First step in Miata-dom!

Keith Tanner wrote: A bad O2 sensor will certainly hurt your gas mileage. So will excessive 6000 rpm top-down driving

But the O2 sensor doesn't have anything to do with fueling at full-throttle, right?

z31: My understanding is that it goes open loop past 4k, so yes?

Will note here that my mileage issues exist despite having the hardtop on about 99% of the time.

z31maniac wrote:

Keith Tanner wrote: A bad O2 sensor will certainly hurt your gas mileage. So will excessive 6000 rpm top-down driving

But the O2 sensor doesn't have anything to do with fueling at full-throttle, right?

No, but you're not going to see 25 mpg if you're running at full throttle anyhow are you? The biggest contributor to fuel efficiency is the looseness of the nut behind the wheel.

The transition to open loop got more sophisticated over the years, moving towards more of a load-based switch. But yeah, the earlier cars flip over at 4000 or so. Around town, the O2 sensor is still going to have a big effect. On the highway, a hardtop will definitely help.

Less concerned about mpg then what seems to be excessively rich fueling under full throttle. Is there a way to adjust that without going standalone? Any bandwidth fixes

On a 1.6, you can adjust that by changing the tension on the spring inside the AFM. I'm not sure how that will affect closed-loop operation, it's not something we play with much. On the 1.8, it's not so simple. I'm sure the Spec Miata tuners have some tricks though.

There's a pretty big sweet spot for fuelling on naturally aspirated cars. Can you quantify "excessively rich"?

Coilovers installed!

Possibly too low, but so far no issues with rubbing, even while experimenting with speed bumps coming in to work.
Rear is a little higher now, going to let her settle before I figure out how I want her to sit.
Guessing that I should likewise wait to get the height dialed in before getting her aligned?

Was bleeding in the first thirty seconds, fairly painless other than that.
Took about 5 hours, not bad considering we were in a tiny garage, and that my buddies drank beers and watched me do the back end but finally pitched in for the front end.

After a week, the verdict on VMAXX is...

Still no issues with rubbing on the front, as long as my driving vaguely resembles sensibility.
Can't match up the ride height front to back, the collars in the rear start interfering with other parts of the car, so the rear is 3/4th of an inch higher
(the planned wheel and tire size increase should take care of that though, now just need to decide between 15x7, 15x7.5, and 15x8)

Did an experiment, drove nicely for most of the last tank of gas, shifting at 3 or 3.5k (don't have anywhere near the discipline to drive nice for an entire tank, except in cases like breaking in clutches)
gained a whopping 1.5 MPG.

Clearly this means I need to just flog her all the time.
Ordered a new O2 sensor, going to see if that helps.
Getting her aligned in the mean time, hoping to get my seat/harness/harness bar installed by Christmas.

This is sort of turning into a build thread, though I hesitate to call it that when compared to almost any of the threads for which this site is known.

The previously mentioned seat/harness bar/harness were installed in time for my second autocross, the harness remains (tucked behind the stock seat) while she's in DD mode for the winter. At some point I'll get my ridiculous (read: hooptie) Nova to the point where she's DDable, at which time the miata will get FM butterfly'd and possibly involved with what you're going to read about immediately.

In any case, a buddy surprised me with something the other night.
Still have not figured out if it will actually work for me (my research suggests GReddy only made these for the 1.6), even so, a nice gesture.

I very much liked boost when it was through my Poopra, can only imagine that a lighter, more agile (and much better sorted, if I may say so myself) car would be at very least as fun, if not much more so

Did you ever contact us about your V-Maxx concerns?

Closest I had to a concern was matching ride height, my guess that a larger wheel and tire combo would get me where I wanted turned out to be correct. 190/60R14 up to 190/60/R15 plus a couple of cranks upward on the front did the trick, only needed to massage the fender a little bit on the driver's side.
Axing the helper springs in the back was the other obvious solution, with obvious downsides, was happy to avoid that route.

So, no issue, no problem

Did new pads and rotors today. (OEM rotors, Hawk HPS pads) Or at least, that was the plan.

Took three hours to do the driver's side front and discover that the driver's side rear rotor is stuck on.
Decided to bail on the rears for today, naturally the passenger side front took all of 20 minutes.

Bedded the pads per hawks instructions, now have a car that stops badly with a brake that rubs on the drivers side.

Really hoping that it'll be better after everything cools back down.

Days like today remind me why I'll never actually turbo or heavily modify this thing.

EDIT: google just informed me that the screw holing the jack in place also works to unseat the rotors, good to know for when I tackle the rears.

