Planning my budget turbo build and pricing the radiator right now. Running my current one is not an option, it is quite yellow. Options are CSF (expensive), CX Racing (I'd be ok with), or the OEM replacement $80-90 ones on amazon. Plan is to run either a 2554 or SR20 turbo, either way it will be water cooled. No coolant reroute. Daily driver, no expected track use. Goal of 12lbs, 200-220whp. I've seen one thread of someone running a stock rad, and just wanted some more confirmation.

Can I get away with running the oem replacement radiator? I was thinking I could wire both my fans in parallel to come on at the same time (although this could have adverse effects https://forum.miata.net/vb/showthread.php?t=606268).
Just trying to save here and there. Appreciate any help!

 

do you have A/C or not? if you use your AC you will overheat. been there done that.
without A/C you should be ok with stock radiator.

the problem is not the turbo making extra heat, is the intercooler is blocking most of the air flow through the radiator.

you will need to close off the mouth where the air comes in, and direct it to go through the radiator, not around it.

 

I have ac but deleted my ps and won’t be using it. Probably will take it out.

 

high rpm driving creates heat.

the formula for a cool running miata is:

1. Ducted radiator, so the air is forced to go through it, and not around it.
2. stock undertray in place under the engine
3. decent radiator (i have moshimoto)

for me to keep my miata cool on the hwy running AC and cool on track days, it took all of the above, plus hood vents.

 

Right. Maybe i wasn’t clear, i have the capability to run ac, i just don’t (im not paying for an idler pulley )

I’m learning towards a CX unit just for safety and peace of mind...

 

I run the cheapest all aluminum ebay radiators in all my cars except for my single track speed radiator in a car.

 

CSF is a good buy. Ebay-esque all-aluminums are a frugal alternative. Avoid stock.

 

Aaaaaand can of worms officially opened. I’m happy with the price and hundreds of success stories from cheap aluminum rads

 

I'd also recommend the cheap aluminium rad over an OEM replacement.

I've had the same ebay alloy radiator in my track car for 10+ years, now boosted and it does the job admirably, even now with an intercooler blocking the bulk of its path. No air con though, and only one fan. (only for in pits, dont need any fans out on track!)

 

Solid testimonial! Do you run ducting/cutouts or shrouds of any type?

 

I didn't run any ducting or cutouts, and both fans/factory shrouds for the first 9 years naturally aspirated.
When I boosted it a year ago, I removed the air con fan & shroud, and fabbed up some ducting to push more air through the radiator rather than around it.
Its not a particularly comprehensive setup, prob 70% effort as a first attempt, and then I'd run it and see if I needed to to go further. (If it overheated, then my plan was bonnet vents (eg Singular style) and a more focused attempt on channelling ALL air through the heat exchangers
As it turned out, its run 4 events so far, on the fastest track we run on and didnt have any issues, so havent bothered with bonnet vents or further ducting.

 

I replaced my Supermiata crossflow with a $100 ebay rad because of leaks and the street performance is the same. Haven't had it out on track other than drag racing though.

 

So what do you do for fans with the cheap alum rads? IME they're generally a fair bit thicker than stock.

 

I actually put my eBay rad in last night. Had to file out the top holes on the fan to get them to fit but hey 10 minutes of work was totally worth it. It fit perfectly to the radiator support holes and pins. Car is still apart while I replace all the hoses but it looks promising and i don’t expect any issues. Fans fit just fine in the car. Sure it’s tight but they don’t contact the sway bar or ac lines. $112 shipped

 

I too opted for the cheapest aluminum eBay radiator after reading a few threads on the subject. Also went with a cheap eBay silicone hose kit to top it off. Car is still a work in progress so no testimony yet but I’m positive it’s better than my old leaking stock radiator haha

 

My alum rad is 42mm thick, and the factory fans fit on just fine without modification.
Yes, they are a little closer to the motor and sway bar, but nothing that causes any issues.

 

Stock fan and some aluminum tape to seal.the top and bottom of it.