First attempt at buggy build

[CSR]

Well, I pulled the trigger. I've been lurking here for awhile, and I even posted in my newbie thread that I was designing a buggy in Solidworks. I guess it's time to put up. I've designed what I hope will end up being light weight with a good strength-to-weight ratio. I'm calling it the Mosquito, and its target weight is under 2000 lbs. The vehicle will be set up as follows:

- homemade chassis made of 1 1/4" .120 wall DOM
- toyota axles with 5.29s, longfield fronts, chromo rears, six-stud knuckles, trail creeper drive flanges, front lockright (hope it survives), rear detroit
- PSC full hydro steer
- four link front and rear with 12" fox 2.0 airshox
- toyota 4.7:1 transfer case
- tracker/sidekick 1.6L 8v engine with auto tranny using OTT kicker 4 adapter to mate tranny to 'case
- 39.5" Iroks on 15" trailready beadlocks

As of this posting, I've already done a lot of work, so I'll put in a bunch of photos right now with explanations later. Again, this is my first attempt at this sort of build, so I welcome all the input I can get since I'm long on theory and short on practical experience. Also, I REALLY need to find a pre-OBDII tracker/sidekick with an 8v and an automatic as I am ready to fit a drive train in it. Please let me know if you have one and want to sell it. Anyway, on with the pics...

 

[RockMonkey]

Why 1 1/4"? I would seriously consider making at least the main structure out of 1 1/2. I understand you're going for light weight, but you'll probably end up replacing bent tubes quite often if you go too small. It might also end up as heavy or heavier, since you'll likely need more bracing with the smaller tube.

I would also do another pillar behind your A pillar that goes down to the bend in the door bar, and then down to a node on the rocker. Especially if you're going to use 1 1/4" tube you'll want the A pillar well braced.

It looks like you're planning on putting the radiator behind the seats. I did that on my last build and would not do it again. It works fine in the rocks, but at high speeds the radiator does not get the air flow it needs, and the motor gets hot.

 

[CSR]

more pics...

 

[CSR]

Thanks for the input. I've already built the chassis structure out of 1 1/4", and it does turn out that I need a lot of gusseting. Oh well. As for the radiator mount, I think I have the engine in the CAD rendering drawn a lot bigger than it really is. Hopefully I'll have room to get the radiator in front. BTW, the CAD image doesn't show a lot of the gusseting that will be in place when it's done.

More pics...It's late and I'll post more tomorrow

 

[Greg]

Nice work so far! I love the idea of a smaller-scale, light-weight buggy. Looking forward to seeing this progress, so keep us posted!

 

[Bart]

Love the lightweight look, but I agree with RockMonkey on the tube size. Too late for that, so make sure and gusset it. Safety is key. Nice looking rig.

 

[Vonski]

Like Rockmonkey's post above, I too was wondering about the 1 1/4" OD tube. Just brace/gusset the hell out of it and see how it holds up. It's not like it will fall apart or fold in half or anything, so go for it.

I've gotta give ya credit, as it looks as though you're staying true to the specs outlined by the software. Anyone can draw or generate pictures/blueprints, but actually building it is a whole different deal.

 

[Herzog]

Really cool build! I'll be watching.

 

[Vonski]

You'll find that everyone here is an expert and will happily throw in their .02 (and I'm no different).

So, having that said, here's my own recommendation...

Prior to setting up your front end, mounting your drivetrain, and having a front driveline built, seriously consider running a high-pinion Toyota 3rd member (for the extra strength and driveshaft angle).

 

[CSR]

OK, I took Rock Monkey's suggestions to heart and added to the A-pillar as shown in the new drawing. The gusset will extend down to a node in the rocker even though it's not shown. I bent it to give some extra room for getting in and out. Let me know what you think. I also did some measuring on a tracker drivetrain and my engine bay. It looks like I might be able to get the radiator in front if I tilt it back a bit--which raises a question: Is there a drawback to tilting a radiator, like with air pockets or anything?

