Fluidyne for daily driver
 

Is there any downside to a larger radiator like the Fluidyne for stop and go traffic? I would like to replace my radiator, and don't want something so big it needs a lot of airflow to be effective.

umm...bigger means it needs less airflow if i am not mistakening which makes it better for stop and go driving.

I read somewhere that if it's too thick it will be counter productive at lower speeds. I get stuck in bad traffic at least once a week. I don't know at what point larger becomes worse.

high preformance radiators should be fine. That is what they are desgined to do. If anything, the radiator fan will kick on and youll get the benefiets from there.

What you are referring to has to to do with air flow blockage throu front mount intercooler. The thicker the core, the less air can get to the radiator and therefor decreased heat dissipation.
From just the radiator standpoint, larger means more surface area, which means more heat dissapation with or without airflow. While it's true that if the core gets thick enough, it will reduce airflow, it would have to be thicker than anything that is out there for that to be significant.

Stop and go traffic doesn't provide enough airflow no matter what radiator you have. All you can do is seal up all the gaps between the radiator and bodywork, and ensure your radiator fans are both in working order. You will be better off with an upgraded radiator anyway, as you will get rid of the stock plastic end tanks that degrade and split after time, which could obviously cause major problems.

That's what the fans are for, other wise according to Kento's logic all cars would overheat just sitting and idling because there is 0 air flow. When any car is designed, the cooling system is engineered to achieve thermo balance. The fans provide more than enough airflow for proper heat dissipation (that's why they come on and off, other wise it would be on all the time). At higher speeds, the ambient airflow exceeds that of the fans to provide more heat dissipation due to higher engine output (higher rpm). In stop and go traffic I doubt you would be sustaining 3000 rpms or higher.
If a car is over heating in slow traffic, there is a problem with the cooling system in general.

I spend a lot of time in stop & go traffic while driving around town. My Fluidyne works fine. In fact, any radiator will work fine, as long as it doesn't leak, and the fans work properly.

Your logic requires a bit more reading attention....

go with a koyo .. theyre larger than fluidynes .. fluidyne = 50% more than stock .. and koyo = 100% more than stock

any radiator is good as long as its not stock. if you havent done the fan mod i would suggest it or at least drive in traffic with your parking lights on.

ps
get a beater. fd's should never see traffic or a drive through window. :D

fitment is a bit more a problem with the koyo in the stock location b/c it is thicker - or so I've read here.

i have a fluidyne and my mods aren't too far off stock. works well. pretty low temps overall even in NY stop and go traffic.

I have a koyo and with my car being a daily driver, I get stuck in traffic all the time. I have zero problems with water temps.

ive heard about fitment problems with koyo's thats why i went with fluidyne .. but my fluidyne did not fit perfectly .. had to do little chizzling on the fan's bolt holes inorder for it to line up (more work than i anticipated) .. way i see it .. might as well put in another 30 minutes and get yourself a koyo .. cause youre gonna end up trying get it to fit anyways .. and in the end have a larger radiator .. oh yeah and koyos are cheaper

if you want ill do a 1 for 1 trade .. my fluidyne (w/ less than 200 miles on it) for a koyo radiator

Get a Koyo, the fittment is not bad at all. You basically have to turn the two upper brackets around and grind them down slightly. The bigger rad and the fan mod will make a big difference in your temps. Switching to the Koyo made on average a 10-15 deg C difference in my water temp (verified with the PFC) both in stop and go traffic and on the highway.

Larz, the Fluidyne has been hit or miss, some people have had no fitment issues, then others have had to hack for a few minutes. Regardless of which you go with, either will be a significant improvement over stock, That, and you should trust me since we have like Avitars, lol.

Chris-

how much do koyos run?

www.rx7store.net <-- go to cooling then radiators.