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MG MGB Technical - Suspension lowering on R/b models

Hello, I have read some other threads about suspension on a b.
Now i will be lowering my MGB 1978 by as much as i possibly can within reason, as i have a sebring that has been practically converted to track use. My issue is in all reality i want to lower the car by at least 2 1/2 inchs more if possible. inevitably stiffening everything up in the process.

What are the options? I recognize that using lower springs will cause negative camber on my front wheels is this a real issue?

Also lots of people suggest cutting apart the leaf springs and taking some of them out. I want the car to have the same ride height but is seems you can slam the front and only lower the back by an inch. What is the most effective way to sort the ride height.

Any ideas would make my day!

Seb
SGE Granville

Ride height is measured separately at each corner, or at the very least front and rear. You can't have the same ride height if you lower the suspension. You can get shorter, stiffer front springs to lower the front, which does alter the steering and suspension geometry, but then alter the steering rack and column to correct one, and fit different A-arms to change the other. But surely negative camber (where the tops of the tyres are closer together than the bottoms) is a good thing, giving you a wider track for free and a more even tread to road contact pressure for better grip on the outside wheel (which has the greater load) when cornering. With the rears you can buy flattened conventional springs, turn one of the leaves over of your existing springs, fit lowering blocks (which puts more stress on the U-bolts), or fit 2-leaf parabolic or 1-leaf fibreglass springs. Some of these require telescopic dampers. But unless you install better axle location as well the more the compliant the spring is in the up and down direction the more it is likely to move from side to side, and twist putting more angle on the rear UJ.
Paul Hunt 2

sorry i meant i want the same ride height all around the car..interesting tho
SGE Granville

Seb,

I would recommend getting lower springs at say 600lbs, these can be baught from a company called faulkners at around £40 per spring. if the car is to be used for track days you want some negative camber. I would recomend the same setup i have on my race car:

Negative Camber Wishbones
Offset Negative camber top trunion bushes
nylatron bushes everywhere
alloy subframe locating kit (can be purchased from me, let me know if you want some)
Stiffer shock valves (dont by pre uprated off the shelf shocks)

All of the above can be purchased from mgmotorsport.

However this may not be ideal if you are using the car on the road as an everyday car, due to the stiffness.

Hope this helps

Ollie
Ollie

Seb, for the front, in addition to shorter higher rate springs you probably should look into some lowered spindles which will keep your camber in a reasonable range while getting the car low enough. I don't know of a source in GB, but here in the US these are available from MG Limited / Killer Beez Racing http://www.mgbracing.com/. Photo of the spindle compared with a stock item attached.

Bill Young

I've heard these are not that great, and didn't want to try them at the silly price, i believe i was quoted about £245 delivered. as for the rear, i woulde suggest solid front and rear shackle bushes with parabolic springs MG motorsport can lower the springs for you also, then an inch alloy lowering block with some decent shocks, if you have not got much to spend, GAZ seem to be the best out of the cheap kits.

Best regards

Ollie
Ollie

Yeah thats great! im looking into loads of things and have come across mgmotorsport. before. The lowered spindles do literally look as if the lower inch has been cut then MIG'ed on the top half.
I did not realise they were an option.

Are there any kits that complete that lower the car as much as i need in one shot?
SGE Granville

Seb, you can also redrill the spring hanger holes at the rear. You can move the hole up by up to 45mm.
I have done this, plus fitted one inch blocks to get the ride height I want. Which was standard chrome bumper height. I did not want to go any lower as I am using a large bore exhaust. I just clear (most) speed humps, gutters etc. and thats with the exhaust adjusted to within 2mm from the underside of the middle cross member.
Redrilling the spring hanger hole is particularly good for "fine tuning" and getting the rear to sit exactly he same as the front.
Not hard to do but you do need to use a centre punch and drill small pilot holes first.

A pan hard rod is a real plus. Thats next on my list to things to do. Judging by the slight rub marks on inside of my rear wheel arches that axle is moving from side to side about an inch in corners, which can't be good at all. I have 195 by 60 tyres.
Peter Sherman

Seb: No one makes a kit to lower the car that much because the lack of suspension travel would make the handling dangerous on the street or even rough tracks.

