dunnkruger
Samba Member
Joined: August 19, 2016
Posts: 1
Location: East
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 Posted: Sat Aug 20, 2016 1:03 am Post subject: 1970 VW Baja, Suspension |
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Good Day,
New to the forums and wanting to finish my 70 Baja.
Read stickys, searched most of the day for info however I would like to ask the forums additional questions specific to suspension setups.
First car was a 1970 VW Baja and have built four of them over the last twenty years and used Jeff Hibbards Book, Baja Bugs & Buggies.
Purpose of Car
Daily Driver.
Occasional Race.
Desert, Mountains, Lakes, Rivers, Streams, Beaches.
Occasional Jumping.
More interested in durability, strength, and finishing than I am about getting anywhere fast.
Would like to be economical, I can make and fab, have machine shop and more time than money.
King & Link Front End
Questions
What is the expected travel in inches with the stock widths, stock lengths front and rear trailing arms with torsion bars?
What are the typical lengths available for front and rear trailing arms?
What is the typical length combinations used for front and rear trailing arms. IE: What front length/width trailing arms are used with 3x3 rear arms, 4x5's, 5x5's, and so on.... How do you figure what matches front and back widths/lengths combo's, best practices?
When are you forced to go with coil overs in regards to the lengths of the front and rear arms?
Would it be possible if using longer arms front and rear, keeping torsion bars, to use air shocks to support the additional leverages?
The coil over support shocks designed to be used with the torsion bars. What size arms are they designed to be used with? Is there a point when coil overs or something else should be used?
If moving to a coil over setup how many coil over shocks are needed in front and rear? Are there best practices? typical setups, weights?
Fox coil overs are pricey. Has there been any other creative setups such as possible DIY methods using Macpherson Struts, Sleeves, DIY Coilovers, AirBags?
In regards to using the stock steering boxes, has anyone attempted to use steering dampers such as used on typical 4x4's to deal with bump steer?
So many options but I was unable to find info on what arm lengths/widths to use front and rear together (best practices) and what is the cutoff or what lengths require coilover setup.
Its been a while so I wanted to get updated on the any new stuff out there. I don't want to get crazy wide where the fenders are pointless. If I can stay reasonable in widths and travel? Maybe some pics with examples?
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dustymojave
Samba Member
Joined: January 07, 2007
Posts: 5802
Location: Lake LA, Mojave Desert, SoCal
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| Posted: Sat Aug 20, 2016 6:01 pm Post subject: Re: 1970 VW Baja, Suspension |
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| dunnkruger wrote: |
Good Day,
New to the forums and wanting to finish my 70 Baja.
Read stickys, searched most of the day for info however I would like to ask the forums additional questions specific to suspension setups.
First car was a 1970 VW Baja and have built four of them over the last twenty years and used Jeff Hibbards Book, Baja Bugs & Buggies. |
Great! Good source of info, that book.
It would help us help you in many ways if your avatar told us where you actually live. "East" doesn't tell us anything. EVERYWHERE is east of something or somewhere else.
| dunnkruger wrote: |
Purpose of Car
Daily Driver.
Occasional Race. |
What sort of racing?
- street racing?
- drag racing?
- race your buddy down a narrow forest trail?
- short course offroad racing?
- impromptu race up the face of a dune?
- Baja 1000?
LOTS of options
| dunnkruger wrote: |
Desert, Mountains, Lakes, Rivers, Streams, Beaches.
Occasional Jumping.
More interested in durability, strength, and finishing than I am about getting anywhere fast.
Would like to be economical, I can make and fab, have machine shop and more time than money.
King & Link Front End |
All of the above make sense and a reasonable goals for a Baja build.
| dunnkruger wrote: |
Questions
What is the expected travel in inches with the stock widths, stock lengths front and rear trailing arms with torsion bars? |
OK. For the purposes of this discussion I'm going to presume link pin front end and IRS rear. You've specified those above.
So...King pin after market shock towers come in various lengths off the shelf, and custom fabricated front shock mounts nearly always match those standards, even if they weren't trying to match them. The fact that offroad shocks come in standard lengths that match those sizes has a lot to do with those standard towers. The numbers refer to the wheel travel potential if shocks of that travel length were installed on arms with the lower shock mounts inline with the link pin.
Stock shock towers would be called 6" towers if anybody were to assign a designation of that sort to them. The next size up is 8" then 10". So putting on 8" tower kits or a Warrior beam with 8" towers, and the standard modified shock mounts on the lower trailing arms, with 8" travel KYB, FOX, Bilstein, or whatever shocks will provide about 8" of travel.
But...If you do not use a lower shock mount at the link
| dunnkruger wrote: |
nt on the arm...I get 10.25" of wheel travel with my original 800,000 mile 1958 beam, arms spindles, torsion leaves, etc. and 8" travel shocks. Ain't nobody gonna get any more because that's all the spindles and arms will allow before things go over center.
I've encountered LOTS of offroad race 1600 buggy and 5-1600 Bajas (both classes have to use stock length/width arms in front) with 14" travel shocks and getting about 9" of travel.
Stock width and length rear with VW hubs and 930 CVs, 1600 racers get about 12" of travel. Back in the 80s, I was race prepping a 1600 race buggy that had been set up with 16" of rear travel. Heavy on the "up" travel. The problem was that 3" of travel was with the bottoms of the 33" tires above the belly of the car. The body in a Baja limits some of that potential up travel.
