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MG MGB Technical - suspension and tire updates to im prove handling

Hi Everyone,

I have a '64 mgb roadster with 4.5 inch wire wheels and need to buy some tires. I live in the California, Sierra Foothills and think my car is well suited for zooming around the narrow windie roads we have here. There seems to be quite a bit of controversy over the size and kind of tire for my application. I also plan to modify my suspension for better handling. For starters I have a set of plastic bushings to replace the rubber ones and at this time I will install the camber changing A frames. I need a sway bar, my car didn't come with one. What sway bar should I use? How about one for the back? Anyway, my question is: what do I need to do to make my car handle it's best? I am not building a race car. Your help will really be appreciated. I Thank you in advance.

Later,

Charlie
C.E. Campbell

I wouldn't recommend plastic bushings. Polyurethane is typically the choice for performance upgrades. Superflex is my choice, but Superpro is also good. Just make sure the bushings have stainless steel inserts.

A stock 5/8" sway bar or slightly larger at 3/4" should be fine up front. In the back I would leave the bar off and use fairly soft springs. This helps keep the live axle under control. The stiffer you make the rear, the more choppy it will be in a turn with bumps in the pavement.

Performance tires are getting difficult to find in 14" sizes. You will get several varying opinions on what is "best", but since each car, driver and road condition is different you may have to experiment. I have a list of the tires I've tried on my cars over several years here: http://www.mgnuts.com/tidbits/tires
Make sure your shocks are in good order as well. If you suspect they are getting worn out (which is typical after 20 years or so) or if they are leaking, send them to Worldwide Auto Parts for a rebuild that will put them in literally better than new condition. Their web site is http://www.nosimport.com/

Hope this helps!
Steve Simmons

I agree with Steve, get Poly bushes with centre sleeves. Not so sure about re-con lever arms, they don't last long,they've been re-built many, many times! I'd go for adjustable telescopics, and maybe parabolic springs. At the front certainly a 3/4" anti-roll. On mine I modified a Ron Hopkinson telescopic conversion and it works really well.
As for wheels and tyres, if you can afford it go up to 5 1/2" x 15" wheels with 185 x 65 rubber. This set up handles my V8 (200+ bhp) no problem.
Allan

Whilst you can get problems with rebuilt lever-arms they are so much cheaper than buying new (and especially new telescopics) it is worth getting an occasional early failure, I've only had one in 17 years.

I've replaced the POs telescopics with the original lever arms. For a start one of them started leaking after only a few tens of thousands of miles, and I had to relace both at great expense. They lasted longer but eventually I became aware of a very bouncy ride at the back, by which time the adjusters had siezed anyway. For many years the only telescopics have been way too hard, anything other than the softest setting being very harsh. Unless you do go for parabolics for their greater compliance, which need telescopics with their greater damping, and positive axle location piece-meal changes have very little benefit for the money. And even then whether it is worth it for road use is highly debateable, especially for a standard 4-cylinder. Even the factory V8 had conventional springing and damping.
Paul Hunt 2

When I mentioned plastic bushings, I meant polyurethane, the ones that Moss sells to replace the crummy rubber junk that comes with the car. My experience is that they only last a year or two and they are ready for replacement. I think they should work OK. My shocks work well and my wheels are in good shape. I will take the advice on the sway bar, it is what I was going to do. I think any bar will be better that none as long as it isn't too big. I am down to my tires, I need more information on tires for my skinny rims. I wish I could afford wider ones. I think 5.5 inch is the way to go. Will 185/70 fit in my skinny rims? The wheels I bought cheap has 185/60's and they seem to be working OK but it is time for new rubber and I don't know what to get.
Charles Campbell

A year ago I installed new tires on my wire wheeled '73. I went with Kumho Power Star 758 size 175x70x14. These tires handle very well; I have no complaints on the winding, hilly roads in the Applachian foothills around here. The 175 width fit better on the narrow 4.5 inch rims and don't come close to any body panels, like the 185s sometimes do. Also, this size tire (14" by 70 profile)has about the closest overall diameter to the factory original size tires, if you worry about the accuracy of your speedometer and that sort of thing. Finally, Tirerack.com has them priced at $36 each! So far they show little signs of wear and grip very well. I'm pleased.
David Burke

