122 replies to this topic

[Willy_sa]

Epic work!

[scrapveiw]

I got the rear anti roll bar links made up today ,the wings and front panel welded on and sealed , the front wheel arches cut out and drilled ready for the bolt on arches , the steering rack and mounting bracket repositioned to eliminate bump steer.

 

[scrapveiw]

[scrapveiw]

The above picture shows the re drilled holes for the rack that now sits 1" higher.

[james_k]

Been following this thread and really is some inspiring work you're doing. Might be a bit of a dumb question but how does moving the steering rack up by 1" eliminate bump steer?

[exuptoy]

My favourite build on here!

[scrapveiw]

front hub , before and after the bead blast cabinet.

[scrapveiw]

added a couple of diagonals and a cross brace with harness mounts

[scrapveiw]

Just a few more pics

[scrapveiw]

Been following this thread and really is some inspiring work you're doing. Might be a bit of a dumb question but how does moving the steering rack up by 1" eliminate bump steer?

Thanks for following the thread.

 

 

Ok , if you move all pivot points on the wishbones up 1" from the standard mini geometry and you don't adjust the height of the rack to suit , you get bump steer as the proportion angle of the rack joints no longer correspond to the proportion of angle on the wishbones. I said on a previous post that i had kept the original mini geometry except i had lifted the pivot points by 1" hence lowering the car by 1" .

 

This is the best way i can explain it as follows-

 

Lets say that you have two wishbones( hypothetically )  the same length on the same side of the vehicle pointing at 90 degrees , then you have your steering arm and track rod end pointing in the same direction and the same length between pivots , pointing at 90 degrees , this would be perfect as you would not get bump steer.

Now lets say you move just the rack  up an inch , the angle of the steering arm now becomes 100 degrees , but the wishbones are still at 90 degrees.

therefore when the wheel travels up ,the distance between the rack pivot and the hub centre will become greater as the steering arm reaches 90 degrees, and the distance between the wishbone inner pivot and the centre of the hub will become less as the wishbones reach 80 degrees,Creating bump steer. all the joints on the front must work 95 percent in harmony with one another , otherwise you're in for a proper white knuckle ride.

 

I know this from experience . a chap i know used to do his own mot repairs on a mk 2 escort , he bought it to me one day and said the car was trying to kill him .I took it for a spin and low and behold every bump i hit , the car tried to throw its self across the road . upon inspection he had fitted a track rod end in upside down .Dont ask me how !

Edited by scrapveiw, 29 May 2014 - 12:06 AM.

[james_k]

Thanks a lot for explaining, it makes a lot more sense now! I didn't realise you had altered all the other pivot points but now knowing that, it makes sense! I wasn't too sure what bump steer was in the first place but now after your explanation it's a little clearer.

 

Thanks again!

[scrapveiw]

http://www.ebay.co.u...984.m1423.l2649

 

And the blackbird mini is for sale again , this time described as being built by z cars , 

 

[scrapveiw]

Edited by scrapveiw, 03 June 2014 - 09:59 PM.

[scrapveiw]

It took me all day Saturday to remove the spatter ,rub down , prime and spray the rear cage .Its hard to paint something with no corners , every time i thought i had finished , i found i had missed a bit ! , got it in the end though.

                                                                                                                           

Edited by scrapveiw, 03 June 2014 - 09:58 PM.

[scrapveiw]