As we already mentioned, Mazda used a different head gasket on NBFL (MK2.5) cars to promote the coolant flow into the back of the engine. They did it by closing some of coolant passage holes in the gasket - restricting the flow into the front thus forcing more of the water to the back. You don't need to be a rocket engineer to see it's definitely the cheapest and simplest solution, but far away to from being really efficient. Does it cool bit more evenly? Probably, but overall you're getting less coolant through your engine at any given moment = less heat dissipation. We don't see this as a great idea, especially if you're trying to improve your car, so we offer you a better option - a coolant reroute with older (98-00 NB/MK2) head gasket. That's what we call a proper solution!
Our reroute solution is compatible with any 1989-2005 Mazda MX-5 Miata except for Mazdaspeed models. Our reroute is made to last and the installation is fully reversible, so it can be reused countless times (with new gaskets, of course).
In case you have EGR system on your 99+ car, you will need to modify the EGR pipe at the back of the engine. This is an easy job for any shop or experienced mechanic. The second option is to remove the EGR system, which might or might not be legal depending on your local laws.
Definitely not, however it is the ultimate solution for saving the rear pistons, valves and spark plugs from getting cooked :-) There are many other cooling system improvements, from getting more airflow (cooling plates, ducting) to better radiators and oil coolers. These modifications will help you lower the temperatures, but won't make it even across the engine.
If installed properly there are no risks or drawbacks related to coolant reroute. The only disadvantage we know of is slightly longer warm-up time (because you're going to use up to 1 litre of coolant more). Coolant reroute does not introduce any danger to your engine and other parts.
Coolant reroute does not affect the car structure, engine's behaviour nor emissions in any way. You should not experience any issues with technical inspection. From our experience the inspection will not even notice this modification.
By offering coolant reroute parts for (almost) peanuts we provide every owner with an opportunity to improve their MX-5 Miata cooling system. We understand only a few people are able to make their own reroute parts, so we seek to help out as many as possible. Thanks to all the happy coolant reroute users we know we're on a good way.
Our aim is to offer the highest possible value for your money and provide unique, effective product designs. We use the earnings for development of new, exciting parts and ideas, which we offer at SkidNation.com. Easiest way to support us (and your engine's lifespan) is by getting a reroute kit for yourself - or you can start with just a simple "like" on our page. Thank you.