[curtis73]

Originally Posted by MatobaImportRacing

(Most Importantly) What kind of acceleration/speed can I expect? If my reasoning is correct if the whole shebang weighs 600 pounds with me (165 pounds) in the drivers seat and I use a non-vtec B18 (which I have lined up now) that produces about 100 HP and 85 Ft. Lbs. of torque (is this reasonable? I don’t have many much experience with older, non-Vtec Hondas) it should have a power to weight ratio of 1/6 or a 450HP Civic. Does this make sense?

What is the best way to relocate the shift-linkage, clutch cable, throttle cable, and break lines?

What is the best suspension setup for this type of off-road buggy?

What is the best motor-mount setup? I can imagine that bouncing and jumping a buggy with no real unibody would shear motor mounts really quickly.

What are the heat considerations involved with putting a shifter-kart seat (layback style body is at about a 45 degree angle) a few inches in front the engine?

Where should the radiator be located? Is it possible to run it air-cooled?

Would it be possible to modify the Honda rear-axle to use it as the front axle in the gokart?

How should the steering rack be set up? I assume that turning the front axles would be much easier than the rear, is this correct?

Would a buggy of this size need power steering? Along that line, would the front breaks (in the rear of the buggy) off a Honda be sufficient without front break?

Where should the battery and the fuel cell be located?

What kind of weight bias should I shoot for?

MY KIND OF PROJECT. Find something you want and then find a way to build it. I love it. I'll try my best with your questions. My strong point is general knowledge, but little of it is based on off-road stuff.

OK, first one; the 450 hp civic. First of all, I doubt you'll be able to have it be that light. I think 1200 lbs is more reasonable. Figure 300 for the engine/tranny, 300 for the frame, 160 for you, another 200 for suspension stuff, gas tank, springs, 13 liters of coolant, 5 quarts of oil... the list continues. The other thing to remember is that acceleration is exponential. To double your acceleration, you need to increase your power-to-wieght ratio by much more than 2. Going from a 16-second quarter mile at 200 hp to an 8 second quarter takes more than just bumping your hp to 400. 8-second times are more on the order of 900 hp. Someone here might know the actual numbers.

2) Clutch, brake, and throttle are easy. The clutch and brake are hydraulic systems, so its a matter of re-plumbing lines. Keep things the same and you should be fine. The shift linkage will be troublesome. You're lucky in one way; the civic's linkage is already cable controlled. If you can somehow find cables of the same strength but long enough to reach the tranny, you've got it made. Put on your fabrication hat and be creative.

3) suspension. Tough one. For the front, you can get a dune-buggy style torsion bar. Its just basically a big bar that you weld in, but inside it are torsion bars. On the outside end is an arm with a spindle. Simple, durable, fool-proof. Add some cheap shocks, and the suspension part is done. The trick is going to be brakes up there. You can order dune buggy axles with brakes, but the chances they will be the right size for the brake fluid you supply them is slim. That's a brake engineering lesson all in itself which I can show you, but not in the area of a forum post The rear suspension is going to give you headaches as well. The easiest way would be to just weld in the civic subframe and use the suspension it comes with. Tempting, but not wise. They are designed for just enough travel on a civic, maybe a few inches up and down. You need off-road kind of travel; several inches. You can't modify the strut suspension for that kind of travel easily. You'll also need different springs... big list there. You'll also have steering to deal with back there. You'll need to find some way of rigidly fixing the steering so it can't turn.

4) Motormounts should be solid, or a rubber suspension bushing. Normal motor mounts would shear, so I suggest either welding them solid or using a fully supported rubber bushing. It consists of a ring (about a three-inch section of tubing) on the frame with a rubber collar inside it, then a steel collar inside the rubber. The outer steel mounts to the frame, the rubber in between, then the motor bolts through the center. No rubber shear can happen that way.

5) Seat in front of the engine. Well, there are several. The surface of the exhaust manifolds can reach 1200 degrees or more and glow cherry red. Not good. The other issue is if you blow a head gasket, throw a belt, or bust a coolant hose, you are wearing it. Four gallons of 230 degree boiling water and steam will be on your head, shoulders, lap, and worst of all; crotch. You don't want to mess with that. What I suggest is mounting it about 6 inches in front and completely isolating the engine with an aluminum firewall.

6) radiator. Put the radiator where you find it most convenient, but not above your head or behind the engine. I suggest running steel tubing to the front and putting the radiator and some electric fans up there. Again, you should separate you from the radiator with a firewall incase of... well, see the crotch reference above. There is absolutely no way of making a water-cooled engine into an air-cooled engine. Different animal altogether.

7) rear axle in front. Yes you could modify it, but way too hard. Do the torsion bar front. The double wishbone/A arm setup like Reed said is a superior system, but its not just something you can throw together and have it be road worthy. There are serious issues with static and dynamic instant centers, roll centers, bump steer... I suggest just a buggy front. Its literally a weld-in.

8) You don't need power steering, nor do you need a rack and pinion. I suggest a junkyard steering box connected from the pitman arm to the spindles with two adjustable rods. Simple, strong, darn close to ideal on a solid front axle. No, you shouldn't eliminate front braking. Its not legal on the street and its not safe on the trail.

9) battery and fuel cell should be up front. In case of either rupturing, they will be far from the engine. They'll also help balance out the car.

10)weight bias. You should always shoot for 50/50 or close to it, but don't worry about it. You'll be way off with the engine in the back. Make sure you have enough weight on the front, otherwise you won't be able to steer. Its not just a case of enough to keep the front down, either. I'm talking; at 30 miles an hour, if you try to steer, it might go straight.

My only other advice is this. Although it doesn't have to be street legal, try to keep the parameters a street vehicle has. I don't have room to go into all of it here, but there are reasons why cars are engineered with a 70/30 brake bias, specific weight distributions, and certain other things. Although it seems like a good design idea to eliminate front brakes, just remember... there's a reason for automakers to spend all that money doubling their design cost, it must be worth it.