MG Sports Cars

Just wondering ur thoughts on whether I should go with stock leaf springs with an added leaf or go to some form of 4 link suspension on my MGA hot rod. I have a rear end out of a Chevy S-10. I don't want to spend a fortune on some elaborate 4 link rear if I don't have to. The car will be driven as a cruiser, not interested in high performance turning or straight line. Any comments would be appreciated.

Leaf springs are just fine for what you are after.

What do you hope extra leafs might achieve for you? Surely not better traction or ride quality. If your goal is to prevent spring "wind-up" by adding leafs, you'd probably be better off with some sort of traction-bar device installed under the spring pack. Here's another good alternative: [www.britishv8.org]

My car had Pinto leaf springs and frame slappers under it I originally was going to rebush everything then I decided to go with the 4 bar. The ride with the leaf springs was acceptable but with the load from the traction bars you would get some noise from the bushings and any where else it was rubbing it the wrong way.

How does the car ride and handle, leafs vs 4 bar?

I hope to answer that question by at least August I just got the car painted and I'm doing a pre assemble for the stripes and clear as we speak.

Hey David,

Your question is simple.
The answer, not so much.
If your car is truly just a cruiser then the leaf springs, as Rob says, are just fine for what you're after.
Even if you are going to hot foot it every once in a while. Leaf springs, can and have, been made to handle this since god was little.
Talk to a good spring shop in your area. They can custom build a spring pack to suit your needs.
The draw back to the leaf spring is (A) wheel clearance and (B) the ride quality deteriorates rapidly as the springs torque handling goes up. Particularly in a light car such as yours.
Teflon strips or sliders built into the spring pack, or greasing and wrapping. Along with carefull shock selection. Will go a long way towards smoothing out the ride.
If your fabrication skills are up to it. A nice upgrade that is relatively easy on this car is a three link suspension. The front leaf mounts are perfect for the lower two arms and the cross over pipe at the trans tunnel is a good spot for the upper link. The battery boxes can stay where they are. Add a panhard bar and some coil overs and and away you go.
A four link isn't that much harder but your going to lose your battery boxes and gain a little complexity.
There are lots of other suspension options, these just came to mind first.
Your best bet is to realistically evaluate your performance goals for the car.
Then ask everyone that you can, what they think.
Just as you've done here.
You are going to get a mountain of opinions as every situation is different.
You just need to pick the one that fits you.

I hope thats helpfull

Cheers
Fred

You do not necessarily have to lose your battery boxes when installing a four-link.

The Classic Conversions Four-link is designed for the chrome bumpered MGBs and can be fit to a rubber bumpered MGB with minimal modification to the battery box.

Just to stir things up: have you thought about going with an IRS? That truly makes a world of difference in the ride quality and handling department. The only sacrifice is weight, but for a iron V8 engine swap the weight in the back tends to balance it out. The complexity wouldn't be any worse than a 4 link except for the work involved in either narrowing it or adding flares. I've used bigger cars for the IRS ( Jag, Vette and GTO ) but some of the Japanese stuff looks like it would accomplish the same thing and not have as much weight.

Bill

It’s about 15 degrees here in Dallas right now with snow and ice still ever where for a week so the “B” is getting no attention what so ever, but what can I say, I’m not riding the Harley either so it'll have to get over it. At present I still have the stock rear axle and leaf springs, which is Ok for a stock 302, but knowing my personality, the 302 may not stay stock forever. I really like the four link above and it’s well within our shops ability to fabricate. I’m using an Odyssey battery which has been relocated so the boxes aren’t an issue. I’ve always used a Ford 9” but I assume it’s too big so I also want to go with an 8” for the better range of gear ratios. What should the brake backing plate flange to flange distance be for a metal bumper car (1972)?

"P"

I'm with you Bill. I've built two bolt-in Jag IRS assemblies. One has been driven a bit, neither are on the road yet but it looks like they are going to be a great suspension. We'll know more by summer. You are right, it does cost a bit more but I think the ride and handling will be worth it.

JB

Quote:

What should the brake backing plate flange to flange distance be for a metal bumper car (1972)?

Paul, before you commit to an axle width, you need to decide on a wheel first - the wheel offset will determine your flange to flange width.



