2011 Mazda2 "Not so SRS-BZNS" STF build

It's daily driven on stupid spring rates and homemade strut housings. Read the whole thread to see the details! Long time reader of GRM, and lurker of these forums, just now joining though. I'm making progress on my 2 so figured I'd cross post here because the 2 forums are s-l-o-w and frankly I like reading about a variety of cars/projects/etc. I had a 2009 Mazda3 2.0l/5spd that initially I got into autocrossing with... I REALLY wanted a Miata but a newborn son put that on hold. I auto-xed the 3 for about a year or so and decided I wanted a smaller more fun to drive car but still with a back seat. I drove a 2 at work(I'm a tech at a LARGE used car dealer) and it was just a stupid fun to drive car. I auto-xed it on some mixed crappy all season tires(Kumhos and stock Yokohamas 320 and 420TW IIRC?) to get used to the car. Over the 2014 season I added a DDM Works rear sway bar(the first thing you should do to one of these!) and it made a huge difference. I also built a rear motor mount because I'm not about to pay $90+ for some steel and $20 bushings. For the last event of the season I added some camber bolts to get about -2.2deg of camber up front. Made a nice difference to enjoy the last event of the year. I heel-toe like an idiot, and the pedals are too far apart to do so, and I hate aftermarket pedal covers with a passion so I made a throttle pedal extension so I can downshift somewhat smoothly. I also adjusted the brake pedal up just a bit to get the pedal height relation correct for me. ...

Looking forward to seeing what's next.

Moving on to this season I wanted to go full hog on the suspension so I'm building housings for Koni 8610 race inserts for the front, and as per Lee Grimes at Koni the normal Mazda2/Fiesta/ST rear Koni Sports should be adequate for the 450-550lb rates I want to run. I am currently waiting on the rear shocks to show up(backorder) but I'm making progress on the front in the meantime. I hope to be finished by the end of May at the latest.

Some GC Ebay knockoffs I got from a guy named Jeff who autocrosses a 2 in NJ:

NHBB 5/8" spherical bearing for the top, the upper spring perch is from Turner Motorsports, normally meant for 2.5" coil on a BMW Koni strut... perfect for my purposes. The Koni race inserts have a 14mm thread, 22mm shaft, and a square shoulder which these are meant to fit.

I have a bare strut housing made by Martin Valent of TM Family Racing in WV. I just ordered a blank tube that holds the insert + gland nuts made from MR2 gland nuts.. I'll be welding my own ears onto the strut tube very shortly.

Loosely assembled:

Here are the upper strut mounts I STARTED to make:

...But then decided it needed to look cooler, I'm heading over to my friend's garage some time this week to cut these out:

The spherical bearing holders are from Pegasus Auto Racing.

I got some 15x7.5 TRM C1 wheels with ZII Star Specs for some actual auto-x rubber this year. Here's a pic mocking up ride height in the rear:

And how it sits presently:

Fr3AkAzOiD wrote: Looking forward to seeing what's next.

Ha me too!

Anyway I have 400, 450, and 550lb springs to play with so far, I'll probably add 500lb springs to my box of goodies at some point once it's sitting on the new hardware.

Special tool to press into the spherical bearing retainer during welding to prevent/minimize distortion:

Ha.

In not-so-exciting news this past weekend I changed the engine oil and trans fluid, and replaced the spark plugs. At 49k they were causing misfires at idle... supposed to go to 75k. Yep.

Now in case you're wondering... yeah it's not really typical for a Mazda2 owner to have somewhat decent fab skills.

I came from an offroad background, with my build from bone stock to this documented on JeepForum and Pirate4x4.

So yeah. I downsized just a bit.

The offroad thing just got old having to pack up for several days to make a trip worthwhile, break stuff semi-regularly, then the horrible task of cleaning it up/fixing/maintaining when you get home.

And it was my daily driver in that form for about a year and a half when we moved from VA Beach to Ohio. My tolerances of "streetability" are a little higher than others.

Auto-x is fun because it's like one or two days a month to have some automotive fun among friends, and not really have any seriously involved tasks to do before/after.

