ccw998

My FD is rebuilding the engine right now, should I upgrade the radiator to aftermarket at this time? I will use my FD for a daily car. Any idea?

CowsniperRX7

iTrader: (3)

Yes. It can't hurt. It will keep the temperature down and that is allways good.

spurvo

yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes yes

I went with the Fluidyne. Fit was ok, but they didn't really weld it "straight". The fan mounts were misaligned such that the drivers side is lifted off the radiator about 1/4 inch (just sealed it with ducting tape (high temp shiny stuff)) and the upper hose mount was so low to the body of the radiator that I had to trim a pretty big chunk from my fan mount. And I had to get a little inventive to properly seal the radiator on the sides to the body to force the air through it. For $512 shipped, I expected a little better. Still, it's WAY better than plastic end tanks held on with bent over aluminum fingers.... i.e. the stock time bomb...

Air-Rex

Yes, I assume you've gotten rid of the plastic AST also.

Mercury

It should be one of your first mods along with a PowerFC. I daily drive my car ~60 to 70 miles a day, and trust me keeping an eye on your boost, injector duty cycle, water temp and air temp is a must! It saved my *** a few times.

Mercury

I am with you 100% on this one. Mine burst 400 miles away from home. ='[ You don't want this to happen to you... And if you dont have an acurate water temp gauge then it's quite easy to over heat the motor... and that means rebuild time... as your O rings are going to go out sooner than later. <TRUST ME>

ccw998

So on the PFC commander, what 's the difference between the stock and the aftermarket radiator?

Hyperite

PFC ain't a radiator, it's an ECU (read Engine/Emissions Control Unit). It's a computer, not a radiator.
~Tom

Lost Time

Um, nothing. I've been running the stock radiator in South Florida heat for years now and with a manual fan switch OR altering the fan turn-on temps to 90c I have never been unable to keep the temps below 87c. It's up to you, but it's not necessary.

RonKMiller

While the OEM radiator is perfectly capable of cooling, it WILL eventually leak and leave you stranded. They all do. Whenever you put a new engine in you really need to completely rebuild the cooling system as well.

This means new radiator, new hoses, new water pump, new T-stat, new caps, etc. An additional major expense? Absolutely, but it will keep your new motor happy for a long time.

You can go the all aluminum aftermarket route with the Koyo, Fluidyne, etc., but they are all grossly overpriced.
Are they shiney, pretty, and have that racer boy image - YES!, but to pay a huge premium for a part that will never be seen once it is installed is a waste of money.
They offer absolutely no additional cooling power (unless you are running BIG horsepower) and aluminum is LESS efficient than copper/brass for transferring heat.

I would recommend an all metal copper and brass unit from www.RadiatorExpress.com. Sure, it weighs an extra 2 lbs. more than the OEM unit, (yes, I weighed it) but fits perfectly and is a 2 row which theoretically cools better than the 1 row stocker.

I am VERY pleased with mine, and the $175.00 I paid for it leaves a few hundred left over for other goodies. (like water pump, hoses, t-stat, etc.!)

If you order one make sure you specify for a manual tranny - if you get the auto tranny unit it will come with a couple of extra nipples on the bottom that you will have to cap off. Oh, yeah, it also comes with a LIFETIME guarantee.

flunkysama

iTrader: (4)

If you rephrase the question to "Will my car overheat with the stock radiator?"
you then need to ask yourself the following.

1. Do I do alot of stop and go driving?
2. Is the engine modded? (More horsepower means more heat)
3. Do I do drive in a hot climate?
4. Do I use the A/C alot?
5. Do I drive in high altitudes (Thin air hurts the effeciency of a radiator.)
6. Any mods to run the fans earlier/more/harder?
7. IMHO, a car with dual oil coolers is less likely to overheat than a car with only one.

If you have alot of miles or you think the previous owner(s) didn't change the anti-freeze and flush the radiator regularly, then a new radiator would be a good idea.

twinturboteddy

Great post and advice.

As far as the stock radiator. I've owned 2 FD's. The stock radiator started leaking (very slowly) on one. Had it replaced for 120 installed.

On my current FD, the stock radiator with the fans constantly going, cruising, the temps stay at a very decent 89C constant. The stock radiator isn't so much a problem, it's the leaking part.

cavellm

cooler = always better

adam c

iTrader: (2)

Just got my new Fluidyne today. Not installed yet. Sorry Spurvo, $420 shipped. I hope mine fits better than yours.

