24 Hours of LeMons - '94 Mazda MX3

[kcbhiw]

It's been a while since I've performed a build. After building the turbo Miata and AWD Tracer and competing in the GRM Challenge for five years, it's time to take a different turn, so to speak. I've competed a number of times with my Hong Norr buddies in the 24 Hours of LeMons with a first gen CRX over the past two years. After numerous engine replacements and ultimatey the car being sold off, Hong Norrth was without a LeMons racer.

All of that said, it was time to construct a replacement LeMons racer. The plan was to build an MX3 and that plan was derived through a 3 hour long discussion between Mike and I on the drive home from the previous LeMons event. I happened to source a 94 Mazda MX3 for $80 just by means of a passing comment last June. This car happened to just fall in my lap. Score. All that was missing was the engine and gearbox and a very light hit on the driver's side front. Furthermore, Mike had the driveline from an Escort GT sitting in his basement that was sourced from an essentialy free running donor.

With the help of Mike, Wayne, Les, Tommy, and Wil of Hong infamy, we've built the car over the last several weekends. Needless to say, things have progressed quite well.

Enough banter as the build story contains only localized excitement, on to the pics I go.....

From it's former "final" resting place:

 

[kcbhiw]

(Re)assembly:

Wayne on the jack straightening the radiator support:

 

[kcbhiw]

Cage Installation

The worst part of the entire project was the measuring and overall thought process of bending and installing the cage (using DOM of course):

^^^That's one grimy happy dude.

Holes cut in the floor to lean the cage forward to weld the top tubes. The holes were covered with 1/4" plate and welded:

Yours truly butchering the welds:

...or maybe not

As it stood with all four wheels on the ground (finally!).

 

[kcbhiw]

Sound Deadening Removal

I'd always read about this but have never seen it done. Apply dry ice to the tar-like sound deadening material on the car's sheet metal, let it sit for a few minutes, swack it with a hammer, and it breaks right up. Well I'll be damned, it works like a champ! Tommy has a machine at work that can make this stuff and arrived with 30 pounds of it. Pretty cool technique if you ask me.

Tommy rockin' it:

 

[kcbhiw]

More of the same....

Thinning the wiring harness:

Completed cage:

Ready to drop in!

Ten keyed electrical connections and the engine's wiring harness is removed with the engine...LeMans style. Two minutes and the harness is completely disconnected. The reverse is accomplished in the same amount of time. This makes things much faster if the engine needs to be swapped mid race. A standby engine will be ready with its own harness attached (along with gear box and other essentials) ready to go. A driveline swap should take no more than 45 minutes.

This it the main power harness quick disconnect:

Engine in place...that was easy:

Makeshift header. A tubular header from a Kia Sephia was used and the collector chopped off. The pipe size is therefore changed from 1.75 inches to 2 inches:

 

[kcbhiw]

And some more....

It's alive!!!

Painted cage:

Meh...more to come later. Quickest build thread evar.

 

[Antoine]

MX-3 LeMons Special...Love it! Great build thread so far...Nice to see you back in a Mazda...Would you be willing to sport a couple Mazdas247.com decals for the Community...I'd be happy to provide them for you!

 

[CorkSport]

You should have picked up the FD Rx7 in the first picture as well!

-Derrick

 

[kcbhiw]

MX-3 LeMons Special...Love it! Great build thread so far...Nice to see you back in a Mazda...Would you be willing to sport a couple Mazdas247.com decals for the Community...I'd be happy to provide them for you!

Certainly!

You should have picked up the FD Rx7 in the first picture as well!

-Derrick

I was wondering how long it'd take for someone to mention that. Unfortunately, it wasn't avaiable for sale.

 

[CTt3P5]

Another awesome build you have undertaken. Looking forward to following your progress and wish you all luck in the race!

 

[khaosman]

What race are you planning in competing in?

Look forward to seeing how your build thread progresses!

Any good parts from your CRX I could steal cheap-o style? Our 89 Civic Si is doing well, we just finished 3rd at Mutually Assured Destruction of Omaha. Horsepower and small fuel tank are our main problems. Our normal transponder mounting point failed us this race too as they were go-kart transponders. We had to remount and missed green by a few laps

 

[kcbhiw]

What race are you planning in competing in?

