PART NUMBER: 61-1845
The best direct-fit high performance radiator for the MX5. Period.
High-demand cars such as turbocharged, supercharged, and racing applications need maximum cooling ability. For many years the next-step beyond the standard aluminum radiator upgrade was to move on to a custom multi-pass racing radiator. Those radiators packed massive cooling ability, but also come with massive price tags and are not direct-fit; required custom brackets, didn't fit with factory fans, and so on.
Our new Triple-Pass radiator is the first of its kind; a cross-flow, triple-pass configuration using racing radiator technology throughout that still drops in without any other modifications, and doesn't have the price tag that comes with "custom". Fits with the factory brackets, fans, and hoses.
- Triple-pass flow design makes the water pass fully from one side to the other through the radiator THREE times instead of ONCE, more efficiently using ALL the frontal area of the radiator and giving the water more time to shed heat.
- Advanced fin and tube technology:
Utilizes CSF's specially-engineered "B-tubes" which are made from thinner and lighter aluminum but are still stronger than conventional 0-shape tubes. The core features louvered fins with a denser packing. More fins per inch than standard cores means more surface area for cooling and thus dramatically higher efficiency.
- 32mm core for peak efficiency and light weight:
Conventional high-performance radiators with low fin counts and standard tubes have no choice but to increase the core thickness to get more cooling. This core is about double thick compared to stock yet still less than two inch race cores. The two inch core units slows down the air more, and that hurts efficiency, so you get diminishing returns as the core gets thicker and thicker. A thicker core also means a heavier radiator. The new generation of radiator advances used in this unit allow us to achieve a new "best" for cooling ability without any need to dramatically increase core size. This 32mm core allows for fast airflow, further improving performance, and keeps the weight well below classic 2 inch thick racing radiators. The relatively thin core also means the unit can drop in place of the factory unit without the need for relocating anything.
BRIAN'S APPLICATION NOTES: This project started after I compromised a normally aspirated 2.5 liter motor in my 2006 'Project Blue' during a hot August autocross day despite having a performance all aluminum radiator in the nose at the time. The motor didn't actually fail but got briefly hot enough for piston ring tension to be seriously compromised with resulting loss of peak horsepower measured at 20 percent on the dyno a few days after...OUCH. We ended up rebuilding that motor with high compression pistons and I had learned my lesson on giving an upgraded NC as much cooling as available when any track or autocross use is planned. At about the same time we decided to push our supercharged 2.0 2007 to over 300 hp and found we needed more cooling in that NC than our current selection of radiators could provide, we needed an $800 Ron Davis race radiator over 2 inches thick in that car until this triple pass was developed to accomplish the cooling just as well without near as much weight and without fitment challenges that came with going beyond 32mm thickness used here. Thus, for those racing boosted 2.0 and 2.5 and those racing even normally aspirated 2.5 we suggest this is a critical insurance policy that saves you money in the long run! Works great in combo with our singular hood vents (which draw even more air through the radiator).
Will install in automatic trans Miatas but lacks the transmission cooling line, so plan to add a simple Hayden trans cooler that typically runs about $20.
- The factory radiator hoses will install as-is on this radiator. However, we like to trim 1.25" of length off the driver's side hose on the end that connects to the radiator for perfect fitment.
- Do not try to re-use the factory spring clamps that hold the hoses on the radiator. Those clamps wear out over time, and the nipples on aftermarket radiators can have tiny variations in diameter from the factory ports, so you don't get adequate clamping with the factory spring clamps. We recommend changing those clamps out for worm clamps, which you can get from any auto parts store. This ensures you can tighten the hose down appropriately and have no leaks. You MUST check clearance to condenser, factory condenser installs not real consistent and you want to make sure nothing will rub a hole in the new radiator, bend consendser brackets for clearance as needed.
Along with triple pass radiator upgrade we also recommend upgrading your water pump from the factory NC pump to the Ford MOTORCRAFT unit with better fin geometry and construction, part number PW625 available at most auto parts stores. That pump is a good upgrade for all NC's, but will especially help with pushing the coolant through the longer path of the triple pass radiator.
On our Budget NC 2.5 liter for three FAST days at Laguna Seca Raceway:
Also a prime reason our Supercharged 07 with built 320 hp motor has been safely racing that motor for a full decade!
Video clip below doing Laguna front straight in 10 seconds, if you want to go fast like this, you need this kind of cooling!
On our latest 2.5 NC at Sonoma Raceway:
Not much to say here that Brian and crew haven't already covered in the description: this radiator is completely as-advertised.
I purchased my 2.5L-swapped NC2 in January of 2023 with the knowledge per the prior owner that it generally cooled fine, but did not enjoy sitting in traffic, especially with the A/C on; i was able to confirm this in 60 degree temps in January, seeing water temps of 215 at some points. Being in Texas and wanting to use the car outside of the track as well, that just wasn't going to fly. Car had a radiator of unknown origin in it which had clearly seen better days by the time I pulled it out.
Today driving the car in traffic in 93 degree weather with the A/C cranked, the highest water temp I saw was 197; while in motion at highway speeds it's not even remotely that high. Really looking forward to getting out on track now that I have faith in the cooling system.
Install is a pain, I will be completely honest, but that has nothing to do with the radiator and everything to do with the stock location. Did not have to make any modifications, everything bolted back up just fine, maybe even better than with whatever radiator came out of the car.
I went ahead and bit the bullet and installed the stainless overflow tank at the same time as well, but I neglected to buy new silicone coolant hoses the first time around and immediately learned what a mistake that was on my second test drive: I wound up blowing the main coolant hose and wound up have to dig back in to replace them. Don't be like me, just knock it all out while you're in there.
I just installed this radiator on my 2006 Miata with a Garrett Turbo. On the drive home, I saw a good 20% reduction in operating temperature. The turbo combined with driving at high elevation creates extra heat. I am confident this radiator will enhance performance, reliability and my driving confidence.
Had Rocky put this in along with a 2.5 swap. Just got back from pushing it hard in upper eighties weather at ORP. Performed great!
Incredibly made product. Sad part is it's buried so deep in the nose-cone nobody will get to enjoy looking at it. The fit- amazingly perfect. Installation a hassle - but no fault of the product. Just the nature of the job.
It's too good! It's winter in GA and I had to block off both openings in the grill in order to limit airflow through the radiator. Can't wait to test it at some track days this summer and see what it can really do.
Fitment is mostly okay. The side air channels do not line up as well as on the OEM Radiator. I discarded the clips and used zipties to attach them. The fitment of the passenger side small radiator hose was also iffy. The male fitting for the hose is ever so slightly too small in diameter. I tested multiple different hoses and compared against the OEM radiator. I double clamped the hose and everything is fine, but I wonder if this could be improved.
Overall happy with the product and would recommend despite the few shortcomings.