Bronson M

iTrader: (1)

https://www.flyinmiata.com/na-flyin-miata-springs.html

They list the spring rates for you to match, you absolutely don't need helper springs to recreate these springs in a strait rate. Helpers are less than 100lb/in and normally 25lb/in so all they do is keep the spring from rattling. If you unload a corner to that point it's not adding any grip.

As long as you don't have 9" wide wheels they'll fit.

HarryB

They'll fit. And it sounds like a good idea to me. I was looking for a set in EU for mine like forever, as importing them new from the US would not make them a reasonable option. Almost had a set of 2.5" ones in the same rates (350/250) in order, plus 100lb/in helpers, but then a set of Maruha coilovers came my way so I ditched the idea. Still have the parts though (sans springs), so I may give it a go one day.

M.Adamovits

Hi gents,

I completed my DIY coils this past spring, and got the first real test this past Saturday at autox. Overall it went well, finished 15/95. Car details are as follows,

1990 with stock power
MSM Bilstein shocks
5x coil sleeves
5x dual purpose 36mm bump stop kit
Front springs: eibach 2.5" 800# 6" length
Rear springs: 400# 6" length
NB top hats
FM front bar
Racing beat endlinks.

Ride height hub centre to fender f/r: 12 1/8" / 12 5/8"

Some notes after the first event..
The rear coil sleeves are out of adjustment, the rear cannot go any lower.
Rear shocks are ~1/8" off the bumpstops at rest, front shocks are quite close as well. Extended tophats are definitely needed in the rear, possibly small extension for the front as well.
There is a clunk from the front end when driven hard as the car transitions from one side to the other, not sure the cause yet. My first suspicion is the spring against the tophats as theres no spring isolators.. anyone else experienced similar noise?

Overall I'm very pleased with the car, just needs a couple tweaks..

proctorsilex

Tires? That is a lot of spring to unload enough to clunk. The lack of isolators could be the source like you think.
A loose fastener could clunk too.
Even if it is a new sound coinciding with the new suspension set up, it could be an old problem. Last year, I had a semi random clunk under braking and/or transitioning on track. It grew in frequency then I got it to a shop who said it was worn caliper guide pin holes. I got it apart at home and found that it was the control arms sliding off the original bushings. The arms were slamming and rubbing their mounts. Pretty obvious when you see the shiny metal circles on the subframe mounts, the small clearance on one end, and all the exposed rubber!

M.Adamovits

225 rs3's on 9s.

Forgot to mention, I have replaced all the alignment cams, and inspected all the control arm bushings. I also checked all the suspension bolts after hearing the noise the first run, they were tight.

I suspect it is either related to the front springs against the collar or top hat, OR the sway bar contacting the upper control arm. Car has adjustable endlinks but they are a touch too long currently , need to shorten them.

Plan is to pull the wheels and look for any sign of contact around the front end and go from there..

ridethecliche

iTrader: (2)

Thanks for all the help folks! Especially Stefanst and Bahurd.

concealer404

iTrader: (3)

.... Where are your helper/tender spring sliders?

ridethecliche

iTrader: (2)

Do folks tend to run different spring rates when using extended top hats? I.e. do you go to a higher rate?

I don't really have much to go on... but I feel like I could have done with a higher rate both f/r. I'm probably wrong though.

Will fix.

M.Adamovits

If you need higher rates with the extended top hats, you needed higher rates before, you probably just didn't notice because the car was sitting on the bumpstops.

What are your spring rates?

ridethecliche

iTrader: (2)

I just swapped over from base nb suspension.

Running msm's with 450/300. Rears have extended tophats. i should double check my endlink adjustment. Might be out of whack.

There's also a good chance that it feels 'off' to be because I'm so used to riding on the bumpstops at all times. I honestly doubt that this isn't enough spring for me given I've only driven the setup on the street and folks here have run them on track with good results.

bahurd

iTrader: (8)

What makes you think you need higher spring rates? Cause it rides "nice" so make it harder?

M.Adamovits

Depending on your goals and uses, your rates will be fine.

Did you make or buy the extended top hats? If bought, where? ISC?

ridethecliche

iTrader: (2)

I honestly can't describe it haha, but that might be it. I think it may have to do with adjusting the sways as well.

I think that the setup seems less stiff than earlier because im not on the stops hard everytime I turn hard.

I have them in the rear only. I bought them used but I think they're 1.5 inchers.

M.Adamovits

Why?

ridethecliche

iTrader: (2)

Height was changed. I think the endlinks might need to be adjusted to their optimum level.

I'm just hypothesizing here. I'm mostly surprised that it doesn't feel stiffer for how much higher the spring rate is. I do think that it's more of a function of not constantly riding the bump stops though. That's the best explanation I can come up with.

concealer404

iTrader: (3)

550/375 on fresh NB bilsteins with special sauce speedthane bumpstops and extended rear hats is downright plush. I'm not surprised you're taken aback at the ride quality with 450/300 or whatever it was you're running.

If you like it, don't change it.

ridethecliche

iTrader: (2)

Yeah, I think how soft it is, is really throwing me off haha. I feel like I could have gone stiffer with no ill effects. Looking forward to running these for autocross!

M.Adamovits

You could have gone stiffer without ill effect, but what you have is perfectly reasonable.

RE: Sway bar and lowering. Correct me if I'm wrong, but with the exception of the links or sway bar contacting something, the link lengths will have no impact on ride quality, just effectiveness of the sway bar.

ridethecliche

iTrader: (2)

If they're not set up correctly, i.e. tensions are different on either side, it'll affect ride quality as the wheels move up and down and during turns, no? This is probably a tiny part of what I'm feeling though.

As I said earlier, I think a good part of this is that the fact that things feel plush and I'm not on the bumpstops all the time probably makes it feel 'less stiff'. I'm pretty confident that this setup is better than my stock base suspension hahaha.

I think AidanJ and sixshooter were on these at the spring rate I just started on and they moved up as they needed more spring for the track.

sixshooter

iTrader: (12)

It was enough spring for all-seasons or older 200tw tires to stay off the bumpstops at the track. Hoosier SM takeoffs were sticky enough to lean the car over more because I was cornering faster. The spring rates you have are awesome for a DD that occasionally goes autocrossing or track driving.