fabricated box tubing frame?

[oldtinsmith]

[quote="pontiacgp" And for the rear 4 link you can fabricate a 3 link so the rear axle doesn't turn the wrong way when you are trying to corner[/quote]

pontiacgp,
Is that what's "rear steer"?

Doug

 

[RITTER]

I am thinking about using the El Camino frame I have and removing the C-channel (between the front and rear clips) replace it with box tubing and incorporate some of the bracing designs from these other aftermarket chassis :idea:

It was amazing how much you could flex this frame. My buddy and I picked it up to carry it into my basement and it flexes A LOT!!!

 

[pontiacgp]

[quote="pontiacgp" And for the rear 4 link you can fabricate a 3 link so the rear axle doesn't turn the wrong way when you are trying to corner

pontiacgp,
Is that what's "rear steer"?

Doug[/quote]

with the geometry of the 4 link when you compress one side that side will move forward and the other side will move back when the body is lifted...when turning left your back end is turning left. If you have ever watched dirt racing you'll notice the inside wheel will move forward when the body lifts off of it. That's what you want but the 4 link does the reverse.

 

[jbracing]

thats the first i heard of a 4 link actually doing a rear steer that wasnt with the turning direction. how bad is it actually

 

[pontiacgp]

when I had my car off the frame and had the rear mounted without springs and shocks I was surprised how much the rear moved when I lifted one side. We raced metrics for years..that's G body on this side of the track..and at a short track they weren't bad but soon as you hit a half mile, longer corners and higher speed the leaf cars, camaro, nova and phoenix would take over. We'd be off 3/10's a lap on a goo day which is huge. With he leaf cars there is an adjustable spacer to move the axle forward on the right side and it didn't take much to upset the car. On asphalt it would mess up the wedge if you went too far but it just shows how little it takes to affect the car going around corners

 

[jbracing]

ya we call them metrics around here too lol. i race on a track thats a hair under half mile. now i have also considered making a set of modified trailing arms to set the rearend of the car up for rear steer. how much this would help in the corners i would like to see. how much it would hurt the car down the straights i would like to see as well

 

[pontiacgp]

the higher end Nascar cars use truck arms for the rear. The longer the arm the less arc to affect the rear. If you can just get rid of the opposite rear steer you'll be good. The metrics that do run the 1/2 mile here use a 3rd link set up. The panhard bar helps to keep the rear in place. The side to side movement of the metric rear is another problem. The adjustable space block is only used in leaf spring cars so the only way you can do it is with uneven rear control arms

 

[jbracing]

i think im going to have to play around with different length trailing arms this winter. make up two or three sets to set the axle in and play with them to see where it gets me. they have to be stock. otherwise fabricating adjustable tubular ones would be simple enough