JPSC Forum

Posted this on the chat list aswell, so apologies for the double post, but ....

Can someone point me in the direction of some instructions on how to do DIY tracking / wheel alignment please.

Photos of the DIY tools to do the job would be brilliant.

Thanks,

Pete

Hi Pete,

Not tried it myself, but this might be helpful?

http://www.elantragtclub.com/id554.html

Jek

Tracking measurement via stringing. Strangely, written for heavier cars than JP's, but principle remains the same.

http://www.hummerknowledgebase.com/susp/string.html

Pete,

petercoll wrote:Can someone point me in the direction of some instructions on how to do DIY tracking / wheel alignment please

I frequently, every couple of races, completely check the suspension of my race Fury using a collection of devices that I've made myself. I am a wee bit anal about all this though as it's makes a huge difference for a race car. (For example, just try pushing your car around on full lock and compare it to how easy it is to push with the wheels pointing straight ahead.)

I check the wheel camber with this device:



This is just a spirit level with a couple of M6 bolts tapped into it. Assuming the car's on a level surface then I adjust the little bolts, which are pressed against the wheel rim, so that the spirit level is vertical. I then measure the length of the bolts with a vernier caliper (a proper one, not one of those nasty electronic ones) and do a little bit of trigonometry to come up with the camber angle. In fact, I did all that in advance and the numbers are written on a bit of masking tape on the spirit level. An alternative is to buy an inclinometer like this one and read the angle directly. (Although, you'll have to set the zero position on the gauge first.) If you like that idea, they're on ebay for around £20, just search for "inclinometer".

As for tracking, I made this device:



That's a bit hard to see, so here's one of the ends a bit closer up:



Essentially, it's a sort of giant "C" shape. Because of of the "fingers" on the end you can arrange to get this positioned so as touch the outer side of the wheel rim on both the left and right hand side of the car. So, for example, if I want to set the front wheels to toe out a bit, I:

1. insert the thing at the front of the front wheels,
2. adjust it so that the "fingers" just touch the rim
3. move it to the rear of the front wheels and
4. check that the fingers don't quite touch the rear of the wheel rims by the amount I'm aiming for.

Not as convenient as using a laser alignment gauge but a lot cheaper. If you're aiming for toe-in then you'd start at the rear of the wheel rims.

I also check that the rear wheels (my car's an IRS one) are pointing straight with respect to the front wheels. Unfortunately, I don't have a photo of the device here but it's just a lump of 1" square ally extrusion that fits snugly into the wheel rim. Attached to this (by some duct tape!) is a small laser pointer I bought from Maplins. I've also got a little cardboard gauge that I attach to the front wheel hub with something sticky, blutack works well! I put the ally in the rear wheel and read off the gauge how far away from the front wheel hub the laser passes, and then do the same on the other side of the car. Ideally, the measurements will be the same. The track on the Fury is a little wider at the rear than at the front; this wouldn't work if that wasn't the case.

Note that all this is the laser equivalent of the traditional chassis "stringing". In fact, if you seach for "laser string" on the 'net you'll find a lot of devices that do this for you. Mine's just cheaper!

The order that things are done in is quite important. I do this:

1. check the ride height front and rear
2. check the camber front and rear
3. adjust the front toe
4. measure the rear toe and the longitudinal alignment. If I'm clever then I can adjust them both in one go, as I use the rear tracking adjustment for both.
5. Finally, I do the whole lot all over again to check it's right, and worry if I don't get the same measurements for everything.

I've also got a bump steer gauge that I made which comes out occasionally. If you want details, ask and I'll dig the photos out of that too.

It takes a Saturday to do, really...

HTH,

Tim

(Edited to fix the photo URLs. If they disappear again email/pm me and I'll sort it.)

Brilliant thanks Tim. I had something in mind like the 2nd and 3rd photos.
Will see what I can come up with over the weekend.

Pete

Tim,

I assume the black rod shown in the pic is threaded internally - where did you get this from ?
(I mean the longer horizontal one in the pic).

Thanks,

Pete

petercoll wrote:I assume the black rod shown in the pic is threaded internally - where did you get this from ?
(I mean the longer horizontal one in the pic).

It's not really black, it's just some mild steel tubing that I tapped to fit some M10 studding into. The nut that you can see just acts as a locknut. have you got access to welding gear? It's going to be pretty hard to make this without. But then, I reckon you could make the equivalent with wooden doweling and plywood...

T

Thanks Tim.

I reckon I can get away without having to weld, given what I have in the garage, but I do need about 6" of hex rod or similar, tapped with an internal 10mm thread - still looking .....

Pete

And here is what I have come up with.

A piece of spare box section steel cut to right length, to run between the wheels.
10mm threaded bar firmly bolted to it at each end for the uprights.
10mm internally threaded connector as the height adjustable component. This has a 6mm thread tapped through it for the adjustable bolt that touches the inner rim of the wheel.
All parts are readily available on Ebay.

The critical part is that it is rigid (for repeatability), and it is. I have just used it on my Striker, and it works a treat. You just move it between the leading and trailing edge of the wheels until you have the mm offset you need.

Pete




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Hi Pete
looks good what measurment did yo set the wheels??
regards
Paul