i've searched and found nothing specific to my needs except one but it was for an fd. anyhow i went cruising a couple nights ago through the canyons, and while cruising uphill my temperature started to rise. now, i'm in california and we've been having a heat wave but in the canyons it was cool. i know since i was going uphill i was putting a load on the engine which caused my heat increase, so im asking what significant cooling upgrades can i perform to keep my fc in the right operating temps while going uphill. by the way its a 91 FC NA all stock for now and it runs fine. id just like to get to the top of the canyon easily and in one piece so to speak LOL. i know a better radiator than the oem rad is needed, but id like to learn what radiator would be best, and what other mods can help thanks guys

 

So what were the actual temps you were seeing?

 

around 200F on my temp gauge as high as 210. i realise that's about normal especially under uphill load. the stock gauge went up from its middle position as well slightly above middle and the stock gauge is what worried me. yeah i have the aftermarket gauge as well LOL. i guess i was psyching myself out but i would like to keep a bit cooler. i installed a brand new oem thermostat a couple days prior and all is fine along with new hoses and aluminum thermostat cover/neck.

 

A simple Koyo radiator should solve your problem. If you still have the original radiator then you should probably replace it anyway because the plastic end tanks get brittle and crack over time.
RX-7 Store - Koyo Radiator

 

yeah i was looking into a koyo rad that same day lol. was looking at forum member juan's jauto since they are cheaper J-AUTO - Bushings, Suspension, Parts for Mazdas . i think he has a storefront and its not too far from me anyhow. would there be anything else or the rad is all that is needed.

 

You barely have an overheating problem, the new radiator should be all you need.

 

i thought so. thanks i mean the stock gauge stays at the middle during normal use but on the mountain going up it gets hotter and it caused some concern. again thanks for the help and recommendations. i guess a rad upgrade will be my next buy

 

If you have a real temp gauge, why are you paying any attention to the stock gauge?

 

/\.this is all you have to do.
..unless you want to go all apeshit and spend countless hours creating ducting,electrical Efan,then a Big *** Alt upgrade..etc,etc..(stop the madness!)

You took a spirited drive,the car got warm.

Now,If the Stock gauge Hit "H" and coolant spilled out of the front of he car I would be concerned.
Since it didn't,then I would ponder the new rad for a reliability upgrade.As Evil Aviator said,those plastic ends are just Crappy.

 

Oh I don't know about that.
Given the harsh environment, a part that lasts for 20 odd years can hardly be called "crappy".
Let's see what a Koyo looks like in 2035 before making a judgement call.

 

since its still connected and works fine(as fine as the stock s5 gauge can be LOL) i take it into consideration. i guess it will take me a bit to completely disregard it

yeah i guess like i said before i probably psyched myself out when saw it get hotter than normal. the funny thing is that same night my friends car crapped out somehow and he had to coast all the way down the mountain since his car wouldn't fire up.

 

** Thread Hijack alert **

Does water wetter help to keep the operating temps down?

 

I think it's snake oil.

 

I'd agree and say instead that after 20 odd years they become crappy.

The Godspeed is another option. It is just a Chinese knock-off of a Koyo N-flow. It does require modification of the stock fan shroud in order to retain the stock fan/shroud setup, but so does the N-flow. So far I am happy with mine.

 

how good is the godspeed in the long run? i read this thread a bunch of times https://www.rx7club.com/2nd-generati...iators-835115/
and it seemed fine but im not too sure about it. it said some koyos would fail(not sure of the circumstances though) ill look into the koyos and godspeeds. i wanted a fluidyne but 500 bucks for a rad seems crazy LOL. unless i get this new job ill probably get the koyo. would the n flow cool better? and does rad thickness really matter on a daily?canyon car?

 

I've only had mine for 6 or 7 months so not sure on how good it will be long term. So far it has been great. Temps stay solid though I haven't did any extended hard runs. Just some redline blasts through the 1st three gears then back to normal driving.

I think the N-flow would cool better than the standard replacement due to being a dual pass. The N-flow and Godspeed( if the separator mentioned in the other thread is mounted right) should be equal since the Godspeed is a N-flow clone and a touch thicker.

