Locost
This project is based on a Champion Motorcar Co., CMC, Miata kit. It was not a complete kit but just a frame, control arms, sheet aluminum, fenders, and a scuttle. I opted to use a different engine than the Miata 1.8. I found a company that was selling off new Ford Ranger 2.3 Duratec engines for $450 each, so I bought a pair. The big reason for using this engine and not the Miata engine was the power potential and a weight savings. In the UK SBD Motorsports is getting over 300hp from a naturally aspirated 2 liter! My goals aren't quite as lofty, I want a car that's driveable on the street as well as the track. The engine, as it stands now, is a 2.3 liter Duratec with stg3 Crane cams, ported polished big valve head, Suzuki GSXR throttle bodies, Caterham CSR stainless headers, 12.5:1 forged pistons, Cosworth con rods, polished crank, Exedy 3 puck clutch, and exedy flywheel. Based on what I've seen published by different Duratec engine builders this engine should put out around 240-260hp.
Fitting a RWD transmission, not off a truck, proved expensive. 2006+ Miata transmissions were available but expensive. I opted to use a 2003 NB Miata 6sp and adapt it to the Duratec.
Fortunately the NB 6sp bellhousings can be seperated from the transmission body. I seperated the bellhousing and milled 5/8" off the face, machined up a 5/8" aluminum adapter plate, and used a combination of clutch parts to mate the engine and transmission. The cluch I used was for a Mazda6, it also uses the Duratec 2.3 engine. The input shaft of the Mazda6 and NB Miata transmissions is the same spline count and diameter. The throwout bearings are different, I cobbled together a throwout bearing using the Miata center with the 6 bearing pressed over it.
The CMC chassis seems to be ok, their control arms weren't. The rear control arms were not symetrical, the suspension mounts were not in the right place. As it came from CMC the rear suspension could only achieve positive camber and not even the same amount from left to right. I had to cut the top mounts and move them inboard 1". After that I opted to make new lower control arms because the arms that CMC made had no provision for toe control, and needed to be rebuilt anyhow.
03 Dec 2011
15 Mar 2014
25 Mar 2014
05 May 2014
18 Oct 2014
01 Nov 2014
14 Nov 2014
14 Mar 2015
17 June 2015
11 July 2015
24 Sept 2015
Melee 2018
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