Mercedes Overland Building/Tuning

[VerMonsterRV]

I want to wait until it's built up and I get the final weight before I order any shocks/springs. Coming from my racing experience, you typically 'corner weight' your car, getting a weight for each wheel before adjusting spring height, spring rate, rebound/compression on shocks, etc. It makes a huge difference in how a car handles.

I only tweaked my Land Cruiser with a simple lift/shocks, but for this rig, I really want to dial it in. With the costs involved, I want to get it right the first time with the suspension.

I hear you guys on the super singles, since mine is 22.5" rims, quick google search here in the states shows a ton of available wheels/tires. Hard to justify what I'm sure will be massive shipping costs to get 5 wheels/6 tires here from Europe.

Anyone know what offset I need for the 1224 SK so the rims can swap front to back? Anyone know the bolt pattern spec's?

I haven't looked into the 10 lug rims as ours is the 8 lug, but I think they are the standard lug pattern. I would think your offset would be very similar to ours Set with 5 rims 11,75x22,5/8-hole/ ET110 ACCURIDE (EUR 249,-/piece) - Expedition truck (expeditions-lkw.de) , so 110mm.

So here is my 2 cents, your trip will not be significantly different if you have new rims/tires vs old rims/tires (well unless the tires are terrible and you get a blowout). You will be a bit slower and take slightly more time. We did this with our truck, driving all the way from Florida to Vermont. Now if you want to wait on the springs, the shocks alone shipping will run you about $200-$300. The springs are much more. I searched around a lot here in the USA before I bit the bullet and ordered from Germany. Just couldn't find anyone that was willing to build the springs in the USA. They are 6' long with "military wraps". I also looked for a shock supplier in the USA, either due to Covid or just lack of interest it was once again a no go (talked with all the major off road brands). So Marquart it was. But, if you're planning on doing all the work yourself, even with the shipping cost I would bet it would be less expensive. A couple of reasons, if they ship outside of the EU you don't pay VAT and labor rates in Germany are high. We also shipped our rims in, but the 8 lug is not readily available in the USA. But, we could shop around for our tires, pretty amazing the differences in prices between shops for the same exact tire.

I also think this, although it is best to get the exact weights and tune to your load, the reality is the selection/options are pretty slim. Plus we all seem to end up roughly around the same weight. My guess is you will end up around 20k lbs when finished. You could build lighter, but you would have to really work at it. Our 20k is loaded with all our toys, food, fuel and water.

So in a nutshell, if you are on a budget and are planning on mostly DIY, get the truck as is and drive it home. If you're planning on paying someone to do the mechanical work here in the USA, well then try and get it done in Europe prior to shipping.

 

[RoamIt]

I really appreciate the advice you guys are sharing- Thank You!

I do plan on doing a lot of the mechanical work myself, not only to save money, but I don't want to be broken down somewhere and have no idea how things work/fit together. Installing shocks, springs, etc. is well within my capabilities. If I have to import springs/shocks, I'm OK with that.

I may go ahead and order the wheels from Europe, since your guys sources there know these trucks.

 

[VerMonsterRV]

Oh, although not trying to convince anyone about the turbo swap here is what I think I learned. And I really mean "think" because I am no mechanic and am relying on someone with way more experience with these engines.

Swapping the turbo doesn't necessarily mean more power. What it means is there is more boost available. Without more fuel there is no more overall power or higher temps. Apparently diesels don't care if there is more air available, so no mixture issues. What did change though is more available power in the lower rev range. Why? Well our injector pumps are also controlled by boost pressure, more boost down low means more fuel down low, which means a bit more grunt from 1400 -2000 RPM's. Which is great for climbing hills. This is without any injector pump changes and it is ok to leave the engine just like this. I don't think this is possible with just an injector/pump adjustment. Now if you do a similar injector pump adjustment that is being talked about then you can make more overall power with a broader torque curve than just doing the injector/pump adjustment. I say similar because I am not sure what the stand alone pump tuning would be. My guess is they would adjust the overall fuel delivery, but not the boost side as the boost level doesn't change. With the turbo upgrade pump adjustment you also change the boost side. I have installed an EGT and boost gauge, just need to finish the power wiring to it, which I plan to do before I attempt upping the fuel delivery. I don't plan on maxing out the fuel delivery, will do it in very small increments, not seeking out the max available power or stress on the engine (which I suspect would be the exact same HP as the injector/pump mod). Time will tell, but so far I have noticed the extra grunt in the hills. But any injector pump changes, with or without the turbo will increase EGT.

