koyo running hotter than stock???

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I know the first response I'm going to get is "SEARCH" so don't bother, I already have. I love Zilvia for that :hsdance:

I just replace the stock radiator with an aluminum koyo, new waterpump also,
I have dual 10" electric fans which are always on.
I've bled the system repeatedly but nothing seams to work.

The stock temp gauge is showing even higher than it was before...
Shouldn't the temp ATLEAST stay the same if not go down?

Whats wrong, how do I get the temp to go down?

[SoSideways]

How did you bleed it?

Something tells me you're not doing it right or doing it enough...

[bp057]

Have you boiled the thermostat to verify its working? I am running an alum koyo with FAL fans, I run mid 180's. Is your lower hose getting hot?

[smelly240]

this has been a problem for a number of people with the koyo alum rads - with a number of different cars.

obee had a problem - went back to stock - no more problem - my roommate's talon needed 2 12 in fans and it still runs hot without the heat on in summertime.

My car used to never get hot - now it gets hot but no overheating to date.

Seems to me that copper koyo rad is 10x better than the pretty aluminum one.

theres even a writeup where someone verified this.

[rocksteady_racer]

I'm guessing it's mostly the electric fans. I've heard horror stories about those. I was thinking about running the stock fan with a modified shroud but I haven't decided on that yet. It does sound like you didn't bleed it well though but I could be wrong and it's just the fact that chincy electric fans do nothing. Another good point is that there were tests done with custom plates and or the black plastic shroud on the bottom of the radiator and a custom plate on top and the tests proved it dropped it 30 degrees on cruising speed so I'd see if that helps you out any too.

[slider2828]

I read that review of plates and I have done that too.... Bleed it again and tray again, but I have used the stock shroud without modications wtih the alu koyo... Bolts straight up, just put the shroud on first then the fan...

[SoSideways]

Yeah but the aluminum Koyos are PROVEN to have TOO HIGH of fin count, which prevents proper air flow THROUGH the fins, which is what cools the coolant off ultimately.

The copper Koyo, which is basically the Yashio Factory copper radiator in rebadged form, is actually superior in cooling the car, along with Altima electric fans.

Only draw back about the copper radiator is that it's heavier than the aluminum radiator, but if you move the battery to the back of the car, then you've pretty much just "fixed" the weight distribution issue of having the copper rad.

[japslapsilvia]

i have never had a problem with my koyo and electric fan setup. i think most people have problems with electric fans b/c they just stick a fan in the middle of the radiator and expect it to be supper efficient, i built a complete shroud around my radiator and have the fan about 1" away from the cores surface and its completly sealed. i can take a pic and post if need be.

to the OP, what mixture are you running? water/coolant? water/waterwetter etc?

[DaPCWiz]

i have never had a problem with my koyo and electric fan setup. i think most people have problems with electric fans b/c they just stick a fan in the middle of the radiator and expect it to be supper efficient, i built a complete shroud around my radiator and have the fan about 1" away from the cores surface and its completly sealed. i can take a pic and post if need be.

to the OP, what mixture are you running? water/coolant? water/waterwetter etc?

I'm actually in the middle of making a custom setup and I'd love to see pics of yours....

[japslapsilvia]

I'm actually in the middle of making a custom setup and I'd love to see pics of yours....

shatty pic i will snap a better one tonight
http://i68.photobucket.com/albums/i7/japslapsilvia/DSC00153.jpg

i made it out of 18ga sheet metal, bent the sides on a brake, welded the cornors, and put that foam strip around it to seal it

[Addicted2Kouki]

You are gonna need more than just that one lil fan.
That setup is not very efficient.

It might even cool better without any of that with no fans driving down the street.

EDIT: nevermind, you listed dual fans in your original post.

I have a setup similar with 12" instead of 10" dual fans.
Ill post pics sometime soon.
maybe its the fans not pulling enough?

[drft911]

In my personal opinion the stock gauge is not so accurate. It only shows you when its cold and when its warm and when you car is in the process of overheating. you might want to get an aftermarket gauge with actual numbers. after i did my koyo with no shroud and and w/stock fan, front mount, and ac condenser(ac not on) my numbers were 170-175max. I've had my car run 175-210 with the stock one. also make sure there's no restrictions of air on both sides of radiator or any loss of coolant (leaks).