I have not been able to purchase a 3/4 sway bar anywhere. Anyone have any ideas?
karl

I have been running Kumho tires on my 5.0L Ford conversion for 2 years and find they are a great tire, good traction and road holding.They seem ok in the wet , but the car is pretty loose in the wet anyway. Although Im using a 195/60 -14 size, I know they have other sizes in various models. Kumho developed their tires in conjunction with SCCA.
Gil Price

Rebuilt lever shocks are not all the same. Rebuilds from Peter at Worldwide come with a LIFETIME guarantee against leaks. Yes, they are that good. Plus, they give the proper ride unlike most tube shock conversions. They also mount in the proper geometry, again unlike most tube shock conversions.

185/70R14 will fit 4.5" rims, but they are definitely pushing it. You may get some sidewall slop when compared to a narrower tire but that's about it.
Steve Simmons

I have a 73 roadster, and in 2003, I made some changes to the suspension which I feel has made a significant improvement in handling. My times in the autocrosses show that also.
I lowered my car by one inch by installing CAHT-21 springs in the front, and de-arching the rear springs. The front springs are not only lower, but have an increased spring rate. My dampers appeared to be functioning fine, so I left them alone. I upgraded the inner A-arm bushings to the V8 style with the steel centres. I installed the Evolution II sway bar kit, which includes a 7/8" bar in the front, and a 9/16" bar in the rear. I did not change any other bushings as they were in good shape. With my plain 175/70 Uniroyal Tiger Paw tires and the above mods, there was a definite improvement in handling. I am now using 185/65-14 Fulda Attiro tires on my 4.5 x 14 inch wire wheels, with which I noticed a further significant improvement in handling. I feel as though the sidewalls do not flex much as I find there is more response in turn-in. My autocross times improved about 4 seconds in total compared to other cars I run against. What I had been noticing was that it was difficult to get the power down coming out of a turn during autocrosses, so half way during an event, I removed the rear sway bar. The second half of the event, I found a further half-second without the bar. So that rear bar is now sitting in my garage. Now the car likes to understeer on really tight courses, but the its great on more open autocrosses, city streets and winding country roads. I would like to try a 1/2 inch bar in the back - I may adapt a front bar for the rear.
My next goal is to replace the wires with Minilite replicas 15x6, and a further upgrade in tires.

Hope this info is helpful to you.

Erick
Erick Vesterback

Charlie,

I have gone to 15 X 6 Minilite replica rims with Dunlop 55 profile tires. Not a problem with clearance. Love the way it handles and rides, and it looks mildly nasty. As everyone suggested, feel free to go up to the 3/4 bar in the front and use a urethane or prothane set of bushings.

A 7/8 bar is good pretty much only for competition or the heavier MGC.

The Minilite replicas are now available in 16 inch sizes. It would be intersting to hear about someone's experience with those!

Tom


Tom Balutis

I've had, so called, new lever arms fail after a few thousand miles, there's a good reason why they're not used today. They're only one, evolutionary stage, removed from friction dampers. Go for good quality, adjustable, telescopics at the back. I've had Spax on 2 B's now without any problem. At the front the problem was always that the available conversions, used quite short dampers, within the spring pan. Because they were short, they overheated. Putting the dampers outboard of the spring, gives a better length and therefor removes this problem. A problem, I might add, which the RV8 suffers from.
Allan

Years ago I replaced the standard 9/16" sway bar with a 3/4" unit from Moss or V.B. My 74B had no rear bar.
I upgraded to Minilite 14" rims ( check catalog for width) And went with 185/70 Perelli tires. This was a very nice improvement to my handling. Also each tire was 2lbs liter than the old tires/rostyles. Have fun! Bob
Bob Ekstrand

I have a '64.

Thicker oil in the lever arm shocks at the front, 3/4 inch anti-roll bar, chrome bumber GT front springs, MGB GT V8 wishbone bushes (pressed in by someone with a good press), and negative camber wishbones.

