MG Sports Cars

In the article on Les Gonda's MGB race car I saw a mention of caster correction wedges from John Targett. I contacted John to find out more about the wedges, and decided to order a set. The wedges are made of nylon, and only cost $60, a fraction of the cost of the well known aluminum wedges. John's wedges can be used with or withoput the subframe mounting pads. If used with the pads, spacers for the front mounting studs are supplied so that the front pads are not crushed as the mounting nut is tightened. A further feature is that the wedges snap over the rear stud which helps to ensure that they are properly positioned.

The correction wedges significantly lightened the steering, and have no noticable effect on other aspects of the handling.

I also ordered a set of nylon bushes for the upper kingpin to A-arm mount. These bushes provide more positive location of the king-pin and should help to preserve the suspension geometry under hard cornering. In addition, they reduce suspension friction/resistance, which is always a plus. Moss also offers nylon bushings for this application, but I ordered mine from John along with the caster wedges.

Larry,
Did you have to correct the steering rack angle? I know with the metal wedge kit it is supplied with washers to re-align it.
Also how did you contact John for the kit?
Thanks,
John

I added John's caster wedges to my '76 last Winter. You WILL have to shim the steering rack to regain the steering shaft geometry with the u-joint at the firewall.
Personally, I was expecting more of a change to the steering effort and was disappointed with the result - on the other hand, Jack Renaud added them recently and advised that his steering effort improved.....perhaps it's a function of tire footprint, ride height, or the brand of beer I drink.
John - you can find Targett Motorsports in the "Contact" "Vendor's" directory at the top of this page.



Edited 1 time(s). Last edit at 12/09/2008 10:26AM by ex-tyke.

I installed these wedges on my Sebring gt in early '07 after reading the article in the mgb driver.....I agree with Graham, I really was expecting a more noticeable change...frankly I can not tell much difference.

Looking on the internet, caster wedges get mixed reviews, with some drivers noticing no difference and others finding a big improvement. It seems to be the same here.

Caster action causes the car to lift as the wheels are turned; the more it lifts, the harder the steering, and the greater the restoring force. Because MGBs are reasonablty light, caster wedges do not make much of a difference in normal driving. However, under hard cornering, the effective weight on the outer front wheel increases subasatntially, and the steering gets much heavier. I noticed a big improvement on high speed curving freeway entrance ramps, but not too much in more sedate driving, as expected. Reading the reviews of the factory MGB V8s a common complaint is that the steering gets very heavy undewr hard cornering, which is consistent with my observatons.

Other factors that can affect the benefits from caster wedges are wheel offset, steering rack ratio, and tire width. When the wheel offset results in a small scrub radius, the steering will be very heavy when the car is not moving because the tire will be twisted about its contact patch. With a larger scrub radiuus, the tire can roll as it is turned and this lightens the steering. (When the car is moving the tire also rolls as it is steered which is why the steering is much lighter then.) Caster wedges have no effect on scrub radius effects. A low geared steering rack, as was used on later rubber bumper cars, provides more leverage and reduces steering effort, which also reduces the benefits of the caster wedges. However, cars with quick ratio racks (quicker than stock) always seem to benefit from the wedges. Wide tires also can benefit from caster wedges. At low speeds, most of the increased effort from wide versus narrow tires is due to scrub radius considerations, and the caster wedges will not help much. But in high speed corners, wide tires develop greater G forces than narrow tires, and this increases wheel loading which makes the benefits of caster wedges more obvious.

Considering the price of John's wedges, it is probably worth experimenting with them if any of the above caster wedge favorable conditions seem to be present.

Does anybody have advice on the best front crossmember pads to use. I'm replacing the front crossmember in my BGT that is upgrading to Ford 302 motor. Are the stock rubber pads acceptable or is there advantage to upgrading to some kind of poly or nylatron. I don't want to lose "driving comfort" but obviously want the best handling I can get.

I don't find the stock rubber pads to be acceptable with a 4cyl, much less a more powerful engine. The pads deteriorate, especially if they get oiled from an engine oil leak. I found them missing from a friends 4 cyl B, with dangerous slop in the front cross member.

I like the red poly pads sold by several vendors, matching front suspension bushings and spring pads.

Martyn, when you say you're replacing the front crossmember, do you mean you're re-installing the a stock cross member that's been modified for 302 clearance or your replacing it with an aftermarket crossmember? If it's aftermarket, check with the vendor... Ted, for instance, designed his IFS to bolt up with no pads.

Rob,
I'm using a modified stock MGB crossmember. I would dearly love to install Ted's crossmember but.....
Thanks,
Martyn

Those wedges look like something that might be helpful on my car, but I wonder, just how much do the cushions relly do anyway? Has anyone run with and without them? I recall when I had delrin suspension bushings that the worst thing was the squeaking. As far as the ride, I don't remember it being particularly harsh but the handling was a little more precise. Is it similar without the pads?

Jim