Von, the front axle is already set up . But I'll honestly be pretty amazed if 1.6 litres of fury and a slush box can break it. I'm also not a very aggressive driver. If you look at the drawing, it's a pretty dang straight shot to the front pinion flange from the drive shaft front output at ride height because the vehicle is pretty low slung (18" of ground clearance). I also made the front upper links a tad longer than the lowers so as the axle droops, the pinion rotates upward a little to stay pointed roughly at the t case output. Hopefully this will keep the u-joints alive.

Another question I have:
-When I have the thing assembled and all of the significant sprung weight in place, do I just let nitrogen out of the air shocks until the rig settles down to my desired ride height? Or do I need to find somebody with a regulator? They came from the factory charged at 200 psi which is WAY too much for this thing.

I'm still looking for an automatic 8v pre-1996 tracker/sidekick. Keep your eyes peeled, folks.

More pics...

 

[CSR]

front axle truss and beginnings of hydro ram mount. The truss and ram mount are made from 1.5" .250 wall DOM.

 

[jswainthug]

I think this thing is looking killer!!! Keep up the posts!

 

[jpest]

Looks like your making good on you 1st buggy build attempt. I sure wish I had the time and patience for a project like that

 

[Vonski]

Von, the front axle is already set up . But I'll honestly be pretty amazed if 1.6 litres of fury and a slush box can break it. I'm also not a very aggressive driver. If you look at the drawing, it's a pretty dang straight shot to the front pinion flange from the drive shaft front output at ride height because the vehicle is pretty low slung (18" of ground clearance).

By "driveshaft angles", my thoughts were more about getting it up away from the rocks and less about the actual operation of the driveshaft itself. In the case of this particular build, the extra strength of a high-pinion would just be a bonus (although the low-pinion should hold up fine).

 

[I Lean]

I'd like to see your rear control arms lower where they meet the chassis. You have bellypan stuff down lower, may as well flatten out the arms.

 

[jsudar]

I like it a lot. You may want to consider .095" wall tubing for braces and stuff that won't touch rocks. Wall thickness makes a much bigger difference in pounds per foot of tube than diameter does. And stiffness goes way up. For example:

1.5" x .095" = 1.426 lbs. per foot
1.5" x .120" = 1.729 lbs.
1.75" x .095" = 1.679 lbs.

With that said, I now have a severe case of buggy envy. My drive train alone weighs more than your entire buggy will.

 

[CSR]

Carl, you raise the point of the rear link angle. Here's my thinking:

Having read a LOT about antisquat, instant center, axle steer, and roll axis, I decided I can't have the best of everything in every regard and that my first priority is to have slightly over 100% antisquat. I would like the rear to lift just a tad on acceleration to keep the rig from nosing upward on steep climbs. This meant aiming the links upward a little bit to put the instant center slightly above the center of gravity. I can live with some axle steer on articulation since I won't be competing and trying to avoid cones. The upward link angle also lowers my roll axis a bit, but I tried to get the thing low to the ground anyway to keep a good deal of the weight lower than the roll axis so that I can (hopefully, maybe, crossing fingers...) get away with not using sway bars.

Again, this is all theory. I've only read this stuff and I'm experimenting. I welcome any input to set me straight if I have it all wrong. New links would be easy since I have enough 1.5" .250 wall DOM left over to build new ones if this experiment blows up in my face.

p.s- donor vehicle located. I just bought a 1994 sidekick with a 1.6 16 valve instead of the 8v. I wanted the 8v for simplicity, but I got tired of waiting and this one came available. It also has a 4-speed automatic which is supposed to be pretty strong for its size, and I just read on "some guy's" website that you can just unplug the TCM and shift the tranny like a manual w/o a clutch. I'm hoping the added complexity of the 16 valve wiring doesn't eat up too much time.

Here's some pics on the t-case 4.7:1 gear install. I've never rebuilt a transfer case, but the video on the Trail Gear website is really good and detailed.

 

[TJDukit]

As for the tilted radiator I know they used to do it in the old Stingray Corvettes so that shouldn't be a problem as long as the top of your radiator is still the highest point in your cooling system.

 

[Bart]

You should have no problems with a tilted radiator.

 

[notajeep]

Looks sweet.