[SnakeKack]

Fuck I just ordered a Koyo Aluminum Rad. I got Altima fans that are gonna go on with it. I hope that I don't have the same problem.

[wangan_cruiser]

i have a koyo all aluminum rad. with taurus dual spd fan set up. thermostatic switch for low speed then switch from the cockpit for the high spd. never had a problem. itll be a lil bit higher from normal but on hot days car never overheat. taurus fans came with a shroud that almost cover the rad. ill post pics

[japslapsilvia]

You are gonna need more than just that one lil fan.
That setup is not very efficient.

It might even cool better without any of that with no fans driving down the street.

EDIT: nevermind, you listed dual fans in your original post.

I have a setup similar with 12" instead of 10" dual fans.
Ill post pics sometime soon.
maybe its the fans not pulling enough?

the setup i posted is a single 10" fan and its cheap e-bay fan and it pulls temps down really fast, i am using a greddy MSS for fan control and water temp, fan comes on at 85*C and off at 75*C, i also have the stock SOHC A/C fan as a pusher to come on at 95*C and off at 75*C.

the shroud makes the small 10"fan more efficient so when it comes on its only on for a short amount of time.

[rb25_s13*CHUKI]

I'm running a koyo and a clutch fan with shroud on my fc and It stays cool as fuck.. like super duper duper cool.

[Style]

koyo aluminum sucks, upgrade to PWR radiator or Greddy or Blitz

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Damn, that was a lot of posts, couldn't get on till today...

BPO - Never boiled the thermostat, my guess is if ANYTHING is wrong this may be it... But I've not once overheated, just the stock gauge is higher than it was originally.
I have an aftermarket watertemp gauge, I just need an adapter for the temp sensor.

japslapsilvia - I can't see pictures (firewall blocks most everything) If you could email me a picture of the shroud that'd be great. Especially since your single 10" fan pulls enough, my twin setup should be more than enough.

I'm probably around 60/40 coolant/water...
Would this make that much of a difference?

SoSideways - I've already put my battery in the trunk but I'd rather not spend the extra money on another rad if I don't have to... I usually research everything before I buy, but this time I just took a couple friends word for it and now I'm stuck with this problem.

BPO - Im gonna see tonight if the lower hose is getting hot, If it is I'll pull the thermo since that was never changed when the SR went in.

[djcobra]

NISMO T-Stat + SR Clutch Fan with SR Shroud + Koyo Rad + (50/50 mixture) = gives me max of 70 degrees celsius (158 fahrenheit) on my setup.

also Daily driven ~320whp.

Steve.

[lightsource]

NISMO T-Stat + SR Clutch Fan with SR Shroud + Koyo Rad + (50/50 mixture) = gives me max of 70 degrees celsius (158 fahrenheit) on my setup.

also Daily driven ~320whp.

Steve.

You're in Calgary, ambient temps?


So what's the verdict exactly? Is the Koyo Copper better than the Koyo Alu, and if so, what's better than the Koyo Copper or Aluminum in both cases?

[renegade_ewok]

From a technical standpoint, copper conducts better than aluminum.

[lightsource]

From a technical standpoint, copper conducts better than aluminum.
Correct, but it's more dense, requiring more powerful cooling to cool it down. Correct?

[renegade_ewok]

Correct, but it's more dense, requiring more powerful cooling to cool it down. Correct?
Doesn't matter how dense it is - if you bring the copper part of the aluminum to the thickness that you need huge fans to pull the stuff through, then you have lost the conductive advantage of copper and the radiator sucks.

If you buy a copper radiator that is properly built, it will outperform an aluminum one. Problem is they might be more expensive.

[SoSideways]

Correct, but it's more dense, requiring more powerful cooling to cool it down. Correct?

SR20DET Radiator Test (http://home.satx.rr.com/nissanweb/RadTest/RadTest.htm)

Read the test.

[djcobra]

Here you go;

Calgary City Information (http://www.foundlocally.com/Calgary/Local/Info-CityInfo.htm)

info on that page is average but not true, we usually hit around 28-35 degress celsius during the months of June/July/August sometimes in Sept.

[adstudio3d]

wow, if I lived in Calgary and was debating whether or not to buy a copper or aluminum rad, this thread would be very helpful... haha
I haven't gotten the chance to play with the car yet, but I just ordered a nismo thermo anyway. It can't hurt so might as well replace it since I have to take it out anyway.