Have I bit off more than my truck can chew?

[99gmccrew]

I just bought a newer 5th wheel. Never had a trailer before. Always had motorhomes. I'm extremely excited to try it out. My first mistake is my truck is a short bed. Little did I know, long beds are the preferred bed of the 5th wheel trailer. Live and learn. My trailer weighs in at 12,500 empty, 14500 loaded. Will I be able to get over the hills with this much weight? Will I damage my trans or engine? I have the gauges, new intake and exhaust mods. Any suggestions. Thanks in advance for your comments.
Steve

[JoeyD]

You need an intercooler. That is one big ass trailer for any truck let alone the 6.5. Not only is it heavy it must have a huge wide drag. You will need more power so start shopping.
As far as the short bed with the correct hitch placement it should be OK.

[DmaxMaverick]

That's a lot of weight, as well as profile, for a stock truck.

If you aren't interested in the intercooler upgrade, consider a water mist system. Much less expensive, and, IMO, better than an intercooler. The drawback would be the high volume of water needed. I've heard of folks plumbing their RV fresh water storage to the truck for the mist. Easy setup. Pressurized water on tap. I've considered doing it myself. It would be simple enough with a boost operated regulator. Guess that's another subject.

Cooling should not be a problem. I'd suggest getting your hands on a JK fan clutch. If not, be sure yours is working well. Clean the outer surfaces of the radiator. A lot of debris can get built up between the A/C condensor and radiator, restricting the airflow and insulating the heat in.

Just don't get in too big of a hurry, and drive by the gages. If you don't already have one, consider a tranny temp gage. Keep your EGT's down, and the rest will stay in check. There's no shame in letting the late models pass you on the grades.

[ktmracer]

i`m right there w/ you man. we regularly tow a 5th wheel toy hauler that weighs in @ around 13,500lbs ready to go to the track.i am seriously considering the intercooler and larger exhaust.the truck has airide and a lot of other neat gadgets but no performance mods
we aren`t first to the top of the hill but we always seem to make it. just drive like you`ve got a little sense and watch the egts and engine temp and you should be fine.
i`ve had a chance to drive all the new trucks,ford,chevy,dodge, and they are killer strong but i just haven`t been able to make myself sign on the dotted line.(yet,anyway!!)

[tanker]

Steve, ever heard of the "little engine that could"? Well you will get there a little slower than most. Keep an eye on your EGT's and as mentioned above, get an intercooler. Summer heat, big hills and a heavy load, don't mix too well.
Safety is also a concern.
There is a fellow near us that tows a tri-axle Travel Supreme 18,000# trailer with a 6.0 gasser. So he is over 24,000lbs gross weight.
Good luck with your new home. [img]smile.gif[/img]

[rjschoolcraft]

The intercooler is the only way to go if you are serious about towing. The water mist is a gimmicky band-aid that works for people who don't tow long distances much. There, that ought to get me in trouble. I've towed close to 10,000 miles already this year. The intercooler completely changed my Suburban.

[99gmccrew]

Guys, when I bought this truck 6 mos ago I told myself I would keep it for ten years. It now has 89k on it. I see that dmaxmaverick has 500k on his 6.2. That's incredible. Ronnie joe I remember when I first joined you suggested I look into an intercooler, but first get the gauges, intake and bigger exhaust. I took your advice RJ and I've done most of your suggestions and I'm extremely happy with the performance difference. I'm glad I've gotten the great advice from everyone. I think to make this truck, (that I really love),last ten years, I'm going to have to really consider putting on that intercooler. Who has them, how much do they cost, and can I do this myself. How long would it take to install? I've done all the minor mods myself. I've become pretty mechanical out of neccessity and not trusting mechanics with my vehicle. Thanks for all your help everyone.

[rjschoolcraft]

I use the Spearco unit that Kennedy sells. It is a straight forward installation, but requires some patience and a little intuition. The installation instructions from Spearco are not very good. In fact, they had mis-marked one of the tubes showing the flow in the wrong direction. After I figured that out, it went much more smoothly.

