2025 MK Sportscars RX5 250

[MK Sportscars USA]

USA 7s crew - I'm listing this here first, and would love to see the car go to someone in this community.  If it doesn't go fairly quickly, I'll be publishing it elsewhere - but wanted y'all to have the first crack at her. 
 

MK Sportscars RX5 Turbo

$42,000

Located outside of Baton Rouge, LA. 

 

Built by MK Sportscars USA, car has current registration and title, as well as an NHTSA issued 17 digit VIN. (VIN number 002)

Should be very easy to register in most states. 

 

Based on the NB Miata drivetrain, she’s been pepped up with a small turbo, that makes her a blast to drive.  Very quiet, very torquey, but sneakily fast.  Boost is incredibly smooth, starts to build at about 2200 RPM.  No sudden surge to upset the car, almost no turbo lag. 

ECU is managed by a Motorsports electronics ECU.  The car was tuned by Alex at Digitune – very, very reputable tuner for the ME ECUs, and a miata specialist.  (Great guy to work with by the way)

I’d estimate 210  wheel HP.  Turbo is limited to 11PSI, could be increased, as there is electronic boost controller installed.  She’s quite quick already.  11 PSI is a good safe limit for reliability IMO.

The Innovate PSB-1 gauge above the wheel displays both intake pressure and air fuel ratio via a Bosch wideband O2 sensor.   

Roll hoop can be removed and upgraded to an FIA cage should it be desired in the future, chassis is provisioned for the cage already – ie – they are swappable. 

Today’s cost is $29,800 for this kit imported to the US. 

Plus you’d still need a low mileage donor miata, as well as adding the costs and time to refurbish the parts.  

And then build it….

 

Car has about 150 miles on her since she was finished.

She’s been shaken down thoroughly, and is ready for pickup today.

 

If the buyer wants to add weather gear, wind deflectors, fender guards, or any accessories, I’d can supply and install if desired. 

Parts were sourced from an NB Miata, 80K on the odometer.  Unmodified donor vehicle, was in great shape and drove perfectly.

 

Cold start video here:

Cold Start

 

8 Minute test drive video:

Test Drive

(Forgive my lack of video editing skills)

 

More pics:

RX5 250 Pics

 

Parts replaced with new during the build:

Front and Rear Wheel Bearings

Axles

Pads and Sport Miata Rotors

Differential seals, all

Differential braces welded to housing

Transmission seals, all

Upgraded Flying Miata Shifter Rebuild Kit

Water Pump

Thermostat

All engine seals

Valve Cover Gasket

Timing Belt and tensioner

Fuel Filter

Lower Ball Joints

949 Racing Clutch

949 Racing 8.8 lb Lightweight  Flywheel, perfect match in this lightweight car – like OEM miata engagement

New Spark Plugs

 

Detailed Specs:

15 x 7 / 15 x 8 Wheels with Falken Azenis 660 tires, 205/50 F, 225/45 R

Innovate WB/Pressure Gauge

ME221 ECU

Limited Slip Differential

Larger Sport Brakes / Rotors

Wilwood Front Brakes with stainless braided Goodridge lines on all 4 corners

Mintex Brake Pads (Soft)

2” 4 Point Harnesses FIA certified

Coil Over Single Adjustable Shocks

Odyssey AGM Battery

Walbro fuel pump

Bosch EV14 640cc Injectors

Radian Fuel Rail, converted to return style system

12” Cooling Fan / Oversized 55MM Radiator

Front Mount Intercooler

Electronic Boost Controller

Removeable Headlamps

Suede steering wheel included, some pics show leather – I didn’t care for the leather one.

SAE bulkhead fitting under the dashboard for a battery tender. 

Multiport USB charger with voltage display. 

 

james@mksportscarsusa.com

 

Edited April 10 by MK Sportscars USA