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Guys:

Wanted to run an idea by you, see what you all thought. I like offroading, and, love track racing, but, only have the time, space, and money for one more project. Unfortunately, this typically makes people have to choose, but I have been thinking on this, and, have an idea...

What if, you design a tube frame chassis that cna do both, with a few easily swappable parts?

Here are the requirements I was thinking of:

Want something good off road, and that requires:

• good ground clearance
• 4 "wheel" independent suspension
• all wheel, or 4 "wheel" drive
• 4 "wheel" steer
• relatively high speed, somewhere around 50-60 mph.
• long travel suspension, somewhere in the 16-18" range.
• would be freakin epic if it happened to float...

For the track side of life, you need:

• good suspension adjustability
• light weight
• lots of power
• relatively high speed, unless I kept it to short tracks, or autocross, then a top speed of around 75-100 would be fine.
• all wheel drive

Initally, this dosnt look like something that will work, cause what works for one will not work for the other, but, here is what I was thinking:



Build a central structure. It will hold the driver, engine, drivetrain, fuel tank, and all the other systems.

At each end, there will be a detachable substructure, with the differentials inside, and dual A arm suspension setup, with a cantilevered inboard shock mount:



Each set of ends will be setup with the right gear ratios in the differentials, right type of brakes, snowmobile tracks for the offroad setup, and wheels and tires for onroad, different length A arms for the different widths, spring rates, ride heights, ground clearances, etc. Heck, you could even put wings on the onroad subframes for downforce.

Would need to be light for both, so, I am tossing around two different substructure ideas, eithe a fiberglass moncoque, like the older covettes, where everything mounts to bosses in the glass, or,a steel tubular frame, with aluminum skin. Both have advantages/disadvantages, so will need to think on it more.

The engine will be either a Ford SHO V6, or V8. love the idea of the DOHC, all aluminum forged rotating assembly V8 used in the last SHO, but, they came with automatics, so, I'd have to use a mercury cougar 5 speed transaxle, which, are about as durable as glass.

The older V6 would be a better idea, revs to the moon and back, which, will help with the double reduction I am going to get. Tehy are also light, despide an iron block, and VERY small, and VERY narrow, which will help, since I'll e mounting a transaxle drivetrain forward and backward The best BMW ratio I am aware of is 2.73: 1, and the transaxle already has a reduction in it, will need to see what I can do for a top speed if I raise the engine rev limit to 8500-9500 RPM. Might give me just enough speed. The V6 transaxles are tough cable shifted manuals, and quaife makes a torque biasing differntial, which, would make it AWD, since the transaxle differntial will be the diff between the fron and rear ends. The V6 engine is also forged bottom end, iron block, and LOVES boost, so, I'd supercharge it to around 450 HP, with a 9500 RPM rev limit, and it would be a monster.

Will use BMW AWD differentials for a 3 or 5 series AWD car. Theyre tough, light weight, cheap, easy to mount, come in a variety of ratios and differntial options, and, used flanges to mount the driveshafts and axleshafts, so, uncoupling the driveshafts to swap ends will be easy.

Will probably use BMW spindles as well, since they are 4 link syle, but, not sure yet, still have some thinking to do on that. The tracked offroad subframes will have steering ability on each end. A simple matter or running hydro lines to the back to connect to a cylinder, like I did with the steering on the truck's tie rod.

So, Am I crazy, or does anyone else besides me think this will work?

