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Flyin' Miata coolant reroute

Main body of reroute, not all parts shown
Flyin' Miata coolant reroute

From: $299.00

To: $387.56

Price as configured: $299.00

The best coolant reroute on the market - unless you have a turbo. Then it's really the only coolant reroute on the market!

Made in the USA

Exclusive to Flyin' Miata



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 an off-the-shelf 180F "Superstant" 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. We also have a version for MSMs with their original stock turbo, and if you have a non-stock Garrett turbo on a MSM engine you need the Garrett connection kit with the extra MSM parts. 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. Please note that our hard lines aren't compatible with the 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, although fitment is easier for 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.

Installation Video:

Why do you need a coolant reroute?

Additional Information

Additional Information

Part number 09-6002x
Fits: 1990, 1991, 1992, 1993, 1994, 1995, 1996, 1997, 1999, 2000, 2001, 2002, 2003, 2004 (non-MSM), 2005 (non-MSM), MSM
Manufacturer Flyin' Miata
Flyin' Miata exclusive Yes
Fits Exocet? Yes
Proposition 65 Warning: Cancer and reproductive harm
California emissions Emissions regulations do not apply

Customer Reviews 3 item(s)

Overall awesome product
Overall really good product. I did have to retap the large hole on the thermostat neck block off plate, because the boot absolutely would not thread into it. By the grace of God I had the correct BSP tap from when I tapped my oil pan for the BSP turbo drain fitting from kraken. I would have been less than happy if I didn't have this tap but probably would have just had it welded shut. After that the included bolt threaded right in. Also seems like the bleeder is finicky. I had it tightened down as far as I feel comfortable and it was still leaking about a drop every several seconds out of the bleed hole. Tightened a little more than I wanted to and seems to have buystopped but we'll seem.

Note from FM: that hole is an M16x1.5 thread, not BSP. We have adjusted the instructions to make it easier to get the bolt started in case of any minor thread deformation.
Review by chad / (Posted on 6/19/2020)
Great for 1.8 turbo miatas
Easy install if you have the engine on an engine stand, which is the way I installed this. Instructions are decent. I must say they could include a hose clamp for the large hose going to the radiator. When I got to the gasket install the instructions say something about peeling off and placing the sticky side of the gasket to the reroute. None of my gaskets had an adhesive side. Don't know how much that matters. It's close to the firewall but very manageable. Love the one piece design. I know it would cost a lot more but I would love to have a pre-bent hose instead of the vibrant straight. It would make this so much cleaner. Something like the il Motorsports re route. Would definitely recommend to anyone to has a 1.8 turbo Miata! The ports on the reroute is the reason I purchased this setup. Two thumbs up for sure and just a few small complaints but no regrets with my $350 purchase.
Review by Jordan / (Posted on 5/12/2020)
Expensive but Effective
I installed this kit on my forged 1.8bp before installing it into the car, making it extremely easy to install. Coolant temps now read 175 degrees F when im driving and spike to 185 at idle. The only time the engine has been able to get past 200 was after the car was turned off. I am running this with a stock radiator/fan, naturally aspirated for now. The bleeder is a little tricky at first but just use a small 1/4 inch wrench and its possible. Thread sealer on all threads! They included enough piping to get from the reroute and stretch under my skunk2 manifold and back up to the rad comfortably. This reroute has lowered my temps and cleaned up my engine bay. I would highly recommend this for anyone that is looking to go FI now or down the road (as they include turbo water feed block offs). Pricier than other reroutes in the market but much better engineered. Well worth the price if you want the best for your engine.
Review by Mat / (Posted on 4/29/2020)
Click here for instructions for this part.
Flyin' Miata coolant reroute (currently on backorder)

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Price as configured: $299.00