[quote="dunnkruger"]What are the typical lengths available for front and rear trailing arms? |
Front - stock, 1x2.5, 1x4
Rear - stock, 0x1, 2x3, 3x3, 4x5, 5x6, too damn big!
| dunnkruger wrote: |
| What is the typical length combinations used for front and rear trailing arms. IE: What front length/width trailing arms are used with 3x3 rear arms, 4x5's, 5x5's, and so on.... How do you figure what matches front and back widths/lengths combo's, best practices? |
Stock front arms get used with up to 3x3 rears. Longer rear arms are usually offset with at least 4" front arms. Although sometimes only 2.5s in front. IT is good to have a bit of difference in track width ((IMPORTANT - center of tire to center of tire) for stability. A square car wants to wander. Front wider or rear wider doesn't make a hell of a lot of difference. Wider beams (originally +5") were invented to put the outside edge of the narrow front tire even with the outside edge of the wider rear tire (not center of tire) so the car would track straight in 2-track trails. But putting wide front wheels and tires is hard on front suspension and steering components. "Best" beam and trailing arm widths need to be determined with consideration of the intended wheel and tire package in mind.
"Best practices" is a term that companies and many individuals have so over-and miss-used that it's become meaningless in my world.
| dunnkruger wrote: |
| When are you forced to go with coil overs in regards to the lengths of the front and rear arms? |
Most 4" front arms made these days are made for through rods and are not square broached for torsion leaves. There are a great many older 4" arms around that were made for torsion leaves though. So if you buy brand new 4" front arms, you will probably need to go for coilovers.
In the rear, most reinforcement of stock arms causes a need to re-locate the rear shocks, which pretty much necessitates mounts to the cage. A set of springs for King/Fox/Bilstein, or whatever brand coilovers cost about the same as a good quality pair of rear torsion bars. So some maintain that as soon as you need beefier torsion bars is then time for coilovers. I don't agree with that view, but it makes some sense.
| dunnkruger wrote: |
| Would it be possible if using longer arms front and rear, keeping torsion bars, to use air shocks to support the additional leverages? |
Yes. Fox makes them. If you're thinking of air shocks like old Gabriel HiJackers?...Stop! We're talking an offroad vehicle here...Not a '70 Chevelle.
| dunnkruger wrote: |
| The coil over support shocks designed to be used with the torsion bars. What size arms are they designed to be used with? Is there a point when coil overs or something else should be used? |
I'm not sure what "coil over support shocks designed to be used with the torsion bars" you're referring to. If you mean EMPI with the chrome coils?...Stop! Those are something the dog left in the back yard. Latest Rage is offering some longer travel coilover shocks for a little under $100 each these days. They look to be better quality than the EMPIS. But I haven't dealt with them and will not judge them until I do.
| dunnkruger wrote: |
| If moving to a coil over setup how many coil over shocks are needed in front and rear? Are there best practices? typical setups, weights? |
1 per corner. Maybe 2 if racing. Additional shock such as a bypass help, particularly in the back.
| dunnkruger wrote: |
| Fox coil overs are pricey. Has there been any other creative setups such as possible DIY methods using Macpherson Struts, Sleeves, DIY Coilovers, AirBags? |
Lookup F-O-A or ADS for less expensive rebuildable off road shocks.
| dunnkruger wrote: |
| In regards to using the stock steering boxes, has anyone attempted to use steering dampers such as used on typical 4x4's to deal with bump steer? |
"Bump Steer" is a result of poorly setup steering geometry, where vertical movement of the wheel induces lateral movement as well without moving the steering wheel. It should not be confused with hitting a bump or other obstacle overcoming the steering box and hold on the steering wheel, causing the steering wheel to turn and the wheels to steer at a different angle.
Bugs came from the factory 1961 and later with steering dampeners. I recommend using a dampener for offroad if you are not using power steering.
| dunnkruger wrote: |
| So many options but I was unable to find info on what arm lengths/widths to use front and rear together (best practices) and what is the cutoff or what lengths require coilover setup. |
See above.
I have a friend who has a 4 seat buggy with a 400hp Honda V6 with 5x6 rear arms and Sway-A-Way torsion bars and Rancho shocks. I just drove it a month ago. It's still a kick in the A... Conventional wisdom would say there are several aspects of that car that won't work. "Best Practices" are out the window with this car and it's used as an example of why I dislike that term.
| dunnkruger wrote: |
| Its been a while so I wanted to get updated on the any new stuff out there. I don't want to get crazy wide where the fenders are pointless. If I can stay reasonable in widths and travel? Maybe some pics with examples? |
Typical fiberglass Baja fenders are pretty pointless with 3x3s and 4" front arms. Custom fenders can be made that will cover tires.
Based on what you say above, I would say offhand that the best compromise combination for you (without knowing where you're going to use the car), would be a mid-grade car:
- +6 beam with 10" towers mounted 4-6" forward of stock. A potential alternative for the link pin beam, if you want to stick to stock beam location, would be to use a BugZila conversion beam.
- Stock front torsion leaves cut and re-drilled for grub screws with outer layers replaced with full-width leaves
- Latest Rage forged 2.5" arms
- Latest Rage forged combo spindles
- HD off road steering rack with 2 turn lock to lock ratio
- 3x3 rear arms with VW hubs
- 002 Bus gear box
- 930 CVs
- F-O-A or ADS shocks with 2.5" bodies
- Suspension seats
- And the full roll cage to tie it all together.
_________________
Richard
Offroading VW based cars since 1965
Tech Inspection 1963 - 2012 SCCA/SCORE/HDRA/MORE/MDR +
Retired from building Bajas, Fiberglass Buggies and Rails in the Mojave Desert. Also Sprints & Midgets, Dry Lakes, Road Race cars. All types New and Vintage
SoCalBajas Member
Kicked Cancer's A$$...1st and 2nd round...Fight ain't over yet. |
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