Well, I was looking through some odl threads finding out about tire fitment on a 4ws to see what the biggest I coudl go while lowering the car and not scrubbing the rear febnder on the tire. I ofund out that about a year ago I had made a thread about it and completely forgot about it.. anyways. Other threads i saw when I searched for 4WS had an Insane amount of controversy about the function of the 4WS system, how it worked, etc. I have been trying to put together a document to post up here with everything I know about the system so people can stop being confused. For now, I'm posting a graph I found that shows the range of steering movement from the rear wheels in comparison the the steering angle/steering speed ABOVE (and including) 18 MPH. here is the graph



arguments that the rear wheels only turn one way above 18mph can now be put to rest. The stories about the 4ws being akward and changing direction mid turn can be deemed true by looking at the graph between roughly 180 and 220 degrees of steering wheel rotation. If you happen to enter a corner and turn the wheel about 220 degrees, the wheels turn about -.2 degrees. after entering the turn, you realize the wheel is turned a bit too far, and back off about 40 degrees of steering wheel rotation, the 4WS system coudl and probably will calculate that the wheels shoudl be turning the other way now and will end up being turned at about +.2 degrees. That being said, there is definatly room for some akward vehicle movements, But in my eyes, not enough movement to really send the car out of control. It's late and I'm tired and this seems like a good place to stop, but if anyone has any questions related to 4WS in any way, ask them here so I can get you answers and so that when i go through making the document about 4WS I can have the best list of questions people have answered. with asking alkl the questions here, maybe this will eventually be FAQ'd and i'll just edit this post with a bunch of answeres and post the PDF of the document I create with everything in it. this document will contain links pictures, diagrams, and hopefully everything you need to know about 4ws and probably stuff you don't NEED to know either. haha. well I'm off to finish up some CAD drawings for some parts i'm making for the lude, but i'll keep checking back to this thread to answer any questions anyone has. -later

 

Dude think about what youre saying, I haven't run through many corners where you rotate the wheel any more than 180 degrees, the steering ratio on the prelude is plenty to turn a car pretty sharp with much less than 180 degrees.....

the part of the graph where it is over 180 degrees is meant for parking situations....

So honestly, I doubt in any real world situation the prelude will be in trouble like that....thats a very sharp corner....

 

It's pretty rare to have such tight turns on the average backroad.

However, in my experience of driving various backroads, the mountainous, elevation-changing routes will often have tight hairpins that require over 180" steering wheel rotation.

on the graph, good info!

 

The graph is for 18mph or higher, thats some Blues Brothers parking.


The real scary part is if your trying to recover control, move the wheel alot to correct oversteer, and the tail swings out more then normal, although I doubt you would even notice if it was on dry pavement where things happen too fast for the system to realy function.

 

Yea true matt....I didn't realize that it was for 18mph+

And you're right, the thing can't possibly steer fast enough to keep up with quick adjustments

 

if I can get the right hook-up for my computer to get video from my camera transferred I can sho wa clip of "picture in picture" of me turning the wheel various speeds and how quickly the rear wheels will react. I'm at work now so I can't type much, but there was a thread in the archives that had link to a review of a 4ws equipped prelude and the person who wrote it was saying about how sometimes there is some weird behaviour happening at the rear wheels.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by bb4ever &raquo;</TD></TR><TR><TD CLASS="quote">And you're right, the thing can't possibly steer fast enough to keep up with quick adjustments</TD></TR></TABLE>

I guess you'd be suprised at how fast it does move. as fast as I can turn the steering wheel the rear wheels keep up with what I'm doing. I don't know how it woudl react say, if I was in a drift, and you know how you can pretty much let go and the wheel whips back real quick from lock to lock? well, I have never seen that because I don't feel liek losing that much control of my FWD car, but I plan on doing some pretty detailed experiments where I can see real close how the rear wheels react under certain steering angles, speeds, vehicle speeds etc. But I won't let it all out of the bag until i'm finished and have results to share.

bottom line is, the rer wheels turn pretty darn quick, and video fotage will come soon to show details.

EDIT: does anyoen have any questions that even though you may know the answer to, woudl be good to share in this document i'm making? I want to cover everything possible


Modified by shutta at 3:19 PM 10/23/2006

 

I've already started one, you can see it here:
http://www.superhonda.com/foru...95664