RallyX MZ3

Moving my 2004 Mazda 3 from Stock to Prepared for rallycross this season and thought I should document some of the build. Here is everything I did over the last season and half while I was running in stock.

The car right after I bought it.  Over 200K on the car, but engine was replaced and only has about 125K.

• painted Mazda MPV wheels from a junkyard with new Hercules Avalanche snows.  Color - Caterpillar Yellow

• NGK spark plugs
• Ignition coils
• Cosworth stock panel air filter (now discontinued) - https://www.rallysportdirect.com/part/high-flow-replacement-panel-filters/cos1-20002274-cosworth-high-flow-synthetic-air-filter
• One of the Rear Motor Mount bolt holes was badly stripped and had to tap for a new larger one. (very difficult with transmission still in car, even with the Harbor Frieght ratcheting tap wrench)

• Prior to my first event found a crumbled rear shock mount and replaced both along with new Kyb shocks. (There's a piece of concrete in there for some reason too)

• First event (Susquehanna SCCA Rallycross, Oct 2019) with the MZ3, only my second rallycross overall.  I did OK and had blast! Had several repairs after this listed below. 

• Corksport skid plate  - https://corksport.com/2004-2013-mazdaspeed-3-and-mazda-3-skidplate.html
  • after breaking part of the radiator shroud where the corksport skidplate mounts, I had custom brackets fabricated by Jim's Welding and Automotive in Manheim, PA. 

• blew a tie rod, and replaced inner and outer on both sides.

• stock exhaust had a rusted hanger and nearly fell off. Decided to replace the exhaust with a CBE stainless one from Racing Beat

• New stock trans mount after finding mine was in two pieces.

• Winter 19-20 rust repair on the rockers including some grinding and cheesy use of expanding foam, bondo, and undercoating.  Yes I know it looks horrible., like really really bad.  Like who is that guy who couldn't even cut off on a straight edge.  Is there some kind of reward for worst rust repair?  Like maybe someone can come to my house and fix it the right way for me.  

Before

After

Measuring up with cardboard template for cheap-as-hell Sunpie mud flaps. Why is there always a leaf in my pics?  - https://www.amazon.com/gp/product/B07JC8ZMTG/ref=ppx_yo_dt_b_asin_title_o07_s00?ie=UTF8&psc=1

Didn't like how I moved around so much during runs, so added a Corbeau 4-point harness (not really liking it as it rides up to high, even after I mounted it to a harness bar).  This pic is from before the harness bar, but it didn't improve much.  I may ultimately go with a 5 point harness.

I'm not normally a graphics and stickers guy, but even though the car is inspected and registered, I don't daily drive it, so I decided to try it out.  The hockey stripes are for a later model Mazda 3, but they fit for the most part.

• Numbers from TrackDecals.com. 
• Stripes from ProMotorStripes.com
• Mazda Contingency decals from soloperformance.com

In addition to the above, I also did a Hotchkis Rear sway bar with Mazdaspeed 3 swaybar links (first I tried a set of Proforged  links which clunked and broke after one event.  That catches up to where I am now before I make the move to Prepared.

In progress on the following:

• Lightweight flywheel from Fidanza (ARP bolts are on their way to replace the reused OEM hardware.)
• Exedy Stage 1 Clutch
• Did the rear main seal and pilot bearing while I was in there.  (That pilot bearing was a PITA!!!  Ultimately had to dremel it out. )
• M Factory LSD will be installed in a transmission I found on car-part.com. Install by Chris Windsor of Windsor Customs when he gets back from the races in FLA- https://sites.google.com/view/windsorcustoms/home.  These FoMoCo trans have the ring gear riveted to the differential.  So the rivets have to be drilled or milled off.  I thought it best to leave that to the expert 
• (BTW, the floor jack is insurance, just in case.  the engine is actually being held up by a Harbor Freight engine support bar.)

