radiators
 

Hi all the rx7 gurus

I drive me car as a daily driver and i dont race and stuff... I like to cruise around ....
My car gets very hot... due to the climate aswell as it is 80-90farenheit.........
I am thinking of changing my radiator ...which one do you ppl recommend or you ppl recoomend an intercooler

thanks

For a radiator,I would recommend either Koyo or Fluidyne

Intercooler isn't going to do anything for your coolant temps.

The Fluidyne is generally a good stock replacement. However, if you are having hot coolant temp problems, you might want to see what's going on with your stock setup:

1. Check your radiator fins and make sure they aren't all mashed up
2. Make sure you have the sides of the radiator blocked up so air cannot escape around it
3. Make sure you are running a good mixture of coolant and water. i.e. run a lesser amount of coolant in the mixture for warmer climates
4. Make sure your radiator fans are working properly.

PFS. :)

http://www.pfsupercars.com/

Listen to Mahjik.....

In regard to #2: make sure the undertray is installed!

Dave

Thanks

If you have the stock plastic rad , get rid of it ! , it will fail sooner or later . The NEW koyo Nflo rad is an excellent option at a very affordable pfice , I got mine for $335 on ebay! I have a fat 4" thick FMIC blocking everything at the front and my temps cycle between 180 and 190 deg F when I stump on it !, and this is because I set my fans to turn on at 190 I also have no ducting or the OEM undertray.

Radiatorworld.com has a very good copper/brass (no plastic) OE replacement for under $170. I have that.

Dave

They don't ship internationally which is why I didn't bring them up originally. The non-USA guys (and gals) can probably find someone in their area to get them the more popular brands.

AHAH!

I didn't realize that...

Dave

i love my koyo, got it for $300 shipped omn ebay.

Doesn't that just mean that your fans are efficient at pulling air through your radiator? It doesn't mean the rest of the system is efficient... Seems to me the first goal should be to stabilize temps without the fans and only need them in extreme conditions like sitting in traffic where you're getting no air flow.

Don't forget about the FC thermoswitch that Dale Clark posted some time ago. That will turn the fans on sooner.

If you're just cruising around, I don't know if I'd bother with the Koyo. Too much of a hassle to install compared to the Fluidyne. The items that Mahjik posted will make more of a difference to check.

I agree. And don't forget the freakin' coolant thermostat. Put it at the top of the list, as it is a common failure (on any car).

The stock rad should provide adequate cooling under your conditions. Mine certainly did, before one tank failed after 10 years and 139,000 miles.... Seriously, during the summer I was able to drive uphill in 100+ (F) ambient temps with the A/C on without ever having any heating problems.

Koyo recommended
 

I don't believe the stock radiator is sufficient for a tuned FD. I also suggest the Koyo, but since it's twice as thick as the stock radiator, you might have some clearance issues reinstalling the stock intercooler duct.

When I installed the Koyo, I actually drilled out new holes next to the original mounting points so that the Koyo sits lower. This will allow you to reinstall the stock intercooler duct and places the Koyo in a better position to receive cooling air.

I have pics below showing the holes I drilled to relocate the mounting position of the lovely Koyo.

Hopefully this will save you the time of installing your shiny new Koyo only to find that now your intercooler duct doesn't fit.

The Koyo and the Efini downpipe have made the most dramatic difference in engine temperatures of all my mods.


juicyjosh

For street driving, it is.

What are you talking about ? you cannot stabilize your temps . while sitting still, this is what the fans are for ! if you let your car idle and disconnect the fans it will get hotter and hotter ! When the car begins to move and air is forced through the rad my temps actually begin to fall ! causing the fans switch off. If you do some hard driving your coolant temps WILL rise , even though the car is moving at a fast rate , this is because horsepower makes heat , an efficient cooling system will keep this temperature increase to a minimum and actually stop the rise at a certain temp , this is why I said 180degF which is normal and 190 which is when I'm doing some hard driving . My last combination of the stock water pump , "normal" Koyo and Large NPR FMIC (2" thick) would get up to 205 deg in traffic and sometimes 215 while driving hard !

Yes it is. It may not be the most reliable piece, as pointed out by Marcell, but it has adequate core volume. The limiting factor is airflow over the core and getting the airflow through the core is the key. I agree that it [stock rad] should be completely adequate for street driving and even some racing.

Incindentally, For those of you interested in this sort of thing, I measured core airflow with instrumentation on my stock ('93). Fans were on high (with the car stationary) and discovered that they draw approximately 1800 cfm through a stock rad + a/c condensor core. Hood was closed, undertray was in place, no battery or box in engine compartment (important). Note that a thicker rad like a Koyo is going to be somewhat more restrictive and probably reduce this airflow number somewhat. Unless you can increase the airflow through the core, there will be no cooling benefit to a larger radiator except to say that it can hold more heat which will eventually have to be dissipated.

http://webpages.charter.net/jargap/koyo.jpg

koyo ftw

thanks for the info guys

I'm just saying that it seems to me you are using your fans to bandaid the problem of the 4" fmic and complete lack of ducting. With my upgraded radiator, smic, and plenty of ducting my temps never rise above 195 (without fans). The only time my fans come on is in traffic or if I'm driving extra hard at the track and the temps rise above 210 (set by the pfc).

If you are talking about your temps rising to 190 when you're sitting in traffic idling, I apologize, I must have mis-read your post.

Ok , I get you now and you may be right since all my driving and testing was done without ANY duct work or the oem under tray . I have since completed a duct that completely connects the radiator core to the back side of the intercooler , so all the air that goes through the IC will also go through the rad . , I'll let you'll know how it all works.

the "NEW" Koyos are made with less fin density for improved air flow through the core.

to each his own...
 

It's really weird how people swear by the stock radiator and praise the small 1" core and make a Koyo sound like a waste of money.


Umm... don't get a larger radiator then... whatever works...