Glad you joined the forum! I'm pretty sure I work at the LARGE dealership in VA Beach that you used to work at . I'll be following the build!

sethmeister4 wrote: Glad you joined the forum! I'm pretty sure I work at the LARGE dealership in VA Beach that you used to work at . I'll be following the build!

Haha yeah. I think you showed up on my FB friend recommendations.

Anyway, picked up this little guy to try out. Got it for $10 since I had otherwise useless gift cards to Walmart, I try to avoid the place normally.

I need to find some time to fill it with acid and babysit it for a few hours while charging.

I'll probably go the LiFePo4 route down the road like mazdeuce did but this was $10, can't beat it.

Glad to see more 2 owners on here! Cool build so far.

Cool build with actual fab work. I saw this over on the sandbox and was intrigued. I still say the 2 is a great car.

Thanks guys!

So top hats 2.0 are ready for welding on Tuesday night.

And how I looked after cutting them out freehand with a 4.5in angle grinder...

And mockup of how I'll mount the 7.2 lb battery:

The battery fits between 2 of the original battery tray bolt so a simple strap will work well. I can either go redneck and use all thread and a flat piece of aluminum, or what I want to do is just make several bends in a piece of aluminum and bolt at the bottom. Need to figure out which is lighter, I suspect the full aluminum strap.

For the positive side I'll be undoing the 12mm nut and just attach it directly to the post. For the negative side I just got a 24in long cable with 3/8" hole ends on both sides. No 12in in stock. I got additional end terminals to cut and crimp to the shortest length needed.

Only mod needed for the 12v side is to trim this small plastic tab from the fuse bracket at the bottom:

In reply to iadr:

Yes, I'd love a portaband, but I don't use one enough to justify buying. When I build another Jeep/buggy then that will be high on the priority list. I've basically got these plates and then a few rectangular brackets to cut out at the bottom of the strut housings and I'll be done. I'm working out of an apartment single car garage myself, the fun tools are at friends' places so I'm trying not to clutter up their stuff much.

In other news: the camber plates turned out pretty tits looking!

Very happy considering I was unfamiliar with my friend's 30 year old 460V 3 phase machine! 20min of practice on scrap seemed to pay off.

I pressed in some 1-3/16" solid rod with some high temp anti-seize to hopefully keep the bearing retainer from warping too much from the heat. Seems to measure round with my digital calipers so I'll say it was a great success

Nothing real crazy update wise, been taking some measurements since threaded shaft space is at a premium on the 8610 series struts. There is approx 44mm of threaded are on the strut shaft. The upper spring seat takes up about 5mm of that space. The complete width of the spherical bearing ball alone is just short of 16mm wide(15.88mm or 5/8"), so that's 21mm gone right there. Without a spacer of any kind there is no way to get any angle to account for camber/caster/steering/etc. With a 5mm spacer that Koni sends you it's not even enough to clear my bearing retainer.

I WILL be grinding on the spherical bearing retainer to lose most of the "lip" because frankly it's no use to me and is just eating up a TON of potential angle. I THINK the 5mm spacer would be usable with some grinding to this lip, but I've only eye-balled it so far and I hope this is the case.

Here is everything assembled, it appears to have enough angle here since the bearing isn't 100% pressed all the way in, but you can see where it will be hitting the spring perch when some space is taken away between the two.

This is with the 5mm spring perch, 30mm worth of spacers + spherical, and the Koni supplied jam nut only... as you can see all threads are gone.

And here you can see the difference between the two Koni supplied nuts(about 10mm wide for one, 6mm wide for the thinner jam nut), and then a nylock nut I picked up from Ace Hardware which is about 12mm wide.

So I'm having Martin Valent of TM Family Racing make me up some custom spacers to these specifications which will help me gain back about 4mm of shaft space.

Ignore the "x4"... I'm getting spares to have on hand. Only 2x of each type will be needed.

If you're paying attention I'll still be 2mm short. Remember I suspect a stock 5mm spacer may suffice between the spherical and the spring perch, if this is the case I'll be perfectly set.

