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Hi Guys. I have been contemplating suspension mods lately and would like a bit of assistance. Pashn8 took me for a very short spin in his SE last night and I am in awe of his ride. He obviously has the 17\" stock wheels and his car is much lower than mine but the control over bumps and the compliancy is incredible. Obviously his car is much newer than mine but I would like mine to approach this sort compliance while being as low as his. Also it has to be done reasonably cheap.

This is the idea so far. KYB AGX shocks, FCM bumpstops, bush replacement, and I was thinking of some sort of adjustable spring platform utilising the King springs I have at the moment. I know Uncle Arther got some adjustable spring platforms for his Koni's made up and wondering if I can do similar with the AGX shockies. Or maybe use the spring platforms from this kit http://cgi.ebay.com.au/90-91-92-98-MAZDA-MX5-MIATA-SUSPENSION-COILOVER-SPRING_W0QQitemZ110265444835QQihZ001QQcategoryZ33582QQssPageNameZWDVWQQrdZ1QQcmdZViewItem. Anyone have any idea if this would work. The main aim is to take 1 more inch out of my suspension and give it compliancy over bumps while keeping control. Some of the roads around where I live are shockingly bad and it feels like the suspension is having trouble dealing with it as well as just crashing over bumps.

Anyones suggestions are most welcome

Ben

Don't forget that the SE also has alot more undercarridge bracing

SM wrote:Don't forget that the SE also has alot more undercarridge bracing

And the chassis is at least 30% stiffer.

If you want a truly compliant ride in all conditions you need progressive rate springs.
Getting a good spring rate is the hardest part, and everyone has different opinions.
Dampers are no biggie and KYB AGX have a good reputation.

This is obvious, but just in case, get the AGX for NA's cause it has 8 settings wherease NB's only have 4.

Bushes make a HUGE difference. IMHO, installing polyurethane bushes all round makes the same, if not bigger/better, handling improvement than anti-sway bars.

....buy an SE....

Ben, you are welcome to take Tweety for a drive and see what you think.

Tein Flex, super pro bushes and whiteline adjustable sway bar at front (none at rear).

J

bruce wrote:....buy an SE....

That is probably the most unhelpful advise I have ever received. I am quite happy with my car thanks. As for everyone else, I appreciate the advise so far. Would underbody bracing contribute that much towards it? I was planning to do that soon but maybe not quite yet. Pashn8's car is also using King springs which I'm assuming will be the same rates as mine although he got them 10mm lower. Juffa I would love to go for a spin in your car but that would just make me envious of your Flex's which I can't afford. Do you find your ride nice and compliant but controlled? Keep the advise still coming, I do appreciate it.

Ben

bruce wrote:....buy an SE....

what bruce said

apart from that.

tread very careful with rushing into doing the lot.

Konis & Kings are very mediocre in my opinion. However, they do the trick. But it sounds like you are looking for something more compliant that the Koni king set up
If I was to do it again I' d be doing the following

OEM bushes all round
Tein SS coil overs
front & rear lower bracing as well as maybe the top tower brace as well.
BD or MX5 plus roll bar
NB8b OEM RIMMS WITH THE Federal RS596 R tyres
Power steering
sways...I'd start with the stock SE ones or equverlent
Torsen LSD


if you haven't read the thread with different type set ups & feed back.
I would suggest you do.

everyones opinion is very subjective including mine.

try to test drive your planned setup in someone elses car first.

Having attended the Heasmans Tech night I had some very decisive questions answered.

One thing the KYB (and Koni) have that is lacking (in a big way) is bump adjustment, which IMO is as (if not more) important that rebound adjustment.

Bump is the compression (downward travel) of the shock and accounts for a lot of the \"crashing\" i experience over bumps.

I have Eibach lowered springs on mine which i feel are a little more giving than kings. The car does crash over bigger bumps (especially around corners) but handles quite flat. I should note that it has polyurethane bushes, front and rear brace, stock waybar on the front (no rear).

The KYB has the perches spot welded on and would take some mods to make fit the coilover sleeves. I would look at a better shock setup, the konis do have 3 perch heights which will allow for lowering, but you are in effect making the spring behave differently as you've lengthened the amount of available travel for the spring. Let me explain...

Say your static weight on the spring compresses it to 300mm (stationary), by lowering the perch height 25mm your car lowers by 25mm. This however has a negative effect on the spring in its opposite direction of travel, it extends past its elastic flex point (beyond 325mm) therefore for it's first moment of compression it will accelerate to return to its normal point, the above 2 brands of shock will slow the rate of return on the compressed shock but not the extended one, so the suspension 'squats', reducing the travel for the next bump (especially on rough roads) making your car crash over the next bump by hitting its bump stops.

