Busy weekend

Author
Discussion

chris71

Original Poster:

21,536 posts

244 months

Tuesday 10th April 2007
quotequote all
locking wheel nut (made of a substance with all the physical properties of case-hardened chocolate) which someone had overtightening to the point it just disintergrated when we tried to take it off. Four hours of heavy engineering with a chisel and a cutting disc later it came off in two pieces with the alloy more or less unscathed

Anyway, replacing the front springs and dampers has helped greatly with the handling, not surprisingly as the top coil had sheared on one side, leaving a substantial difference in spring length and there was also a big difference in damping rate between the two units. On the back the springs looked more or less ok, but the dampers were practically seized. All four have been replaced by KYB AGX dampers and FM springs.

The first thing I noticed is that the ride heights are still unequal. This seemed to be more pronounced at first - I don't know if that's due to an uneven yard or the springs/dampers settling, but currently one side is riding about a centimetre higher than the other. I'm wondering iof the springs are still taking a while to settle? Overall it is quite a bit lower than I expected from the FM springs (which I thought were close to standard S/RS-Ltd ride height)

Secondly, even though it does now feel much more secure on the road, the initial turn-in still feels a little under damped. It's fine once you've loaded up the suspension a little, but it rolls more than I'd expect to start with. This is with all dampers set to 5, which I gather is already firmer than most people have for road use?

The knackered front spring must have lowered that corner by over an inch - is it possible this bent the anti roll bar over time? I know that sounds like a contradiction in terms If so, could this explain the rather wayward turn-in and possibly also the ride height difference?

Finally, there's still a tugging feeling through the steering on long right hand bends, but the steering arms/balljoints/rack etc look ok. Any suggestions? ......haven't noticed it going left.

The car is handling much better now and is a real hoot to drive, but I think theres still quite a lot of room for improvment. The alignment has yet to be done and it's running a mixed bag of tyres. So I think the plan is to take the car down to Tony at WIM along with a new set of tyres and possibly two new (flying miata?) anti-roll bars.

speedychrissie

2,994 posts

241 months

Tuesday 10th April 2007
quotequote all
chris71 said:
All four have been replaced by KYB AGX dampers and FM springs.


excuse my lack of knowledge but could you possibly provide a link to where these can be purchased? would they be the mx5parts sports handling kit here:

www.mx5parts.co.uk/product_info.php/products_id/352

or are they different?

its just cos i know now that i need to replace my shocks and trying to work out which sets are good is turning out to be a very tricky task indeed!

you said that the ride heights arent exactly what you were expecting, but roughly what are they? i think my car is about 3-4cm lower than i would like it to be and im trying to find out roughly which setups will correct this? (the distance from the centre of each wheel to the highest point on the outside of the wheelarch is almost exactly 12inches front and back on my car)

sorry for all the questions.

chris71

Original Poster:

21,536 posts

244 months

Wednesday 11th April 2007
quotequote all
speedychrissie said:
chris71 said:
All four have been replaced by KYB AGX dampers and FM springs.


excuse my lack of knowledge but could you possibly provide a link to where these can be purchased? would they be the mx5parts sports handling kit here:

www.mx5parts.co.uk/product_info.php/products_id/352

or are they different?

its just cos i know now that i need to replace my shocks and trying to work out which sets are good is turning out to be a very tricky task indeed!

you said that the ride heights arent exactly what you were expecting, but roughly what are they? i think my car is about 3-4cm lower than i would like it to be and im trying to find out roughly which setups will correct this? (the distance from the centre of each wheel to the highest point on the outside of the wheelarch is almost exactly 12inches front and back on my car)

sorry for all the questions.


Can't remember what we measured the heights to on my car - this morning I checked it by the highly scientific method (ahem) of how many fingers would fit betweent the top of the tyre and the wheel arch!

