MGB Front/Rear Suspension Upgrades

[v8250]

To All, I'm looking for advice from your experiences here:

Earlier this year I bought a 1977 MGB Roadster with the intention of converting into mild/fast road spec'. Engine/Ignition/Gearbox/Diff/Exhaust options are straight forward; will be using Peter Burgess engine with Ford 5-speed Gearbox.

But, I am a little confused with the extensive updgrades and mods' for front and rear suspension; simply there are too many available from MGOC, MOSS, Brown & Gammons, Hoyle, Frontline et al.

My thoughts at the moment are as follows:

1. Lower RB to CB ride height
2. Frontline Telescopic Front Conversion with 480lb springs and Castor Correction Wedges
3. Keep Live Back-End adding Panhard Rod as want original rear-end 'feel' but with better axle location.
4. Install Superflex bushes throughout
5. ??Pls advise on which type of rear leaf springs [uprated, parabolic, RV8??]
6. No need for anti-tramp bars as power only 130/135bhp

Any/all help advice would be greatly appreciated; thank you.

[alfa pint]

I've been in the same situation as you twice, but don't appear to have quite your budget!

Old B - 7/8" front anti roll bar, shorter and stiffer springs at the front, parabolics at the back. Upgraded lever arms at the front, koni gas conversion at the rear. Did have negative camber wishbones on the front, but they ate too many tyres too quickly and the steering was ridiculously heavy, so I went back to normal ones. The parabolics were brilliant - the car didn't skip sideways on bumpy corners anymore.

Current B - 3/4" front anti roll bar, shorter and stiffened springs at the front, normal springs at the back (at the moment!) but on lowering blocks, upgraded lever arms all round. The car is noticeably lower and stiffer, doesn't roll anything like as badly and gives me bags of confidence. The car is very nose heavy and I'm thinking about the shims on the front crossmember to lighten the steering up and correct that.

Decent tyres make all the difference too - I'm running yokohama A drives on the current B and they're very good in the wet and more than satisfactory in the dry. I had continentals on the old B most of the time, which were pretty good most of the time too, apart from a tendency to aquaplane in very heavy rain.

The mantra is keep the back soft and supple and harden the front end up, hence the current B is only a bit stiffer than normal.

[v8250]

thanks alfa pint. the note about parabolic springs is useful as have had some negative feedback on these and it's always best to have 'real life' feedback. all agreed on hard front/soft back as with any live axle. the b's shod with uniroyals on 14" minilites and this seems such a "natural set-up" that i don't want to completely lose. interestingly, the back-end rarely skips even under hard driving; and i can be firm with the b' sometimes. i've often thought that b's back-end manners are nowhere near as bad a people suggest. i find setting car up into corner smoothly irons-out excessive skipping/spring wind-up...but definitely needs a panhard rod...and possibly some link arms ala MKII Jaguar.

[alfa pint]

Oh forget to mention, all of my Bs have been polybushed, the current one is on blue superflex ones and they're brilliant.

I've driven a few standard rubber bumper Bs and they're generally appalling on a damp road. I like to be able to plant the throttle a bit at the apex and get the feeling of a rwd car turning in properly. I couldn't do that with the standard rubber bumper suspension heights / stiffness, but can now. My dad owned the current car since 1986 and obviously just got used to it!

[na]

renewing the suspension bushes (unless they are already fairly new) is always a good idea and I personally like the Super-Flex

if you buy Frontline stuff do yourself a favour and buy it from somewhere like MGOC/Moss

you could also enquire about a mildly uprated front (and perhaps? rear?) ARB

a good source of info may be got from - MG BBS

you've covered your tyres but don't forget your brakes, in addition to the normal servicing this may only required renewing - brake fluid, flexible hose set (Goodridge), pads (?mintex 1144?)

a programable 123 electronic dissy from Peter Burgess would help with engine running, in addition to full servicing and set up off course

you seem to already know not to overdo things so as not to spoil the feel and balance of the car

[v8250]

thanks nigel, you must be reading my mind as 123dizzie, mintex 1144, pb rolling road set-up etc is already on shopping list. however, you mention prefered purchase route for frontline hardware should be from mgoc or moss. my question is why not direct? i'm based in oxfordshire, frontline's not too far from home and thought i'd order, then nip-over to collect...once the cb front cross member's arrived from moss

[alfa pint]

Got a funny feeling the steering columns are different for the cross members.

