Budget Dune Buggy Build

[SirMrManGuy]

Started building budget dune buggy/RZR killer with a friend of mine. This all came out of a discussion about a year ago about how we could build a better side by side, and discovered between the two of us we had most of the expensive parts we needed to build it (like airshocks). We have been collecting the other parts for about a year.

Keep in mind that this is going to be a lightweight 2wd dune buggy with manual steering so some of the things we do will be different from a rock crawler (and some of the other decisions will be dictated by budget). Shooting for a finished weight of about 1800lbs or less.

Specs:
1.6l Sidekick/tracker motor tranny tcase - rear engine with the "front" output driving our rear axle
2wd IFS front, 10in Airshocks
Flipped sammi rear axle on a single triangulated 4link with 2 8in airshocks on each lower control arm.
Manual steering rack from Saco Performance
Leftover 31in MT's

http://i28.tinypic.com/2vuyn90.jpg
This is a "center load" rack and pinion. The tie rod ends mount 5in apart, which will allow us to place our lower control arms very close together to provide optimal suspension geometry.

Bought a running 5spd Tracker, beat on it for a winter with only dents and flat tires.
http://baja.terpsracing.com/admin/__include/image.php?f=/home/terpsracing/baja.terpsracing.com/files/media/18/18_d3f9648693b3bac8d4bf52bdbd4c37fb9413d50b.jpg&w=600&h=450&q=90

Almost sad to part it out for the engine, tranny, transfer case and wiring and a few misc bits.


Picked up some 2wd toyota front uprights from Crazy Rays and measured them out. We then sent this and our rack measurements out to our friend who is a vehicle dynamics engineer for the army to optimize our suspension design. I could have probably figured it all out but it what would have taken me weeks probably took him about 3 hours. Going to run about 14.5 deg of rake, very minimal scrub radius, bump steer and about 15in of travel.

Parallel travel simulation from full droop to compression. 15in of travel.
http://www.youtube.com/watch?v=DhQ7zLfRl-0

Ackerman steering simulation. Should have about 100% ackerman after modifying the steering arm a bit on the knuckles.
http://www.youtube.com/watch?v=OXWKxqB_kEQ

http://terpconnect.umd.edu/~grams/Vegard_Simulation_Results/steer_simulation/page_ackermann_angle.png
http://terpconnect.umd.edu/~grams/Vegard_Simulation_Results/steer_simulation/page_camber_angle.png
http://terpconnect.umd.edu/~grams/Vegard_Simulation_Results/steer_simulation/page_scrub_radius.png
http://terpconnect.umd.edu/~grams/Vegard_Simulation_Results/parallel_travel/page_roll_center_location.png
http://terpconnect.umd.edu/~grams/Vegard_Simulation_Results/parallel_travel/page_toe_angle.png

[SirMrManGuy]

Laid out the drive train, seats and hood on the floor. Got the hood for $50 on eGay, might have to section it to make it the right width.
http://i28.tinypic.com/34ijllw.jpg

Bent up a hoop around the engine.
http://i26.tinypic.com/nlzoqp.jpg

Built some motor mounts. The brackets we built mimic the stock mounts with a bolt and a 5/16 dowel pin. Tacked in for now.
http://i30.tinypic.com/2uif8g4.jpg
http://i29.tinypic.com/oaygrp.jpg


More tube.
http://i27.tinypic.com/303ilh1.jpg
http://i29.tinypic.com/2vklsls.jpg


Tacking some tubes up.
http://i30.tinypic.com/18f678.jpg

Transmission cross member using stock rubber mount.
http://i31.tinypic.com/119ovmx.jpg

Tacked on some rear lower control arm mounts. Axle will be flipped from current location.
http://i27.tinypic.com/28ulisz.jpg

Mocking up the rear shocks (that rusty piece of box isn't our final control arms, have something much sicker planned)
http://i25.tinypic.com/hvt2tu.jpg

Going to run a stock Track/kick drive shaft for simplicity. Engine clearance is tight, that pic is near full compression.


