IT Miata ? about spring rates

[Georgethefierce]

what are you guys running for rates on your IT miatas.....I have heard in the past that the SM spring rates aren't ideal for the car.

currently I'm running pretty soft springs (318 lb/in front and 233 lb/in rear) on the Bilstein Sports and will be looking to upgrade over the winter.

[Grippy]

Sounds about right.

[Crusin]

WHAT.......

Please note that the ratings are in lbs, not kgs. The ones you have are good street springs.

[Georgethefierce]

WHAT.......

Please note that the ratings are in lbs, not kgs. The ones you have are good street springs.

correct these are in lbs. which is why I am looking to upgrade

[Grippy]

Your description of "pretty soft" is what sounded about right.
F/R ratio seems a bit off though.

[Crusin]

Those rear springs would work OK with 500 lb/in front springs. I have often wondered how 900/425 might work with stiffer bars front and rear.

[offcamber09]

Those rear springs would work OK with 500 lb/in front springs. I have often wondered how 900/425 might work with stiffer bars front and rear.

Now you are starting to talk 3000# Mustang spring rates- not go-cart , I mean, Miata rates.

[Flatout Motorsports]

Those rear springs would work OK with 500 lb/in front springs. I have often wondered how 900/425 might work with stiffer bars front and rear.

Wonder no more...I am up to 850F and 400R. I started a touch above SM rates at 750/350 and I the car was way to soft (even with pretty big bars).

I am pretty sure I will stay with this set up. Has me running mid-15's at NHIS (North Chicane/South Oval) and mid-02's at LRP in SCCA ITA trim.

She feels tight in the pits but still 'works' on track.

AB

[timmmy]

Gordon and Wil - what are you guys running on the JIC's? I cant remember what mine are, pretty stiff I believe

10-8 maybe? (550F 450R), or maybe 12-9 (650F 500R)

I think Mine are 10-8's with a big tubular bar up front and a big solid int he rear, both set on mid setting. at NHIS recently I was running 3 clicks from full hard ont eh front shocks and 5 from full hard on the rear. (ST3 Street driven 2001 MIata with AC )

Sounds like I could stand to go up some of the fronts, maybe 14-8 would be a good mix. Right now the car is pretty nuetral with teh bias being to rear end loose. The front NEVER pushes.

(must be working whatever it is with the trifecta and all)

Timmmy

[WillM]

I think 550/250-300 would be a good starting point. I ran this setup for a while with a good-sized swaybar up front and decent bar in the rear.

Things like the car's weight, ride height, sway bars, sway bar settings, end links, pre-load, bumpstops, etc., all play an important role.

Some racers have said that the spec Miata rates are too stiff, especially for the rough tracks in NE, while others have said that the rates seem about right.

Then again, Andy & the FlatOut crew are turnign some amazing times in their IT Miata, so what the heck do I know.

I'm running the stock rates that Goodwin recommends on the JIC's. Rates are in kg, and are probably the same as Timmmy's.

[Georgethefierce]

thanks for the replies.....looks like a big jump in spring rates is in my future..

at present i'm on Miata R package Bars F&R and these will have to go as well...any sizes (besides large ) you'd recomend?

[Crusin]

yes

[Crusin]

Oh wiat,,,that should have been Mark's reply

[timmmy]

thanks for the replies.....looks like a big jump in spring rates is in my future..

at present i'm on Miata R package Bars F&R and these will have to go as well...any sizes (besides large ) you'd recomend?

I am running Racing Beat front and rear bars, the big tubular on teh front and the big solid ont eh rear. I seem to recall there may only be one setup for the rear from RB.

Then again I am no expert so others here may have better advice.

H

[WillM]

The first priority should be to identify the goal/use of the car. Track only? Track & autocross? Street legal? At some point, everything is a compromise.

What shocks are you running? Will they be revalved?

I had success with 550/275 Ground Control (Eibach) setup over Koni shocks. I played with a combination of Racing Beat (anti) sway bars and stock bars as well. The car was comfortable on the street and capable on the track. The Konis were kept at the stock valving, and performed very well.

My recommendation:

1. Pick a set of springs and shock combo that are similar to the f/r ratio of the spec Miata or other proven setup.
2. Pick a set of "matched" swaybars, like the Racing Beats. You may want to invest in adjustible endlinks as well.
3. Set the ride height to approximately where you'd like it.
4. Head over to Apex for a corner balance and alignment.
5. Try out different swaybars and swaybar settings to get the car neutral, or however you like it. Do not put any preload on the swaybars - adjustible endlinks will be very helpful.
6. Fine-tune the balance with tire pressures.
7. Collect your FTD trophy.
8. Do not kiss the trophy queen (it's Raj in a wig!).