Cost of Winning: The Monster Mav Chronicles

[badassmav]

Looking forward to it myself;

The boxing of the a-arm provides a longer service life correct?

Correct. But aside from "service life" design considerations, the boxed outer shell provides what a round tubing structure on its own would not. Lateral rigidity. Hit the front side of a round tubing a arm like Marc did to the face of the boxed arm, and it would have catastrophically folded. Round tubes provide torsional rigidity, while square tubes are better for lateral rigidity. Mate the two, and I mean physically weld them together where ever you can, and you can build a structure stiffer, and lighter than you could imagine.

That being said, the biggest advantage in boxing a tubular sub-structure is the redundancy that it provides. We would not have won San Felipe this year if there was no inner frame to our arms, as the outer boxed section failed right at the pivot point when Marc slammed into something hard. Where the weld bung that holds the rod end that is the inner pivot point cracked away from the outer plating, it was the thin walled, mild steel inner tube that kept it from pulling apart, allowing Marc to continue driving as hard as was necessary to bring home the checkers.

Again, it begs for more thought on what role excessive weight has in our limited class of vehicle.

 

[sand shark]

Interesting stuff. I like reading this even though it is way above my technical pay grade.

You should design some suspension components for the masses. They would sell like hotcakes!

 

[DBlank72]

Correct. But aside from "service life" design considerations, the boxed outer shell provides what a round tubing structure on its own would not. Lateral rigidity. Hit the front side of a round tubing a arm like Marc did to the face of the boxed arm, and it would have catastrophically folded. Round tubes provide torsional rigidity, while square tubes are better for lateral rigidity. Mate the two, and I mean physically weld them together where ever you can, and you can build a structure stiffer, and lighter than you could imagine.

That being said, the biggest advantage in boxing a tubular sub-structure is the redundancy that it provides. We would not have won San Felipe this year if there was no inner frame to our arms, as the outer boxed section failed right at the pivot point when Marc slammed into something hard. Where the weld bung that holds the rod end that is the inner pivot point cracked away from the outer plating, it was the thin walled, mild steel inner tube that kept it from pulling apart, allowing Marc to continue driving as hard as was necessary to bring home the checkers.

Again, it begs for more thought on what role excessive weight has in our limited class of vehicle.

I never thought about the internal tubing providing one section of strength and the boxing/plating providing a completely different direction of strength. Its been a couple of years since I was in engineering classes and I seem to have forgotten most that I learned about moments. Thanks for explaining that out!

 

[badassmav]

A Arms:
So, after welding the inner tubular sub frame, I fab'd up the two outside vertical strips and set them in place. Now, I can finally pull dimensions based on the outline that the strips defined, and develop a digital drawing of the top and bottom plates that I need to have cut. The welding jig plate is perfectly square (as close as a drunken welder can get it ), so I can identify one corner of the plate as a reference point, and take my dimensions from there.

After carefully measuring and making a reference sketch, I then transferred the data to a simple 2d cad type program that I have, and develop a working digital file that I can export and have an outside source cut my parts from.

Notice on the pic in the computer image, the right image. The outer rectangle represents the major x and y dimensions of the arm, and the mountain-shaped outline in the center, between the weld bungs, identify the old a arm shape. I've decided to add a cutout in the middle of the arm to add rigidity and a bit of style to the arm, at no expense of extra weight (the material that is removed to make the cutout will be a wash with the material I will back add as a perimiter stiffener around the cut out). Notice, from right to left, the changing of the old shape on the bottom center to a milder shape that allows a larger cross section of material between the center cut out and outside of the arm. In this case, the criteria for the shape were strictly aesthetics, whereas an F-1 engineer would determine the width and shape of the cutout relative to the outer edge of the arm through mathematical calculations. Us desert fabricators are so lazy when it comes to specifics. "Overkill is the key to success" is an old saying that comes to mind here. Our car weighs as much as it does simply because it is built with existing shapes and wall thicknesses of materials, instead of being engineered to maximize power to weight ratio, and stiffness characteristics. Besides, know one that I personally know of has the talent and experience to engineer an off road car like the real race car engineers do. Including myself. Real engineers develop designs based upon mathematical certainties, whilst us lower folks use a much simpler method. The WAG (wild ass guess) method!

 

[badassmav]

I never thought about the internal tubing providing one section of strength and the boxing/plating providing a completely different direction of strength. Its been a couple of years since I was in engineering classes and I seem to have forgotten most that I learned about moments. Thanks for explaining that out!

The "moments" are exactly why I join the two structures together through welding where ever possible. It decreases the distance between the unsupported areas, and therefore, reduces the distance, or moment, that the loads applied has to leverage themselves. The results are either isolating the loads, or sharing them with adjacent or connected structures. Moments, or distances, are what designing a race car is all about. Sometimes they are invisible points in space, such as a center of gravity, and sometimes they are hard dimensions, related to fulcrums and leverage ratios.

 

[badassmav]

Reid...how much ground clearance do you have a full bump?

Here's what full bump on the Monster Mav looks like. The images represent 3" of ground clearance at full bump, although I have since reduced the front to 2" of clearance at full bump.

 

[badassmav]

Interesting stuff. I like reading this even though it is way above my technical pay grade.

