Suspension Questions

[Section 8]

If you have a working suspension system geometry, how do you shorten the arms and wheelbase?

I am thinking of buying the sandcars.net plans, but they only include drawings for the 4/5 seat car. I would like a 2 seater that is a little longer to stuff crap behind the seats but not a full 4 seat length.

Will reducing the wheelbase have any effect on the suspension? The roll center heights won't change, but the line that connects them will get steeper. I wouldn't think that this changes anything suspension wise.

second, how would you shorten the arms on a working design? I don't want to be 93 or more inches wide ( I do realize shortening the arms affects how far the tire travels when you bind the drive joints). If you just take off x inches everything, then the upper link is getting "shorter" than the lower link, and you will have more camber gain, so I don't really see an easy way to do this, and it looks to be more work than just designing your own suspension, which is what I am reluctant to do (having never done it before).

Thanks.

[Gene]

I don't think there is an issue making it shorter. Why make the other changes? It is narrow enough to fit in a trailer.

[Section 8]

My house came with a third garage stall that appears to have been a car port that was "finished" to make a third stall/workshop. The door is 91" to the flexy rubber seals, 93" total.

I suppose a street tire or another front tire on different rims would fit. The paddles used in the rear for measurement appear to be Xtreme 14.5, as they are the standard package tires. I don't know the wheel back spacing, but the wheels are pretty deep.

[Gene]

Yeah, I get it. I have to chang my tires to get in the trailer. Maybe if yougo with 12" rims and 1300 Paddla Trak tires it will fit. Backspacing could be a solution too depending on design.

[punkur67]

when your front arms are drooped out you should have a little inward scrub making the car narrower. I need to droop out the front and use a tie down to keep the arms as close a possible to get it in the trailer. my car narrows 4 or 5 inches total at full droop. Its a very simple thing to do. I just lift up on the front end as much as I can and do the rest with a ratchet tie down. Might be an option. And you can always get some skinny tires for the rear to load the car. I know it sucks but sometimes you gotta do what you gotta do.

[K-fab]

As long as you keep the ratio (of length) between the upper and lower arms the same, then the geometry shouldn't change.

Meaning if you shorten the upper arm 10%, then shorten the lower arm 10% and things should stay the same - don't forget to do the same to the tie rods.

[plkracer]

That's only true under small changes kfab. Usually you have to scale down the whole assembly, including the distance between the upper and lower mounting points. The angles between them would stay the same.

[K-fab]

Yea, now that you put it that way, I believe you're correct. It's still a good way to get close, though, for small changes as you've pointed out.