Steering, Suspension, & Brakes

6.5 degrees of caster in the MX3. That's even more than the 5 degrees in the MGB. Then they used that to provide the centering. I think we may be onto something here.

Jim

I have seen the MGB listed as 7 degrees, as well as 5 degrees. I would love to see someone's alignment printout.

'Engineers behind the new 2014 Mazda 3 have tuned the steering setup of the third-generation 3 to the point that it mimics the best parts of a manual steering system for better response and feedback."

Y'all may convert me yet.

Frontline & Moss Motors both say that the MGB was designed with 6.5 degrees of trailing castor. I have also seen 7 degrees mentioned elsewhere. Either is perfectly fine with me.

Should work well with the MX3 EPS. Local Pick-n-pull has nothing newer than 2011 so they are out. Might look around some though. Wider tires will increase the caster effect. Wonder what the MX3 unit does in limp mode?

Jim

"Wider tires will increase the caster effect"

Taller will, but wider? How so?

Your wide front tires should require less negative camber & a bit more toe-in.

I guess it depends on whether or not they are wider inboard or wider outboard. Inboard wouldn't make any difference but outboard would increase the jacking effect.

Jim

Which is why a bit more toe-in is needed.

Um... maybe? I've found wider tires don't need as much toe in and wear fast if they do.

Jim

As much? I run zero to slightly out. :)

It's always a balance with toe-in & negative camber. A matter of finding the right combo for one's tires & driving style.

The stock MGB caster angle is about 6.5 degrees. A large caster angle gives a strong self-centering action and causes beneficial camber gain during cornering but also increases the heaviness of the steering. Most modern cars have power steering as standard and as such have large caster angles in the range of 6 to 8 degrees or more. For years I had a Mercedes 240 diesel and the shop manual specified 8.5 degrees of caster on cars with power steering and about 4 degrees on cars without (only available in Europe). One of the features of the Fast Cars MGB front suspension is a reduced caster angle (nominal 3 degrees, range 2.5 to 5 degrees). This is a main contributor to a lighter steering feel. Mike Moor has a Fast Cars front suspension in his MGB with power steering. I wonder what the caster setting is? I drove his car at the Auburn meet and it had some self-centering action. I would have preferred more centering, but it did work predictably. I have a Hoyle front suspension in my MGB but since it still uses the MGB cross member I am also running caster wedges to reduce the caster to about 3 degrees. I am considering removing the caster wedges and returning to the stock setting. At that point I may seriously consider adding power steering. I also have the Moss fast ratio steering rack which might be beneficial for a more robust self-centering action; (I wonder how that compares to the Fast Cars steering rack?). Still, in looking through this thread I am not sure if some of the centering problems are related to caster settings.

Larry, after 2014 Mazda used EPS in the 3 and 6 models. You might want to have a look at those.

Jim



Edited 1 time(s). Last edit at 04/06/2023 09:13AM by MGBV8.

I am not aware of Mike having increased his castor any. His was the #1 test prototype, so not sure what his castor angle actually is.

I thought Steve Carrick had the #1 prototype IFS?

Maybe so.

Mike's car is the one that Ted had Bob Senneker test. Bob drove Mike's car with his OEM crossmember (& bolt-on tube shock conversion - it's sitting in my garage). Bob told Ted "You're going to improve on this?" Then, Bob drove it with Ted's IFS & said "You improved it!"

Back when I was considering flared fenders, I asked Ted if he could make it a bit wider for a wider track. He said he could probably make it up to 2 inches wider without upsetting the geometry. Not much later, that became an option.

Steve had the first 3-link in an MGB (with Ted's help). My idea, though. :)

We're getting off topic for this thread, but when Andrew got his IFS from the Sennekers, they told him they're only going to be doing stock width going forward. If they stick to that, he got one of the last wider ones.

Bummer.

I could be wrong, but I believe the only difference is the A-arm length.



Edited 1 time(s). Last edit at 08/05/2022 12:22PM by MGBV8.

The Hoyle front suspension in my car is 1 inch wider (each side) than stock. A few years after I bought it, Hoyle announced the availability of the wider suspension and I obtained a set of suspension arms which I have been using ever since. Looking at their current web site, there is no mention of wider arms which means either they do not offer them any more or the wider arms are now standard. The wider suspension allows my wider wheels and tires to clear the through-the-fender exhaust, with the stock width I had to install steering stops in the rack.

New GPS automatic variable speed controller:


[www.ebay.com]

Nice!
Also that is the Bruno box which Mike Moor uses in his conversions so I'm sure he can get the new version.

Wonder if they have one that works with the Prius EPS?

Jim

They expect to have one for the Prius/Yaris/Aygo box in a few weeks.

Jim