Look forward to seeing how your build thread progresses!

Any good parts from your CRX I could steal cheap-o style? Our 89 Civic Si is doing well, we just finished 3rd at Mutually Assured Destruction of Omaha. Horsepower and small fuel tank are our main problems. Our normal transponder mounting point failed us this race too as they were go-kart transponders. We had to remount and missed green by a few laps

For starters, we'll be at CMP for the third LeMons South event this year (Sept. 25/26), I hope. I'd really like to hit the real 24-hour event in Louisiana this November, but I don't think that's going to happen.

The CRX and all of its parts were sold, so I have no ties to any of that monstrosity anymore, thank god (though, to it's credit, we were able to regularly set top ten fastest lap times each event).

Ahh, good old transponder issues. How I loathe thee.

 

[Rockin03mp5]

your builds are always so interesting. looking forward to this one as well.

 

[Sean2010]

i wants to see this...subbin

 

[kcbhiw]

Thanks all for the support and complements!

This evening, I finished up the wiring and tidied it all up. This includes finishing the driver's switch panel. The car now starts at the push of a button (as opposed to touching two wires together )

 

[Rockin03mp5]

what does the switch between fan2 and main do?

fire the retro rockets?

 

[CTt3P5]

what does the switch between fan2 and main do?

fire the retro rockets?

or maybe it releases an oil slick out the rear?

 

[kcbhiw]

Smoke screen . Actually, it's just a spare, likely for use with lights if we ever do a full 24 hour event.

 

[aMaff]

hehehe, I love it

 

[kcbhiw]

Suspension

I tackled the suspension install tonight. I sourced a set of Escort ZX2 S/R Tokicos from Summit for $200 (new). They're valved for a higher spring rate plus designed for a lower ride height than the stockers typically found on Escorts, Proteges, and of course, MX3s. Granted, the spring rates we'll be running are significantly higher than what they were designed for, but it'll suffice for des 24 Heurs du Mons.

I also sourced a set of craptastic $50 eBay coilovers with mystery spring rates. In all, the quality isn't bad. The springs are probably in the 450 lb/in range (all four of 'em), but who knows. I was primarily interested in having the sleeves and the fact that typical 2.5" ID springs fit them.

To fit these coilovers to the S/R struts, the tube cap had to first be removed. Easy enough, a drift and hammer took care of that in just a few seconds. The rears assembled easily as the sleeve was an easy fit with about 2mm clearance around. Not ideal, but again, this is LeMons. The fronts were a different story as the sleeves were less than a half mm smaller on the inside than the outer diameter of the shock tube. That gave me an excuse to assemble the 10 ton shop press I bought a couple years ago . After applying a bit of force and a touch of grease, the sleeves slid onto the front struts with no real issue. They won't be coming back off without a cutting tool. It's quite a perfect interference fit. The upper spring bushings were machined to clear the strut rods and the front bushings were clearanced even more to accept the upper thrust bearings.

In all, everything assembled quite easily with a touch of modification. I have some other springs rolling round in the basement and will likely use something softer in the rear. There's no weight back there and I don't want this thing to turn too easily.

Tokico:

Strut tube cap:

Before the press:

Sleeve fitted to front strut:

Front strut assembled with bushing and thrust bearing:

Installed:

Ride height arbitrarily set. The car will be corner weighted when all is said and done :

In the mean time, I'm off to the Solo Nationals in Nebraska for a week. If it weren't crunch time now, it will be when I return with only a week before a shake down track day and 2 weeks until the big show. Yikes!!!

As for the current status
-it runs (quite well)
-it sits on the ground (also quite well - gravity FTW)
-electrical is done but needs a bit more cleanup (wheel well area)
-the brake system needs to be filled and bled
-brake pads need to be installed
-the tranny needs oil
-the exhaust needs completion
-vinyl needs application
-brake ducting needs installation
-the gauge cluster needs installation (bracketry)
-the air meter needs installation (bracketry)
-new wiper blades
-a million other things it seems....