Xr1 rear trail

[Figure8racer4]

Curious if there’s a reference point on chassis to square rear end at static on an xr1? New to dirt from pavement and see a lot of talk about coming off mid plate on different cars. I’m used to having a jig point/key stock to pull from but didn’t know if anything chassis wise is even square to check it. I’ve got a few generic setup sheets from rocket but they don’t get into the nitty gritty. Thanks!

[billetbirdcage]

The lower 1/2" mounting tabs for the 4 link are square to the jig (do not use the upper ones).

However what is square? I mean the rear end isn't anywhere near ride height when the car is raced and square with the frame doesn't mean square with the front wheels. My point being is anything you call square at ride height is just a reference point and should be treated as such (just a guide to know where you are and how much change you want to make and how to get back where you where if needed.) Easiest way is just to go off the bar lengths and front to rear position of the 4 link plates.

[billetbirdcage]

You can't use the mid plate as the motor is crooked in the car and not square

[ZERO25]

You could drop a plumb Bob off the front ball joints, then the rearend. Then use the wheelbase difference as a reference!

[TheJet-09]

There's something similar we used to do. Unfortunately a picture would be best (but is well beyond my capabilities on this site). In describing it, though, drop a plum-bob off the zerk of each lower ball joint. Take a 48"scribe and draw an arc on the floor (towards the center of the car. Then, where the two arcs intersect (two points), draw a straight line through those to the rearend. Perpindicular to that line would be square.

I believe that accounted for one front wheel being in front/behind the other, but there may be a fault with that method that I am unaware of.

[crownman25]

theres no way unless you start out with caster on both sides the same because the ford style pulls rf front ahead of the left thus making the rf whhel base longer..

[ZERO25]

There's something similar we used to do. Unfortunately a picture would be best (but is well beyond my capabilities on this site). In describing it, though, drop a plum-bob off the zerk of each lower ball joint. Take a 48"scribe and draw an arc on the floor (towards the center of the car. Then, where the two arcs intersect (two points), draw a straight line through those to the rearend. Perpindicular to that line would be square.

I believe that accounted for one front wheel being in front/behind the other, but there may be a fault with that method that I am unaware of.

Exactly, then you can drop plum bobs equipment-distant from the rearend and measure the wheelbase!

[Henry Every]

Call Barry Wright, his cars have reference points for alignment. LOL