Autocrossing a Mirage

[Loren]

Well... I'm coming to a point where I need to do some serious thinking and decision-making.

It's no secret that I (frivolously, foolishly, misguidedly) bought my Mirage as a dual-purpose daily-driven autocross toy. I autocross a lot... at least twice per month.

The Mirage is a pretty dumb choice for an autocross car. It's slow, under-powered, comes with tiny wheels and tires, is extremely top-heavy with a narrow track. But, I LOVE minimalist lightweight cars, appreciate great fuel economy, and I love beating people in an "underdog" car that they don't think can win. I enjoy the challenge of "driving a slow car fast". The Mirage being THE lightest new car available, and attainable for well under $10k... I dove in.

Stage 0, August 2017: Autocross it once in completely stock form. Won't accelerate, won't turn, and leans so much that it scared everyone watching. They thought for sure it was going to roll over. But, it wasn't. It didn't have enough grip. And all four tires stayed in contact with the pavement.

Stage 1, September 2017: Try to autocross it "stock" class in mostly stock form. Wheels, tires, rear swaybar, and shocks and alignment. Much improvement. Still slow, but at least it can put some power down, and corner reasonably well. Not bad. Until I got really comfortable with it and started pushing it harder. Then, one day I got it solidly up on 2 wheels. Like 4" of air under the front tire. Not good. Instantly decided it was time to move to a "modified" class and further modify the suspension.

Stage 2, December 2017: Install full coilover kit, lower the car 2", improve alignment... and drive. Wow! Cool! Until I got comfortable with it, and then I realized that the inside front tire was regularly lifting an inch off the ground under extreme cornering. Need to do more.

Stage 3, January 2018: Much research into areas of suspension that I'd never explored, namely Roll Center Correction. Learned a lot. Decided to modify a set of lower control arms to be slightly longer, and fit a taller ball joint. OMG, WOW! This was huge! The car felt so much more planted and secure.

Other minor suspension improvements (custom caster plates, custom tie-rod ends for bump steer correction, etc) and some minor power mods continued over the next year. Incremental improvements.

Stage 4, December 2018: Fitted wider tires to the front (205 front, 195 rear) seeking more front grip, better balance, and improved autocross times. Awesome! The car feels fantastic! But, dammit, it's back to lifting a front tire in hard turns. Not a lot, just 1/2" or so. But, frequently. Can't FEEL it. But, other people can see it, and I saw pictures of it. Definitely happening. Definitely not good.

Stage 4A, Last Week: Make some suspension adjustments in search of more stablity. The car feels EVEN BETTER. A bit less body roll, more control and precision. Soooo good!

Then it happened. I saw it happen. It wasn't pretty. Today my co-driver yanked a hard 90-degree turn at 35 mph with a bunch less grace and smoothness than I would. The car has a ridiculous amount of grip. It stayed stuck. But, being a top-heavy beast, it lifted the front wheel again. And not just a little bit. He had the car up to a good 30-40 degree angle! He deftly set it back down without incident. But, holy crap! Just a little more steering input, or a panic-induced correction... and it would have gone over.

And thus, here I am. There are more suspension mods (getting into pretty hardcore stuff at this point, more custom work, more uncharted territory) that I could try. I'm just not sure I want to. I'd love to continue the development of this platform, it just seems too risky. And frankly, I'm tried of spending money on it. The experiment is fun, but not THAT much fun.

I've created probably the best handling Mirage in the US. No understeer. No oversteer. Very controllable. Feels GREAT! And grip for days. It flies through turns and slaloms with great speed and confidence. But, if you have the balls to get too far into that grip... the car wants to go over. I'm just one ham-fisted move away from scuffing the paint on the roof.

It's great on the street! But, I simply can't push it as hard as I want to at an autocross.

What to do, what to do?

[Mark]

Well... I'm coming to a point where I need to do some serious thinking and decision-making.

It's great on the street! But, I simply can't push it as hard as I want to at an autocross.

What to do, what to do?

I just think of the Mirage as cheap little economy car, but it's been fun reading all that you have done with your car. Having a friend already blow an engine & now almost flipping the car over would concern me, too. I value friendships over cars, but it would make me take a pause just the same.

If you scrap the Mirage as your autocross car, what do you see yourself doing? Would you keep your Mirage as your daily driver & start over with something else for autocross? Or would you look for a totally different car that was your new daily driver & autocross car?

Since I am not into autocross, I have to ask. What is the most popular autocross car? When I think of something like this, I think of the Mazda Miata (well balanced, rear wheel drive, and good power for it's size). Not very practical to haul the family around in, however. I've never owned a Miata, but it would be a fun summer car! Practical trumps fun for me. Thus, I own a Mirage instead!

Sounds like you are thinking out loud to us. Not sure the Mirage was designed with autocross in mind. Having said that, you have done a lot with it. Doing more with it, however, may not get you were you want to be. That's the message I am hearing. Still gotta love the thing for being cheap, reliable, & very economical to drive!

[Loren]

I have four main options:

1) Continue to modify the Mirage into what I want it to be. Gawd, I love the idea of a "capable sports car" that gets 45 mpg. But, I'm running out of steam.

2) Return the Mirage to stock(ish), fix the dent I put in the door (dropped something on it in the garage) last week, sell it and buy something else.