Turbotechnologies sells a smaller unit that is used on Tough Guy's project truck.

The Kennedy unit was $1300 while the TT unit is about $900 (IIRC). That sounds like a lot, but I have to say that I count it the best thing that I've done to my Suburban.

[Spindrift]

RonnieJoe,

What data do you have which would support your suggestion that mist injection is a gimmick?

No one can argue the obvious benefits that an intercooler can provide. However, I understand there is data that demonstrates specific advantages when using chemical mist injection: They include:
1. Efficiency - leaner air fuel ratio can be utilized for normal operation.
2. An increase in air charge densities which provides horsepower increase.
3. Relatively low cost of initial investment.
4. The moisture injested by the engine also participates in the combustion process as a super-heated steam, increasing the duration of the pressurization of the cylinder.

Depending on boost levels, the results of these benefits produce:
a. Intake charge cooling - A water only system will lower IAT by at least 170*, Water/methanol will lower IAT temps at least 200*. Methanol acts as a fuel as well as cooling the intake charge in this application.
b. EGT reduction of 100* - 250* is common
c. 18-70 HP increases. Some folks say even more.
d. Increased air charge densities of 3-5 psi

I'm certainly no expert on the topic, but these results are routinely reported by the few, reputable folks who are continually testing, improving and marketing mist injection systems AND Cummins and PS guys who for some reason (maybe because they're running at higher boost levels?) have been more eager than us to adopt this technology. Simply go to their forums and see for yourself.

Clearly, there are certain disadvantages associated with mist injection; the most noteable is the need to lug water on your back (a real PITA). But air-to-air intercoolers aren't perfect either. They are much less efficient at reducing air charge temperatures than mist injection systems.

I say run both systems, if you've got the caaaash. I think the bottom line is that they're two different systems with their own advantages and disadvantages. We're all big boys here and therefore have the ability to analyze both systems to determine what might work best in our particular situation. To suggest that all of those who have gone before and continue to see results from mist injection have relied on a "gimmicky band-aid" is being a bit harsh IMHO.

FYI...I understand that Jim is preparing a feature article on mist injection which is supposed to be out in the next month or so. Can't wait.

BTW RJ, it isn't my intent to start something. Personally, I need to do one or the other so I'm just as anxious as you, I think, to see more test results.

[99gmccrew]

Spindrift, you put up one heck of a counterpoint. Both systems sound like they have their advantages and disadvantages. I myself am swaying towards the intercooler simply because of the whole water tank problem and possibility of running out of water.

Your Burb sounds similar to my truck with mods done. Have you towed anything heavy with it?
If so, how'd it do. I haven't towed my new trailer yet, not delivered. Thanks

[Turbine Doc]

99Crew,
Lowering charge air for power is very beneficial it allows you to jack up boost & add fuel for more power, I run Kennedy's Spearco kit, I have hauled 12,600# loaded GN trailer with my highly modded 6.5 18,700# combined wt Here are some photos to go with the kit if you decide to install one Spearcos install instructions SUK

http://myweb.cableone.net/tbogemirep/

WMI may be as beneficial as IC; Bill Heath swears by his kit, I've not had him steer me wrong yet. For me having to fool with a tank and refilling H2O is too much a PITA, get the biggest IC you can fit-it's always on, and always cooling as soon as you get 10mph air across the IAT temps start dropping, as for efficiency my drop runs 150-200F, rarely if ever have I seen IAT above 120F, haven't summer towed a heavy load; all my towing thus far has been < 85F OAT.

[rjschoolcraft]

Spindrift,

First of all, there is truth in the things that you quote. I've always said that the physics of water mist injection are real. The superheated steam comment is dead on... as long as the water is metered properly for the particular power demand and engine load condition. However, none of the systems I've seen have that type of variable metering system that is controlled by demand parameters.

