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Supercharged111's avatar
Supercharged111
Explorer
Jun 10, 2013

GM GVWR/GCWR chassis/powertrain questions

Starting to do my research here, but it seems very few people ask the questions that I do. I'm indifferent to class A vs class C, I'm after something no bigger than 25' and I'm sure either can accomodate my needs as far as amenities go. I want to pull my car to the track as I do behind my pickup now, but this way to have a place to sleep if the weather is hot/humid, rainy, etc. This will also enable me to make this a family event and not just me disappearing for the weekend.

At any rate, onto the questions. I love to wrench, so that's what my questions are geared toward. What are the GVWRs and GCWRs of some common GM chassis? I'm inclined to thinking that the chassis are pretty much all the same, with a camper slapped on the back of a cutaway van (so the camper part is the variable). The Fords wear an E450 badge on the side, so they're easy to spot, but I'm starting to doubt GM ever gave up anything heavier than a 3500 chassis to a class C motorhome? I know they did 4500 chassis, but my fruitless google searches seem to indicate that they all went to the topkicks/kodiaks, and perhaps the class A motorhomes? If only a 3500 chassis, is that a 12,000# GVWR? What's a camper typically weigh? I don't want to cross the scales overloaded pulling a car trailer and I'm not looking at newer motorhomes either, just something new enough to have overdrive. I can get the power from the motor eventually, which leads me to my next question: when not pulling a car trailer, how well do these behemoths hold OD? I live in CO where the air is thin, and my truck needed a little help performing up here so I imagine an inverted sail is no different.
Class C

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  • pnichols's avatar
    pnichols
    Explorer II
    Jun 10, 2013
    I'd definitely go with a ton-and-a-half chassis - the Ford E450 or Chevy 4500. I don't know about the Chevy 4500 - but with the Ford E450 (over the E350) you get larger brake swept areas, increased transmission cooling, anti-sway bars both front and rear stock, lower rear differential gearing, wider rear track for improved lateral stability, etc..

    I don't know about the Chevy engines used in their 4500, but the Ford V10 will tow just fine - no diesel required whether or not you can even get it.

    I have a Ford E450 underneath a 24 foot Class C and it goes like a scared rabbit uphill and everywhere else - drives like a van with a real truck chassis doing it. From 2005 onwards Ford uses a 5-speed (6 speeds internally) computer controlled TorqueShift transmission that is superb - especially with it's electrically switched TOW/HAUL mode. With it's TOW/HAUL mode engaged, you get automatic downshift gear braking on downhill grades and when braking coming up to stop lights.
  • Supercharged111's avatar
    Supercharged111
    Explorer
    Jun 10, 2013
    A quick search indicated that E-450 GVWR is 14,500 (vs. 12,500 for most 1 tons, right?). I hate to think it, but would I be better off looking at the Fords? I'm not as familiar with them as I am the Chevies with respect to the powertrain. On the Chevies, I know if I get a TBI 454 I can slap a Vortec top end on, convert it to OBDII, and tune it myself. I'm not aware of what I can do to a V10 for power aside from headers and a tune, nor am I familiar with the transmssion they came with (E4OD?) or how much abuse they take. I've read good things about the Ford's powertrain in stock form, but the fear of spitting a spark plug makes me uneasy. With a GCWR of 20,000# on the E-450 and rated to pull a 10,000# trailer, optional diesel engine but it's the 6.0 that like to blow head gaskets and turbochargers. I guess now I research MH lengths and wheelbases to get a better idea of the Fords.

    Edit: decided to put this link in here, some good techy info on E-350 vs. E-450.

    http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/19501818/print/true.cfm

    Another good read, kind of explains why I'm having a difficult time finding a chassis with a lot leftover.

    http://www.rv.net/forum/index.cfm/fuseaction/thread/tid/26387249/srt/pa/pging/1/page/2.cfm

    Chassis overkill pretty much sums up what I'm after, but it seems I'd need to buy newer to get it. . .
  • ronfisherman's avatar
    ronfisherman
    Moderator
    Jun 10, 2013
    Supercharged111 wrote:
    Is it fair to say that most of the 450/4500 chassis are used on Super C's and thus are also equally near their GVWR before a trailer?

    Most Super C's were built on 550/5500 and heavier chassis.
  • Supercharged111's avatar
    Supercharged111
    Explorer
    Jun 10, 2013
    25' is the big end of what I'm after, if I can get a shorter one I'm OK with that too especially if it makes the ass end shorter. The impression I'm getting is that these are not overbuilt, rather quite the opposite. Most of what I'm looking at are on 1 ton frames, aren't they? Is it fair to say that most of the 450/4500 chassis are used on Super C's and thus are also equally near their GVWR before a trailer? I saw on some of the older ones that as you get down near the 20' mark, you run the risk of getting a small block engine. I know more rear overhang will make towing worse, GVWR/GCWR notwithstanding. Should I be looking at a small class A instead? Are those typically built on heavier frames than a similarly sized class C?
  • JaxDad's avatar
    JaxDad
    Explorer III
    Jun 10, 2013
    I think the big issue will be the load of the trailer. Most class C's in the 24' - 25' and around $10k. range will be at or near GVWR before you put any people or supplies in them never mind a trailer.

    The other issue will be the rear overhang, on my 24' C it sits on a 158" wheelbase F350 chassis. In round numbers a 24' (288") unit with a 158" wheelbase, you will have a ~ 8' - 10' rear overhang.
  • ronfisherman's avatar
    ronfisherman
    Moderator
    Jun 10, 2013
    There are some Chevy cutaways that Work Horse modified to be 4500's. Some Chevy vans had the Duramax engine. But they like the Ford's had lower power ratings.
    Gulf Stream built some Class C's on this chassis. But I have not seen one in a few years.
  • Supercharged111's avatar
    Supercharged111
    Explorer
    Jun 10, 2013
    Can you get a diesel in an older class C? Or is it only in the newer ones? I'd settle for an older 7.3 Powerstroke, but that wouldn't exactly be settling. I told myself I wouldn't go over 10k, but the 8.1/Allison combo really has me wanting to up that cap. How new are the Dodge chassis of which you speak? I think the Mercedes would be too new, that's that 5 cylinder, right?
  • Go_Dawgs1's avatar
    Go_Dawgs1
    Explorer
    Jun 10, 2013
    I have an 03 Chateau Sport 26Q on a 3500 GM chassis with a 8.1 Vortec. My GVWR is 12,500 and the tow rating is 5000lbs. Any gas MH will probably be limited to 5000lbs towing. Diesel will go much higher. If you are looking at 25' or less then your weight will be fine and most newer Class C are on the E450 Superduty. You might also look at the Sprinter Class C's some on Mercedes and some on Dodge chassis with both gas and diesel. Look at a couple today. Nice rigs and roomy.

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