Hydro steer or a better idea for big travel off road racer

[bru21]

I want to run 4x4 and massive travel on my new project.

I have seen several ideas at BAJA last year but they rely on howe racks and independent front ends - no front drive.

So far I have 80 series diffs,
with Fox 2.5"x12" coil over +2.5" triple bypass x 14" up front and
2.5" x14" coil / 2.5"x16" triple up back. This is as well as hydro bump stops which will reduce normal (except for g outs etc) travel by about 4" in compression.

I was hoping to use a lever ratio to obtain 20 - 25" travel at the rear and 16 - 20" up front.

the rear is a simple 4 link - done.

the front diff will rise above the motor as it is in front of the motor mounted front mid layout.

up front all I can come up with is:

Panhard + 80 series box for big bump steer as the draglink and panhard will be different lengths - exagerated over the big travel. This was ok on the nissan but it had like 5" of up travel and similar droop.

This might be ok as i can set the drag link and panhard parallel to each other and the ground at ride height - meaning it will be about the same as my nissan was at full droop - when at droop or compression.

OR a forward backward steering box off a truck with a bell crank on the diff and the steering shaft running above the top link,

OR full hydraulic steer like

http://www.pirate4x4.com/tech/billavist ... ndex3.html

sold through ABT
http://www.abt4x4.com/EzyCat2645__34925 ... ering.html

Does anyone know if this is CAMS approved for off road racing, will it handle 160kph safely?

Is this just a shite idea and should i just reduce the travel.

regards

Justin

[discokid]

Bru

you may want to do some homework on what we are running offroad racing. The class leading class 8 ( Extreme 4wd) isnt running that sort of front travel

However good compression travel is a must. I would look at stability first at a top speed of around 200km. If 160km is you top speed youd be wasting you time anyway and a lot of the "top speed stuff" is"smooth" and the quicker cars will get away from you regardless of how good you are over the rough stuff

Also look at John Hendics old Rodeo (PWR racing). Its very quick and simple in design I think it runs rodeo standard arms in the back and a pajero indepedent rear end. Id be guessing but maybe 10in - 12in of travel. Why the aussie stuff isnt like the Baja and handling and stability are number 1

My next car will be all independent with big compression travel say 12 to 14in. in 4wd config

Also check out Dirtcomp ed 10 with the green triton in it that should also give you a good idea of what the top guys are doing

Then theres this being built in WA. If it works in the real world it would be a killer. Again all independent

http://www.proformance.com.au/race_truck.htm

[discokid]

Oops


To answer the steering question

General requirements
http://www.camsmanual.com.au/pdf/offroa ... )_Q208.pdf

See GR 16

Our Class

http://www.camsmanual.com.au/pdf/offroa ... )_Q208.pdf

nothing in there

At the end of the day nothing specific but steering is one thing they do check every event for safety. if your car doesnt handle at speed the Stewards etc can take you logbook off you until its deemed safe

Most class 8s in this country are running standard vehicle steering for reliability and parts availability but there isnt anything wrong with trying something different either

[chunderlicious]

bru, greg jackson runs full hydro on his GQ, maybe get some contact details for him and have a chat about it. i know from the weekend that it doesnt steer at all without the engine running (obviously) so it might not pass safety with offroad racing?

[killalux]

i think full hydro would be too slow to react from what i have heard about it. And as a safety issue you have no mechanical link between the steering wheel and wheels, so all it takes is the engine to stall or belt break and you have no steering at all, not good at 160+kph.
Have you seen the steer setup on ian paltridge's patrol? something like that would be the go i think?? if it will handle the travel.

Or could you do a setup like glenn dobinn had on his cruiser??

[Guy]

Have you looked into any of the relay style setups ? They can cope with some big vertical travel