More cooling air flow too
Added front ducting to cooling system to include defuser in the cooling track intake.
Started on March 4 by perryrace
99 Mazda Miata - Purchased as a damaged roller (no drive train or interior) for $500. The roller was then stripped down to a bare tub and the front core support replaced. The wind shield driver side pillar had also been dented this was also repaired.
I then added a full roll cage with NASCAR style door bars, and widened the transmission tunnel at the firewall by 4”. The firewall to frame rail upper unibody triangle supports were also removed and bracing welded in place of these OEM supports.
The tub was then painted and under coated. A Getrag G60 3.23 limited slip differential, axles and custom hubs were installed into the OEM Miata rear sub frame. The axles and hubs are V8Roadsters conversion parts as are many of the other parts on the car.
An aluminum drive shaft then connects the G60 diff to a Ford T5 gear box. The gear box was modified with a close ratio “motor sports” gear set. A steel bell housing was installed for safety. This bell housing mates the Ford T5 transmission to the GM L33 alloy V8. The L33 is essentially a 5.3 liter LS1. A custom cam, fuel system, LS6 intake, road race oil pan, and headers completed the engine installation via urethane engine mounts. The exhaust was a custom piece with 2 1/2” headers connected to a single 3” rear section that exits via the stock exhaust location.
The cooling system is a dual pass 3” aluminum radiator with the appropriate overflow and venting added. Getting air into the radiator involved making a body kit and hood to ensure enough frontal air flow and once the air had passed through the radiator it is directed out of the engine bay through the hood vents and or under the front mounted belly tray. While I was at it I also made an adjustable rear wing to balance out the aero package.
The suspension includes tubular A arms on all 4 corners with Bilstein coil overs. An extra OEM castor camber bolt was added to provide additional camber adjustment. The brakes are 11.75” rotors and Wilwood calipers with an accompanying Wilwood master cylinder, Mazda 929 brake booster and drivers compartment brake bias adjustment. All of the metal brake lines were made for the car to ensure maximum clearance from heat sources.
The rims were made for this project due to the offset and back spacing needed for proper fitment and are 15” rims with a 4x100 bolt pattern and a 10” width and weight of approx 14lbs each. I am currently running 275-35-15 Hoosier R6 tires at all four corners.
The car weighs in at 2281 pounds, and currently has just over 300HP.
The car has been a blast to build and develop, while testing is still under way, I believe I will soon be running the car in the NASA ST2 class.
Also get your instant access to the digital edition of Grassroots Motorsports Magazine!Learn More