So, in my mind the turbo swap added a bit of flexibility in when the power is available and my main goal was more power down low for hills.

 

[RoamIt]

As I understand it, since I'm starting with a latter model OM366LA, the 300hp tune will consist of adjusting the injector pump/timing. That's the extent of the 'tuning'. On this, I'm going to have to put my faith in 4Wheel24 to really know.

Since it's a Garrett turbo, I was considering a variable vane unit replacement. Not to make more power, but to get more power under the curve.

 

[charlieaarons]

Is anyone listening here aware of a 300hp iteration of the OM366LA from the factory? I am not but I mainly know Unimogs. In those, 240hp was the limit.
If there truly wasn’t a 300hp factory version, I recommend not doing it; it’s asking for trouble. If you do it anyways, make sure of 2 things:
1) install pyrometer (EGT) asap
2) make sure there’s no internal engine upgrades in the 300hp version vs the 240hp version (like bigger oil squirters under pistons for cooling for example).

 

[RoamIt]

Is anyone listening here aware of a 300hp iteration of the OM366LA from the factory? I am not but I mainly know Unimogs. In those, 240hp was the limit.
If there truly wasn’t a 300hp factory version, I recommend not doing it; it’s asking for trouble. If you do it anyways, make sure of 2 things:
1) install pyrometer (EGT) asap
2) make sure there’s no internal engine upgrades in the 300hp version vs the 240hp version (like bigger oil squirters under pistons for cooling for example).

I was told by Martin from Terra-Exp that there are several companies besides 4Wheel24 who do this. Since they build these on a regular basis, I'm going to trust they know what they are doing. According to the VIN, this truck is the latest model, code 356999 10 329135.

Definitely going to install EGT, and I'll look at additional cooling. I realize pushing that power means more maintenance, but I'm OK with that.

 

[Joe917]

Is anyone listening here aware of a 300hp iteration of the OM366LA from the factory? I am not but I mainly know Unimogs. In those, 240hp was the limit.
If there truly wasn’t a 300hp factory version, I recommend not doing it; it’s asking for trouble. If you do it anyways, make sure of 2 things:
1) install pyrometer (EGT) asap
2) make sure there’s no internal engine upgrades in the 300hp version vs the 240hp version (like bigger oil squirters under pistons for cooling for example).

I have never heard of anything more than 240 hp for the OM366LA from the factory. Does not mean it does not exist but 240 hp is plenty, then again,we lived happily with 170hp.

 

[Neil]

I'm with Joe . More than happy with our factory original 170hp.

This desire for more and more power isn't for me.

Our travelling life is pretty slow and sedate so all that power would be wasted on me.

Neil

 

[Geo.Lander]

I was told by Martin from Terra-Exp that there are several companies besides 4Wheel24 who do this. Since they build these on a regular basis, I'm going to trust they know what they are doing. According to the VIN, this truck is the latest model, code 356999 10 329135.

Definitely going to install EGT, and I'll look at additional cooling. I realize pushing that power means more maintenance, but I'm OK with that.

Atkinson Voss in the UK do it like and a couple of other MB overlander truck houses in Germany also, it is a mixture of bosch benching the injectors and fuel pump rebuild, but there are difference stages to this approach also. They tune the turbo for more boost throughout the curve to match the fuel delivery. Hence, since this is possible without a wastegate style turbo I am still confused by the Jon/Stefan method and the intricacies of the different approaches, I am sure both are warranted and have their discrete advantages.

