The best coolant reroute on the market - and the only one that is truly compatible with a turbocharger.
First - why do you want a coolant reroute? Because when Mazda went to put the B-series engine in the Miata, they decided to put the thermostat on the front of the engine for packaging reasons. This means that a large portion of the coolant never goes through the back half of the engine, leading to poor overall heat transfer and problems with the #4 cylinder running hot. Moving the thermostat to the back of the engine where it's supposed to be solves these problems.
We've been selling reroutes for years, and they've been gradually getting better. This one has been designed and tested for maximum flow. We went through multiple designs testing the flow to make sure this is actually true. Our flow area is 8% better than stock, 11% better than the first reroute we sold and 5% better than our previous offering. We even tested flow through the heater so you'll stay warm.
It puts the thermostat right into the head where it belongs so it reacts quickly. It's completely compatible with EGR pipes - not "it works if you hit it with a hammer" compatible, but done right. It's fully electrically conductive so your temperature sensors read properly, and it has a spot for an aftermarket sensor. The reroute housing is a single piece to avoid leaks. Even the thermostat is off-the-shelf 180°F unit so you can run a different temperature if you'd like. There's a bleeder screw on the top of the housing so you're sure you don't have air bubbles. So it's the best reroute you can buy already.
But the big difference is the turbocharger. We worked with the engineering department at Colorado Mesa University to map out all the cooling factors of the Miata engine, and discovered that a water-cooled turbocharger will increase the temperature of the coolant flowing through it by as much as the rest of the engine put together. To make things worse, this very hot coolant is mixed right back into the engine coolant, with no chance to cool down at all. Obviously, we decided to address this. We dropped the amount of flow into the turbo - they really only need the water cooling when the engine is off and they use thermal siphoning to get it - and plumbed it back into the water heading into the radiator so that it's cooled before going back into the engine.
If you are going to be using this reroute with a turbo, our turbo connection kit includes new multi-layer silicone lines with heatshielding, anchors and all fittings. It is designed for Flyin' Miata turbo kits but should be compatible with most Garrett turbos regardless of source. If you have an MSM with the stock turbo, be sure to choose the MSM-specific kit, but if you have a non-stock turbo on a MSM engine you need the standard (not stock MSM turbo) connection kit. You can also build your own but you will have to be sure to protect the turbo water lines from heat for long-term durability. Our turbo hard line kit won't work with our reroute.
Built in the US. Includes everything required for installation. Compatible with stock and FM turbo EGR piping. Compatible with both upright and crossflow radiators. Compatible with our Big Spark kit. Includes all required hoses/lines, fittings and heatshielding as well as plates to block off either the thermostat or the thermostat neck and plugs for unused fittings.
Want even more tech? Check out the development process in this in-depth video!