3) Keep the Mirage as a DD, sell my S10, and buy another autocrossable car.

4) Keep the Mirage as a DD, and put a bunch of money and time into the S10 and make it an autocrossable car. (it's really not too far off, already has suspension and a big honkin' V8... but, it has a "truck" oil pan that allows it to lose oil pressure under hard braking and turns... I have little motivation to wrench on the truck)

I really don't know which way I'm going to go at this point. It's 2am, I've been up since 5am, and only got 4 hours of sleep last night. Maybe after I get some sleep, I can give it some more rational consideration.

Miatas are fantastic autocross cars! I've owned many of them, my first one I had for 7 years. I don't need a family car (I removed the back seat from my Mirage!). But, I'm "over" Miatas. I'm done with the convertible thing. I'm done with 20+ year old sports cars. And, as mentioned, I *like* being the underdog. It's hard to be the underdog when you're driving one of the best-designed sports cars ever made.

Even a Miata is heavier than the Mirage, though. Baaaah!



I'm not ruling out the idea of another Miata. Wouldn't be the first time I've "come back" to a Miata. In fact, it would be at least the third. My autocross cars have been Saturn, Miata, Spitfire, Beater Miata, Yaris, Z4 Coupe, Miata, Mirage... or something like that.

Another thing I like about the Mirage is the "new and reliable" aspect of it. (even though I'm constantly working on the suspension, and we did manage to blow up the engine) Getting into a Miata that's in the same price range wouldn't be quite the same experience.

Not to mention the fact that I'm probably going to lose money selling the Mirage. I still owe $6k on it, and it's probably only worth $5k. Unless I find someone who wants to buy it as-is for a little more. I'd love to sell it that way, it's an absolute blast to drive on the street. It's on in the competition environment where drivers who KNOW what 10/10ths is try to drive it at 11/10ths that it gets scary. Ain't nobody gonna push it hard on the street.

[nickels]

Wheel spacers, or wider offset rims will be one of the only things you can do to keep the rubber down.

Gotta make it wider and or lower.

[Loren]

You're on the right track, my man.

I decided that the one thing I haven't done... and I've been trying to avoid doing, because adult reasons... is SLAM the car to the ground.

But, long story short, that's what I've decided to do. Suspension geometry be damned, I'm going to find out what lowering the CG as far as I reasonably can will do for it.

I started today by dropping the front by about 2.5" from where it was. Now it's solidly 1.5" lower than I've ever had it. In da weeds. Fender liners are not happy. I actually still have 4" of frame clearance, and 3" of muffler clearance. So, at least I'm not scraping the underside of the car on stuff.

Wheel spacers are a good idea, and I do have some 1/4" spacers in the garage. But, the front tire is SO tucked right now, fitting a 1/4" spacer would take major surgery! I'm already rubbing the crap out of the fender liners with the slightest bump or turn. Getting wider would require removing the fender liners completely, and a severe fender roll and pull. Not saying I won't eventually go there... but, one thing at a time.

Here's where we are right now:



Tomorrow, I'm going to see if I have a set of stiffer springs on the shelf that I can put on the front. And I'm going to lower the rear to match the front.

I have a practice autocross on Sunday, so I'll get some feedback on this soon enough.

[Fit]

Here are some videos of the mirage gymkhana in action.
Oh yeah btw its a CVT too! How she did it is to reflash the TCU to operate at a higher pressure and therefore instantaneous response when you accelerate.

Video 1: https://youtu.be/FdYsXmwAFec

Video 2: https://youtu.be/nDFJMtPMhqM

Video 3: https://youtu.be/ZfCkO_3tXCQ

Details of her car here: http://www.rev.com.sg/2018/09/little...hi-space-star/

[Eggman]

Here are some videos of the mirage gymkhana in action.
Oh yeah btw its a CVT too! How she did it is to reflash the TCU to operate at a higher pressure and therefore instantaneous response when you accelerate.

Video 1: https://youtu.be/FdYsXmwAFec

Video 2: https://youtu.be/nDFJMtPMhqM

Video 3: https://youtu.be/ZfCkO_3tXCQ

Details of her car here: http://www.rev.com.sg/2018/09/little...hi-space-star/

Nice videos, thanks for sharing them.

I'll bet this would be one good use of improving the Mirage steering in the way foama described.

[phaux]

Oh yeah btw its a CVT too! How she did it is to reflash the TCU to operate at a higher pressure and therefore instantaneous response when you accelerate.

And this is where you tell us that this custom flash is available to flash for those of us with CVTs ...

Is there any major downside to running a higher pressure? Wears the fluid faster? Risk blowing seals?

[Fit]

And this is where you tell us that this custom flash is available to flash for those of us with CVTs ...

Is there any major downside to running a higher pressure? Wears the fluid faster? Risk blowing seals?

LOL! I believe in Thailand they have done this a while ago. I am just lucky to get to know about it’s existence after chatting with the owner of the gymkhana space star. It costs SGD$600 to flash it. I haven’t tried it yet. I will do this last. After my cams will have to do tuning and perhaps with this flash I can get it on a dyno.

As to how Long the cvt will last running like these is a question mark.

[dspace9]

You're on the right track

Your Mirage looks great lowered, I read up on your mods quite the project! But you have to say for a quick glance, it's crazy how graceful and understated the Mirage can be, especially from this side angle... Nicely done!