 

[DiploStrat]

One more vote for doing the wheels in Europe. The issue is the offset for putting a single in the back. The track will be narrower, but, if you have the right wheels, the difference is minor. Also, with the wrong wheels, your front wheels will stick out too far. Looks cool, but bad for bearings. Doing it right also avoids spacers in the rear.

This beast ain't going anywhere fast. And, even if you can get it over 100kph/60mph, it ain't gonna stop, either. Another way of saying that I would be very wary of massive horse power boosts. In any case, what you really want is low end torque. The 170hp has more than enough horsepower.

And, since we're all giving free advice, a final word of lifting roofs. "Don't!" (Based on the experiences of folks with GXVs with lifting roofs.)

 

[RoamIt]

One more vote for doing the wheels in Europe. The issue is the offset for putting a single in the back. The track will be narrower, but, if you have the right wheels, the difference is minor. Also, with the wrong wheels, your front wheels will stick out too far. Looks cool, but bad for bearings. Doing it right also avoids spacers in the rear.

This beast ain't going anywhere fast. And, even if you can get it over 100kph/60mph, it ain't gonna stop, either. Another way of saying that I would be very wary of massive horse power boosts. In any case, what you really want is low end torque. The 170hp has more than enough horsepower.

And, since we're all giving free advice, a final word of lifting roofs. "Don't!" (Based on the experiences of folks with GXVs with lifting roofs.)

I appreciate the free advice! You guys convinced me, I just sent out some inquiring emails about wheels from Europe.

Martin did say something about the brakes, and I've gathered from chatting with you guys that the brakes are not a strong point, use the engine brake/trans to descend. So I'll be taking that advice. I'll also be taking the brakes apart and refurbishing/new shoes, whether they need it or not!

On the lifting roof, it's a way to get the space I want while keeping the overall length down. Before I commit to it, I'll build a prototype out of plywood and test it.
If you know people who would share their experiences, I'd love to talk to them!

I have some other strange ideas that I want to explore, but I'm just going to have to wait till I get this thing home. I'm very dangerous with a Sawzall and welder, who knows what is going to happen!

 

[RoamIt]

I'm with Joe . More than happy with our factory original 170hp.

This desire for more and more power isn't for me.

Our travelling life is pretty slow and sedate so all that power would be wasted on me.

Neil

My main issue is the hills, not pure speed. Even with 300hp the limiting top speed factor will be the axle ratios/tires. There's going to be a lot of mountains where I want to go, going up them at 28mph would drive me crazy.

 

[mog]

.

My main issue is the hills, not pure speed. Even with 300hp the limiting top speed factor will be the axle ratios/tires. There's going to be a lot of mountains where I want to go, going up them at 28mph would drive me crazy.

Don't worry, I am sure you will be able to hold 35mph
Well most of the time

 

[RoamIt]

A 25% improvement! Awesome! It's going to be the Porsche of Mercedes Overlander's. I'll have to put a whaletail on the back of it.

 

[Geo.Lander]

One more vote for doing the wheels in Europe. The issue is the offset for putting a single in the back. The track will be narrower, but, if you have the right wheels, the difference is minor. Also, with the wrong wheels, your front wheels will stick out too far. Looks cool, but bad for bearings. Doing it right also avoids spacers in the rear.

This beast ain't going anywhere fast. And, even if you can get it over 100kph/60mph, it ain't gonna stop, either. Another way of saying that I would be very wary of massive horse power boosts. In any case, what you really want is low end torque. The 170hp has more than enough horsepower.

And, since we're all giving free advice, a final word of lifting roofs. "Don't!" (Based on the experiences of folks with GXVs with lifting roofs.)

Yea, check the YT videos from the German explorer magazine. Their company truck has a self made lifting roof and it blew off in a storm ?

I think only unicat still do this (and the only ones I know to do it very well). But it's all in the XXL weight class which tell you the extent of the extra weight needed for the hydraulic systems, rams, supporting frame etc..

Lifting bed if you want more space might be the way to go. There are lots of good designs to inspire you out there