the pyro.



On long grades, I generally drive by the pyro when towing and try to hold EGTs to 1100-1200 degF. Then again, I'm a conservative person who doesn't want to walk home!



Rusty

 

[JStraw]

I think I'll blow the dust off of the 14cm2 and give her another try. I haven't pulled with it, I only ran empty with it when I disliked my top end drop out. Heck, with fuel prices reaching towards the alps, it's time to slow on down. Thanks for all the help.

 

[LesStallings]

When loaded and pulling the long grades around Flagstaff, I'll keep it at or under 1,200°F. I sort of use that temperature as my limiter. Totally stock, I could hit 1,200° easily in 5 th. gear, but never in 6 th.

 

[Big A]

I 've spoken with a Cummins Engineer, I won't mention his name( no need to flame). He said you can run these engines at 1300* constant, and have no problems. If any of you are familiar with I-70 westbound approaching Eisenhower tunnel in Colorado, you'll know what a tough and long climb that is. I have pulled that grade at 1300* many times, and have had no problems. I agree with setting a limit at 1200*, but if you venture to 1300 briefly, you should have no problems.

Big A

 

[Driftwood Ram]

I 've spoken with a Cummins Engineer, I won't mention his name( no need to flame). He said you can run these engines at 1300* constant, and have no problems. If any of you are familiar with I-70 westbound approaching Eisenhower tunnel in Colorado, you'll know what a tough and long climb that is. I have pulled that grade at 1300* many times, and have had no problems. I agree with setting a limit at 1200*, but if you venture to 1300 briefly, you should have no problems.

Big A

When pulling long grades at high egt's I have noticed the water temp tends to climb. You need to keep an eye on it also.

 

[daytripper63]

I pull grades towing and hold 1250 and somtimes venture into 1300 all the time with no problems, although as soon as I see 1300 or more I back off

 

[JStraw]

Driftwood, good point about the water temp. I saw mine soar upwards to 215* beofre I throttled down. This was a reading from my sensor in the thermostate housing. The stock engine gauge showed it was 7/8 of the way to the hot zone. Strange that the fan didn't kick in. I've heard it come on in Arizona while towing my fifth but not on this particular pull.

 

[Big A]

Driftwood Ram is correct. I have noticed that if you keep the EGTs at 1250 or lower, the coolant temps tend to stay lower too.

Big A

 

[claykelly]

I have an Excel 30-5 that I pull currently, it tracks and pulls better than my Hitchhiker II did, although you can tell it's heavier. Excel makes heavy rv's, no doubt about it, but quality comes at a price.