Dave Robsons Challenger R/T

Pete · Post by **Pete** » Mon Feb 04, 08 10:23 am

I agree with Dave after my experiences, but the instructions tell you not to do full travel (I assume to avoid damage to the seals).

Still the best way to assure all the air is expelled. I tried short cuts but they don't work.

Its looking good, Dave

mopar_mark · Post by **mopar_mark** » Mon Feb 04, 08 12:51 pm

Havent tried the bench bleeding method myself, but makes sense to me.

I tend to use a "Stiff" leg, basically pump the brake pedal till its as hard as I can get it& wedge the pedal with a piece of wood between the seat & pedal or what ever is easiest.

Then leave the pedal overnight, this then pushes/forces all the air out, well has always worked for me so far. Oh yeah, I leave the lid loose on the master cylinder.

Ooops, early forgot

Cars looking good Dave.
I think its best to do small bits at a time, rather than nothing at all

Dave-R · Post by **Dave-R** » Mon Feb 04, 08 5:17 pm

mopar_mark wrote:I think its best to do small bits at a time, rather than nothing at all

How right you are.

Linda and Sandy know a guy that only does one hour a night on his car. Every night. At the end of the hour he just stops what he is doing and leaves his tools where they are until the next night.

When you think about it he gets 7 hours a week or 30 hours a month in on his car that way without upsetting the wife or loosing out on any social actvities.

That is not a bad way of doing things because when you set a day aside at a weekend to do things you can bet something will come up to get in the way of it.

Dave-R · Post by **Dave-R** » Tue Feb 05, 08 10:07 pm

Had another hour tonight before pancake making duties.

Decided to set the front wheel alignment.

I started off by getting the car as level as possible. Also resting on the LCAs at about ride height.

I set the UCA bushings full in at the rear each side and full out front in order to set max positive caster.

Checking each brake disc with a plumb-bob I could see that each disc was very slightly positive camber by the same amount each side. This confirmed my spirit level readings for the car to be correct.

I then wound in each front UCA bush very slightly to get zero camber on the plumb-bob.

I then zeroed a magnetic camber gauge on one disc at a time and wound in the front UCA bushing inboard some more to give 0.5 degrees negative camber.

Dialing in the front UCA bush also decreases the positive caster.

Looking at the adjustment cams on the inner fenders when i had finished they look to be set exactly the same each side so I think i have it right.

I would normally put a bit more negative camber in but have decided to go for slightly more caster this time and see how it goes.

Anonymous · Post by **Anonymous** » Tue Feb 05, 08 10:31 pm

Did it take more than an hour though ?

Stay well.

Dave-R · Post by **Dave-R** » Wed Feb 06, 08 8:36 am

Sandy wrote:Did it take more than an hour though ?

Nope! Just under I think. Had to get those pancakes on.

You were right when you thought one wheel looked like it had more camber than the other in photos. That means it must have had more caster on one side than the other too.
So much for a "professional" job.

Anonymous · Post by **Anonymous** » Wed Feb 06, 08 11:03 am

Looks great Dave, i'm guessing a lot of people who had been as ill as you would of given up! Good on ya

Mick70RR · Post by **Mick70RR** » Wed Feb 06, 08 7:28 pm

How much caster did you end up with Dave?

BUDGIE · Post by **BUDGIE** » Wed Feb 06, 08 7:32 pm

Mike, you don't use caster sugar in pancakes son......

Mick70RR · Post by **Mick70RR** » Wed Feb 06, 08 7:41 pm

I know Mal, I make them every year and I don't even like em.

BUDGIE · Post by **BUDGIE** » Wed Feb 06, 08 7:46 pm

Snap on the making of them every year........ the master at tossing .....

Pete · Post by **Pete** » Wed Feb 06, 08 7:58 pm

I spent a day doing that on the Barracuda with gauges, Dave - Set it perfect and it drove awfull. Pulled one way on acceleration and the other on braking.

Set it again for maximum caster, bugger the camber, and hey presto! drove like a dream......hope yours works out better. I am convinced this was the cause of the weave at the top of the track.

Anonymous · Post by **Anonymous** » Wed Feb 06, 08 8:17 pm

Dave , are you setting the steering geometry as a mirror image of the FSM?

Dave-R · Post by **Dave-R** » Wed Feb 06, 08 9:28 pm

Mick70RR wrote:How much caster did you end up with Dave?

I knew someone would ask this but i lived in hope.....

The answer is i don't know and I don't care. I have fat tyres and manual steering in a 4000lb car. Too much caster I can do without.

I can work it out by using the camber gauge but it is a pain in the bum to do and not necessarily correct when you are done.

Pete. I had more camber and less caster before and it was fine so it should be OK?

What the hell. It is easy to change. I will see what it is like.

Dave-R · Post by **Dave-R** » Wed Feb 06, 08 9:38 pm

Adam68 wrote:Dave , are you setting the steering geometry as a mirror image of the FSM?

Possibly. The FSM needs to go out of the window mate. The spec designed for old ladies and Yanks that like light steering and not performance.

Obviously the more positive caster (and toe-in) you have the straighter the car runs. But you need negative camber for cornering and controlling under-steer (in a big block car in particular) because the cornering forces induce positive camber which limits lateral grip from the tyres.

If i was setting the car up for drag racing I would have dialed in ZERO camber. That would have given me a LOT more positive caster. But my car has never been set up for drag racing and never will.