• I've downgraded the brakes from 2.3 S brakes to the ones from a 2.0 i model so that I can fit 15" wheels
• I got the calipers from the junkyard.  Turns out you only need the carrier which are even conveniently stamped 15 or 16 for the rear calipers.
• Painted the calipers bit.
• Did brake lines while I was at it .  Good thing I did!

bulging, rusted brake line

• Also gonna do new front lower control arms as this was the result of me removing them to make room to get the trans out.  What can I say, I have more strength than sense sometimes. Or maybe it was just really old rubber that was bound to need replacing

I like it! trying to get my rallyx car ready but I'm always fixing other things. 

How's the 3 drive? It was on my short list years ago, but I never drove one and ended up with something else.

I like the 3 a lot, but I'm really new to racing.  I do pretty good with it, though at one race I came in dead last, even loosing out to a Saturn sedan with an automatic. Last time out I did better. I've had lots of advice from Michael Chilcote who drives a Protoege - https://www.instagram.com/rallytege/?hl=en  and Adam Dellinger who also drives a 3  - https://www.instagram.com/ad_2.3l/?hl=en. 

Following along, good to see a 3 getting some (ab)use.

Not sure if you know, or are interested, but if you want a cheap increase in ride height and rear spring rate, Mazda 5 springs work well, going for the 2012 on rears for more rear rate, I've got the Moogs in mine, with Bilstein B4s for the 5 in the rear:

https://www.rockauto.com/en/catalog/mazda,2012,5,2.5l+l4,1501076,suspension,coil+spring,7512

In reply to paul_s0 :

Thanks Paul. I've been researching about the swap to Mazda 5 springs. You have them in your car?  Did you measure ride height before and after?  Take a look at the chart posted below. It is the specs for the Moog springs  (Mazda 3 on the left, Mazda 5 on the right, fronts listed on top, rears on the bottom).  You'll notice the "free height" of the 5 front springs is only 3 mm more, and the rears are actually 6.5mm less! However the load for the 5 springs is MUCH higher (850 vs 795 for fronts, and 1130 vs 705 for the rear) so I guess once installed, it would probably ride higher even though the spring height is actually shorter, right? (They list installed height specs, but they don't really make sense for the front and would apply to as installed on a 5, not a 3 anyway)

Yep, I went through all that, and other options:

Basically I had MS3 fronts with B4s and Moog 6556 rears with Gas-a-just on a previous Gen1 hatch, that gave a nice balance and around 1/4" lift on the front, closer to 1/2" on the back.  I now have a Gen1 Sedan, and with that I went with the Mazda 5 springs, Moog 81686 fronts and 81695 rears, front ride height damn near exactly the same as the MS3 springs, around 1/4" above standard, the rear was considerably more, over an inch higher, and I cut half a coil from the rears, leaving it a touch over 1/4" higher, but with a considerably higher rate.  With this I've got B4s on the back, and Excel Gs on the front (fitted by PO), front could do with a touch more damping.  B6s all round or Koni yellows would be lovely, but I'm on a budget...There's no RallyX here in Peru but the roads are awful - RallyX spec is about where I wanted it.

With that lot it's a tad stiff at the back in daily driving when running empty, but it never gets too much (for me), and on the loose bits it feels lovely.   I've still got standard sway bars both ends, but the Whiteline ALK on the front, front subframe shoved all the way forward and strut tops as far back/in as possible.  More stuff in my thread.. https://grassrootsmotorsports.com/forum/build-projects-and-project-cars/daily-drivers-in-peru-mazda-3-and-discovery-3-lr3/134498/page5/

In reply to paul_s0 :

Wow, Thanks!  I read through your whole post. Thanks for sharing your life and car experience. I'm definitely thinking about those Mazda 5 springs. It is interesting as far as shocks. For the most part they are interchangeable between the 3 and th 5, but in some cases there are different models, but not always for the same part of the car. Koni Yellows are the same for the rear, but have different part numbers for the front.  Whereas Bilsteins are the same for the front and different for the rear. To me that just reads that they are all interchangeable. Where as KYB uses the same model for both front and rear.  I wish Koni and Bilstein would publish specifications for things like extended and compressed length of their shocks and struts. I found some Koni specs online, but it is for their race catalog.  They don't seem to publish specs for their consumer lines.

