Handling issues

[Vach]

I need help. I have been pulling a small 20 ft TT and have finally decided to upgrade to motorhomes. I read a ton of stuff here,looked at many and decided a small (26-30) ft class A or C would be best for us. Test drove a 2008 Winnebago 29t Access with only 8000 miles and was surprised how poorly it handled. Didn't expect it to drive like my truck but it was a handful. Read some more about wheelbase to length ratios and shocks and tires and alignment and swaybars.

Did I drive a lemon? Are all short wheelbase class c's a handful? Is a short class A any better. Do I have to spend big $ in upgrades to get a motorhome to drive well?

Be gentle, I don't mean to pick on a class or manufacture just have so many questions.

[DUNEBUGGYDOUG]

Thanks Ron, good info

[ron_dittmer]

DUNEBUGGYDOUG wrote:
Ok fellas, I was not aware that the MH manufacturers streched the wheelbase.I thought they only added. behind the rear axle so I guess the old adage of learning something new every day still stands true to form .The official wheelbase listed for 1998 E-450 is 158"and 176 "while for an E-350 it is 138", 158" and 176" .Thanks J-D and the rest of you

CLICK HERE to see the Ford document to outfitters like motor home manufactures on the proper method in changing the wheelbase. There are a number of matters to consider such as brake & fuel lines, wire harnesses, parking brake cable, drive shaft, and welding procedures, materials etc.

[DUNEBUGGYDOUG]

Ok fellas, I was not aware that the MH manufacturers streched the wheelbase.I thought they only added. behind the rear axle so I guess the old adage of learning something new every day still stands true to form .The official wheelbase listed for 1998 E-450 is 158"and 176 "while for an E-350 it is 138", 158" and 176" .Thanks J-D and the rest of you

[Gene_in_NE]

j-d - Your answer sounds accurate. One thing to mention is that the frame stretching was probably done in accordance with Ford's standard. The problem could be it does not apply to what is built on that chassis behind the rear axle. The frame stretching typically is between the axles.

[j-d]

FORD itself made only a couple wheelbases. I think most RV companies order the 158" WB although there's another (176" I believe). The RV companies then have the chassis "stretched" by a specialty company, or maybe some do it themselves.

For example, Our E450/Jayco has a Ford label saying 158" but Jayco has a label saying 218" so the specialty company (Sellars in our case) extended the WB by 60" (Five Feet!). They also extended the rear overhang. Ford has an engineering standard for doing this. If followed, the chassis retains its original capacity.

[DUNEBUGGYDOUG]

Just exactly how many different wheelbases did Ford offer in their E-450 cab/chassis for motorhomes??In this thread several wheelbase lengths are mentioned.I have a 31 footer with 192 inch wheelbase and is hard to believe that so many different ones were produced

[pnichols]

ron.dittmer wrote:
... and I've heard a loss of 1 mpg because of the rear axle ratio. But I find it hard to believe it takes a 10% hit in fuel economy.

I don't measure our small Class C's gas mileage precisely.

I've had many, many tank fill-ups where the number of gallons of gas filled muliplied times 10 came out to be around the elapsed miles since the last fillup ... hence "around" 10 miles per gallon.

However, I use acceleration rates and highway speeds that are very conservative ... probably way too sluggish or slow for many drivers, so our E450 Class C mileage may not be typical. We don't have the additional roof air drag that solar panels create, don't tow, and use very high quality ( and very "slippery"?) engine oil.

[ron_dittmer]

pnichols wrote:
Just as KONI promised, here is their E350/E450 solution to at least a portion of the harsh Class C ride coming from the rear suspension ... at least for my case of a small Class C that under-loads and under-works it's E450 chassis:

http://www.koni-na.com/uploads/KONI_E350450_Cons_PR.PDF

P.S. "Under-loading" and "under-working" the chassis under your Class C is a good thing if the harsher ride in the rear can either be tolerated or otherwise addressesd. Some of the benefits are A) larger brakes for more safety and longer periods between replacement brake pads, B) better transmission cooling for climbing long grades in warm weather, and C) thicker frame steel for less stress induced deformation of the RV's flooring and super-structure.

