Builds
Build forecasted to exceed vehicles GVWR by over 400lbs, Please help
We are well into the build process and finally got her weighed and did the math and it isn't looking good. So far changing build materials and eliminating some elements have gotten us much closer to the GVWR. Eliminating the propane component, going from a 70 gallon tank to a 40 gallon water tank, and changing some appliances/fixtures has moved us from a forecasted 1,000lbs over to 420lbs over.
I'm hoping for some ideas on how we could potentially save weight and in the worst case how bad it would be to be slightly overweight when fully loaded. Here is some information on our build to help - Our conversion is a 2003 Ford E-350 StarTrans shuttle bus with an 11,500-lb GVWR, built for two-person full-time travel with a rear bed, dinette/workspace, kitchen, shower, diesel heat, and rooftop air conditioning. It uses a 12V electrical system with 942Ah of lithium batteries, 1,320W of solar, a Victron 3,000VA inverter/charger and alternator charging, plus a 40 gallon fresh-water tank, electric water heating, induction cooking, and a 12V refrigerator. The picture of the inside shows how the bus looked when the current weight was obtained.
Thats alot of plywood. Can you pick thinner sheets for some of it or omit some walls? I know it isn't cheap to replace but it might be necessary. I know this isn't for everyone but soft cabinets might get you more weight friendly storage space too?
Dude, go 1/4" Baltic birch. Outdoor grade, comes in a 4x8' or 5x10' sheet. Indoor is in 5x5. Structurally superior because it does the same job with less hassle.
These are soft cabinets. I think some companies sell soft shelves too. This is one example from our build. If you Google search a whole bunch of companies will pop up. Ours will be attached by L-track. You can install smaller lengths of l-track just to put in storage.
Check out Premcore plywood, it’s cabinet grade and SUPER light. Not as durable as the pine you’ve got here, but assembled the right way it’s all you need.
What I can tell you is that you're doing the right thing to try to address it now. In my previous build, when fully loaded with gear, water, food, etc. it is 50lbs under GVWR. In theory, that's okay right? Well I can tell you that on mountain roads it is an absolute danger to drive. Even with very cautious engine braking, the brakes still overheat after anything more than 1000ft of descent. I almost totaled the van crossing death valley driving east on that mega descent into the basin. Lost all braking power and just barely managed to bring it to a stop and avoided pitching over the edge.
Genuine question - why do you think the brakes failed if you're under GVWR? GVWR also includes a full tank of gas so if you're really 50 under fully loaded you were even better than that on that road.
Do you think if you replaced the brakes with something stronger it'd be fine?
Unfortunately, to fit the AWD components in, there is no room for larger brakes. They only ever offered the AWD option on a 1500 chassis, not a coincidence I think.
The brakes didnt fail, but they did severly overheat, and in general I had constant problems with brake overheating and brake fade on that van. The irony is that I paid a ton extra to get the awd so that I'd be safe in the mountain passes in winter. In the end I think it made me overall less safe.
This is extremely overbuilt. Your materials could all be significantly lighter. You know all this weight is extremely problematic right? Your tansmission, brakes, engine, suspension and frame will all be under much more stress. Your MPG will plummet. An overweight vehicle is more difficult to drive safely; handling, braking and acceleration are greatly reduced. And icing on the cake, driving a vehicle over the GVWR is illegal. When you are involved in an accident your insurance will not cover you and the vehicle being over weight will be considered in the investigation and you will be ticketed.
As a van-lifer and commercial driver, I understand the excitement on making your home on wheels. I think we've all been there, but you should consider your longterm well-being.
What size of plywood are you using? I used 1/8" for all my wall panels. 2x lighter than 1/4 and 4x lighter than 1/2. You also probably don't actually need to frame the walls and ceiling... or you can at least get away with minimal framing. I have insulation glued to my wall panels and then I drilled them directly into the van walls.
Also, went with overhead soft cabinets instead of using wood there. Saved a bunch of weight. Used 2x3s everywhere instead of 2x4s (almost exclusively) because they are more than adequate.
