Maestro Spring Rates

[Philip Young]

An unusal enquiry:

Looking to uprate the suspension of a Maestro. It might be that something "off the shelf" and o.e. for another model might do the trick - the car is a 1.6, the Bulgaria models used diesel spec springs. How much stronger are they - does anyone know the poundage of my springs as a starting point? Are MG the same length of travel, perhaps a two litre MG spring might be stronger than the diesel ones? Are the two van options, five hundredweight and seven hundredweight, stronger again on top?

Some brand new springs are available on ebay. If they are all interchangeable, are the springs all the same length?

[tezza SG1]

I have been told that the ledbury springs are much thicker and sronger than normal disel ones..i think it was when i was at a car show with my old ledbury maestro. (or they were talking complete and utter rubbish)

[Philip Young]

Just about all springs are out there brand-new (except that is the Bulgaria spec). So, what are the differences?

....thanks.

[E_T_V]

The spring rates are different on a lot of models. Hardest ones I've seen are ledbury van fronts which are thicker than even the TD van springs.

The poundage info isn't out there easily, although if you speak to a spring manufacturer they'll have a book with all the listings in most likely.

Remember harder isn't necessarily better. The terrain that the ledbury cars were destined for meant that they had hard springs and soft dampers making the ride in the UK pretty horrid in my opinion. Good for rough roads and tracks but too figgety on reasonable roads in my opinion.

Austin/Rover colour coded the springs to differentiate their rates. All springs were black but for example a white stripe denoted they were for a 1.3 maestro. A yellow stripe for an mg1600, or two stripes in some cases. NB those were random examples the parts software will give proper examples.

[mgdavid]

Philip,
be aware there are two platform heights for the struts, and many different length and poundage of springs. When new, the springs were marked with a colour paint splash on each coil. Somewhere I'm sure I have a file giving the poundage against colour and model but I've searched high and low this evening and cannot find it. John Dalton has the original file - he used to work for Rover and also has rallied a Maestro at International level - the Himalayan ISTR. If you PM me I may be able to help further....

[countrydude]

If you find that file I would be really interested in that info too. I would suggest making it a sticky somewhere on the forum.

Somewhere I'm sure I have a file giving the poundage against colour and model but I've searched high and low this evening and cannot find it. John Dalton has the original file - he used to work for Rover and also has rallied a Maestro at International level - the Himalayan ISTR. If you PM me I may be able to help further....

[EVO AL]

Some useful info in this.....

Right click and open the photos in a new window/tab to see them Big so you can read the small print!

http://i92.photobucket.com/albums/l29/EVOAL/MG%20Maestros/Suspension03.jpg
http://i92.photobucket.com/albums/l29/EVOAL/MG%20Maestros/Suspension01.jpg
http://i92.photobucket.com/albums/l29/EVOAL/MG%20Maestros/Suspension02.jpg

[Lankytim]

I have 2.0 auto front springs and struts on my diesel Maestro and the ride height is now slightly higher than standard, I think the springs are a bit stiffer, too.

[Philip Young]

Have you put diesel springs onto a diesel car? If so the improvement is just because they are brand-new?

The charts are fascinating but what we need to know is the poundage (old money) of where we are starting off fromt before we consider improvements (also in poundage), so if the 1.6L is say 90lbs, and the diesel 130 lbs, we know what we are going up to...are there any chassis engineers out there who can do an explanation for simpletons?

[E_T_V]

It has the spring rate on there in N/mm its fairly trivial to convert that into lb/inch which is what "poundage" is I believe.

[E_T_V]

1 N/mm = 5.724 lb/in

Lowest spec is 97.3

Highest common ones are 152.8

Highest possible spec ones are 240.4

[Lankytim]

Have you put diesel springs onto a diesel car? If so the improvement is just because they are brand-new?


No, they are petrol springs from a 2 litre auto Montego estate, both the struts and springs were used scrapyard items.

[countrydude]

there is something very up with the table of figures above. the spring rates are given in newton mm rather than newton m

So 20 is a common value for rear springs. That gives a nm value of .02nm

into ftlbs that is 0.014751242

WTF?

It seems to be clear in Dan's head but i don't see how?

i just want an idea of what rates were used as standard on the rear of cars. I have gone too hard on my coilovers so I need to find a compromise, best way is to know what standard is.

[digital efi]

there is something very up with the table of figures above. the spring rates are given in newton mm rather than newton m



The devil is in the detail. :idea:

The quoted rates are in Newtons PER mm (ie the force needed to compress the spring by 1mm)

HTH

[E_T_V]

Standard is 114.5lb/in

[countrydude]

Standard is 114.5lb/in

:o I've currently fitted more than triple that! Thanks dan, i'll order some better rates soon.

[E_T_V]

Id start at something like 200 for the road, or better still if you know what is on the front is XX% stronger then go for something similar % increase on the back to match (assuming the front is ok).

[countrydude]

bizarely I just came back on as i had the same thought, problem is though according to the tables they had 20 nmm on the rear and 19nmm on the front? I have 350 on the front and it feels great. Problem is with no weight on the back it feels way too solid. (The springs we decided on for the back were 300's but 350's turned up) So I have close to what you suggest. I'll have a quick go on the damping adjustments tomorrow before i condem it.

That seems odd to me, I'm familiar with the diesel springs not so familiar with any petrol springs. the diesel springs are definatley harder at the front than the back. I'd be amazed if this wern't true through the range as the O series isn't a lightweight!

i'll ring them tomorrow and see about this, i think maybe a middle ground of around 240lbs? Id start at something like 200 for the road, or better still if you know what is on the front is XX% stronger then go for something similar % increase on the back to match (assuming the front is ok).

[E_T_V]

Damping will have a big effect. You want them a lot softer on teh back than the front typically to stop the rear end skipping, but only time and playing will tell!

[countrydude]

It is amazing though. I have just fitted the clutch so I'm just low rev, high gearchange driving. Even with this handicap the car was so stable in twisty b roads i was leaving everyone else far behind! I have the damping dials in the middle atm so there is a lot of adjustment there. If I can stop it being so crashy I'll happily keep them as the cornering is a blast! i don't have a rear arb so it isn't going to be too skittish at the back, but yes you have a point!

Progress report tomorrow!

[countrydude]

quick fiddle today has come up good, the car now corners like nothing else and doesn't loosen teeth while you are doing it! Once this clutch grips...;)