Mazda Rotary Club

Cars by Model Type => 3rd generation RX-7's => Topic started by: weejimmy on June 14, 2008, 05:35:13 PM

Title: are koyo rads the best???
Post by: weejimmy on June 14, 2008, 05:35:13 PM
need a new rad and heard a lot about koyo but is there any competitors?
 
koyo is fine but just  wonderd what my options are
 
what about just geting radtech etc to make one or a off the shelf one from them.
 
as its going v-mount i wonderd if the shape of a koyo could be a disadvantage????
 
i think!! ill have around 500 bhp ish mayby and i will do some proper ducting too.
ta peeps
Title: are koyo rads the best???
Post by: interloper393 on June 14, 2008, 07:17:07 PM
iv got one fitted and it works great, think theres a pwr rad thats meant to work really well 2 :)
Title: are koyo rads the best???
Post by: RobMatthews on June 14, 2008, 07:25:32 PM
i have a ron davis from america all alloy,profesional looking welds not used it though! but looks like it can handle it self no problem and is chunky size and very good fit with all the fixing holes and fan fixings lining up perfectly.
Title: are koyo rads the best???
Post by: Kevin on June 15, 2008, 08:37:56 AM
Very good radiator, never see really any higher than 85 degree water temps and thats on a spirited drive too!

Fit is spot on too!
Title: are koyo rads the best???
Post by: weejimmy on June 15, 2008, 02:15:11 PM
cool thanks
i think what i ment was is there any CHEAPER rads that work as well?
as the koyo is shaped to fit in a standerd position it is shaped funny, so thought mayby you could get a off the shelf one cheaper like pace intercoolers, for a v mount as you dont need the shaped bits,
Title: are koyo rads the best???
Post by: RemarkLima on June 15, 2008, 03:31:57 PM
I ended up getting a koyo as they have the N-Flo (so a triple pass rad), so anything off the shelf with multiple passes would be best IMHO.

Otherwise if you\'re not worried about shape then the world is your oyster, something off a diesel would work well, the size of the one in my Xantia dwarves the FD one!
Title: are koyo rads the best???
Post by: 20B_boy on June 15, 2008, 04:03:38 PM
Quote from: weejimmy;508428as its going v-mount i wonderd if the shape of a koyo could be a disadvantage????
In all likeliness the inlet/outlets will be positioned inconveniently, if youre going v-mount buy a v-mount kit and be done with it. Will save u a lot of messing about.
Title: are koyo rads the best???
Post by: welshrx-7 on June 15, 2008, 05:16:15 PM
are the koyo rads desighned for modded engines or can they be put on standard setups? i just looking to upgrade my cooling coz it gets really hot under my standard bonnet.
Title: are koyo rads the best???
Post by: SiH on June 15, 2008, 06:06:45 PM
Quote from: 20B_boy;508581In all likeliness the inlet/outlets will be positioned inconveniently, if youre going v-mount buy a v-mount kit and be done with it. Will save u a lot of messing about.

But a kit will cost you a hell of a lot more ;)

I use a Koyo with a DIY V-mount and it\'s cracking - never seen temps over 95 ish on track.
The stock outlets are a pain positioning wise but it\'s do-able with some creative thinking :)

They may not be the best full stop, but they certainly seem one of the best value for money ones. You can get them brand new from eBay USA very cheap ;)
Title: are koyo rads the best???
Post by: Kevin on June 16, 2008, 11:17:11 AM
Quote from: welshrx-7;508593are the koyo rads desighned for modded engines or can they be put on standard setups? i just looking to upgrade my cooling coz it gets really hot under my standard bonnet.

There a good reliability mod no matter what state of tune your car is in mate.
Title: are koyo rads the best???
Post by: interloper393 on June 16, 2008, 11:45:23 AM
even on a stock car your gunna benefit from an uprated rad :) more reliable as they wont split, i got confused lol iv got the greddy fitted to mine with the extra coolent capacity, its awsome! last rex had the koyo and was just as good for keeping the engine coolent temps down, but unless theres plenty of airflow going through it i cant see there being many drops in temps?
Title: are koyo rads the best???
Post by: Kevin on June 16, 2008, 12:08:02 PM
Just a little information logged from PowerFC on streetported FD on standard twins.
Same ambient airtemp when logged with both different radiators.

Standard Radiator cruising in free flowing traffic: 83-84 degrees
Standard Radiator spanked in free flowing traffic: 88-90 degrees
Standard Radiator in que of traffic 5-10mins stationary: 96 degrees

Koyo Radiator cruising in free flowing traffic: 81-82 degrees
Koyo Radiator spanked in free flowing traffic: 84-86 degrees
Koyo Radiator in que of traffic 5-10mins stationary: 88 degrees

Although saying that everytime I see a que of traffic now I whack the aircon on and never really see anything about 85 degrees.
Title: are koyo rads the best???
Post by: weejimmy on June 17, 2008, 12:15:30 AM
well ive made a vmount with my stock rad and a trust intercooler but couldent get temps low enough to map it.
 
its easy enough for me to move or reangle the inlets and outlets if its an alloy rad.
i need to re-think my vmount anyway so mayby a koyo is best and the rad is proberly not the place to try to skimp on
Title: are koyo rads the best???
Post by: SiH on June 17, 2008, 08:02:43 AM
Quote from: weejimmy;509172well ive made a vmount with my stock rad and a trust intercooler but couldent get temps low enough to map it.
 
its easy enough for me to move or reangle the inlets and outlets if its an alloy rad.
i need to re-think my vmount anyway so mayby a koyo is best and the rad is proberly not the place to try to skimp on

Are you using any ducting?
I\'ve using an XSpower intercooler and Koyo rad in my V mount, and the temps are icy cold when on the move :)

However, without any ducting, you may as well have a lump of cheese - a compelte stock setup with the ducting would probably fare better than most un ducted aftermarket ones.
Title: are koyo rads the best???
Post by: Draco on June 17, 2008, 09:05:04 AM
SiH Do you have any pics of your set up please?
Title: are koyo rads the best???
Post by: SiH on June 17, 2008, 09:37:46 AM
There are some in my project thread, i\'ll try to link to some others later :)
It\'s not pretty at the mo, but it works very well.

However, it has one major weakness: Heatsoak when standing still.

So far it\'s done 3 track type things, all quite different.
The first was Curborough sprint track - which was 3 laps, then queue waiting for the next slot, then another 3 laps. Once out and running it was fine, but queueing it got very warm, and the inlet temps were reaching high levels - mid 50\'s and even touching low 60\'s whilst queueing. When on the go though, they then drop like  stone. This was with a vented bonnet.

The second was Castle Combe, where it behaved perfectly - only 1 20 minute session but temps were consistently very close to ambient due to the car constantly moving.
Finally it did Prescott Hill hillclimb track at the weeknd - similar format to Curborough - a run up the hill then queue for the next one. This time with a stock bonnet. Water and oil temps were great, but inlet temps were soaring and i kept having to stop to let the car cool.

So basically the problem is when the car is standing - i guess this is also a problem with the stock setup. I\'m not sure whether it\'s due to heatsoak from the rad to the IC, or the AIT sensor heating up. Eithere way, it\'s not ideal, and I\'m not sure where to go from here. As soon as the car is on the move though, the temps are great.