Coolant reroute for Mazda MX-5 Miata

Reroute benefits
Take a look at drivers experience from around the world.

In my opinion coolant reroute is the most important cooling mod.
- bellwilliam, miata.net forums

Results were good and I see 9°C less than standard system. Success!
- richie2912, mx5nutz.com forums

I wouldn't even think of a real turbo on a 1.6 without a coolant reroute.
- gtxhawaii, miata.net forums

Not convinced? Here are some more:

I did a coolant reroute and erratic temperatures have ceased. Car runs smooth as butter.
- Yosimite, miata.net forums

I'm very pleased with the reroute kit and would recommend it to anyone with a temperature problem.
- jimmyjet, miata.net forums

I installed the re-route almost as soon as it became available. With all the boxes checked, I think I've finally got things under control.
- DeerHunter, miata.net forums

I put the reroute on primarily to equalize temperatures across all cylinders. I noticed a small decrease in temperatures (~5° F) at the end of my track sessions.
- CoralDoc, miata.net forums

I did notice that my fans did not come on at idle, at first I thought that I did something wrong but my car temperature was actually lower. The needle stayed midway instead of just above.
- LLester, miata.net forums

I had overheating problems when traveling through hot areas (>100°F), had to limit my speed and cut back on the AC so as not to overheat. Haven't had issues since, even in 112°F heat last summer.
- JWR-MX5, miata.net forums

The summmer heat would play hell with the power output of my mild-modded 1994. After the reroute, my throttle response, was crisper on 120°-ultra low humidity days on those long high speed trips to Santa Fe.
- Reverend Greg, miata.net forums

And even more...

I noticed the #4 cylinder was a little lower on compression than the others about 6 months after fitting the turbo. I modified my fuel rail and rerouted my cooling system. Since I made these changes there has been no further detioration of my #4 cylinder pressure.
- Ralph C., miata.net forums

Whether or not an owner has a cooling problem isn't the real point. They may not overheat, but the heating/cooling of the engine isn't uniform with the front return of the original system. I'd say for those who run hard, especially in hotter climates reroute is a great idea, along with a better radiator.
- Dragonfighter, miata.net forums

After installing a traditional rear-thermostat reroute on the '92, I noted a decrease in normal operating temp (as measured at the stock CLT sensor at the back of the head) of 5-10°F on average, and also a marked decrease in the vehicle's propensity for overheating (which I define as >210°F) in slow moving traffic. These measurements were taken with a datalogger on the MS, so I'm fairly confident in their accuracy.
- Joe P., miata.net forums

The rerouting kit achieves it's goals of using the radiator more efficiently and flattening out the cylinder to cylinder temperature. The kit sends coolant to the radiator consistently 20°F higher than the stock configuration while maintaining the same thermostat controlled temperature at the back of the head. The kit minimizes the temperature difference between #1 cylinder and #4 cylinder from 20°F in the standard configuration to a 5°F maximum. And that 20°F is a mixture delta, the actual delta is even higher.
- Richard M.

Thanks for reading all the way down here. We tried to copy the whole Internet, but it wouldn't fit, so that's it for now.