What is the ‘best’ radiator? Are Koyo any good?

[M@r]{]

My FD will be in for a rebuild soon and wanting to avoid needing a rebuild again im trying to do everything possible to extend the life of it - so thinking improved cooling for one.  Im looking to replace the standard radiator with an aftermarket one.

So which is the best one to go for?  
What things should I be looking for?  
Ive noticed Koyo do a Copper one and Aluminum?  Then 2 row or 3 row?  What difference does this make?  Are Koyo any good?  They seem quite a bit cheaper. £235-340

Others ive seen are Blitz and Greddy - £350-400

Any advice would be really appreciated as its getting near to D Day and I need to get these bits delivered

Thanks

[Kieron]

If you don\'t have a FMIC the stock one is very good in the stock location.

Might be worth gettign that flushed, cleaned and pressure tested.

[jay]

I have an ARC one and its very good,but not cheap. Keiron is right only worth doin if you get fmic.
 Jay

[Frankie]

My stock one started leaking so I thought might as well take the opportunity to uprate it.  I got a PWR uprated aluminium one from Reworx for just over £400 delivered to my door.  Its very light and holds much more coolant being 39mm thick.  Replaced all the hose spring clips with jubilee clips while I was at it.  It fits in the stock location and nothing else needs altering.

[M@r]{]

I have got a Trust FMIC.

So is this worth doing then?  As in nearly £400 worth of reason?    I really want to do the best I can to prevent the engine needing a rebuild.  Ive even bought a Carbon Fibre Bonnet with a scoop in it!  Thinking Water spray as well perhaps?

[Frankie]

I did it just for peace of mind and have a SMIC. The price for a standard Mazda radiator is over £300 so I thought I\'d pay a little more as I intend to keep the car a long time.  

And when my battery is moved to the boot and I have a single turbo I\'ll be able to see it in the engine bay, looks the business.

[Warthog]

I run the PWR rad from RE:WORX its spot on.  :wave

[Erdin]

i have a koyo one made from aluminum and i dont think much of it, my car heat soaks in traffic this could be due to the size of the rad being so big that the factory water pump cant pump the water out of the rad fast enough or somthing to do with my pullys which makes the pump slower so it dosent cavithat (if i spelt that right) at high revs. then again it could just be my car.

[Warthog]

Look at getting an Electric Water Pump( EWP) fitted mate, my temps stay below 70c. I do have a PFC so I can always see intake and water temps.HTH :wave

[fro]

another vote here for the PWR rad. Fit and forget.. just how it should be

[clive]

i have a koyo one made from aluminum and i dont think much of it, my car heat soaks in traffic this could be due to the size of the rad being so big that the factory water pump cant pump the water out of the rad fast enough or somthing to do with my pullys which makes the pump slower so it dosent cavithat (if i spelt that right) at high revs. then again it could just be my car.

Hi Erdin,

Real puzzled that you feel your water pump can\'t keep up, I ran a HUGE rad that was twice as thick and also dimensionally bigger than a KOYO on my car and the only problem I ever had was getting the car warm enough to open the thermostat !!!

I did however deliberately ran a standard size water pump pulley because as I have often said, under drive kits are to stop cavitation at high revs on race cars and not FD\'s sitting in traffic ticking over on a hot summers day when they need all the water flow they can get !

BTW, my company has sold quite a few Koyo Rads with never a problem or any kind of complaint and also as one of our here members knows from when I fitted a PWR rad for him, I was absolutely appalled that the thing did not want to fit in any shape or form without lots of modifications, i.e. butchering the thing in, indeed if he hadn\'t have needed to drive away I would have sent it back and fitted a Koyo.  

Hopefully this was just one of a bad batch and the guy was just pain unlucky as I must admit I have never heard any other complaints about PWR.

[M@r]{]

In your honest opinion do you think it is worth paying the extra £150 than buy a Koyo?  Are they as good?  I dont mind saving a bit of money but not at the expense of quality / capability

Thanks

BTW, my company has sold quite a few Koyo Rads with never a problem or any kind of complaint and also as one of our here members knows from when I fitted a PWR rad for him, I was absolutely appalled that the thing did not want to fit in any shape or form without lots of modifications, i.e. butchering the thing in, indeed if he hadn\'t have needed to drive away I would have sent it back and fitted a Koyo.  

.

[clive]

Personaly I would only go for the big Alloy Koyo rad out of the Koyo\'s you mention but bear in mind that what I said in that the PWR rad could have been just a one one off bad luck thing.

Lets see what is said by other people as for all I know some may have had a bad Koyo as well.

[DreXeL]

I\'ve got a copper Sugita rad with a Greddy FMIC and I see water temps of around 79-85. Creeps up to low 90s when driving hard.

[Frankie]

Personaly I would only go for the big Alloy Koyo rad out of the Koyo\'s you mention but bear in mind that what I said in that the PWR rad could have been just a one one off bad luck thing.

Lets see what is said by other people as for all I know some may have had a bad Koyo as well.

The problems you had with the PWR rad might have been because there are 2 types, stock replacement and race. The first one is 39mm thick and I think the race one is 57mm. The stock one is a straight swap and holds about a litre or so more than the mazda OEM rad.  I changed mine with no issues in my garage.

The race one is considerably bigger and requires a bit of fiddling to fit in a standard car.