I would say yes thickness matters on a daily. On mid to upper 90 degree F days in stop and go traffic is where my copper/brass stock replacement I had previously really struggled. I had seen it hit 210 to 220 before. This Godspeed might've hit 200 this summer and cooled down faster in the same scenario. I would expect the N-flow to do the same.

 

thanks for the info. i had read on here that thicker rads don't really matter for a daily but i guess since i canyon carve it would make a difference. anyhow thanks for the help guys much appreciated.

 

It would help keep the temp down if there are hot spots, but I don't think it will do much otherwise. Its primary purpose is to provide lubrication and corrosion-resistance to the cooling system in situations where glycol-based antifreeze is not allowed in racing events.

"Godspeed" is a generic brand name used by various low-budget Asian manufacturers. There is no one Godspeed radiator standard, therefore you don't know the quality until you take it out of the box. You may get a good one, or you may get a bad one.

The cooling system is binary, in that it either works or it doesn't. Just as long as it works, more cooling capacity does nothing for performance.

Thicker radiators are not necessarily better. It depends on the construction. Generally speaking, a thick radiator is not good for a street car because most street cooling problems occur at low speed or when stopped, and it is difficult for a fan to move a lot of air through a thicker radiator.

A single-pass is usually best for the street, a double-pass is usually pretty good for race cars that have a high-flow water pump, and a triple-pass is usually good for low-speed situations where there is little airflow, such as drifting events. The problem with double-pass and triple-pass (n-flo) radiators is that they require much more pressure to move the same amount of coolant. If the water pump is stock, then the pressure will go up and the flow will go down, which will actually make a double or triple-pass radiator less efficient at higher vehicle speeds. If you want to learn more, see SAE 892466.

 

Thanks for the info. I figured as much from that godspeed thread.Im a firm believer In "you get what you pay for", so I didnt want to chance It with my car. Thats the kind of info I was looking for. I guess I just didnt know how to word it. So even for spirited canyon runs a single pass koyo is what I would need even for the uphill? the n flow and other double/triple pass rads would actually be aginst my best interest.? Thanks will definitely read the link as well.

 

Just tossing this out there: The Koyo radiator can be found on Amazon. I got mine there for $267 shipped. The fitment was perfect in my S5 NA. Having a new radiator with no blockage vs. a questionable factory radiator that is 24 years old is a no brainer when trying to solve overheating issues. I autocross my car in PA and have no issues with the Koyo. The piece of mind from dumping the plastic radiator is worth this upgrade alone.

As for water wetter? I've been using this product in all my cars for over ten years. There is a chemical term for what the product does that escapes me, but in layman's terms it allows the water molecules to make better contact with the metal surface. Hence better heat transfer. Now if the inside of you engine cooling passages are gunked up with sludge and 2 bottles of stop leak, you're not going to notice a difference. On a fresh rebuild with 60/40 water/antifreeze, I've seen 10 degrees difference using the product. In a race engine with 100% water, I've seen a 15 degree improvement. That's my experience and of course everyone has a opinion...

 

thanks great info. i didn't even consider amazon lol. i already had planned to swap the rad anyhow when i first got the car at the beginning of summer, but other things kept coming up and i never got around to it. mainly because the rad is so old was the reason even though it is still running good(besides the uphill push). i had done a complete coolant flush, hose replacement, new thermostat, and aluminum thermostat neck just a couple of days prior to the canyon run. first canyon run with the 7. i guess since im in california and we have been in this damned drought for the part 3 years on top of this damned heat wave we've been having for the past 2 weeks could have contributed.

 

It is supposed to decrease the surface tension of the coolant. If you don't know what that is, water that beads up has a high surface tension and water that just glides off a surface without beading has a low surface tension. This is how soap works.

(Btw, please for the love of god don't even think of putting soap in your coolant)

 

In your case I don't think it will matter because your car has so little horsepower.

Yes, it is called a surfactant. Antifreeze also has this property.

 

yes i know i'm just a slow lowly na LOL.

 

I'd like to read the paper if I could find it for free. I remember reading another thread on here where people were debating this. I just went for the cheapest option at the time. Is there a high-flow water pump available for the FC? I might consider upgrading when my current one fails.