the stock radiator is not small at all...it weighs so little because it is plastic

both versions of the Koyo are heavier than stock when dry. And heavier still when wet (the larger one also holds more coolant)

Skip the NISMO Thermostat unless the car runs HARD in hot climates at all times

 

Not necessarely, The thermostat is great for keep your car cool, I live in Michigan, and my temp has dropped a good amount due to the combo. Plus if you often drive your car hard you should get the thremostat. And about the stock radiator, I have had both and now use the koyo, I noticed it's performance was very poor when street or drag racing. And that was without F/I. Now that I am F/I my car would be constantely over heating with stock cooling. Plus what is 5 lbs gonna do when you have 450 rwhp, that weight you are comparing isin't going to do crap, 5LBS????? haha thats my backpack in my car when going to school. The weight issue is a joke. The only problem the koyo brings to some people is the fitment problem, some people fit perfect and others need adjustments.

 

I have then radiator in my car, so I agree on the weight - its a street car, so I could care less

I had the thermostat in my car and found it to be an utter waste of time. The heat did not work as well with it in, the car ran richer with it in (since my initial tune was done with the stock temp thermostat), and in the winter I got repeated check engine lights because of low thermostat efficienct (I forget the code# but I have posted it many times). Lower coolant temps are not necessarily a desired thing.

As for the stock radiator, I could not imagine anything more than a pure track day car needing something more than the stocker. I've done tons of track time on the stock radiator, and never gave me any issues (NA). For me, the Koyo was given to us to test fit, and that's why it is in my car to this day

 

The stock raDIAtor can be put through quite a bit...but i have seen coolant temps rise extremely fast with the stocker..the stock radiator is a single row, pathetically inneffecient piece... i agree that if anybody is planning on tracking their car (road course) or just wants the extra margin of safety of running cooler engine temps...upgrade your radiator... my car overheated after 3 laps on a road course...overheated street racing....that is with water wetter and the stock radiator..unless your temps outside are 30 degrees at all times...u will need a bigger radiator if you want the temps remain reasonable

my current coolant temps never get above 185-190degrees doing hard 5th gear pulls on the freeway with 16psi! before, i would see temps as high as 210-215...nearing more...i wouldn't push my car in 5th gear for that reason, now i can hold 5th gear and see very safe temps across the board

 

Anyone know which Flex-A-Lite fan fits the 350Z with Koyo radiator? I checked out their site but didn't see anything specifically for the Z.

 

i ASSume the overheating was after the turbo install. many folks have run many track days on the oem radiator with no issue - when NA. i've run a ton of days, including a bunch at VIR - every lap, WFO to redline in 5th - without even a hint of water temps getting out of hand. oil on the other hand...

now that my APS single is finally getting buttoned up, i've got a giant C&R (as wide as my intercooler, 4" tall, 4" thick) oil cooler i've got to figure out how to mount that ought to do the trick! i've got both oil and water temp sensors also waiting to go in, so i'll be able to monitor actual temperatures. i expect to be on track in february - i should know from that weekend whether i'll have to replace the radiator...

ahm

 

Bumping this thread since the temps have definitely got warmer recently. When I make the purchase for a Koyo down the road, wondering if I should just get the thicker one....regardless if there is a fitment issue.

What is the price difference between the two sizes? Does anyone know?

 

About $100 @ retail... 36mm vs 53mm. A new 55mm version was on ebay for around $390 shipped. So the prices aren't too bad...

Long story short, I had to get a new radiator because of an accident. The Ins. company was going to replace it with a stock one, so I took advantage of this situation and picked up Sentry's Koyo to be installed instead. I also picked up a new Nismo stat locally and installed it in about 20min. while the whole front end was off. So basically I'm coverd for weekend track events and just beating on her over summer for around $200 now.

Something postitive had to come out of this whole situation

Thanks for the heads up on the upper hose having to be trimmed...

Zquicksilver

 

they list like this:

Core Dimension: 15-3/4" x 28-11/16" x 5/8"
Top / Botton Header: 1-7/8" / 1-7/8" x 29-13/16"
Genuine Koyo Part Number: A2576 <-- for AT

so which version is this? 35mm or 55mm?

Thanks

 

The price difference is only a few bucks. Some vendors charge the same price. Some people go with the thinner on to fit the plumbing for their turbos. Other than that, get the fatty.

 

Is this radiator beneficial to NA? I do plan on TT this vehicle, but that's still a ways off. maybe spring of 07. Also, can this be a DIY?

 

Does anyone have an APS TT with a Koyo? What size do you have and how was the fit?

 

Yes, its a DIY. If you're going TT, get the thinner radiator. I know one member on here has the Stillen rad with the APS TT