Miata content - disconnected front sway bar and my clueless driving

Car Background -- NB1 K24 Miata, 245 Toyo RRs, Xidas with soft-ish springs, RB front bar and Mazdaspeed rear (cookie cutter street car suspension).  Full weight with AC, both tops, carpet, roll bar, etc.

Me Background -- 12 years DE experience, 5 years instructing, I'm no slouch but I speculate I'd do no better than mid-pack in local-level sprint race.  I have 0 car set-up skills.

The issue -- Mid-Ohio is my home track, doing a DE the last couple of days, while changing the tires to go home yesterday I noticed that my front sway bar was disconnected (bolt fell out).  I suspect this happened in the last 2 days based on the last time I checked everything over.  Problem is I ran my fastest lap time ever right before I noticed it, 1:41.7 on the pro course setup.  That's substantially faster than I've ever gone before.  I've never been particularly attentive to set up, I tend not to fiddle with tire pressures throughout the day and I never change shock settings or anything like that.  I just show up and drive around any understeer/oversteer issues I happen to encounter -- it's just DE, after all.

In retrospect the car felt a bit looser than usual but I thought maybe I was just finally pushing the front tires enough to really get them to grip.  I never suspected at the time that I was running with no front sway bar.  Based on the internet comments I've read it should have been a death trap, but it actually felt pretty nice and I didn't have any "moments".  I just dialed back my trail braking and everything was good, and I think the effect was that my corner entry speeds were higher pretty much everywhere.  I need to pull my AIM data down and confirm but that was my seat-of-the-pants analysis.

So... what does this mean?  What do I do now?  I'm embarrassed because I didn't notice that a key suspension change.  I'm also embarrassed that I may have missed a loose bolt the last 2 or 3 times I swapped wheels.  I really wish I new when exactly it failed, and I wish I had noticed the change.  But do I reconnect it or was the car way too tight before?

A-B-A test at the next DE?

Lap times don't lie, although what has me curious is why a "backwards" change netted a positive result.

Pete. (l33t FS) said:

A-B-A test at the next DE?

 

Lap times don't lie, although what has me curious is why a "backwards" change netted a positive result.

Ugh, see this why I'm dumb, A-B-A testing it never even occurred to me.  I'm just so used to not thinking about setup changes but that seems like the obvious answer now.  Thanks. 

What are "soft-ish" spring rates? I've never driven a car with the front bar disconnected, but in my mind for what you described that should have been a fairly substantial handling change. Your time isn't exactly setting the world on fire, but definitely isn't slow either. I would think plenty fast enough that major changes in setup like that should be very noticeable. I guess I'm wondering if there's some other issue somewhere else such that the bar wasn't doing very much to begin with.

And bring the pyrometer. It could be that the increased roll is letting you utilize your fronts better. If you see a more even gradient of tyre temps across the tread you'll know it's the faster setup for that track.

dps214 said:

What are "soft-ish" spring rates? I've never driven a car with the front bar disconnected, but in my mind for what you described that should have been a fairly substantial handling change. Your time isn't exactly setting the world on fire, but definitely isn't slow either. I would think plenty fast enough that major changes in setup like that should be very noticeable. I guess I'm wondering if there's some other issue somewhere else such that the bar wasn't doing very much to begin with.

700/400, which I *think* is soft enough that the sway bar would be doing a fair amount, but I dunno.  As far as I know it's a fairly normal Miata, other people have driven it including SM racers and nobody seemed surprised by anything.

Wondering now if it was just my driving, like maybe I've been trail braking too much and overslowing into corners and this forced me to get off the brakes in a way.

In reply to steronz :

Disconnect the other end too and just make sure it swings freely. I had a binding sway bar I fought for months and never thought to check. 

In reply to steronz :

Again I'm not an expert, but that's enough spring that I could see it being a relatively minor difference. When I read "soft" springs I was picturing like barely more than stock.

At 700/400, you've got a front bias to your spring rates. I'm going to say you fixed your handling. I like a car to be a little looser than is sometimes fashionable.

LOL at those rates being considered softish. That's not far off what I run on an aero-equipped 500+ hp V8 Miata. I know, I'm not one of the cool kids. 

Interesting.  Supermiata sells front springs from 550 to 1400 in 100 lb/in increments, so I I figured by "only" picking 1 up from the softest these were relatively soft.

OK, sounds like I shouldn't be freaking out about the fact that it wasn't a handling nightmare.

That's probably a reflection of the valving in the Xidas. No point in selling a 300 lb spring if you'd be overdamped with it.