Project Goals Intended usage is my daily driver, testbed for new widgets and demo car for those that want to see how the suspension works. The goal was simply to take our completely stock, high mileage and rough looking 95 R package we picked up in 2010 for $750 and turn it into a clean daily driver that should pass OBDI emissions testing in every state. I was after a very clean OEM look. No wild aero or graphics.Pretty spare and stock looking under hood. It scales out at about 2180lbs with a splash of fuel.
Suspension We fitted Xida-S with 700/400 rates. RB 1.125" #54105 front sway barar is the 14mm with urethane bushings. Our urethane control arm and diff bushings, SuperMiata end links. Diff is the stock 3.9 with a type 1 Torsen.
Brakes are our SuperMiata Wilwood front with our special directional vane two piece rotors, XP10's up front, XP8's in back, stainless lines all around with Motul RBF600. The car has an NB front subframe and depowered steering rack.
Engine We have gone through two motors in this car, one from a bad overrev (my fault), one from too many trackdays without an oil cooler. Now it has a bone stock JDM longblock we picked up off ebay for $1400 shipped. The JDM engine is identical to the USDM except 10.5:1 CR and the square top intake manifold. We run 5W30 synthetic street oil. Since this car has a metal core cat, we couldn't run a high zinc race oil without contaminating it. Header and exhaust are Racing Beat ECU is a DIY Autotune MS3 Pro.
Phase one - Emissions compliance As an experiment, we initially built the car with an EUDM header and heatshield to retain a full OEM appearance and functionality. We also kept the OEM NA8 airbox and NB2 MAF. With all that OEM hardware and a cat, we squeaked out 126whp on CA91. Guessing another 2-3whp with 93 octane fuel as we were det limited when tuning for 126whp.
Phase two - make a little power Next we added a K&N CARB legal 57-0348 intake kit. With that kit installed we made 131whp. Next we added a Racing Beat 56008 header and made 139whp. With the header, our emissions compliance went out the window.
We found however, that intake temps were still very high. The culprit turned out to be the plastic crossover tube. Plastic has high thermal inertia. It soaks up heat slowly but also releases it very slowly. Basically it heat soaks and stays hot regardless. We wrapped the OEM tube in foil tape and that slowed the heat soak noticeably but it still would not shed heat once hot. The next step was to replace the crossover pipe with an aluminum piece to try to get rid of heat a bit quicker. The only CARB legal intake we could find was a K&N 69-6000TP for a 99-05. This kit was a huge improvement in design over the questionable efficiency and safety of the snorkel intake of the 57-0348 NA8 kit.
The aluminum pipe helped a bunch. We went a step further and applied self adhesive thermal barrier wrap to the crossover pipe. The MS3 Pro is running speed-density and doesn't require the MAF so we deleted it. Now we are at 145whp.
For now the car has no oil cooler but we'll add a 9 row Setrab with -10 push on hoses and Mocal thermostatic sandwich plate. Koyo 37mm radiator and Koyo cap with M-Tuned reroute.
Drivetrain 6 speed trans running Amsoil MTG. Clutch is a our own SuperMiata 1.6 (200mm), organic sprung hub. Lightweight 8.8 lb Cr-Mo flywheel. 15x9 6UL's on 225/454 RS3's running about 30psi. I painted the wheels Ford tungsten gray code T8.
Miscellaneous bits Harnesses are G-Force 5 pt camlocks. Seats are OMP Grip with custom made fixed brackets. Bar is a Hard Dog HC DD. Wheel is a Momo 350mm mod 78, NRG 2.5 QR and Momo hub. We added a Sparco.
We added our V8R frame rails for added torsional rigidity. They cut down on cowl shake and generally make steering response at the limit a bit crisper. Headlights are E-Code 55/65 halogen lights so we can actually see where we are going once the sun goes down.
John, our engineer, did a partial wire tuck under the hood. The relay box and ECU are behind the pax airbag cover.
Driving it It's a hoot! The tuning and bit of compression give it fantastic throttle response and torque way down low. The gearing and light flywheel let it zip through the gears like a kart. The ride with the 700/400 Xida-S is very firm but not harsh at all. Feels a bit lumpy at very low speeds but smooths out and begins to glide once you start hammering it. Exhaust has a pleasing and not too loud growl through the midrange that changes to a muffled bark at high revs. Brakes feel amazing. Sensitive, tons of power, no fade. The XP's dust quite a bit but that's typical.
Track time Over the last year we have run this car on several road course and it's proven quite fast/ At Buttonwillow 13CW, it ran 2:02's on the RS3's and 4.1 ratio. This is about 2s under the Spec Miata lap record there. We also did a NASA TT at Chuckwalla, won and set a lap record in the process. It would be a tad quicker with 4.3 ratio but that's raises revs on the highway so we ent the other way.
at Chuckwalla
http://youtu.be/CXWqcvYBhug
At Laguna Seca in the rain
http://www.youtube.com/watch?v=EqrfndXUl90&