Sorry guy, I was advised against nylon bushes by a very successful MGB racer who reckoned they only work at Silverstone where the surface is smooth, at all other tracks they don't work well on the bumpy surface. This is very old advice, perhaps the polyurethane ones are better and work on the road.

Don't touch the rear, the softer it is the better, make sure the rear springs are oiled and don't stiffen with rust..

John.
John Prewer

a word of warning ,keep away from the spax coversion as i had three sets fitted, with in a week they start banging ... the problem is the angle of the shock absorber, i went for 25% up rated lever arm .
daz

Has anybody tried removing the small lower blade to improve the "softness"
Trevor

Some people have reversed one of the middle leaves to *lower* the suspension, you can only soften it by derating the dampers or going for single leaf or parabolic springs. Removing the short plate will do very little, I'd suspect. If you go too far with lowering *or* softening you will be continually hitting the bump-stop. The stiffness is designed to support the weight, which is why you do generally have to fit telescopic with more damping when fitting single or parabolic springs. Most people go for *more* stiffness, not less, although as has been said unless you are on a very smooth surface that is likely to worsen road-holding anyway.
Paul Hunt 2

Tom-
Who makes the 16" Minilite replica? What width are they?
Steve S.

I have been through the complete cycle with the suspension on my 75 roadster.

I had an extra complication of a Rubber Bumper shell with Chrome springs and no mounting mods. The ride height was much too high.

I tried front and rear Spax Conversion kits and lowering blocks at the rear. I also went to yellow Poly bushes every where.

The result was a better handling but a much too hard and rattly car!!!!

After talking to 3 or 4 V8 builders and racers of B’s and C’s I have gone back to uprated lever arms, reverse eye lowered springs and Superflex Bushes all-round.

There is a lot of recommendations out there designed to sell you mods that do not make much difference off the track, I should know I bought most of them.

One odd example is that one chap who races B’s told me due to odd circumstance he had to remove the V8 front callipers/disks on his B and run with standard ones. There was no difference at all. He swears by Mintex Pads that’s all. His argument is that the thicker V8 discs hold the heat more so causing as much problems as they solve by heating up slower!! This is of course on the track.
The only difference between the V8 and std is spacers in the callipers.

Regards

Dave
D M Tetlow

John,

The nylatron bushes are effectively solid, working just in rotation and therefore not providing any compliance. I some in my GT, then took them back out before my teeth rattled out. The poly bushes have some compliance, seem to work much better than rubber.

Dave,

The V8 pads have a larger swept area than 'ordinary' ones. But you can put V8 pads into ordinary calipers. Most of the uprated pads (whether Mintex, green stuff, etc) work well from cold. I had an Mk2 Escort Mexico with pads that didn't work well from cold - the first few stops of any journey were a bit hair-raising!

Everyone,

Nobody's commented on the negative camber? A very good move I say, makes a world of difference to turn-in. Also, please don't understimate the need to 'match' components - springs, dampers and anti-roll bars all do different jobs but are linked as a system. Obviously the combination depends on what you do with the car. I've got 600lb springs, 30% uprated lever arms (valve), poly bushes, negative camber, 7/8" bar and 185/60 tyres. Roadholding is great, but the ride is shocking!

Neil
Neil22

Okay folks - I'm going to open a really big can of worms. I keep reading people recommend adding a 3/4: anti-roll bar to improve handling and not that I am disagreeing, but it's more bling than anything else.

If we define "improve handling"; we assume we mean handling for regular street driving (track/race not included). Assuming that all stock suspension components are in food working order, the biggest improvement to handling is tyres. Put a set of 185/60-14 performance tyres and the handling will be excellent and probably suffice for 90% of the people under 90% of conditions. Personally a 3/4 sway bar is a waste - it stiffens the ride and make the car too rough for today's pot-holed filled roads.