On a budget, i would look at a used bilstein setup and valve it accordignly (by a specialist) so the shock has a very defined bump/rebound setting. Match the shock to a lowered set up progressive springs, then get the perches set to your desired height for the car and spring.

I have one adjustment setting for road use and one for the track (obviously firmer), but i could happilly live with a fixed setup if it meant my daily drives are more compliant.

ok end story

ampz wrote:Having attended the Heasmans Tech night I had some very decisive questions answered.

One thing the KYB (and Koni) have that is lacking (in a big way) is bump adjustment, which IMO is as (if not more) important that rebound adjustment.

Bump is the compression (downward travel) of the shock and accounts for a lot of the "crashing" i experience over bumps.

I have Eibach lowered springs on mine which i feel are a little more giving than kings. The car does crash over bigger bumps (especially around corners) but handles quite flat. I should note that it has polyurethane bushes, front and rear brace, stock waybar on the front (no rear).

The KYB has the perches spot welded on and would take some mods to make fit the coilover sleeves. I would look at a better shock setup, the konis do have 3 perch heights which will allow for lowering, but you are in effect making the spring behave differently as you've lengthened the amount of available travel for the spring. Let me explain...

Say your static weight on the spring compresses it to 300mm (stationary), by lowering the perch height 25mm your car lowers by 25mm. This however has a negative effect on the spring in its opposite direction of travel, it extends past its elastic flex point (beyond 325mm) therefore for it's first moment of compression it will accelerate to return to its normal point, the above 2 brands of shock will slow the rate of return on the compressed shock but not the extended one, so the suspension 'squats', reducing the travel for the next bump (especially on rough roads) making your car crash over the next bump by hitting its bump stops.

On a budget, i would look at a used bilstein setup and valve it accordignly (by a specialist) so the shock has a very defined bump/rebound setting. Match the shock to a lowered set up progressive springs, then get the perches set to your desired height for the car and spring.

I have one adjustment setting for road use and one for the track (obviously firmer), but i could happilly live with a fixed setup if it meant my daily drives are more compliant.

ok end story

Ok, going on this it sounds like I am not going to be 100% happy unless I spend 2k plus on flex's minimum. At this stage it sounds like maybe I will get second hand Koni's, fatcat motorsports bumpstops, keep the current springs and lower it via the perch and then replace the bushes. Does this sound good? Where does bracing fit into this in importance? I will be looking at bracing soon but I wasn't planning on it yet, but if it is going to make such a massive difference to the compliancy of my suspension setup then I will plan it sooner rather than later. Thanks very much for the advise so far, I am learning more and more.

Ben

Bump is the compression (downward travel) of the shock and accounts for a lot of the \"crashing\" i experience over bumps.

You would need a aftermarket damper that allowed you adjustment of both high and low speed compression damping.

Too much highspeed comp dampening will lead to a crashy ride.

Too much rebound can also lead to rough ride over a series of bumps as the suspension packs down.

The other thing is to look for digressive valved shock absorbers.

Bracing probably will not make the ride any more compliant. A roll bar and other bracing will make your suspension work harder. bracing makes the chassis twist less. SO IF YOUR SUSPENSION IS BAD....it would probably make it more obvious that its bad.
However it adds to the handling character of the car once you have shocks & springs sorted.

which then becomes more like the SE package

meanmx wrote:... Where does bracing fit into this in importance?

With an NA6 bracing will make the most immediate and noticeable difference to the ride quality. It was one of the only mods I did on my NA6 that my wife noticed. You don't need to go crazy - the MX5 Mania style front and rear chassis braces and the seatbelt tower brace from an NA8 will make a big difference for little money.

It won't stop crashing/banging from worn shocks, but at least the car won't feel like it's going to fall to pieces around you.

Considering the low cost, ease of installation and effect on ride quality - it'd be the first thing on my list if I ever got another NA6.

A stiffer chassis will allow you to tune a better ride/handling compromise.

That is one of the reasons why manufacturers are always striving to increase rigidity in a car's chassis.

rjastra2 wrote:A stiffer chassis will allow you to tune a better ride/handling compromise.

Agree....

For the recent Heasmans zealots, have you had them price up a bilstein revalve, new springs and a coilover conversion? its approx the same as a set of Teins or similar brought in from the US,