Second, I have personally been involved in applying this technology to a 7000 HP base gas turbine engine that was boosted by a three stage low pressure compressor to about 9000 HP. The WMI (or more precisely, water-alcohol injection) brought the full take-off power up to about 11000 HP. Significant, huh.

As I have pointed out over and over, though, those systems in aircraft use are only used for a boost during take-off...thereby gaining my "band-aid" comment. In this particular case that I speak of, it was added because the engine was not capable of meeting the take-off requirement without major redesign and the project didn't have time for that. Plus it was a demonstrator engine, meant to demonstrate the feasibility of another emerging technology. Plans for a production version did not include WMI.

Having speant many hours behind the wheel of my Suburban while towing heavy trailers, I've come to the conclusion that WMI is not appropriate for continuous use. All of the discussion I've seen is about a boost triggered system that does not come on utill around 10 psi of boost is achieved. In some parts of the country, towing the load that I tow, it would be on all the time (I've seen 11 psi sustained boost in Colorado and other western states) and the water supply would be crucial. I doubt that enough could be carried to really make it beneficial. People talk about 30 or 40 gallon tanks...that's 250 to 330 lb. of dead weight added to the rig when the tank is full. Further more, when running sustained boost levels of 8 or 9 psi, the system would not be on and the cooling effects would not be available. I've seen my egt's rise pretty high (pre-intercooler installation), as well as coolant temperatures, in just such instances.

With the intercooler, the cooling is there all the time, without me thinking about it. My egt's are significantly lower all across the board (average of about 350 F, some cases much more). For those who've installed WMI, I'm glad you're happy with it. I cannot believe that it is practical for anyone who tows significant miles per year for sustained periods of time. As I said in a much earlier post, I towed 996 miles in one day back in November. Started at Las Vegas, NV in the morning and stopped in western Kansas for the night. The only time boost levels dropped below 10 psi for the whole day was on decels on mountains. I sure would have hated to stop repeatedly to fill a water tank to keep my engine performing as desired.

How many over the road trucks use WMI? Think about it.

[Turbine Doc]

One more concern of mine with WMI has been water quality long term, whatever deposits, metals, minerals are in the water will be fed to your engine. Even with a filter on the water there is only so much "stuff" a filter can protect against.
It may be paranoia on my part, just one more of those things though which points me more toward IC over WMI.

The turbines I work on are a bit larger than the ones Ronnie Joe is talking about 5000 to 60,000 Hp depending on model but work identical; we use a type of WMI on stationary GT plants a water curtain that the engine pulls air through to lower OAT for more Hp on hot days continous duty.

One of our concerns is water quality, most sites have huge demineralizer and filtration "beds" to keep water as clean as possible. Even when waterwashing a turbines dirty compressor, demin water is the prefferred for wash and rinse.

For a tow vehicle requiring sustained cooling for me IC again better of the 2 IMO, WMI works does cost less than IC I am just happier with KISS systems, (keep it simple stupid), tanks-weight-clean water-valves-switches-pumps doesn't fit my idea of KISS for long term, just me feel free to disagree.

Ronnie 3 stage LPC??? what engine Pratt ???

[ 04-25-2004, 09:07 AM: Message edited by: tbogemirep ]

[ibelyea]

When I had my 98 extended cab, I pulled a 12,000 thruout the US. Spent a lot of time in WA.OR, ID and Montana using this rig.
I added Kennedy's Sperco IC (Large one and easy to install), Kennedy exhaust, Jet chip and a retuned pump to -2.04 offset. While it doesn't come close to my DMax it was very strong and durable. Just watch temps.

[rjschoolcraft]

TBO...

That particular engine was an Allison Model 578-DX. This was a demonstrator engine that was based on the Allison 570/571 engine which derived from the military T701 for the Heavy Lift Helicopter. The airframe never made it due to combining gearbox failures.