So it finally happened, Koni offering FSD shocks for the E350/E450. I can't wait to hear from people who get them on their class-C.

You are absolutely correct pnichols in saying there are great benefits to getting an E450 under a rig that is normally built on an E350. The long list of benefits is challenged only by the harsher ride, a modest cost increase to purchase, and I've heard a loss of 1 mpg because of the rear axle ratio. But I find it hard to believe it takes a 10% hit in fuel economy.

[RambleOnNW]

We'll be looking for your full report for the FSDs, including before and after accelerometer data. 🙂 Here's an example smartphone accelerometer app.

Shocks cannot be optimally designed for a wide range of vehicle weights e.g. Bilstein having Comfort and Heavy Duty shocks, and Koni's adjustable shock. It will be interesting to find out if the FSD works well for both 10,000 and 13,500 lb vehicle weights.

An interesting note: The FSD is an oil-filled shock, Bilsteins are gas shocks.

[pnichols]

ron.dittmer wrote:
There is a draw-back to excessive CCC margin. The ride will be exceptionally harsh. Considering it's a house with contents, less harsh is better. There is a delicate balance between quality of ride and excess CCC with no real formula to follow.

Just as KONI promised, here is their E350/E450 solution to at least a portion of the harsh Class C ride coming from the rear suspension ... at least for my case of a small Class C that under-loads and under-works it's E450 chassis:

http://www.koni-na.com/uploads/KONI_E350450_Cons_PR.PDF

P.S. "Under-loading" and "under-working" the chassis under your Class C is a good thing if the harsher ride in the rear can either be tolerated or otherwise addressesd. Some of the benefits are A) larger brakes for more safety and longer periods between replacement brake pads, B) better transmission cooling for climbing long grades in warm weather, and C) thicker frame steel for less stress induced deformation of the RV's flooring and super-structure.

[ron_dittmer]

There is a draw-back to excessive CCC margin. The ride will be exceptionally harsh. Considering it's a house with contents, less harsh is better. There is a delicate balance between quality of ride and excess CCC with no real formula to follow.

[OldRadios]

Empty is 10,702. max with tow is 19,050. Diff is 8,348. Even if I towed it's max of 5,000 that still leaves 3,348.

If it was a Chevy chassis, empty would be 10,550. max would be 17,550, Diff is 7,050. max towed would be 3,500 so I'd have 3,550 left.

You still have to worry about each axle weight and there's no way I'd have room for even close to that much weight distributed over each axle but it's there. Some I looked at were well under 2,000 pounds left when pulling something. A few people, gas and water can equal almost that.

The plan was find something under 27' with no slides with a 450 chassis then weight and handling should not be an issue. Did not want to be driving something that was at or near it's max capacity all the time.

[j-d]

... additional 8,348 pounds ...

Your coach may have a lot of NCC, but I find that figure hard to believe. Coach's empty weight would have to be around 6,000 pounds. Or am I missing something?

[OldRadios]

Tire pressure is important but when looking at models for our purchase last year I always compared the base weight with the gross combined weight rating. There were quite a few that after adding the weight of a couple of people, a full tank of fuel, and a tank of water they could barely carry a dozen eggs.

Weight was one of the reasons we decided on no slides and going with the E450 chassis. My 27Q will carry an additional 8,348 pounds of fuel, water, people, toad, and junk. I doubt I will ever come close to that. We tow a trailer with two Harleys and a canoe so thats around 2,000 pounds (towed weight). Still leaves me with over 6,000 pounds for us and everything else.

It's a 2006 (2005 chassis) and I have absolutely no issues with handling at any speed and it's all original equipment.

Looking at some of the longer models I'm sure the wheelbase on many is too short. Some look like you could jump on the rear bed and make the front wheels come off the ground.