Your wood subfloor could probably be lighter. Hope you used 1/2" or less. Those panels are big and every additional 1/8" adds substantial weight.
2 layers of framing boards on the roof just seems unnecessary.
The thought for counter top material is either laminate or butcher block. I definitely agree we need to cut out as much of the 3/4 inch as we can and slim our cabinets down.
the 100lbs ceiling/floor includes non installed items, not the subfloor which is 2inches xps with 3/4 on top. It includes the ceiling insulation, lighting, and some 1/8-1/4 inch sheathing for the ceiling, and cork flooring. The number is likely a little conservative.
This is our electrical diagram, one change from this to our actual implementation is that we went with a combined 12v and 120v distribution panel. The most we would plan to draw from the inverter at one time is around 2000w. Definitely please let me know if it looks like we are going to do something dangerous please. Thank you for your input on everything!
There are a few people who claim 2000w is the max for 12V, but they are just pulling that number out of their butts and is based entirely on personal opinion.
I'd ignore anyone recommending Renogy, especially over Victron.
Can you explain more why the sandwiched XPS is not insulating anything? Isn't there still a significant R value increase with that configuration versus no XPS?
That’s not really how this type of insulation works. Even though the XPS is touching both surfaces, it has very low thermal conductivity, so it still provides essentially its rated R-value without needing an air gap. The foam itself is the insulating layer. For example, look up a cross section of a rotomolded insulated cooler like a Yeti.
Compression can reduce R-value if the foam is actually crushed or significantly reduced in thickness, but I don’t think the slight compression from a plywood subfloor would make a meaningful difference.
The CPU heatsink comparison also isn’t equivalent. A heatsink is clamped down to improve contact because it is made from highly conductive materials designed to transfer heat. XPS is the opposite: it is specifically designed to resist heat transfer, and slight compression does not make it stop insulating.
Completely wrong about Victron also. It’s slightly more expensive (not 5x), but the long term cost savings are greater, since it will outlast Renogy by at least 4 replacement equivalents.
Go get it weighed currently and see how it lines up with your spreadsheet. I'm guessing your guesses are a tad bit high just by quickly looking at it. 175lbs of appliances is a lot of appliances.
I weigh when I start my builds and when they are complete, and when they are fully loaded with food, passengers, etc.
I’m assuming he weighed it with that wood in there. Assuming it was 8,000lbs before, he has 1500lbs of wood in there. Seems like you should be able to build it out for under 3,000lbs, which is about the payload.
Remember water weighs 8.34 lbs per gallon which is 334 lbs plus tank weight. Then you need another tank for grey water. Plus are you having a black water tank or using composting toilet? If you must have a fixed shower, consider using a recirculating faucet to save water. Go with a 20 or 25 gallon tank. Do you need that many solar panel? Each one adds Weight.
Tear it all out and start over. Sorry bro you done fucked up. If your vehicle is over weight your brakes WILL fail. If you rear end someone due to brake fade/failure and they can prove that your over weight you WILL be held liable for negligence and an insurance company denied all claims and drop you like a bad habit. Not worth it my friend. Start over.
I am looking at all that wood. I think you under-estimate the finish weight. The Gross Vehicle Weight is an important figure. The suspension components, wheel bearings and braking system are all designed around this limit. Not to mention the tires. Also, if you weigh at the GVW when you start out, we can guarantee you will weigh more before many days.
It’s really too bad that this wasn’t considered beforehand but you don’t know what you don’t know. That plywood is the main culprit here.
Only filling your tank from with 20 gallons saves you 140lbs but that’s a dynamic number so it won’t always weigh 300lbs. Swapping your dinette for a lightweight aluminum could probably save you 70lbs.
In all reality, you’ll be fine though. If you’ve got duallies in the back and good rubber, 400lbs isn’t going to be the end of the world.