The 578-DX was used as a prop-fan demonstrator. If I could figure out how to post pictures, I'd post one. The basic T701/570 engine was boosted with a specially designed 3 stage compressor for the project. The engine flew on a McDonnell Douglas MD-80 out at Edwards AFB.

I spent the bulk of my time at Allison working on the Model 250 helicopter enigne. The 250-C40B produced 715 HP from a 275 lb. package. That's a power to weight ratio of 2.6:1. I designed the power train gears for the engine gearbox (along with many other components of that engine). The engine is used in the Bell Model 430 helicopter. Ron Baur flew a 430 (second production ship with the third and fourth production C40's) around the world establishing the current speed record for helicopter circumnavigation of the globe.

[ 04-25-2004, 10:05 AM: Message edited by: ronniejoe ]

[Turbine Doc]

My apologies to the topic digression Jets are my 1st passion.

RJ
how many stages of LPT to drive the LPC, my only Allison experience is T-56 direct drive inputing to a gear set to turn a 2.5 MW gen set for ships power.

3 stages of LPC new to me, the LM6000 derivative of GE 80C-2 60Kshp has a 4 stage LPC ("booster" in aircraft engine terminology) driven by the LPT supercharging more or less the 14 stg HPC which is direct drive from the 2 stg HPT, during ramp up to load; the LPC air is bled off to about 30% power then blocker doors are closed to super charge the HPC/engine.

have you ever worked the T-700 GE that has a neat compressor axial into centrifugal.

[JoeyD]

Originally posted by ibelyea:
When I had my 98 extended cab, I pulled a 12,000 thruout the US. Spent a lot of time in WA.OR, ID and Montana using this rig.
I added Kennedy's Sperco IC (Large one and easy to install), Kennedy exhaust, Jet chip and a retuned pump to -2.04 offset. While it doesn't come close to my DMax it was very strong and durable. Just watch temps.

What did the Jet chip do?

[rjschoolcraft]

The 578 had two stages of LPT driving the LPC...a two shaft engine, IIRC...that was about 15 years ago. I think there were two stages of high pressure turbine to drive the 14 stage high pressure compressor. The boost compressor was added specifically for the demonstrator program and had variable geometry vanes. We used the variable geometry to modulate flow through the boost compressor (and thereby, the amount of boost), not just to prevent surge during start. We later applied that technology to the lift fan system for the Joint Strike Fighter. You can read more about the Propfan engine here and here. The last photo (of the MD-80 at take-off) is of the system that I worked on.

I haven't worked on the T700, but the smaller version of the 250 (the Series II) has six stages of axial feeding one centrifugal compressor (C20B, C20F, C20J, etc.) or four stages of axial feeding one centrifugal (C20R). The compressor is driven by two stages of high pressure turbine (HPT) which is gas coupled to a two stage power turbine that connects through the engine gearbox, to the main rotor tansmission and to the main rotor in helicopters. The Gas Producer spool (HP spool) rotates at 51,000 rpm, while the Power Turbine spool rotates at 33,000 rpm (100%).

The T800 (for the now cancelled Comanche) has a two stage centrifugal compressor...that's a funny looking beast.

You mentioned the T56... That engine has been a workhorse since 1955 (coincident with the small block Chevy V8). The industrial engines that I'm consulting on now for Rolls (Allison) are derivatives of the T56. They share more than 80% common components.

Edit: The system doesn't like that first link that I posted. Here it is without the "URL" button... http://vesuvius***c.nasa.gov/er/seh/profan.html

Edit: Still doesn't like it. The three stars should be "dot jay ess". Hope this works.

[ 04-26-2004, 05:13 AM: Message edited by: ronniejoe ]

[a5150nut]

The 250-C40B produced 715 HP from a 275 lb. package. That's a power to weight ratio of 2.6:1.

How could we hide this under the hood of a 94 K2500?

[Turbine Doc]

You could hide it but couldn't feed it, much as I love GTs they are thirsty.