I do a lot of stop & go driving, so my engine does get hot at times. The upgraded radiator should help a lot. I didn't want to go with a cheap one. Fluidyne is a good brand, and I didn't want to skimp on this one.

xurotaryrocket

I shelled out the extra cash for the Mazda Competition Radiator. Excellent build, all aluminum (no plastic) and no fitment issues.

It does a good job, but nothing really helps out in stop and go traffic like the fan mod.

New oil coolers in the spring should help even more.....

ccw998

Before I rebuild the engine, I always saw 90c-96c on the PFC commander.

Yes, I do alot of stop and go driving. The weather in Vancouver is hot in Summer, so I use the AC alot.

So, should I upgrade the radiator or do the fan mode?

Kas_Rx

Hi Ron,

do you have any more info about the brass/copper heat transfer opposed to alliminium radiators?

I'm not interested in spending big $$ on something that will be of no greater benefit, hence $425 on alliminium.

thanks

JONSKI

RonKMiller,
Do you think the RadiatorExpress.com radiator be less likely to leak than the stocker?

rpm_pwr

yes yes yes replace it.

My radiator blew two weeks ago. When I pulled it apart I found that the AST nipple had broken off the lower end tank. When I had the rad out of the car I realized both end tanks were so brittle I could crack it with only finger pressure. Needless to say that POS hit the bin.

I've since dropped in a PWR core. Despite some major bleeding dramas I've got it seemingly sorted and I couldnt be happier. Yes it's aluminium, but it's twice as thick as stock. Yesterday I had the car stuck in traffic for 45mins not getting above 20km/h and I didn't once crack 90degrees. This is all in australian summer heat!

IMHO a new stock (or stock-like) radiator will do the job but just barely. Expect to crack 100C on a bad day at the track with a stocker. The worst thing is that even if your water seals hold up, the higher water temps increase the risk of detonation. Not to mention higher water temps mean hotter engine bay temps with all the associated troubles.

In short never expect the stock radiator to last 10 years. It could cost you a motor.

-pete

RonKMiller

Nothing I can put my hands on right now. There are tons of discussions and factual evidence on the net about it.

RonKMiller

Since it is all metal I think it will last longer, and yes, much less likely to leak over time.

The plastic end tanks always go on the OEM, or the crimps fail. You can't fault Mazduh for trying to keep the weight to an absolute minimum, lots of 2003 cars come with plastic end tanks - even freakin' Mercedes!
Hopefully the plastic is improved by now......

RonKMiller

Air density is really not a factor since it is more than offset by an average 3 degree F drop in temperature for every 1000 feet you climb in elevation.

I sure do agree on the dual oil coolers or if you have any mods blocking airflow.

rpm_pwr

Just had a look around:

It seems that despite what the first link says, the current copper-brass radiators are heavier than aluminium rads. Despite this, they flow better (up to 30%) and can cool better (up to 35% better).

The case for aluminium radiators is largely environmental. It is important to realise thought that core design plays the biggest role. Tradional copper-brass radiators are heavier and a lot worse flowing than current aluminium cores. It is really only the latest copper-brass radiators that perform better.

http://www.cuprobraze.com/cuprobraze...whybetter.html

http://www.autospeed.com/A_0976/P_1/article.html

http://automotive.copper.org/


-pete

rpm_pwr

actually radiator express is a good example. Have a look at their lineup; they're all the same dimensions, but they recommend the aluminium for track racing. Why? Because of the core design. Whereas it's technically better, high efficiency traditional copper-brass exchanger cores seem to face a few manufacturing issues

-pete

adam c

iTrader: (2)

"It seems that despite what the first link says, the current copper-brass radiators are heavier than aluminium rads. Despite this, they flow better (up to 30%) and can cool better (up to 35% better)."

I'm not sure where you got this info, but it is exaggerated. If two metal radiators (aluminum and copper-brass) are built exactly the same, there is NO WAY that one will flow 30%, better or cool 35% better. In fact, I would bet that there are no measurable differences if flow, and less than 5% difference in cooling.

If the figures you found are published somewhere, it is from an unfair comparison between 2 dissimilar products.

Adam