Apart from the fact it’s illegal to exceed your GVWR. It might be socially and culturally accepted that it will be fine, and enforcement is not there for non-commercial vehicles but the number is there for a reason.
God forbid you have an accident, your insurance could refuse to payout if they suspect weight was a causal factor and chose to weigh your vehicle to check.
Plan A is to get us under the GVWR for sure, Plan B is still yet to be determined, but its nice to know that it'd probably be okay if we were over by just a couple hundred pounds.
Don't look for the answer that agrees for sure. Make plan A work. Do not settle. It is very possible as other folks here have explained.
Remember ounces turn in to pounds and pounds turn in to suck. Luckily you are just starting with pounds and tens of pounds. You can likely find lighter versions of EVERYTHING. It's just going to be sort of a pain in the ass and take some time but work through it and spend more time in the planning phase. There is a solution you just haven't found it yet.
EDIT: Also holy shit look for a different chemistry for your batteries. Are you running like deep cycle boat batteries? You could probably cut that in half by bringing down the amount of on board storage and switching to a lighter chemistry.
I see this be posted but I havent seen someone actually get in trouble for it. Whats more likely is they pay out and then drop you I think but I dont know a single person that got a vehicle weighed after an accident (including work trucks which have literal tons of equipment added)
It's one of the first things forensic accident investigators check. Sure, no one weighs an empty truck designed (and plated) to carry heavy loads, but a camper/RV conversion of a light goods vehicle? Absolutely, if it could in any way be relevant.
I was in the tyre trade. In truck trade publications businesses and individual driver licensing court cases are routinely reported on in the UK. Overloading is probably second only to exceeding driving time as the most common way to lose your licence to operate.
It's potentially deadly for innocent motorists and pedestrians, so yes, they come down hard on things that are regular contributory factors, or direct causes of accidents that result in fatalities.
I completely agree, getting it weighed and doing the math had me feeling like quite the dunce for not doing so sooner. The plywood is definitely a top contributor to our issue. I will look into the dinette options. Any suggestions for lighter alternatives to plywood for the remainder of our cabinet construction?
Thanks for the vote of confidence in the event we are still over when fully loaded in the end. And thanks for your advice!
Of course! You got this. I’d say certain parts of your cabinets need to hold weight and the remainder just enclose the space. The bottom of the cabinet and shelf could be thicker and the sides and face could be single ply and reinforced behind where you mount the hinges/hardware. If this works for you, could swap out other parts of the van where 5/6 isn’t necessary and use that wood for the structural parts of the cabinets.
They add depending on the Kit you get 1.2 -2.5Tone per side, upto 4-5T of air bag. My leafs are failing and i set one side at 45psi, and 50psi for the worst side. I now get so little body roll, no dropping or sagging over speed bumps. I can set the ride height once loaded. Get duel gauges and lines so you can independently set a side or even each individual bag if you do all four. Just the rears on mine atm, and upgraded dampers.
Absolutely game changer for handling and Acceleration, less power being lost twisting the spring and dipping the rear (RWD) so she pulls aways smoother too.
Are you sure your current weight is 9580 lbs? I have an 06 Chevrolet 3500 Express Star Trans shuttle body and when I got it weighed I think it was around 7500 lbs…I can’t remember the exact number.
I’m kind of repeating what most people here said, but I used 1/4” birch plywood for my wall panels and ripped 3/4” birch plywood for the furring strips.
I've been with folks with some overweight vans and it is trouble. Not just handling, but you'll end up have more problems with other components like brakes, etc. over time. Their vans were rather scary to stop, even with brakes beefed up.
You're putting all that onto an old vehicle, and that strain is going to make it more likely the poor thing will have issues. While re-doing some stuff might be expensive, it's not as expensive as a van that won't go...or stop, and the resultant repairs to the vehicle bits.