You don't actually need the lower crossmember, just modern shorter springs from the B Hive.

[na]

v8250 you have mail

[Mactheknife]

v8250 said:

To All, I'm looking for advice from your experiences here:

Earlier this year I bought a 1977 MGB Roadster with the intention of converting into mild/fast road spec'. Engine/Ignition/Gearbox/Diff/Exhaust options are straight forward; will be using Peter Burgess engine with Ford 5-speed Gearbox.

But, I am a little confused with the extensive updgrades and mods' for front and rear suspension; simply there are too many available from MGOC, MOSS, Brown & Gammons, Hoyle, Frontline et al.

My thoughts at the moment are as follows:

1. Lower RB to CB ride height
2. Frontline Telescopic Front Conversion with 480lb springs and Castor Correction Wedges
3. Keep Live Back-End adding Panhard Rod as want original rear-end 'feel' but with better axle location.
4. Install Superflex bushes throughout
5. ??Pls advise on which type of rear leaf springs [uprated, parabolic, RV8??]
6. No need for anti-tramp bars as power only 130/135bhp

Any/all help advice would be greatly appreciated; thank you.

I'm on a CB car which has been lowered further, but my experiences are as follows for what its worth:

1. Lowering to CB height, yes its a good idea. Lowered CB cars can be to low for speed bumps etc, but CB height is optimal unless its a track day car.
2. Telescopic dampers are an option, but the lever arm dampers with uprated valves are also a good, and a far cheaper option, you can change the damper fluid to suit too. Moss have details. My local MG garage persuaded me not to change to telescopics and I agree with them now its done, I'm pleased I didn't go down that route.
3. Panhard Rod, yes do it, makes a noticable difference. Had one on my last MG, going to put one on this one too.
4. Superflex, yes, good idea on the front, works well. Keep rubber bushes on the rear springs, Moss recommend the nylatron bushes for the rear, but they are too hard (road noise is horrendous) and the bush sockets in the chassis need reeming out to fit them. The back end should be softer than the front. Just a point on the superflex inner bushes (metal sleeve part), they can be a tad to long and might need trimming to get a good fit or they can develop a 'clunk' under acceleration or braking even though the bolts are fully tight.
5. I have uprated rear springs fitted (lowered CB), its a good match for the front and still keeps the back end loose enough. Very pleased with them, but can still be skittish cornering hard on rough surfaces at high speed. Maybe parabolics are a better option if its it budget?
6. Might want to think about anti tramp bars even with that amount of power if its going to be driven hard. Takes some of the twist out of the drive train. My next mod after sorting the body work out.

If you want some interesting suspension mods have a look here BritishV8

ETA: I didn't have Alfa Pints problem with negative camber wishbones and heavy steering, probably a combination of factors there, but I also didn't get all the benefits of the mods until I got decent tyres fitted. If I did it all again I would stiffen a CB but not lower it.

Edited by Mactheknife on Monday 26th September 23:43

[V8_chitty]

For what its worth I've got a NGTCV8 (Based on an old BGT) and put the Hoyle double wishbone setup on the front and is still got the live axle with Panhard rod on the rear (with spax shocks, std springs).

The front allows adjustment so you can set your own amount of negative camber, ride height etc - mine weights up nicely and I can chuck the thing round any corner without fear of losing grip. No problems with tyre wear either but then I only do around 3K PA.

The rear end is still a little bit too jiggly but the Hoyle rear is a pricey option whereas the front is a no brainer imo.

Good luck!

[v8250]

To All, thanks for all good input so far. After some interesting phonecalls today the spec' has changed to the following:

1. SuperFlex all round
2. Front keep L/Arms with 25/30% upgrade
3. Front Lowered Springs @ 480lb rating
4. Castor Wedges + 3/4" ARB
5. Rear Lowered to CB height
6. Rear Springs Std
7. Panhard Rod + existing std ARB
8. Keep with what appears to be v-good UniRoyals

Invest telescopic damper conversion budget into engine/'box. What do you think??