I have a 64 MGB and have removed the sway bar - but do have sticky tyres and a totally 100% rebuilt suspension/shocks. The car handles much better than my midget and is very go-cart like - yet it is "soft" enough to have a comfortable ride over today's roads.
gerry
gerry

Absolutely. Tyres make a huge difference, even different makes of so-called standard tyres. I ended up with a pair on the rear of the V8 that were really intended for use in hotter temperatures than the UK, and the rear would break away in the wet with the slightest provocation. I swapped the fronts and the rears over and it was much better, with little if any detectable increase in breaking away at the front (whilst the loading is close to 50:50 one tends to load up the front, whereas the rear tends to be unloaded. Having driven two V8s one with the Ron Hopkinson kit with rear anti-roll bar and one without, and one with telescopics and one without, IMO the rear bar makes little difference to overall handling on the road, but does seem to locate the axle a bit better. On the one without I could feel it moving about more with my backside, and it was only through that I discovered one of the drop-links had snapped on the car with.
Paul Hunt 2

Gerry has this one right. 99 percent of people toss on a sway bar not even knowing what it does! A front sway bar is going to make the car "push" or understeer trhough a corner. I would do all my mods, drive the car (on a track ) and then decide if I want to put a sway bar on the thing front or rear.

Go though the whole suspension and make it like new. Make sure the kingpins aand tie rods are in top shape. I like the poly bushes myself, but V8 bushings and stock rear pring are not bad.

Don't bother lowering until you have driven it with the renewed suspension. You may not need to lower it.

Worldwide autoparts has good re-built shocks. LOTs of positive feedback from their customers. Apple hydraulic seems to be out of favour lately.

Toss the wires in the bin. They are probbly no good if original anyways. Call Dayton and buy a set of 6" tubeless wires. Toss on a set of modern 15 by 210 50 profile tires or 195-60 if you want to stay stock size.

Tires make the car stop and turn. The rest of the parts just follow whatever those little bubber patches do.

Keep things in perspective:

Remember that this is a 44 year old car and that no matter what you do, a stock Honda will always run circles around you! Enjoy the car for what it is.
Pete

Poly bushes - neg camber arms on a CB car - 7/8" up-front/no rear bar (unless you are happy with oversteer) - stock or up-rated stock shocks - tyre pattern/rubber to suit your roads/potholes - 175 on stock 1800 wheels or 185 on stock V8 wheels (Yes you can fit wider but the benefit is doubtful) - 195/50 or 55 on SAAB 6" alloys (yes they fit without mod).

Priority ? 1. Bushes/shocks =2. Selection of rubber to suit and the sway bar.

Sorry if this offends.

Roger
(Tried allsorts and made all my own mistakes over 40+ years)

PS Pete perhaps the Hondas go faster in Canada.
Roger

Yellow bushes are a bit harsh but I think worth it to know what the car is doing.

Consider the caster correction kits as well. Much cheaper than power steering.
B D Hird

Goodday friends of the knitting circle -this thread touches on a problem I'm having with rear end of 73 BGT. PO fitted "Performance" brand minilite replicas and when I bought the car I felt the rear end sagged, so bought new rear springs.From Heritage spares in Sydney. The result was slightly better in terms of ride height (tho still a bit low) - but here's the rub (pardon the pun) - left rear tyre outer wall touches the lip of the wheelarch under very little load and slight road bump. The local spring people looked at the new spring and reckon it is twisted (poor manufacture) - does anyone know whether this would "drag" the back axle across slightly when evrything is fitted up? I reckon we need to go across about 5mm towards the rhs, to achieve a centred back axle with no contact either side; also still need to raise the rear end by 1cm at least. All advice gratefully accepted, thank you.
John Hall

John,
Check the archives for threads regarding offset axles on B's.
It is apparenetly a common problem with all of our cars.

PS How did you survive all of your rain, you could share just a little with us.
Terry
T J Malloch

Terry M. - thanks for the lead mate - I once tried to join up and have access to archives, without much luck - I'll certainly try again tonight. I'd also love to know what is a commonly sought-after ride height for the BGT, just for normal road use. Will try the archives for that, too. At 58.5 cms to top of wheelarch, I reckon mine is a good 1cm too low. Cheers ... John.
John Hall

John,

I too am running 14X6 Performance Superlite Minilite replicas on a 73 B/GT - with 185-70s . Same rubbing. Replaced the rear shox with Worldwide rebuilts and rear springs with John Twist's eight-leaf replacements. No change. I can get it to rub on the right also. Very easy to get rubbing on both sides over bumps - even when not pushing it - when carrying a passenger and all the luggage she needs. 8^)

These are the size recommended for MGBs - 18 mm + offset. They also offer a 26 mm + offset and I wish I had bought them. Anybody want to swap? Otherwise, I love these wheels.

