Engine & Drivetrain

East Street Racing Engines

If you want the best, that is what we have to offer.

East Street is currently offering engines before only available in our 35,000 plus cars. These engines are the best in the business. They win every weekend at every track in the country. They always make more HP than the competition. They powered our cars three National Championships and Sprints wins the five of the last six years running, along with multiple Runoffs poles, podiums and national wins. Your choices are simple, you can buy from us or follow those who already have.

Torsen swaps (1999/05)

These swaps will bolt right into your 90-93 SM. This will replace the fragile Mazda Comp differential and give you years of worry free racing. The swap comes with all the parts necessary to install into your car. It comes with the 4:30 torsen differential, the aluminum housing, both CV axles and the drive shaft. the swap come with a 6 month warranty.

Rebuilt Race Ready Transmissions

We are offering our Race ready rebuilt transmissions to the SM community. These transmission are fully gone through, All the synchros,sliders and shift forks are changed. We harden the shift forks for improved durability. We start with a street version, not a wore out trans that came out of a race car. We have sold over 350 of these transmissions and they really are the best out there. These aren't assembled by someone in their spare time, These are built by a professional who builds manual race boxes daily. They shift better than any I have ever driven and I have used them all. These transmissions have far less drag than any of the competitors units out there as well. They are set up perfectly and no detail is over looked.

We warranty all our transmissions for 60 days, races included. Who else does that?

We sell 90-05 transmissions, we don't need a core.

If you would like the showroom package of a bead blasting the case and new plated bolts please add $200, but IMO this is a complete waste of $$$ and not in my own car.

All boxes come with new hardened synchro springs and the counter shaft sleeve.
Add to cart then select your model year.

Blue Printed Rear Knuckles

We are offering race ready ready knuckles. These come with new Mazda bearings, disassembled and cleaned and repacked with our racing grease that will reduce the drag. We then press them into the rear knuckle. We also install a new Mazda bushing. These are are ready to install on the car. These roll great! We do not re install rear dust seal.

These come with long studs or standard studs, please click the appropriate option.


Standard studs $250, long studs $285

Blue Printed Front Hubs

We have blueprinted front hubs available. These are the best rolling hubs out there bar none and the longest lasting. We start with new OEM castings as they are the ONLY ones that are heat treated all the way through the race and not just surface hardened. We completely go through these hubs, add new seals and install the highest quality steel ball bearings available ( standard bearings as not of the same grade and not as smooth and do not roll as free) . These hubs come with standard length studs. If you would like long studs, add $30 per hub. These hubs roll better than anything out there. This is what we use on all of our race cars that we build.
We are now offering a 6 month warranty on the hubs, races included.


$220 short studs
$250 long studs

Fuel Pressure Regulator (99-05)

This regulator is engineered to work the same way Mazda designed the original system to work. With one regulator, with a return back to the tank. This ensures proper regulation of fuel pressure/pulse to the fuel injectors. Other products on the market piggy back a second regulator that does not return excess pressure to the tank but bleeds it off with the injectors opening and closing. This can cause an uneven pressure and pulse that the injectors can see, which can lead to fluctuating A/F ratios. In addition, regulating the fuel pressure by constricting the orifice size is tuning on the razors edge. You are limiting both the volume as well as the pressure of fuel supplied to the engine. This system does not limit the volume of the fuel, just the pressure it is delivered at. A large fluctuation of temperature when using "other products on the market" can lead to an extreme lean condition which can have catastrophic results, usually ending with an engine failure.
This kit is made to the highest standards using AN 6 and OE quick disconnect hardware. No hose clamps are used in this system at all. There is also no cutting or modifying of the OE hoses. All hoses are professionally made custom for the application and crimped to the fittings. The regulator is made by the leading manufacturer of fuel systems. This kit comprises all the best parts possible. Don't be fooled by cheaper inferior products on the market.
Our regulator is mounted in the trunk and not in the engine compartment. By mounting the kit in the trunk we keep it away from the heat of the engine compartment which can effect the temperature.
Adjustment is simple with one screw and the kit comes with a liquid filled gauge to monitor your pressure. There is also an additional un-used port on the regulator which can be used to add the optional fuel test port kit fitting.
Monitoring and tuning your AF ratio can help get the most performance out of your engine. This is the kit to have.
This kit comes complete with the following items:
• Adjustable Fuel Pressure Regulator
• Professionally made custom fuel lines (2)
• Instructions
• Liquid Filled Gauge
• Replacement Fuel Line

East Street Racing Heads

This is an inexpensive way to get your car to top power

For Sale - East Street Racing Cylinder Heads
We are selling our racing heads to those who don't want to buy an entire engine or just want to replace a poorly performing or currently illegal cylinder head from one of our competitors. We build the heads to the letter of the rule and push each area to the edge of the spec,but never beyond. Our heads are simply the best that can be bought, period. Look at the results of our cars Sprints Qualifying four of the top 5 cars, Runoffs three of the top four cars had these heads, at the Runoffs Pole, Runoffs win, second and third along with Two NASA championships. We are simply making more power than anyone else!
$2000 exchange on 99 up
$1750 exchange on 90-97

$500 Core Charge

1990-2005 ready to install

Hub seals 1990-2005

These seals are not available new or aftermarket anywhere. We have had them specially made for the SM hubs. We use these seals in all the hubs we build. The seals also provide far less drag than the factory seals. We only sell in pairs

Gusseted rear differential housing

After breaking several of these and finding myself parked on the side of the track and missing the entire race, we decided to start offering these to our customers as well. If you have not experienced this yet, you will at some point. Don't let this ruin your weekend. A hard bump draft or stacking up at the start off a race and getting hit in the rear usually results in a broken diff housing. we have all seen this happen many times. We started gusseting these diff housings with 1/4 aluminum plate cut on the CNC. We don't start with a broken housing as most do and weld. We start with a good virgin housing that has not already failed. The cost of this part is less than what you will lose in entry fees of one race the first time it happens.

ESR Competition radiators 1999-2005

Originally built and designed by Sam Henry of Springfield Dyno. This is the latest revision to the most effective radiator in the Spec Miata marketplace. There's a reason that so many winners and champions use these radiators, they work better than anything else out there. They have been used on 6 of the last 7 national Championship winning cars.

This is a true triple pass radiator which channels the water from side to side multiple times ensuring a substantially longer cooling time in the radiator and pulling even more heat out of the cooling system. Many try to copy, but none have been nearly as effective.

Three main attributes for this radiator are:

Reduced cooling system operating temperature. We have consistently seen 20-30 degrees cooler temperatures running this new radiator vs a 54mm Koyo radiator or a few of the other copies of our radiator.

Reduced intake system air temperatures. During controlled dyno tests, we have seen 15-20 degree drops on intake air temps.

Reduced weight off the nose of the car. Compared to the Koyo, this new radiator weighs approx. 2.5lbs less when fully filled.

The simple facts are that if you keep the coolant temps below 190 degrees, you are going to make more power. Also, if the intake air temp is cooler, you will also make more power.

This is really one of the must haves if you want to make power for a whole National race distance, even tucked up in a tight draft.