MG-Cars.info

Welcome to our Site for MG, Triumph and Austin-Healey Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Lowered front springs

I need to replace the front springs on my 1971 Roadster. Currently the ride height is 32cm (12 1/2 inches). This is measured from the centre of the wheel to the chrome strip.

The car also sags to the drivers side - this can be observed in the rear springs having an 1 inch difference. When the car is on low axel stands, the rear ride heights are identical.

I've been looking at the Moss catalogue and the options are as follows:

Standard 480lbs - 36.5cm
Road/Uprated 480lbs - 36cm
Road/lowered 550lbs - 35cm
Road/sprint 550lbs - 34cm
Race 660lbs - 33.5cm

Reverting to standard springs would make the ride height increase by too much. Does anybody have any experience of using the Road/lowered springs or any advice on spring choice?

Many thanks,

James.
James Stewart

Personally, unless you are a 10/10ths driver, or use it on the track, I wouldn't go for race springs. Also uneven fronts will affect the rear end. But B's always sag on the drivers side, that's where the added weight (You!) and the fuel tank are. Assuming you haven't got major rot to the spring hangers, broken springs or worn shackles, swap the springs over and replace the bushes with urethane. With any luck, then it will sit level with you in it and a full tank!! Also bear in mind rubber and chrome and Gt's used different springs.
Allan Reeling

I've got 600lb, 8in springs on my GT. The distance between the wheel centre to the chrome strip is 13.5in but the ground clearance (to the sump) is about 4in - certainly too low to get over the majority of speed bups without scraping the exhaust. It is rock hard; too hard for the road but the cornering is exellent.

I'm running 185/60 tyres which would be about 3/4" lower than 165 standard section tyres. So if you are running standard tyre size you have got some seriously low springs or there must be differences from wing to wing.

HTH,

Neil
Neil22

The Moss springs are made (understandably) in the easiest and cheapest way.

They simply use the same gauge wire for all of them and get the higher rates by removing varying numbers of coils. A shorter spring with fewer coils will be stiffer than a longer one with the same wire gauge.

Problem is that if you want a stiffer spring - a good idea on an MG, within reason - but don't want to lower the car and put up with the reduced ground clearance (if you aren't racing, who needs that aggravation?), you need to make up some spacers

These can be made to fit on the top of the spring and space it down, raising the car back up to stock (or whatever you like) ride height.

IMHO, these should be offered by Moss and the other vendors - they are cheap and easy to make and might enhance sales of their springs to people that would otherwise not buy because they didn't want to drop the car.

Kelvin, are you out there....

They could also sell springs with the same wire diameter but wider coil spacing, but I think that the spacers would be easier and cheaper. I see that they already offer two lengths for the 550 lb. springs, which by the way are a good choice for the street.
Bill Spohn

You can buy the spacers - I got mine from MG Motorsport I think. They also faxed me a drawing, suggesting that I made my own from plywood. But there is a limit to how many you can use because they reduce the engagement between the spring and the spring pan.

The spring rate is dependent on the material, wire diameter and coil diameter and number of coils. So to produce springs with the same rate but different ride heights then Moss must be setting them differenly. And if they're doing that, they can make them any height you want within reason. But they are not going to offer an infinite range - I suppose they are assuming that stiffer springs are part of a logical suspension upgrade which would logically include a lowering of the ride height.

Neil
Neil22

Thanks for all the info.

I opted for the Road/lowered 550lbs (35cm) front spring in the end. Fitting them was easy, just removing the lower fulcrum bolt and the anti-roll bar.

The old springs were about 1 1/2 inches higher than the new ones, however, the car now sits 1 1/2 inches higher than it used to.

The difference in the handling is quite amazing. This is one of the easiest and most worthwhile improvements yet.
James Stewart

I fitted the AHT 21/480 lbs uprated springs when I rebuilt my 1980 LE roadster.I was delighted with the result.
I recall at the time I used the recommendations from the separate Moss tuning catalogue. This listed their ideal front and rear spring combinations. I would give them a call to make sure you have got a good front/rear set up as I'm not sure if they still produce the tuning catalogue.
Moss have got a VAT free sale on this weekend for most orders(Nov 9/10/11)
ph barton

Neil, using plywood spacers for this purpose is just wrong and that business should know that and shouldn't recommend it.

The plywood will eventually degrade and in any case you don't want to put the spacers on the bottom but rather the top, and they must be machined to preserve socketing of the guide tube into the spring.

I am surprised that any business would tell anyone to do it the cheap and shoddy way.
Bill Spohn

Here is a proper spacer, that works in combination with a deeper locater spigot. The springs are 550 lb. beside stock springs.

Bill Spohn

This thread was discussed between 30/10/2007 and 11/11/2007

MG MGB Technical index

This thread is from the archives. Join the live MG MGB Technical BBS now