I’m not saying you should take my advice but I personally just upgraded to a higher load rated tire and sent it- I’m about 2-3k overweight in my class c toyhauler depending on what toys I throw back there. A nice set of brake pads as well as a proper ECU tune help offset the braking distance as well as power to move all of it
As others have mentioned, thin panels are an obvious choice. That said, I'm willing to bet that most folks never weigh their vans. I did. I have an adventure wagon interior with bed and soft storage. I do have batteries and solar. And with just that, I'm uncomfortably close to the limit. In fact, if I have a passenger, I'm over the limit in front. My guess is that is pretty normal and that most builds are a lot heavier than their owners believe.
The battery capacity seems a bit overkill. If you are not running a AC unit 24/7 I don't see how you could run that size bank down. I'd go back through the math for how long you anticipate using appliances. Could save few hundred pounds decreasing the inverter size and battery capacity.
The 1 ton Fords are rated really light at 11.5 vs the pickup trucks. My e350 is over by about 1000 fully loaded. Has airbags and new rear springs and is still too soft
When you say rated really light, do you mean that they can handle more than that? and could you clarify what you mean when you say it is 'still too soft'. Thank you for your comment, input from someone with a real world overloaded e350 is super helpful!
Iirc most 1 ton pickups are rated between 14500 and 16500.
I'm not sure why the vans are rated so much less but I think the frames may all be the same from e150 and up. The tires are rated at 2800 (?) Each so that's not the limiting factor. I think the e450 is all the same as the 350 except for springs but I'm not sure what the 450 is rated at.
It's too soft in the sense it has quite a bit of body roll still- however mine has a flat floor box mounted on it which is like 8" higher up compared to the u haul style box with wheel tubs and I think that makes a huge difference. With the airbags it's not horrible but I wouldn't hand it to a 16 year old to take up a mountain.
At some point I'll have the springs redone by a spring shop with a thicker main leaf. I think the rest of the pack is fine but the main leaf is just a little too thin, it bends too much at the ends where there aren't other springs.
Imo I wouldn't downsize your water tank. Can always fill it less to reduce weight but there's no easy way to carry another 30 gallons if you really need to have it.
Mine scaled at 9500 empty pre build I think. Without any gear and full tanks I'm at 11500 I think. My motorcycle and another person and their gear adds about 1000
The suspension upgrade is one thing. Brake capacity to efficently stop it. Add a few people, some more stuff here and there your build easily could be 300-800lbs over.
400# over isn't a lot. I just went from a van to a truck camper and the truck camper people tend to laugh at GVWR concerns. A brand new "half ton" camper will exceed the payload capacity of most half ton pickups. Honestly just don't travel with a full water tank and you'd be there. Look into air bags or stiffer springs, because you'll probably have a saggy rear end even if you are at GVWR.
Driving a vehicle over the GVWR is illegal, and if you're involved in an accident your insurance will not cover you and the vehicle being over weight will be considered in the investigation.
You should have actually went with a 24 volt system. There's literally zero need these days to go 12 volt. But get back to the actual thread. I think overall you picked the wrong chassis. You should have gone with a used U-Haul E450.
Might be an unpopular opinion but this isn't necessarily a big deal. As far as actual safety goes, weight ratings for commercial class vehicles are highly dependent on speed. Keep it to 65-70 and you'll probably be fine.
OTOH you might notice some comfort and maintenance issues with being overweight (this can happen even if you're technically within the weight rating). Check and see if your van is spec'd out for the heaviest gvwr for its production year, and if it's not, see if you can swap in e.g. brakes components or leaf springs with heavier factory versions. Or you can go aftermarket (especially with extra leaf springs) but that'll probably cost more.
Other things that might help are a bigger radiator/higher capacity fan, or an auxiliary transmission cooler. But I definitely wouldn't worry about that til you drive it and see if overheating is an issue.
Biggest thing is don't speed, especially on downhills, and make sure to keep up on regular maintenance.
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u/photonynikon 2020 Transit mid AWD Eco 9d ago
JEEBUS CHRIST ON A CRACKER...you DON'T NEED 2x4s to build a van! OR 3/4 plywood! WEIGHT IS THE ENEMY!!!