78 replies to this topic

[Rob Burgoon]

Does anyone know how dramatically you have to adjust the rear to get it to match the front?

 

My 1.8 handles weird.  With the front and rear full soft (no spacers up front), I had oversteer.  I've added spacers and set both sides of the front bar to stiff.  How stiff does the rear need to be match the front?  Does fully stiff rear match a fully stiff front?  Does the front set with one stiff one soft match a rear with both stiff?

[Alberto]

I usually run mine soft.  Occasionally, I have run in the middle location at Laguna which helps me in some corners.

 

How are your shocks?  any chance they are blown and you are hitting the bump stops?

 

Getting oversteer where?  mid-corner, corner exit?  Same behavior on both L and R turns?

[Rob Burgoon]

I usually run mine soft.  Occasionally, I have run in the middle location at Laguna which helps me in some corners.

 

How are your shocks?  any chance they are blown and you are hitting the bump stops?

 

Getting oversteer where?  mid-corner, corner exit?  Same behavior on both L and R turns?

 

Shocks just came back from the dyno, they are good.  Oversteer in all parts of the corner and pretty much all "normal" corners, same left and right.  No bumpstop issues.  The ride was rough and the corner grip was poor, so I raised the car and that fixed it right up.  Still have the oversteer though.

[Jim Drago]

Rob

You didnt have these issues before rebuilding shocks? I have had this problem every time I tried someone elses shocks other than out of the box Mazda

[tburas56]

Rob

You didnt have these issues before rebuilding shocks? I have had this problem every time I tried someone elses shocks other than out of the box Mazda

 

+1 straight from mazda...

[Alberto]

Rob

You didnt have these issues before rebuilding shocks? I have had this problem every time I tried someone elses shocks other than out of the box Mazda

 

Hmmm....  Good point.  I remember having a similar issue when I had Tri Point / Pro Parts rebuild and revalve my Konis on my RX7 track car.  The revalve changed how the shocks responded when putting power down making the car more subject to oversteer.  I think they had cranked up the rebound a wee bit too much.  I wound up using softer rear springs (400 to 350 #) to compensate.  The revalved Konis helped handling and response in every other way beyond that on that car.

[Keith Novak]

When you raised it up, did you adjust the toe to match the settings at both ride heights or did you just raise it?

[Rob Burgoon]

Rob

You didnt have these issues before rebuilding shocks? I have had this problem every time I tried someone elses shocks other than out of the box Mazda

 

The shocks were not rebuilt recently. Just dyno'd.

 

I fixed toe up front, left it in the back, but I had oversteer on a smoother track too at the lower height.

 

Is nobody willing to share the difference between adjusting up front and in the back?  Is half a hole up front equal to 2 holes on the rear sway?

[Caveman-kwebb99]

No idea on your question. But i do remember driving.a 97 with adjusable front bar. Car was undrivable for me untill we decided to make front bar full stiff and rear bar was full soft... car had oversteer everwhere i.went from almost 2 seconds off the pace to outside pole instantly after that change. The car was still a little twitchy but it was a rocket.

[Tom Sager]

The shocks were not rebuilt recently. Just dyno'd.

 

I fixed toe up front, left it in the back, but I had oversteer on a smoother track too at the lower height.

 

Is nobody willing to share the difference between adjusting up front and in the back?  Is half a hole up front equal to 2 holes on the rear sway?

From my experience which may vary from others.  I never liked the smaller front bar on full soft. I wouldn't necessarily say that I prefer the smaller front bar either (at least at some tracks).  Swapping the front bar and making no other changes to the car made the car oversteer more  than desired so I countered that with more negative camber in the rear and/or running the rear bar not on full stiff.  There are a lot of other variables at work here (ride height, tires, the track surface and driver preference).  It's probably going to take a test day to find happiness.  

[Rob Burgoon]

I hate the f*cking small front bar.  Still pissed about being forced off of the old one for miller.

[Rob Burgoon]

Can't believe nobody can say if the rear bar is the front bar's bitch or not.

 

Thinking out loud here.... the front bar is much thicker.  A leverage change of half an inch is going to have a larger impact on the front bar than the rear since the front bar is thicker, right?

