MG Motorsports Forum

Hi,

There seem to be a fair few guys in the know about racing MGBs on this forum so I thought it would be a good place to ask for a bit of advise on the best setup for the front suspension of an MGB race car.

I want to lower the front of my MGB race car and I have been looking at using the dropped spindles which don't appear to be commonly available in the UK. If I fit the modified spindles how to I reduce the increase in bump steer? Do I need to adjust the rack and steering arms, and if so by how much?

Also, is this a beneficial modification or am I better off fitting a lowered spring. The front springs I currently have fitted are 8" 800lbs.

Thanks
Joe

Joe, You need to talk to Dave Headly in Colorado,I don,t have his # handy maybe Hap can post it,anyway, he builds dropped spindles and several B racers use them.

Dave's website:

htttp://www.fast-mg.com

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1956 MGA, Charleston, SC



Edited 1 time(s). Last edit at 2008-09-29 08:46 AM by Bubba.

Dave Headley's dropped front axels are not suitable for street use. His modification is such that the "dust" cover between the bottom and top trunnion is not usable there by allowing for all sorts of dust, debris, and water easier access to the trunnion bushings with subsequent faster wear. If you do decide to use on a street car, you will need to grease quite often to "clean out" the trunnions. Dave’s axels also raise the roll center, a good thing, and provides some dynamic camber gain, also a good thing. As for Bump steer, I used Dave's dropped axels on my pervious B racer and IIRC, I did not need to adjust for bump steer - Stock steering arms with Dave's axels gave me about zero bump. I was using shorter spring for a total drop of about 2 and 1/2 inch. Whatever you install, you will need to measure the bump steer and make suitable adjustments to approach zero steer. I have seen some reverse the steering arms, left to right and right to left with various degrees of bend in the arms to approach zero bump. Some also use spherical rod ends with a thur bolt and spacer to adjust bump steer. This will require drilling out the tapered hole to accommodate the bolt.

John,

What length and lbs spring are you using?

Thanks
Joe

I still have the old springs and will check tonight.

Dick Lueing sells them off the shelf as well. www.mgbracing.com

They are about $500 and you send him your cores.

Dick Luening's spindles are also available through John Targett at Targett MotorSport, which might be an advantage to you (living in the UK) because John travels home to the UK with a very full suitcase from time to time, and that might save you shipping costs.

Here's what they look like:


Here's contact info for Targett MotorSport:

I don't think Dick and Dave use the same procedure to drop the axel. With Dave’s you get a different suspension geometry. The trunnions are moved apart by 1 inch by lengthening the king pin an inch and welding a 1 inch long tube to the bottom of the swivel axel. This drops the car an inch and provides additional dynamic camber gain on bump.

I believe Dick’s process just raises the axel relative to the two trunnion points by removing an inch from the top of the swivel axel and adding an inch to the bottom of the swivel axel, thereby retaining the stock geometry and lowering the car 1 inch. You can see this in the post above.

With Dick's process, you do not need to modify the kingpin. With Dave's you have to cut the kingpin at about its center point, add an inch spacer and weld.

I think I still have a set of the Headley dropped axels and will try to post pictures tomorrow.




Edited 1 time(s). Last edit at 2008-09-29 11:41 AM by JohnP.

The swivels I got from Headley are stock length, he milled 1" off the top and welded a 1" sleeve on the bottom. Internal dust covers still worked ok, the swivels work on stock kingpins.

While I agree that if a taller kingpin is used, there would be a change in negaive caster gain, the units he supplied me fit stock kingpins, there is no additional length between trunnions

JohnP Wrote:
John, You are right. As a result, my bump steer is not zero like what you got from Headley. This is something I need to sort out this winter.

Apparently Dave sells two styles. Mine have the longer modified kingpins with nothing machined off the top of the swivle axel and one inch added at the bottom.



Edited 1 time(s). Last edit at 2008-09-29 12:43 PM by JohnP.

Joe, another option on your side of the pond is Bob Yarwood. He's located at
60 Whitchurch Road
Audlem
Cheshire
CW3 OEE

01270812083

He currently is racing a B in your neck of the woods.

Another option Joe is to deepen your spring pans. Works very well.

Here is a picture of the two different types of dropped axels that I know of. The lower one is from John Targett. The upper one is from Dave Headley. You can see the weld on the Headley version. It precludes removing the king pin and using the dust cover.