WOW!!! YOUR MIND THINKS FAST... WOULD IT WORK? I AM SURE IF THERE IS A WILL THERE IS AWAY, AND HAVING SEEN WHAT YOU DID WITH THE M, I PREETY MUCH HAVE NO DOUBT YOU WILL SUCCEED AGAIN. WILL IT BE PRACTICAL? THIS ONLY YOU CAN TELL. I OFTEN REFER TO CARS AS IF THEY WERE GUNS. THE REASON WHY THERE IS SO MANY GUN/CALIBER CONFIGURATIONS IS BECAUSE THE TARGET DICTATES WHAT ONE SHOULD USE FOR OPTIMUM RESULTS. HENCE A 22LR IS AWSOME FOR PLINKING. WOULD IT KILL A MOOSE? IF SOMEONE COULD STICK THE 22 INSIDE THE MOOSES EAR AND FIRE, I GUESS THE MOOSE WOULD EVENTUALLY DIE. WOULD IT BE MY FAVORITE APROACH? NO WAY. BACK TO CARS. I HAVE SEEN AT TIMES VEHICLES BUILT BY MASTERMINDS LIKE YOU, THAT HAVE A "CROSSBREED" NATURE. SOMETHING OF ONE WORLD, COMBINED WITH SOMETHING FROM ANOTHER WORLD. THEY ARE IMPRESSIVE, DON'T TAKE ME WRONG BUT THERE IS ALWAYS SOMETHING BETTER THAT WAS ASSIGNED ONE JOB AS OPPOSED TO COMBINATION. PLUS, DO THE MATH FIRST AND SEE THE TOTAL COST. MAYBE IT WOULD BE MORE COST EFFECTIVE TO RUN TWO PROJECTS IN THE END, EVENTHOUGH YOU DO NOT HAVE SPACE OR TIME. AGAIN, I WOULD LIKE TO HAVE THE BEST OF ONE WORLD THAN A LESS THAN BEST OF TWO WORLDS. GOOD LUCK

It seems to me that the Chenowth sand rails used in the Baja runs back in the '70s would fill your needs. They were VW powered, but a little engineering would allow you to use any drive line you wanted.

(I'd like to have a Citroen 2CV truckette with a Mehari driveline, myself. 600cc of rompin', stompin' twin-cylinder power churning mud with all 4 wheels! )

I think the biggest question un-answered is "how offroad capable do you want it?" Speaking with almost 20 years of dedicated hardcore offroad experience, and more than a few capable rigs under my belt, I'd be more inclined to say that your setup, as outlined will do two things, but neither of them well. Lets start with the offroad part first, as that will be alot harder on the driveline than the track portion will.

Unless your plan is to run 30" tires or smaller, ditch the car diffs, they just won't stand up to the abuse. 30" tires won't get you very far offroad either. So, lets say that your leaning towards a 33-35" tire. That would be at the minimum end of the scale for the average offroader for tire size. My personal preference for axles are the solid ones - fewer moving parts makes for more dependable and stronger drivetrain in the middle of nowhere - and reliablity is key when faced with a 50 mile hike to civilization. IFS might ride better, and handle better at speed, but it is really known as Inferior Front Suspension when you start to push it with obstacles, and heavy offroad tires. I would suggest a 3 or 4 link design solid axle setup at both ends using Toyota axles. They have all the benifits that you are looking for, excellent aftermarket support, good range of gears, lightweight, and ridiculously strong for their size.

Fred Williams, of Peterson's Offroad magazine had a project called the "fun buggy" about two years ago, inwhich he basically set out to do what you're scheming about right now. His ride turned out to be a very well engineered, and capable machine, that would serve as an excellent source of inspiration. I say build it for offroad first, then make it go fast. The other way around just dosen't work. Lifers buggy suggestion would also be a good direction to go. Another thing to investigate would be some of the baja race trucks, they'll do 125mph through some of the worst terrain on the planet, and are only 2wd, and can spank just about anything on the track if you've got the nerve to push it to the limits.

The only real problem is that going fast, offroad, isn't cheap...

Highway, track, or completely off-road makes no difference. Speed is always expensive. There just ain't no way around it!

Josh, maybe you could try and build something like these :

hmmm, Maybe I need to define what I'm looking for a bit better. I know it wont crawl up a sheer rock face, or, run roud a race track will full on race cars. Looking to build something fun on road, while being fun offroad, and, by offroad, I mean out in a field, in a mud pit, down a two track, etc. not into hardcore trail wheeling. done it a few times and all that happened was a broke stuff and it pissed me off...

