RedTurboMiata

shane welcome to mf, you should create an intro thread with pictures of your ride.

sixshooter

Sorry I'm late. I've been sick and now I'm playing catch up at work and don't get as much forum time as I'd like.

I have the 450/8" front and they are just a wee bit too tall. The 7" would be perfect. I have the '00 Sport Bilsteins and they have no problems controlling the ride with a 450 rate. A 450 spring isn't rough or harsh at all and was better than stock because I don't feel it crashing into the bumpstops anymore. It is controlled and not bouncy. I have 275# rears and if I didn't have a big FM rear bar I would need 300# or 325# to be balanced with a stock rear sway or probably 350# with no rear sway.

If you intend to track the car, my 450/275 is coming up short even with FM sways F and R on little 195/14 Hankook RS2s. If I go with a wider or stickier tire I will be hard against the bumpstops when cornering. And these are shorter than stock bumpstops. My next stop will be 550# F and ???# R if I go to 205 or wider tires.

You will be pleasantly surprised how well your car will ride on 450/300 on the street. It really feels more comfortable than stock to me. Surprising but true.

And 7" should be ok in a 300 rear if they don't have 8" and you don't have a super-short coilover adjuster. I have secondhand Ground Control adjusters and would probably be just about as happy with the ebay ones.

hustler

I've had both on my daily. The MSM Bilstein has more less highspeed rebound force, significantly more low speed rebound force, much less highspeed compression force, and much more low speed compression force. I think they're the second best option for our cars next to Xidas. 450/300 is a great combo on the MSM shocks, terrible combo on the standard HDs.

For the record I have 600/400 springs on my daily, 700/400 springs on my turbo car. I like a car that turns and since the daily is slow, I like that extra rate in the rear, but I could go for less rear swaybar in the daily.

hustler

Spring has very little to do with ride quality, it's all about valving/shim stack and bleed. With the fancy shocks you can run crazy spring rates like my car, and it rides very smooth, smother than my Bilsteins by a long shot. A good example is how the ASTs on my daily compare to the Bilsteins I took off. When I went over a speed bump, junction block i the highway, or the little metal track in the gate at my apartment in the Bilsteins, it felt like the car was coming apart and the dash sounded like it was falling off. With the 600/400 springs these examples at low speed are a bit more abrupt but controlled...the body of the car moves, not the shock, due to spring rate. If I go over them at 20mph or above, the speedbumps are ultra-smooth...like "not spill your coffee" smooth; you're letting the spring do the work, not the shock because higher spring rates require less highspeed force to keep the wheels on the ground. Funtunately/unfortunately, the valving on my track car with the higher rates is better in every way on each example. When you load either car up on highspeed, the high rebound force keeps it flat.

That's today's lesson, bitches.

Track

to further add some data on what hustler is saying, here is a ton of dyno plots courtesy of Shaikh:








Lastly, here is a quick site on reading these plots:
http://farnorthracing.com/autocross_secrets20.html

Track

As you can see in the graph 2 and 4, the NB sports are pretty close to MSM Bilstein. Its just that the MSM Bilstein has slightly more compression and rebound.

On my NB Sports, I am teetering on the edge of oversprung with 550 springs in the front. I would say those MSM Bilsteins would be pretty spot on for 550s or even more than that if need be.

Since the NB sports/MSMs are pretty well sorted, I think the key is ride height and bumpstop choice (given a proper spring rate for the grip available). Drop it too much and you are going to get on the bumps often!

Hustler not sure which HD you are talking about (NB or NA), but if its the NA, I certainly understand why you dislike them. The NB Sports (I think the NB HDs are the same, just slightly larger shaft) are quite similar to the msm Bilsteins.

I think if you wanted to stay with Bilsteins and wanted a super budget setup, buy some used msm bilsteins! They are great!

hustler

http://forum.miata.net/vb/attachment...3&d=1176000500
lol @ those Bilstein HDs. You basically have to run a stock spring or the car will make you nauseated with all that rebound force at high-speed. Since we're doing teaching today, it's also important to note that shock dynos only tell you velocity, they do not show you how the shock handles jerk and quirk (I believe this applies here).

When I was running the Teins and the Bilsteins, loaded-up bumps mid corner (or whatever) devestated the car. In the Teins it fell apart on the bump, in the HDs it fell apart after the bump...I think this is a function of compression and rebound damping failure. With the fancy shocks that handle jerk better. I think the fancy shocks handle the rebound and compression better to absorb the bump and return the tire to its position pre-bump in the track. It's crazy the way nice shocks ride on the track, you can go careening over curbs and the car doesn't care. Enter turn 2 at MSR-H at speed requires that you use a 3" tall curb, while the car is loaded, in 4-wheel drift...and f/r traction is constant. Its awesome.

hustler

I disagree. I like a stiffly sprung car, but at 450/325 on the MSM shocks, it's nearing the point of discomfort on the street. There's not enough bleed to run more spring, and I think that will also benefit you on the track if you use the curbs. However, I'm not a real shock expert...where is 949 to answer these awesome questions.

BTW, read Tito Ortiz's PDFs on valving, it's awesome.

Track

yea of course for the street you would not want to run something that high. I don't disagree with you there. All I am talking about is the maximum spring rate that the shock can control.

The rest is good, I like the NB bilsteins personally, not so much the NA Bilsteins though. Granted people complain that the NB bilsteins don't allow you to get "low enough", I am perfectly happy with 5.25" track ride height and I have yet to even bottom out anywhere on the street.

who da fudge is tito ortiz? You are not talking about the UFC guy right?

hustler

Look at this baller shock dyno:

Awesome diregressive rebound action. These valves are going in my track car next year.