I've been thinking about getting a larger radiator with a lower operating nismo thermostat for a while.. any of you guys done this and is there any problems in doing this??

Also I have a Import Auto, so I have heard I will need to get an auto oil cooler if i change my rad.. why is this?.. how does the normal radiator affect the auto oil cooler?.. and I have also heard that the jap import has a smaller oil cooler than the english one? why is this?

 

finally, is the fan on the ZX a Viscous which works constantly on the radiator, because if I was to get a newer radiator, i.e. a Koyo.. I am not sure if I would be able to keep the stock front fan in place, and might have to buy 2 12" fans to fit to it.. it seems like the stock fan is running constantly..

 

my integra R when I fitted a new radiator to that I also fitted a new fan and lower thermostat and a lower temp fan switch.. their doesnt seem to be any lower temp fan switches available for Z's?..

 

Please let me know guys! Cheers!

A larger radiator is good but why the lower temperature thermostat?

Check this out http://www.carnut.com/ramblin/_cool3.html

If you change your radiator to an after market jobbie, more than likely the new one won't have an inbuilt trans cooler

 

The viscous fan is good when you have some revs on but at low speed electric comes into it's own. If you get a good one, they dont have to be noisy and can pump a lot of air.

 

their doesnt seem to be any lower temp fan switches available for Z's?

No .... they have a viscous fan :headvswal

The one electric fan they do have is for the air con but will switch on if certain conditions are met with the air con off i.e. they're stinkin hot

Here is some experimenting from an NZ site ....

 

With the standard thermostat (76.5'c) I found the car to run at 82'c full time. You could put the hose on the rad and drown it in cold water and still 82'c maintained.

 

So that's why I went out & spent $200 on a Nismo 62'c item.

 

Once this was installed & the system bled up a test drive was carried out, this showed on the road @ around 80kph the temp sat around .... wait for it ..... 82'c.

 

Also, don't forget the ECU will add more fuel if you run the temperture too low (cold start enrichment) which stops around 70 / 75 degrees from memory

 

Sorry if you guys are in feren, faren, farenhegiht, farenhieght ..... ohh not celcius

so what are the trans coolers like to fit? - are they hard to find?.. what is involved in changing/replacing one?..

I always liked the cooler operating thermostat idea, when my ITR's radiator blew on me when it over-heated one time, I thought I don't ever want any over-heating problems again, EVER! - I bought a mugen lower op.temp thermostat.. and since Nismo is the mugen of Nissan, I figured since it worked a treat for me the last time, might aswell go down that route again lol.

to be fair. the 300zx doesn't seem to take long to warm up at all, but i'm thinking since you mentioned cold start enrichment, could that cause problems with idling at a later date?.. from what I read about the 300zx's they just constantly need maintenance once you start "messing" with them.. and by messing, i mean just generally driving them lol

The standard rad has a pathetic built in oil cooler. Even if you stick to the stock rad then its a very good idea to fit a bigger autobox cooler.

 

A 13 row 235mm oil cooler is ideal for the Autobox

A 19 row 235mm oil cooler is ideal for the Engine oil

 

You fit them in on the radiator support bracket under the nose panel, and extend or replace the existing rubber oil pipes to reach.

 

The UK model has larger oil coolers because they are used to higher more sustained motorway speeds which require extra cooling.

 

The stock viscous is fine with an Aftermarket radiator, no reason to change it.

 

Change the waterpump too (unless you have evidence of it recently being changed), and replace all the engine cooling hoses, its when these perish from the engine bay heat that causes problems.

 

If you do replace the thermostat and waterpump then make sure you replace the two top rubber hoses that sit under the cambelt covers that connect the metal water hardpipes to the block instead of reusing them, a very common place for leaks to occur.

 

Dont buy a Nismo thermostat of ebay, most of the "nismo" stuff on there are cheap fakes.

Edited February 15, 200916 yr by Yowser

The UK/ Europe rad is supposed to have about 30% more cooling capacity than the JDM one. They also have a diff oil cooler as well. It was all about being able to cruise continuously on unrestricted autobahns at very high speeds.

I agree with the stuff on thermostats. It is pointless using a lower temp one. It is also a fallacy that a giant radiator will make for it to run any cooler than the minimum size radiator needed to dump the maximum heat output on the hottest day. The correct thermostat regulates the heat dumped to the radiator and if it doesnt need to dump much then it wont. Just try to get an engine with a broken jammed open thermostat to warm up! It doesnt happen. It just runs cool and drinks fuel.