[Mactheknife]

v8250 said:

To All, thanks for all good input so far. After some interesting phonecalls today the spec' has changed to the following:

1. SuperFlex all round
2. Front keep L/Arms with 25/30% upgrade
3. Front Lowered Springs @ 480lb rating
4. Castor Wedges + 3/4" ARB
5. Rear Lowered to CB height
6. Rear Springs Std
7. Panhard Rod + existing std ARB
8. Keep with what appears to be v-good UniRoyals

Invest telescopic damper conversion budget into engine/'box. What do you think??

Sounds good! What about the anti roll bar on the front? 7/8ths or 3/4 inch?

[alfa pint]

Having tried both, 3/4" is more than good enough for road use.

Sounds like a really good package there OP! Let us know how you get on -I'm really keen to hear about the castor wedges on particular.

[v8250]

Mactheknife said:

Sounds good! What about the anti roll bar on the front? 7/8ths or 3/4 inch?

3/4" but not sure whether to go for 137lb or 170lb? I want the front to be 'planted' but not 'heavy' or 'dull/flat'.

I could go for 7/8" @ 228lb but would this be too harsh??

+++Anyone know the 'real' difference between SuperFlex and SuperPro bushes??

[Mactheknife]

I went for the 137lb 3/4 inch anti roll bar, the front is certainly planted, but not too harsh either. The 170lb one is supposed to be for competition use, 137lb for fast road. I'm happy with it and wouldn't want a harsher one now. I also fitted the blue superpro bushes. Roads are far worse than race tracks so you need something a bit forgiving.

[alfa pint]

^^^^ This. My old B was almost painful when you went over a catseye, let alone something from today's mineshaft depth potholes.

[na]

I've got Super-Flex front and rear on my Midget and they were 'softer' feeling than the the 2 year old yellow (fast road) urethane bushes they replaced

be carefull with what 'weight' of damper fluid you use in the uprated LA dampers see MG BBS Archive for discussions on this and valve rates

personallly I prefer near standard size steering wheel, road wheel and tyre sizes for for better steering feel (tyre pressure may need to increase from '70s manual for modern tyres)

many B's appear to overdo the "upgrades", balance front to rear less at front less required for rear IMO

[v8250]

thanks again to you all for good feedback.

nigel, it's interesting what you say ref' superflex being softer. i have read that the shore-rating is only 10% gretaer than standard rubber. also, i agree ref' with damper fluid spec' and that many B's appear to overdo the upgrades. i'm guessing that people forget that a vehicles 'movement' has to come from somewhere :. too rigid a system on public roads will the body will take a hammering.

have seen this happen to some cars ran in historic rallies...cars rebuilt solid as as rock...half-way through the event everything's being shaken apart; which is not so good if you're up a mountain at three in the morning with fuel lines, fuse box, and exhaust dropping-off!

Edited by v8250 on Wednesday 28th September 09:40

[oily mist]

Thanks for interesting posts. I'm just turning to lowering my dear old 'B' as it seems to be standing on tip-toes (possibly looks worse because the RB's are off as it's just had a respray so it's temporarily lost some weight).

I changed to parabolics a couple of years ago and what a difference! Probably didn't help that the old cart springs were pretty grotty so the friction between leaves was huge. The car's habit of jumping off bumps mid-bend was slightly amusing on familiar roads but downright dangerous otherwise. Parabolic ride is so much nicer.

So now I'm looking for front springs about 1 1/2 inches lower and similar drop at the rear. I've had a good look at the spring hanger and am tempted to redrill them rather than fit blocks. Hoping this preserves the firm front/soft rear feel and also looks right height-wise. I haven't seen much about modifying the hangers - is this because it's just a PITA compared with fitting blocks?

There are all manner of other jobs to do while I'm putting it back together - roll-on July and the run down to Le Mans.

[terenceb]

Dont think you'll get much joy with the rear hangers,not enough room to modify them really. Leave them as they are. Front springs need to be 660lb,sounds a lot but is just about ideal for road/track use.Use the longer bottom w/bone arms fro B Hive,fit standard V8 inner bushes,this will just about wipe out all understeer.