Edited 1 time(s). Last edit at 02/05/2011 05:11PM by ex-tyke.

Thanks Graham, I kind of knew that but didn't think of it; guess I'm getting too old for this. We have a wheel manufacturer in California who makes wheels for us, and they supply off-sets to order but it limits our choice. I can get them through our street rod shop for a very reasonable price; it’s what I usually do. They are heavy by most standards, and un-sprung weight is an issue, but I’m building an everyday driver that will never see a track. I’m not flaring the wheel wells at this time, mostly because I don’t have the talent. I’ll go through the archives to see what others have done because one thing I’ve learned is re-doing it because you didn't have a plan is an expensive approach to car modifications. I’ll take your advice and plan it out before I put anything on order. I suppose I should decide on a wheel width, what size tire, and where it will set, then decide on the offset, and go from there. Has anyone tried a 9" rear end? I ask because I have one.

David,

A similar conversion was carried out by Bill Spohn on his fibrefab bodied "A", having had a read through it it appears he retained the standard rear set up suspension wise, which I thought a little surprising might be an idea to drop him a PM to see how it handle the power of the V6,he has a 3.4 chevy engine and it appears you are using a bored 3.8 Buick V6.

[www.britishv8.org]

There is a simple and economic trick that you can use to control the torque of the much more poweful engine, don't forget there was only 68 BHP in there originally and you will probably have 200+ BHP and a lot more torque.

What you do is, assuming you will replace the tired old springs you already have is to take the old springs apart and using two of the long leaves is to cut them just behind the U bolt position then mount them to the new springs, you can remove the bottom short leaf of the new springs when you reassemble

The half leaves will run forward and sit just below the front spring eye position, they will not increase the spring rate at all but will act as a sort of traction bar and stop the axle winding up under torque reaction, I am told that it also has the effect of increase traction on launch so simple cheap and effective.

Kevin.

"There is a simple and economic trick that you can use to control the torque of the much more poweful engine"

Yep, skinny tires. ;-)

Rick, I like this as there isn't any welding on the body itself. I couldn't tell from the pictures, how does the coil-over attach to the body at the top, just standard brackets?

"P"



Edited 2 time(s). Last edit at 02/13/2011 12:45PM by pspeaks.

Yes...the four-link kit from Classic Conversions utilizes brackets *supplied by CCA) to the shock mounting position on the frame rails. The only welding required was for the tabs on the differential. (Not counting the battery box adaptation for the single-battery rubber bumpered MGB).







Edited 1 time(s). Last edit at 02/13/2011 01:32PM by mowog1.

Thanks Rick, that's a gigantic help. Now that I see it laid out, except for the shocks of course and axles, there isn't anything there we couldn’t fabricate in our shop including narrowing the rear end. The only question would be is it cost effective to do it ourselves? My battery boxes are in terrible shape so I relocated the battery and plan to remove them anyway. All I have is a 9” Ford so I guess I’ll have to look for an 8” but they aren’t that hard to find. Thanks for the info.

We kind of got away from David who asked the origional question. How is your project going?


“P”



Edited 1 time(s). Last edit at 02/13/2011 03:14PM by pspeaks.

"Has anyone tried a 9" rear end?"

Yes. Steve Carrick & Martyn Harvey both run 9" Ford rearends. They are generally considered too big, heavy, & overkill for our little cars. Then again, it depends on whats under the hood & what you are gonna do with it.

Steve used an aluminum third member to reduce the weight by 20 lbs.

Thanks Carl, I was thinking of the weight also and I produce nowhere near the horsepower to need a 9”. I sometimes get a little frugal and want to use parts piled up in the shed to save money but that’s not always the best way to do things. The 9" I have has been narrowed for a T-Bucket anyway.

In retrospect I think I should say something about fabricating parts or components in our shop that I see on this site. We, for all practical purposes, have turned the shop into a hobby and cigar lounge with an occasional beer if the machines aren’t running. All government contracts are complete and we no longer produce parts for sell. Most of us are almost 70 years old, retired, and have no intention of starting another business, nor coping someone else’s craft or intellectual property to sell, nor will we manufacture parts and give them away. On the other hand, anything anyone in our shop dreams up and gets posted on this site is fare game and you’re welcome to it.