Apparently the mazda specs for a mk1 are
Rear 346mm - 395mm. (13.6 and 15.4" )
Front 328mm - 377mm (12.9 to 14.8" )

This doesn't sound right to me - from memory mine are more in the region of 330mm with the KYB AGXs and most people with aftermarket suspension seem to run the front at 12 to 12.5" with the rear about 1/2" higher (from the wheel center to the arch)

I had a look through mx5ocforum.co.uk for that info and I think I saw your car (a light blue mk1?) in the process and that definitely looks low.

If it's any help the KYB AGX and FM spring combintation seems to be very popular for 'real world' driving and I've spent the weekend down in Devon taking mine out over extremely bumpy, pot holed country roads and I never managed to ground it. Not tried suburban speed bumps yet though!!

The kit you gave the link to is not the KYB AGX adjustable damper it's an older fixed damper and the springs are mx5parts own units, said to lower the car by 13mm - compared to standard, so I'd say that would still be significantly higher than the car I saw in the pictures.

Mx5parts do stock the AGXs too, but I got them from performance 5, here www.performance5.com/handling_suspension.asp as I've heard a few people say the Flying Miata (FM) springs that P5 supply suit them better.

The other common kits seemed to be Tein Super Street and Gaz. These are rather more expensive and not quite so robust according to some, but they do have the key advantage of having height as well as two-way (bump and rebound) damping adjustment, if you're really particular about how the car is set up. I went for the AGXs instead because although most suppliers had a recommended shocks that was said to be marginally better (for a price increase) nobody could agree on what that was, yet they all said the AGXs were atleast 'good' and well proven.






Edited by chris71 on Wednesday 11th April 10:57

speedychrissie

2,994 posts

241 months

Wednesday 11th April 2007
quotequote all
cheers for all that info. very useful.

the pictures of the light blue 5 are mine, and since that thread i have been even further convinced that my car could do with being higher.

the shocks and springs you got do seem to be very popular as lots of people on the mx5ocforum talk about them. i will have to look into them more. cheers.

out of interest, how long did it take you to fit the new set? how many people? and what problems did you encounter?
i am trying to work out whether it might be possible for me to fit them myself instead of spending about £200 to let someone else do it. but if i encounter a major problem i dont know if i would be able to sort it and then i would be majorly stuck.

chris71

Original Poster:

21,536 posts

244 months

Wednesday 11th April 2007
quotequote all
speedychrissie said:
cheers for all that info. very useful.

the pictures of the light blue 5 are mine, and since that thread i have been even further convinced that my car could do with being higher.

the shocks and springs you got do seem to be very popular as lots of people on the mx5ocforum talk about them. i will have to look into them more. cheers.

out of interest, how long did it take you to fit the new set? how many people? and what problems did you encounter?
i am trying to work out whether it might be possible for me to fit them myself instead of spending about £200 to let someone else do it. but if i encounter a major problem i dont know if i would be able to sort it and then i would be majorly stuck.


Changing the springs wasn't too bad. It took two days in total, but that's first time round - getting up at 10am, regular coffee breaks, stopping early, ooh and grinding the locking wheel nut off and rebuilding the top mounts after a misprint in the Rod Grainger manual caused us to overtighten and shear a bolt, etc tec rolleyes

We basically used the Miata.net method www.miata.net/garage/miatafrontsuspension.html

Removed the anti roll bar drop link bolts, shock bottom mounting bolt, anti roll bar mounting bolts (to get the top wishbone out), top wishbone bolt, top mounts. Then attached the new shock to the wishbone, jacked it up to compress the spring and repeated the whole procedure. On the back we did a similar thing, except we used a spring compressor to pre-assemble the 'coilover' units.

It's fairly straight forward, but the main problem is finding bits which are coroded up and simply getting to a few of the bolts. I'd say one person with a clean car full of nicely greased bolts tightened to the correct torque could change each corner in under 2 hours, but as soon as you shear a bolt or have to drill one out things get a little more complicated.

Tools were just a standard socket set (two sets plus a few ring spanners would be useful for getting both ends of a few bolts or whatever) some mole-grips, spring compressors, hammer for 'peruasion' and atleast one jack.

Only real problem specific to the suspension was a few corroded and/or over tightened bolts which we had trouble getting off. These can be a pain though apparently.