I believe physical dimensions for the dampers between the 3 and the 5 are the same, it's only the valving that differs.  The Bilstein B4s are the same part number for the 3 and the 5, they're obviously on the 'slightly-overdamped' end of the spectrum with the stock 3 spring rates.  The B4 rears with the 5 springs (233lbs) damp better than the Gas-a-justs with the 197lb rears, although the B4s are on a sedan and the gas-a-justs were on the hatch.

Interesting that the Koni yellows are specced differently on the front - the front of the 3's and the 5's ought to be almost identical - it's the weight at the rear that differs.

If I were to change springs again I'd be tempted by the 5 springs on the front, but with the Moog 6556 springs on the back, the 5 rear springs are a touch hard especially in normal use only 1 up.  Unfortunately the 6556 seem to have gone out of production!

Not a great photo, but here you can see the ride height (and castor!), this with the standard 205/50 R17.

Awesome.  Tirerack has part number 8741-1487 for 2004 Mazda 3 Koni Yellows for the front and part number 8741-1490 for the 2012 Mazda 5.

I'd like to see this confirmed, but I could swear I saw a post from Lee @ Koni saying do not use yellows for rallyx.

Anyway, this seems like a fun build.  Following along.

Always love seeing another rallycross build thread!  I'll be following along!

When you get to the point of choosing rally tires, be sure to consider your gear ratio & speeds versus the tire size.  While there's not a huge difference in tire diameter, you can make small shifts in where your power band is in relation to speed.  Check out the "Tire Size" section of this article I wrote for some guidance.

You definitely want to do something about that harness.  It will mess you up if you hit something in front. The laps should be low, across your hips.  That's what the 5th point does - it holds your lap down when you tighten the shoulder straps.  
 

decades ago I had to crash a car at a pretty low speed driving from the back seat with just a lap belt.  It rode a little lower than yours and at 15-20 mph I thought I had done some serious internal damage.  Vs other crashes at higher speeds with proper belts that I didn't even feel 

never again!

Some parts came in today.  Did the rear brakes using PowerStop's stock replacement rotors and pads.  My goal in rallyx is to touch the brakes as little as possible and around here our runs are usually less than 90 seconds.  So I didn't want to waste money on performance rotors and pads. 

I also swapped to a spin-on oil filter housing.  1st gen 2.3L have the cartridge type filter and housing, but you can swap it for the spin on housing easily.  It pays to shop around.  Some places have the spin-on "conversion listed for $90.  But I was able to get the housing and gasket shipped for under $30 from Werner Mazda.

That brand new housing looks funny on my crappy looking old engine.

In reply to FooBag (Forum Supporter) :

Thanks Jim. Your articles are so helpful!. I've been reading and rereading them since I started. I still look at your what Rallycross packing list the night before every event.

In reply to jfryjfry (FS) :

Yes for sure.  It is a little better with the harness bar. I also wear the regular lap belt at the same time when I race.

gszczyrbak said:

In reply to FooBag (Forum Supporter) :

Thanks Jim. Your articles are so helpful!. I've been reading and rereading them since I started. I still look at your what Rallycross packing list the night before every event.

I'm actually David.  I guest authored that article on Jim's blog.  I figured it was smarter to keep all the rallycross articles together than post separately. 

In reply to FooBag (Forum Supporter) :

Oops!  Yes I can see that now. Also a great article that I have read before. 
 

Got a great deal on 15" Mazda 929 BBS look-a-like wheels via eBay.  Who new that there is low demand for 25 year old 929 wheels? . They came in today and I was sweating if they would fit with my downgraded brakes or not. Fronts fit with 4.5-5mm clearance (Is that enough? ) , and rears have plenty of room.

pic from behind the wheel showing clearance of caliper to rim

Haven't decided yet, but think I might paint them gold and run them without the center caps.