That's about as far as we got this week, gonna figure out the rear suspension next then maybe build the front end.


Also have to finish the disk brake swap for the sami rear and 5 on 4.5 conversion. If anyone has sami front calipers I'll be happy to give you money/beer. Also need 2wd toy front calipers.

[lowdown]

cool work but where do you plan on running a dune buggy around here?

[SirMrManGuy]

For lack of a better name, we've been calling it a dune buggy. Think of it more of a side by side on steroids, good for going fast down fire roads and such. My friend has a cabin in PA on some hunting grounds which has a decent bit of access roads for wheeling (private hunting club), thats where the pic with the tracker was taken.

[Numijunior]

cool work but where do you plan on running a dune buggy around here?

Same way you ride 2wd quads here... BUMP IT :D

Seriously, alittle speed goes along way with light stuff like this or quads. I know I've made them go lots of places they should'nt have been lol.

[Happy Bear]

What do you plan to use for front axle shafts? Are the stock toyota units capable of dealing with 15" of travel? I couldn't imagine that they are. I look forward to watching the front suspension build.

[Z28YJ]

2wd

[Happy Bear]

Picked up some 2wd toyota front uprights from Crazy Rays and measured them out. We then sent this and our rack measurements out to our friend who is a vehicle dynamics engineer for the army to optimize our suspension design. I could have probably figured it all out but it what would have taken me weeks probably took him about 3 hours. Going to run about 14.5 deg of rake, very minimal scrub radius, bump steer and about 15in of travel.


What are these for? I assumed by upright you meant the center section of the IFS 4wd system. If you are going 2wd do you intend to use low range often? Is the tcase simply to get the driveshaft pointed back at the rear axle?

[SirMrManGuy]

What are these for? I assumed by upright you meant the center section of the IFS 4wd system. If you are going 2wd do you intend to use low range often? Is the tcase simply to get the driveshaft pointed back at the rear axle?

Uprights=Knuckles for independent suspension. The stock ball joints on them have enough misalignment to them to cover our range of travel so we'll be using them.

Yeah we're using the tcase for low range (not often) and to point the output at the rear axle. The normal "Rear" output will be capped so it doesn't leak.

BTW if you are wondering about what we're doing about the 5spd's shift pattern, the answer is nothing for now. We're gonna get it running and see if we can deal with shifting backwards. I can't imagine it will be much of a problem, it only took me 5min to get used to driving on the other side when I was in Australia, so this can't be much different. If it really bothers us we'll build some linkages to fix it.

[zucruisers]

if you want a better driveshaft option, i know somehow its possible to drill and tap the output on the tracker tcase, and use a sami/tracker pinion flange or sami tcase flange to eliminate the slip yoke, then use a sami driveshaft

did you happen to keep the diffs from the tracker?...the front r&p can be swapped into the sami 3rd with a can and spacer kit from spidertrax...
sami's have high range reduction in the tcase so the axle gears are 3.73's...tracker's dont so the r&p in them are lower, 4.30, 4.62, and 5.13's

unless you already know this then it doesnt matter;)

pretty cool build though, i've thought about doing something similar someday...but we went a slightly different direction with our tracker build:lol:

[SirMrManGuy]

Didn't know about the tracker gears! Good news, we still have the tracker. :thumbsup:

I'm sure we could make something work with the drive shafts if we are breaking a lot down the road, but our current link setup doesn't have much drive shaft plunge and the angles are decent. We did have to swap a axle side flange from a Sami onto the end of the shaft, the U-joints are the same but the holes on the flange have a different spacing.



BTW It's pretty gutted but let me know if anyone needs any tracker parts. It has a nice plastic top.