Typed a bunch of stuff, then lost it.

Front left still rubbing, still much diminished braking.

Possibilities that spring to mind:
Didn't push piston in all the way.
I didn't use the shims that came with the Hawk pads as they interfered with my ability to actually slip the caliper over the rotor. (The set of pads being replaced had no shims... also turned out to be in great shape, despite all the noise they were making)
Chalk it up to being a berkeleywit, use AAA the second time in a week to tow to shop where someone who more than vaguely knows what they're doing can look at it.

Question mark?

Or, you know, it could be something as simple as the dust shield having been bent just enough to rub on the rotor.

Now that it's not making awful noises, I've come to the conclusion that braking isn't compromised, it's just less of an on/off switch than it was before.

Oh Snow, you so silly.

'Slight' increase in wheel and tire size.

Ooohhhh, I like the look of that, what size wheels/tires/offset, etc...?

Advanti Storm S1 15x9 +35
BFG Rival 225/45

In my neverending quest to get my buddies (who have mentioned wanting to try autocross) to actually... try autocross, I've offered either to loan my 'old' wheels and tires for the event or just for them to co-drive my car...
sadly, no takers yet.

Wow, those cars will ingest large quantities of wheel and tire, won't they...

As to needing someone to co-drive your car, just let me know man; road trips are fun, right? I should send you a picture that was taken at the Sierra Vista autocross, I think my first one (yes, sadly, I spent years thinking about it, but only this year started to participate) where a spectator is riding with one of the club guys. A Miata, sideways and at speed going around the cones, and the spectator has a grin on his face a mile wide.

It's the perfect advertisement for both Miatae and autocrossing.

That car looks great. It seems you bought yours a few months after I got my 90 that's also red lol. I've been on the edge of selling it but this thread kinda makes me wanna order the suspension it needs ( pretty sure it's still on the orgional stuff.. ) and do a track day.

Man, that looks great.

I suspect pretty soon you're going to want fender flares or at least the factory mud flaps. When I first installed Star Specs on mine, I couldn't believe how much crap those things flung up on the sides and rear end of the car, and that without the width and offset you have there.

Oh, and if your friend turn down free autox in a turbo Miata, you need better friends.

In reply to kazoospec:
Last time I checked my car wasn't turbo, but yeah, he's nuts.
Funny you mention flares or mud flaps, I have a set of each sitting in my garage.

In reply to OldGray320i:
Arizona isn't that far away.
I too took a number of years before I went cone hunting.
Rolled the front fenders and trimmed away some of the liner, the rear is untouched
(That's actually as low as the VMAXXes will go in the rear, without tossing the helper spring)

SnowMongoose wrote: In reply to kazoospec: Last time I checked my car wasn't turbo, but yeah, he's nuts. Funny you mention flares or mud flaps, I have a set of each sitting in my garage.

Oops. Saw turbo picture above. Assumed large helpings of snail powered goodness. Oh, and was too lazy to read everything.

I also check mine periodically just to see if the "turbo fairy" has visited. So far, no luck.

Short of 'extreme' measures such as yanking the roll bar and swapping in an open diff, thoughts on what I can do to give myself a fighting chance in STR?
(er, the diff + less wheel would drop me to STS that is... I have the tires and wheels for STR and enjoy the LSD too much on the street, I won't swap it for a dual purpose car)
Obviously there's a lot to be gained by improving my driving, that'll come with experience...
Intake + more autocrossing = success?
Hell, just more seat time?

TL;DR version: tips to improve an outclassed miata other than 'be a better driver' ?

Wait you're 6'3" and you manage to fit under the bar with a helmet? In the stock seat!?! Did I miss a post or something?

I sold my Miata because I just couldn't find a way to fit myself, and I'm only 6'1". That is awesome you found one with a hardtop. Makes me want to go buy another Miata! Hmmm.....

Try going back to 14" wheels. Put some really good 195mm tires on there. I've found that my Falken-equipped Miata was so much faster on the track than it is now with my 225mm 15" BFG Rivals. For what it's worth, my BFGs came with a Miata I bought from a friend... they're new, though, so age isn't the issue. They just don't seem like they give me any more grip that the Azenis tires gave me, even though they're much wider. They are MUCH heavier though, and decreasing weight might give you a good boost.

Awesome car though. I love the color. It looks like you made some improvements to the paint since you started this thread. And I love the black accents where the chrome was.

In reply to Desmond:

I don't fit under the bar.
I also don't yet do any driving that requires me to pass a broomstick test.
Aluminum seat bolted directly to the floor should get me just low enough.
Just.