Cheers,
Allen


Allen Bachelder

John
There are some poor quality springs about but assuming yours are OK, the bushes are the most likely cause of the sloppiness you write about. the front end rubber needs to be good condition and the bush snugly fit into the spring eye. There must not be any play between the securing bolt and the metal of the bush. (Didya fit new bolts ??).
At the back end, worn shackle bushes allow the spring and the axle to drift. Were the shackles and their bolts new ?? If they were, odds on the bush material is the problem - there are two ends to the shackle and you might like to consider a stiffer bush - plastic (readily available) on the chassis end - which will move very little and nylon onto the spring - you coould use plastic both ends but it would contribute to an uncomfortable ride - the mixture is a compromise.

If that is not enough, a piston damper conversion would also help but you might need to think about a torsion bar.

HTH

Roger

PS If the port rear is rubbing on the lip - the starboard inner is on the wheel arch. You might shave the lip but the wheel arch is more tricky.

Good luck
Roger

Allan B. - my rims are 14x6, with 175/75 tyres. Interesting that before we fitted new springs there was no apparent problem of tyre/body contact.

Roger - you make good points;the new springs came with pressed-in front bushes, which I assumed were also new and snug; new front mounting bolts were installed. At the back end, we put in new rubber bushes, but re-used the shackles from before - possibly a factor.I'm starting to think (admittedly in a fog of desperation!)that better, straighter springs + new shackles + firmer neoprene bushes at the back, might be worth trying. That only leaves me with how to raise the rear end another 1cm. My rear end sits at 14.4 cm from centre hub to bottom of chrome strip. Exactly the same at the front, though I'm aware that front shocks are bouncy and when replaced, will bring the front down a tad.
Cheers for now - must go to work! John.
John Hall

Karl,
swaybars-

http://www.whiteline.com.au/default.asp?page=/products.htm

I'm using this on a '75 and I can't see why I can't be used on post '74's. I would like to try a 7/8ths.

http://www.mgocaccessories.co.uk/cgi-bin/sh000001.pl?REFPAGE=http%3a%2f%2fwww%2emgocaccessories%2eco%2euk%2facatalog%2fMGOC_Accessories__Rear_suspension_30%2ehtml&WD=front%20suspension&SHOP=%20&PN=MGOC_Accessories__Front_suspension_31%2ehtml%23aH062#aH062

Steve, wheels
http://www.performancewheels.com.au/superlite.asp#
They have distributors/rep's world wide.
I'm using Platinum (polished rim) 15 by 6, ten spoke with a 24P offset.
These fit under standard guards. The tyres are 95 by 60 Michelin low energy XM1's, which I am very happy with.
I've noticed there is a slight rub mark on the inner (boot side) of the Right hand guard, otherwise no problem. I would like very much to get some 15 by 5 inch dayton wires.
http://www.daytonwirewheels.com/accessories.html
note the adapter. These are the absolute best and can be used tubeless and with a V8, as in my case.


Peter

John
Rear Axle Offset to the left- All MGB's have a bit. From the factory jig. It is actually body offset the other way. If you haven't got offset, it's been in an accident and repaired by some one better than the Factory. I would have between one quarter and half an inch. You can try loosening up the U bolts, and re tightening them with some directional force applied. You might consider grinding back the inner lip on the LH arch a bit. Some people do the NASCAR trick and roll a baseball bat between tyre and guard to both push lip up and guard out a bit. You might consider fitting a pan hard rod, which would help handling allot. (I have yet to do this)
http://www.google.com/search?q=mgb+panhard+rod+kit&client=wyzo&rls=com.wyzo&channel=s&hl=en


http://www.britishv8.org/Articles/MGBRearSuspension.htm
I'd have the RH joint 90 degrees, but the bolt on approach is very clever. I wouldn't mind seeing the other side of that bracket.
and you will see why people make their own!
http://www.mgocaccessories.co.uk/acatalog/MGOC_Accessories__Rear_suspension_30.html

