Summer is coming and every year my Rx-7 tends to run a little hot when sitting in this Northern Virginia traffic and especially so when I go out on an autocross event. Popping to hood so more air flows out has worked for a few years now because it opens backwards but it's about time to toss out the 37 year old radiator for something new. There are just a lot of options at different price points and I'm a bit confused as to what would be best. My main priority is to keep the stock clutch fan and shroud. Here's what I'm looking at:

$300+ Koyo
~$230 Champion/Rotary Works
$150 eBay/Walmart special

The koyo, champion, and rotary works are all 3 core radiators and the eBay/Walmart ones are mixed between 2 and 3 core. What exactly am I gaining in the $100 price jumps between these radiators? They all claim to be of good quality but I see plenty of people on the forum claiming they all work well.

As of right now, I'm considering either the Rotary Works or the Champion. What aluminum radiators are you guys running and how do you like them? Did they fit with the OEM shroud and fan or did you need electric fans and an aftermarket shroud?

Thanks guys for your help

Edit: I should also mention that at some point in the future I'd like to add some more power, but nothing crazy. Probably just an S4/S5 intake swap onto my GSL-SE motor or maybe diving down the rabbit hole of ITBs if I could ever figure that out. Of course tuning would be needed. No crazy numbers, but somewhere between stock horsepower and 200.

 

The Champion 3 row one can also be had on ebay for ~$200-$215 or so. They may need some trimming on the mounts.

https://www.ebay.com/itm/3-Row-Ace-C...0AAOSwwP5a50WO

if you want to buy it once, the KoYo or a Ron Davis are good choices.

 

What exactly do you mean by "buy it once"? Do the cheaper ones have welds that won't hold up?

 

If your plan is to have more horsepower and the cheaper one doesn't meet that need, you could end up buying a more expensive one. I think the Champions 3 row are good for a stockish engine. And for a stock non-tracked car the factorey fan clutch is a good choice. For racing, the electric fans are a good choice because they do not rob horsepower and can be turned on when sitting still or moving slow. Look up MustangHammer. He has a nice setup for racing.

 

Okay I gotcha, getting a koyo is basically future proofing it. From what I read it should bolt up just fine with the stock fan. If cooling is still inadequate with that then it'd be time to look into an electrical fan set up

 

How much HP does a clutch fan rob off of your car?

 

It's not that much. The bigger concern for racers is to keep the engine cool while not moving or moving slow. An electric fan solves that problem.

An electric fan has it's own issues like using more amperage from the alternator and a bigger failure point compared to the clutch fan.

If you have a working clutch fan on a street car, stick with it. Now, if it's bad, finding a reasonably priced good one can be a challenge. One of the other reason folks switch is because maybe they installed some non-stock engine and just don't have the room.

 

FWIW I tried a chinese 3-row. As stated, mount points are "close", meaning some mod of holes may be necessary.
But the biggies were:
1) the FMOC mount points were OFF enough to make a poor fit for the FMOC. Stupid.
2) leaked
$120 I basically had to just junk...
Champion looks good-

Stu A
80GS, back with stock rad
AZ

 

I got friends with turbo cars that use the ebay 3 rows a day they have no problem with it...

All depends on how much you want to spend...

I just bought a $120.00 3 row aluminum rad from ebay and looks awesome...

 

been using a Champion on my 12A BP with no issues.

 

Searcch is a simple thing and gets you information faster. Discussed at length here: https://www.rx7club.com/1st-generati.../#post12266973

For me, KoyoRad still going strong, and I live in the Sonoran Desert where it it's 120F every summer for a few days. No problems with engine heat,

 

I bought a radiator form pepboys. It expanded. Bought a RGT radiator from a radiator shop. the fit was better, and it has lasted +25 years.