[SirMrManGuy]

Didn't get much done this week, built some control arms. Bushings at each end currently, but that may change to flex joints, since the current setup ... well has no flex. Not fully welded yet, so we can change easily. 1.75 lower tube with 1in support tubes.

http://i27.tinypic.com/msc4sh.jpg

http://i25.tinypic.com/zmntlh.jpg

http://i25.tinypic.com/4vl30x.jpg

[zucruisers]

make sure you build a good truss for the sami axle housing, basically going from one side to the other, bearing end to bearing end, and add gussets/bracing to your link mounts, sami axle housings are extremely thin and bend/split open very easily;)

[SirMrManGuy]

We haven't gotten too much done in the last two weeks, work has been getting in the way.

Made some adapters to convert the sami rear to disk brakes and 5 on 4.5 (match the toyota front IFS stuff we're using) Also made some misalignment spacers and weld in ends.
http://i32.tinypic.com/zul104.jpg

http://i31.tinypic.com/2dihmj6.jpg

http://i25.tinypic.com/oic4sj.jpg

Made some brackets for the uppers. The axle will get trussed later on.

http://i29.tinypic.com/28vyosh.jpg

http://i26.tinypic.com/2yn4i7b.jpg

http://i29.tinypic.com/2ewzfcm.jpg


This area will get some more reinforcement but we wanted to see how the seats mount before finalizing the area.

http://i28.tinypic.com/23rsgfs.jpg

Threw the tires on.
http://i29.tinypic.com/5bzqr9.jpg

Got a roll hoop up. Its low, currently sitting at ride height, and it is about 5 foot 2 to the top of the roll hoop, and this is with plenty of helmet clearance.

http://i25.tinypic.com/2yjwq51.jpg
http://i26.tinypic.com/wty8p.jpg

[SirMrManGuy]

http://i29.tinypic.com/35m0du0.jpg

[SirMrManGuy]

Got some work done on the rear structure. Left a good bit of clearance around the engine for the radiator and exhaust (and maybe a turbo setup in the future )

http://i29.tinypic.com/2cy5c5.jpg

http://i26.tinypic.com/34ifx1j.jpg

http://i27.tinypic.com/wvbk2u.jpg

http://i32.tinypic.com/2uszb6h.jpg

http://i27.tinypic.com/jzco5f.jpg

http://i28.tinypic.com/112bkms.jpg

http://i26.tinypic.com/6hnm1c.jpg

[SirMrManGuy]

First update in awhile! Both of us got caught up with work and life and other unimportant crap.

Designed some jigs and made some control arms for the front. Using stock 2wd toyota Ball joints and knuckles.

Upper control arm:
http://i38.tinypic.com/28cix5x.jpg

http://i36.tinypic.com/2ql4m5v.jpg

Only have these 2 cell phone pics of building the UCA's.



Lower control arm:

Ball joint plate, tilted back at ~5deg to center the joint in the travel at neutral ride height.

http://i38.tinypic.com/2gt24xd.jpg

http://i36.tinypic.com/2wgu1k8.jpg

http://i36.tinypic.com/wwde6u.jpg

http://i35.tinypic.com/2r7vvi9.jpg

http://i38.tinypic.com/2ag5s5.jpg

Shock mounts/jig:
http://i35.tinypic.com/2dchb88.jpg

http://i37.tinypic.com/3029quv.jpg

And for some reason I was too stupid to take a picture of the LCA out of the jig....

[96zj]

I am very impressed with your fab work. Nice job!

[b4wscrambler]

I like it.:thumbsup:

What is the car next to the jet skis?

[SirMrManGuy]

I like it.:thumbsup:

What is the car next to the jet skis?
Its the shell of Datsun 280z, my friends very long term project (probably going on six years now). Right now just a chassis and a roll cage.

[Jeepbeater]

I want some information on that welding table. Where'd you get that?

[SirMrManGuy]

Its a Newport Research pneumatically balanced/damped optical test table. There are 4 huge cross linked pistons supporting it designed to dampen background vibrations. Its 4x10ft and has 1/4-20 holes on a 1x1in grid and is filled with concrete.

Got it for a hell of a deal since its out of spec for optical research. We use it for jigging stuff, and its more then perfect enough.