To get that low with a RB crossmember you will have to go with lowered spindles. You can't do it just with springs and keep the car drivable. On the back, go with reverse eye springs, or redrill the mountings and then spacers to get level. The limitation on the rear are the bump stops, which I'd suggest relocating. The RB bump stops mounts are different than the CB ones.

Kelvin
KJ Dodd

I will certainly look into drilling the leaf spring mounts. Gaining a hefty 45mm is a good start. Then blocks thats over 70mm straight away.

For the front i will look into getting harder shorter springs then think about chopping and welding the king pin brackets. that will gain an inch or so then with shorter spring you are gaining at least 80ish mm.

I will have to experiment really.

Nice ideas People!!!

SGE Granville

It's a little more difficult than just loping off a bit of one side and welding to the other. There are new longer bushings to source and then hone. The cut end needs to be finish ground so that it will be a good bearing surface against the upper trunion as well. Considering this is a suspension piece I think I'd leave it to the pros who have done it before.
Bill Young

There is that but im very hands on and have built the car from scratch.

I run a machine shop and thus would prefer to take it on myself. I would obviously source an extra set, butcher them and fabricate them so that they are perfectly square. Honing out the center to run concentric is relatively straight forward.

Although a drop of 70mm can be achieved by moss springs and to be honest i think that would be more than enough although The option is there to go further should i need to...

SGE Granville

The reverse spring eye 110lb rear springs are fantastic.

I've recently fitted a pair to my ex-rubber car using the original spring mountings and shackles and this has lowered the rear of the car approx 2".

The suspension is now compliant, and under power through a corner just sits down and grips, I took it for a drive last weekend through some twisty and empty country roads and was amazed at the difference.

I also removed the rear anti roll bar as this provoked oversteer specially in the wet, I was also advised by MG Motorsport to use the standard bushings at the rear.

At the front I have the Moss coil over suspension system which is adjustable for ride height and damping with a 7/8" anti roll bar. I also fitted the Brown & Gammons de-castor kit which reduces the castor to modern standards of 3 1/2 degrees which works better with modern tyres and lightens the steering to acceptable levels and stops it loading up too much in a corner.

The rear telescopic conversion was already on the car and uses Gabriel shock absorbers which are just about perfect, they were part of the original Moss/Hopkinson handling kit.

Kevin

If you intend to drive your car on the road then personally I would not go muck lower than I have and definitely do not use lowering blocks they are a very crude method of lowering a car and wil promote axle tramp and additional stresse on the leaf springs.

Kevin Jackson

Kelvins point about the bump stops is very important.
Initially I did no alter them and I found that about half way through a corner I would get massive surges of oversteer. Frequent fish tails and on one occasion a seven end for end up in the air, spin out. It took a while to work out but it transpires that the outside bumpstop would contact and via wheel and axle, would lever weight off the inside wheel. I cut about 20mm off the rubber bump stop and the problem instantly went away. A quick fix . On the rubber bumper cars they added in a spot welded cresent of metal that moves the bump stop base 38mm closer to the axle. This fills in the recessed chrome bumper bump stop base. It is very obvious when you look at that area with this in mind. The good news is that the original chromebumper bump stop base is still there under the add on. So you can cut it out pretty easily. You will need to save the 'mushroom" that the rubber bump stop attaches to and reattach this to the exposed surface. Rivets, spot weld, whatever. That plus cutting 20mm off the rubber should do the trick. If you are using telescopic s you can ditch the rubber bumps stops altogether.
Just make sure you have at least two and a quarter inches of suspension travel, or you will get snap over steer.
I suspect that lack of suspension travel was the reason they abandoned the original coils and trailing arms on the first prototype MGB's. Those huge bump stop bases were meant to be spring seats, as the bits on the axle. Once again, obvious in retrospect. Looking at the axle bump plates I would imagine that the springs would have had a pigtail at that end, much like the volvo 240's. There is even a bolt hole in the middle and room for a bolt.
Peter

This thread was discussed between 05/11/2007 and 08/11/2007

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