If I absolutely must, I'll end up machining a mm or two off the bottom of the nylock nut. Or acquire a second pair of jam nuts and machine a bit off one of them. I do NOT want the strut nuts coming loose and potentially destroying the strut inserts.

If anybody has some good input it will be greatly appreciated :)

Also, I know that BMWs use an M14-1.50 strut nut... does anybody happen to know the width of the nut by chance? It would be incredibly helpful for me to know... if it's narrower than the 12mm ones I've got then I'll just buy a few of those.

Moar progress!!

Full droop:

Full bump:

Roughly desired ride height, maybe a bit higher:

Adding beef:

And anti-foldthetabsoveranddie bracket as well:

Burned in with brackets for ABS and brake lines. Need to clean all the weld boogers off then should be good for paint.

Hoping to install everything next weekend! Will be doing the strut cleanup, some more clearancing on one of the upper strut mounts, and painting throughout the week after work hopefully, then start the install later in the day Saturday and wrap up Sunday if all goes well, Monday if things go how they normally do for me

edit: And I'm moving back to the Hampton Roads area to work in Newport News... at yet another LARGE used car dealer. I will start there either June 15th or the 29th, depending on if a replacement for myself in Dayton is found by the 15th or not. Trying to wrap up the suspension to drive it 600 miles there.

<- Just a bit nervous.

And found a local selling some more coil sleeves/perches so I'll be picking those up tonight to use in the rear.

Wait wait wait... Hampton roads grm? Why was I not immediately made aware of this

In reply to e46potenza:

I'll find out when exactly I'll be there later this week hopefully. Do you auto-x or anything locally?

So progress!

And now I'm eating lunch before teardown for install.

Its all in, height set, aligned, and a few problems taken care of.

Had some interference with the rim at -3 degrees of camber:

So a bit of shaving plus dialing some camber out fixed it.

It was just the weld bead causing interference. When mocked it was only tacked. Derp.

And a tiny bit more for a wheel weight kissing it under hard turns.

And now sitting perfect.

I took it out, had some twanging from front springs when turning - weird since I have torringtons, but it stopped after 10 miles.

Had some noises over bumps from the rear, thought it was the rear springs/adjusters, but turned out I left the lower shock bolts finger tight... Forgot to torque once back on the ground... Oops!

It was bouncy in the rear, so pulled the rear shocks and trimmed the bumps 1.5in to start.

Holy.

E36 M3.

It sticks to the road like glue, and actually rides damn well. The level of grip is uncomfortably high for me to push it harder on public roads.

It has a lot of grip accelerating while turning compared to before.

Very little body roll despite having no front sway bar.

Now I put some miles on it to monitor for stuff loosening as I'll be driving it 600mi to Va Beach in a couple weeks. Yikes!

WOW - grab fab work sir. Is this enough grip to create significant chassis flex? Guessing some tie bars may be in order?

The 2 is silly stiff. The front struts are basically tied to the firewall and the rear suspension doesn't really act through the top of the shocks. There's probably nothing to be gained with any sort of bracing.

Subbing for just plain awesome work (and wondering wtf Is my excuse lol)

In reply to 84FSP:

I think Mazduece is correct. Bracing is the last thing it needs.

First being power!

But really when I have it set on jack stands in my garage, it has to teeter on 3 with another one there just in case. Its that damn stiff.

Also you're in Cincy, come on by for a ride! Its looking like I may be in Dayton until the 29th, I MAY try and do one auto-x event before then, but with packing and stuff that might be unrealistic. Or it'll be followed by divorce.

In reply to JtspellS:

Thanks!

Bit of a follow up: been fiddling with the shock settings and it rides very well now. The wife approves, she said she couldn't tell much of a difference from stock.

Probably won't be able to auto-x it until July-August due to moving and stuff, but we'll see what happens. Once I run it some I'll figure out what needs tweaked.

Fun to follow along. Keep it coming.

Looks awesome dude! Maybe I'll actually meet you sometime since you're heading back this way! I assume you are heading to our "sister" store in Newport News for the Retail team? Some of us at work were talking about getting a group together for an autocross sometime soon...maybe you can join us! We haven't picked a date, and if my Maxima ain't back together I'll just be spectating anyway...

Happy packing!