ride height
http://www.mgbmga.co
Peter Sherman

Peter S. - are you serious! - all these years, I'd never heard of MGBs having an inbuilt fault leading to offset axles.I'm still going to try new shackles, hopefully better springs, slightly stiffer shackle bushes, as mentioned yesterday, - BUT, you're right, when I refitted the springs just to keep the car on the road the other day, I did loosen the U-bolts, apply sideways (left to right) pressure while doing them up, and achieved a slight improvement. Without the twist in one spring, I'm hoping for further improvement; and IF I can find out how to raise the rear end another 1cm, the problem of tyre/mudguard contact will go away.I do appreciate your and others' kindness in offering helpful comments. I'll let you know how I get on, without unintentionally dragging a thread away from its intended subject. Am still learning some of the protocols! John.
John Hall

Gospel John,
The V8 conversion types all run into this one because we all almost immediately acquire a desperate need for more rubber on the road and go for larger tyres/wheels and subsequently crowd the rear wheel arch/guard.
One person, at least, shifted his spring perches over half an inch. This generated much (unresolved) speculation with regard to the consequences of his front wheels being out of alignment/track with the back.
Try placing a straight edge along your spring, It might be straight after all.
New shackles are unlikely to help, new bushes will tighten every thing up so will help with axle movement.
Peter Sherman

Actually, come to think about it, the guy at British V8 (link above) did offer longer shackles for higher ride height, which might sit you. However, I don't know if he is still in business. He was winding it down and didn't respond to my enquirery about composite glass fiber springs. Others might make them.
Peter Sherman

Peter - I'm glad you came back, because I forgot to say that the Ride Height item (www.mgbmga.co) appears to have been removed from BBS - does that mean it's gone forever, or is it stored somewhere out in space?
John.
John Hall

It's a terrific site.
All sorts of details. The guy who owns it is retiring/retired and is selling off all his gear. I wish he was still in business, I'd love to get some of his composite springs, antitrampbars and panhard rod etc.
http://www.mgbmga.com/tech/index.html

If that doesn't work, Do a google search on

British Automotive

and on their home page scroll down to
suspension
A variety of articles to look at.
ie rear suspension.

Of course http://www.britishv8.org/
currently by Curtis Jacobson
is outstanding, for seeing how far an MGB can go.

Peter Sherman

http://forum.britishv8.org/read.php?7,1540
Peter Sherman

Peter S. - I'm very interested in the elongated shackle arrangement as shown on the British V8 site. What a simple way of achieving, say, 1 inch at the rear. I'm still going to make sure springs are straight, bushes firm, etc. and then put the idea to my mate at his engineering works. He is a perfectionist, and will do a good job.
PS - do you (or any other threaders) know whether by having the front shocks rebuilt (via Abingdon Motors, Brisbane), the front end will be pulled down a tad? - if so this would affect my measurements when deciding how much to raise the rear. Sorry to labour the issue - I haven't tried any of this before. John.
John Hall

I did my own extended rear shackles, see http://www.mgb-stuff.org.uk/wn_suspensionframe.htm and click on 'Ride Height' and scroll down to 'Extended shackles'.

Any damper likely to be fitted to an MGB will have no effect on static ride height unless they are seized.
Paul Hunt 2

shock absorber rebuilders vary in quality.
Some just replace the seals and valves but don't look at anything else.
I replaced a front one and the new/rebuilt one was leaking less than a year later. The replacement would go up, but would take ages to come down. Rebound no good. The third rebuilt one is still OK.
I'd suggest new ones, MGOC or Moss. There is a group in America who apparently rebuild even better than new. You will have to ask the others or search the archives.
Peter Sherman

Peter, the outfit you're thinking of is Worldwide, which I mentioned in my previous post.

http://www.nosimport.com/shoxcatalog.htm
Steve Simmons

Another vote for worldwide. They don't have it on their website, but they also do (did 7 years ago anyway) water pumps - and also very well.
C Holm

This thread was discussed between 17/02/2008 and 11/03/2008

MG MGB Technical index

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