 

Adding spacers to get the front links more vertical should increase the effect of the front bar I think since the bar will get twisted a little bit further for a given deflection of the lower control arm.

 

My guess is that the front bar is "coarse" adjustment and the rear bar is "fine" adjustment.  I'm thinking with mildish oversteer with front soft rear soft, I should probably try front mixed and rear stiff,  That or leave it soft-soft all around and hope that standing up the end links fixes it.

 

It's off enough that I don't want to point the nose of the car up if I can help it.

[steveracer]

Rob

You didnt have these issues before rebuilding shocks? I have had this problem every time I tried someone elses shocks other than out of the box Mazda

Does that include sending them to Bilstein for freshening?

[Caveman-kwebb99]

Rob, not sure what you are getting at, I have driven 94-97, 99-00, 01-05. Only car I have not driven is a 1.6...

 

In year one i would mess withmy rear bar a little, but thats before I had a clue about how to properly setup on of these cars.  Now that I have a firm grasp of setup my rear bar stays full soft all the time.

 

I would sugest you go to full stiff on the front fo this car, and full soft on the rear, then figure out what setup it takes for the car work properly, stiffening the rear bar is a move to give up grip at the rear, there are other ways to give up grip at the rear, through camber and height adjustments.  Once you get that figured out I dont think you will  look back on the front bar change with such contempt.

 

That change is the same as rules changing tires from toyo to Hoosier, I had to make some changes with my driving as well as a few setup changes. I am just as fast now if not faster but i didnt just wave my majic wand...

 

Go back to Sagers post, Cant say he is agreeing with me fully but He says he hated the front bar on full soft. And then he corrected oversteer with more camber on the rear, not jacking with the rear bar settings.  I do believe if you just put front bar on full stiff and rear on full soft, work through some setup changes you will be right back where you were...

[Mark Drennan]

I hate the f*cking small front bar.  Still pissed about being forced off of the old one for miller.

 

Did I miss something?  Is the 1.6 bar required for 1.8's now?  And only for Miller?  And if so, why and who's bright idea? 

 

Thanks,

-Mark

 

Thanks!

[Keith Novak]

Did I miss something?  Is the 1.6 bar required for 1.8's now?  And only for Miller?  And if so, why and who's bright idea? 

As for the National SCCA ruleset, it's still optional:

 

K-SPEC-M5-SUS8 or may use adjustable 24 mm front bar
from Eibach kit 0000-04-5302-EB.
Eibach kit - front / rear bars 0000-04-5303-EB
Front 27mm non-Adjustable
Rear 15mm Adjustable

[Ron Alan]

It's been optional for a couple years now...maybe John can chime in here and show the mandatory change Rob is referring to...or debunk it?

[Tom Sager]

NASA has specified the small front bar on the '94 - '97 cars at their championship event only since the smaller front bar was approved as an option.  Why I have no idea, but that has been the rule.  

[Jim Drago]

Can't believe nobody can say if the rear bar is the front bar's bitch or not.

 

 

Rob

Not sure what you are getting at with the relationship question?  The relationship is similar to camber on rear wheel vs front?   IMO, they are related, but not so proportionately like I believe you are thinking?  It is whatever works. 

Jim

[Rob Burgoon]

Rob

Not sure what you are getting at with the relationship question?  The relationship is similar to camber on rear wheel vs front?   IMO, they are related, but not so proportionately like I believe you are thinking?  It is whatever works. 

Jim

 

 

It's ok to say "I don't know"

 

Let's change the question a bit.

 

Suppose Ricky Bobby's car handles perfect with the front bar soft and the rear bar soft.  During the night, his rival Rowdy T. Ager changes Ricky's front bar to full stiff and welds the end links in place so the bar functions but is stuck on "stiff".

 

Now, Ricky has 10 minutes before his race and only wants to adjust the rear sway.  Can he set the rear bar fully stiff, and get a fairly good handing car?  Or will it still push?  Or oversteer?  Toe, camber, tire pressure, ride height changes are not allowed for this scenario.