You should design some suspension components for the masses. They would sell like hotcakes!

Word has it that Can am will move the Maverick's rear diff back on a late model release this year. I'll wait until it comes out so I can be certain that my arms jive with their modified rear diff location. (Like I really have any time to work on it anyway!). The kit that I have been developing (mostly in my head!) was to include a complete weld on rear clip that has the diff mounts, and gusseted pivot points already incorporated. You just cut the 6 tubes off of the rear of your car that make up the rear clip, and weld my clip back in the same position. I want to be sure to offer prospective buyers the most cost effective, yet best designed kit that I can. Worry not, for a kit IS in the works!

 

[megadesertdiesel]

Word has it that Can am will move the Maverick's rear diff back on a late model release this year. I'll wait until it comes out so I can be certain that my arms jive with their modified rear diff location. (Like I really have any time to work on it anyway!). The kit that I have been developing (mostly in my head!) was to include a complete weld on rear clip that has the diff mounts, and gusseted pivot points already incorporated. You just cut the 6 tubes off of the rear of your car that make up the rear clip, and weld my clip back in the same position. I want to be sure to offer prospective buyers the most cost effective, yet best designed kit that I can. Worry not, for a kit IS in the works!

sounds interesting.

 

[sand shark]

This will make the Can Am guys very happy or at least the ones that can weld! It would be nice to see something different.

Mega - this will be right up your alley.

Now if you can get your hands on a XP1000 and have some fun with that suspension.

 

[Tzenev]

Sounds like it might be something to compete with the Ct race works rear suspension kit, but I think his is mostly bolt on.


Sent from my iPhone using Tapatalk

 

[AReed]

Sounds like it might be something to compete with the Ct race works rear suspension kit, but I think his is mostly bolt on.


Sent from my iPhone using Tapatalk

Yup, ours is a little more stretch though.

 

[BiggJim]

Where is your droop limit set at relative to the ground, and what is the max operating angle you are allowing your cv's to endure? Because lets face it, every UTE that I'm aware shares the same limitation regarding wheel travel. Deck height. Lots of room left for the cv's to deflect if the ground would allow it! At full droop, we have 21" of ground clearance, and that is only allowing 26-27* of max deflection on the cv's. I don't think that a car that tops out around 80 mph needs more than 17 or 18" of wheel travel anyhow. Just my opinion.

All of our dimensions are OEM. Remember we want to race what we sell. Currently the only change we have made is adding a spacer on our shock to limit the travel at full bump. The stock axles I believe will go to 28 degrees. But again we didn't change any geometry

 

[Johnny]

Dude It sucks to see you having to rebuild the car ... I washed my Polaris RZR to get it ready for the next race !!!! but then again I didn't win ....

 

[badassmav]

All of our dimensions are OEM. Remember we want to race what we sell. Currently the only change we have made is adding a spacer on our shock to limit the travel at full bump. The stock axles I believe will go to 28 degrees. But again we didn't change any geometry

Stock track width as well? Why did I think you were running custom suspension components? Even more impressive that you guys cleaned house at the silver state race with bone stock geometry!

 

[badassmav]

Dude It sucks to see you having to rebuild the car ... I washed my Polaris RZR to get it ready for the next race !!!! but then again I didn't win ....

Yep. It's a sheeit sandwich w/x-tra stink! I've logged more than 250 hours since the Baja 500 puttin' on band-aids, and I'll have another 200 to wrap it up for the V2R. Since I cant afford to drink beer all day, I might as well work! So, are you on again to race @V2R?

 

[BiggJim]

Stock track width as well? Why did I think you were running custom suspension components? Even more impressive that you guys cleaned house at the silver state race with bone stock geometry!

Currently stock track with as well. It will get a +4 track width suspension soon but currently we have been racing what is race proven. Our theory on parts has always been to build something that can be bolted on for the masses. I am sure the stock geometry can be improved upon but can a do it yourself'r install it in his garage without fab shop tools? Probably not.

 

[badassmav]

Light bar:
No skimping here! Marc's favorite time to drive is at night, so to make sure that he would have no problems seeing hazards at 3 a.m., we went with Hella's xenon version of the Rallye 4000 (dubbed the Rallye 4000 xi). They probably weigh twice as much as LED lighting, but the power these little lights have is tremendous. Albeit pricey (the mfg. sugg. retail price is nearly 500 bucks each), they are not to be outperformed. Notice the fine adjustment range that the "adjust on the fly" quick adjust handle offers. It takes 2 crewmembers less than 15 seconds to install the light bar during a pit stop, or 1 guy 20 seconds. The pic of us adjusting them was taken on the way home from last years SEMA show. We stopped off at the area behind buffalo bills to adjust the lights, and test for the 1000. You always know when Marc is coming into a night pit. There is no mistaking the brightness that the lights provide.

I copied much of the adjustment aspect of the design from one of Roger Normans trophy trucks. It's one of Marc's favorite features on the car.

 

[JoeyD23]

I dig the light bar

 

[DBlank72]

Wow! That sir is some light.


KCCO

 

[megadesertdiesel]

big ass lights for sure! adjustable lightbars are nice to have.