HMMMM.... I AM EVEN MORE CONFUSED NOW THAT YOU EXPLAINED BETTER. AS FAR AS I UNDERSTAND, YOU HAVE JUST BUILT AN ULTIMATE M37 WHICH COULD DEFINATELY MASTER THE OFFROAD CAPABILITIES THAT YOU DESCRIBED. ON TOP OF THAT, YOU CAN ACTUALLY HAUL FRIENDS AND STUFF WITH YOU TO THE FUN AS OPPOSED TO A "GO CART ON STEROIDS" THAT YOU HAVE IN MIND. FAST SPEED, I DO NOT KNOW ABOUT THAT, BUT GIVEN THE POWERTRAIN YOU INSTALLED, CHANCES ARE YOU WILL BE FASTER THAN 80 PERCENT OF THE TRUCKS OUT THERE.AS FOR BREAKAGE, I THINK YOUR M MIGHT BE THE ONLY CANDIDATE TO WITHSTAND ABUSE. THOUGH I AGREE WITH ALL THOSE ABOVE WHO SAID SPEEDING OFFROAD WILL COST A LOT. AGAIN, I AM CERTAIN YOU CAN BUILT IT. YET I HAVE NOT VISUALIZED THE "WHY" PART.

simple: the truck wouldn't make a good track car , and, It's too pretty to go beat it mercilessly off road now... Will still play in the sand and such, but, no frame deep mud pits. I spent way too much time making it pretty to do that to it.

HMMMM... I UNDERSTAND THE POINT "TOO GOOD TO MESS UP IN A HARSH OFFROAD SITUATION". ANOTHER SUGGESTION. HOW ABOUT IF YOU GET AN M151 AND TURN IT TO WHAT YOU LIKE. I HAVE BEEN IMPRESSED BY WHAT THOSE THINGS ARE CAPABLE OF OFFROAD, AND THEIR ONROAD ABILITIES ARE NOT BAD EITHER. NOW GIVEN THAT YOU WOULD ENHANCE IT, CHANCES ARE YOU WOULD END UP WITH SOMETHING GOOD TO THE DIRECTION(S) YOU WANT. AND IT WOULD RESEMBLE A CAR A BIT MORE THAT A TUBE DESIGN JUST MY TWO CENTS

Here is my suggestion - Find an older 4wd Subaru. The suspension all bolts to the bottom of the pan. Space the suspension down about 3" and install some 31" tires. Some of the right models actually had a tcase with a low range option. Install a WRX engine, (or the engine of your choice) and flog it repeatedly. This setup covers all the specified criteria - cheap, 4wheel IFS, on/off road capable, and most importantly - FUN....

I think I see where you are trying to get. The Idea of changeable front and rear subframes is overcomplicated I think. Why not just incorporate some adjustability into the Ind. susp. by way of airbags or torsion bar keys. Run 3.55:1 gears ( or whatever you want for street tires), and use a transfercase with low range to correct your gear ratios for larger off road tires.

If I remember right, the Scorpion 4x4 that was featured many times in the magazines and won the Four Wheeler '97 TTC, when it's air suspension was lowered to it's bottom level, it can pull handling numbers similar to the Boxter's in the skidpad and the slalom, and I think that was using super swampers.

Juan wrote:If I remember right, the Scorpion 4x4 that was featured many times in the magazines and won the Four Wheeler '97 TTC, when it's air suspension was lowered to it's bottom level, it can pull handling numbers similar to the Boxter's in the skidpad and the slalom, and I think that was using super swampers.

I THINK I REMEMBER THE SCORPION. WAS IT RUNNING A CUMMINS DIESEL?

That's one of the engines they use for building it, the one featured in '97 that pulled boxterlike numbers had a SBC 350 with EFI.