Jjr Alloy Radiators Any Good?

[boostn0199]

Hrmmm tough decision still want to know if the koyo 53 will fit the shroud and fan without mods.

[urtwhistle]

I have the JJR radiator in my R34 and I have had issues with keep it cool ever ever since it went on. If it gets turned into a track weekend warrior I will be ripping it out and putting a stock 1 into it.

[Blitz]

I ran one of these on my last R33 GTR putting out ~400awkw and never had a problem.

It fitted up beautifully and there was a noticable drop in temps.

[Blitz]

Furthermore, I have just fitted one of the new HPI 'Evolve' Radiators to my current GTR and its a work of art.

HPI are a very well made Jap radiator, and have some funky new top tank technology that apparently makes them even more efficient.

My car copped an absolute hiding at a recent Wakefield day with the HPI unit and it really did its job so I highly recommend it.

[Checkbuzz]

I'm running one of these exact same JJR radiators in my 200rwkw R33 no problems at all and it sees a lot of track work often on very hot days!

As stated it has a machined neck with very heavy welding - I would take this over the OEM top tank or neck in a heartbeat

Fitment was good including the OEM shroud and it is definately cooling waaaaay better than the stock radiator...

Once it was fitted it highlighted the fact that the thermostat wasn't sealing properly becasue I couldn't get the engine up to temperature any more!

From what I have read the quality of these radiators has improved over the years; there were a few problems back in the day but not so many now.

If it leaks or over heats then clearly you would do one of the following:

-Realise that your cooling problem is not due to the radiator that you just replaced

-Send it back to JJR for a replacement that doesn't leak

P.S Careful with the 53mm radiators I've heard stories of them being too much cooling for the street or track unless you are running big numbers.

[Hanaldo]

P.S Careful with the 53mm radiators I've heard stories of them being too much cooling for the street or track unless you are running big numbers.

That's what thermostats are for

[Checkbuzz]

Thanks for that Einstein... but the thermostat can only regulate the flow of coolant.

If the coolant gets hot enough to open the thermostat (i.e. when it is closed and there is no coolant flowing) and then just gets a rush of cold coolant it will close again and if the radiator is over kill for the engine it will never get up to optimum operating temperature especially on cold days and this is not good for your engine.

That's what thermostats are for

[Hanaldo]

Thanks for that Einstein... but the thermostat can only regulate the flow of coolant.

If the coolant gets hot enough to open the thermostat (i.e. when it is closed and there is no coolant flowing) and then just gets a rush of cold coolant it will close again and if the radiator is over kill for the engine it will never get up to optimum operating temperature especially on cold days and this is not good for your engine.

Yes but that is how thermostats are designed to work; the amount they open varies, it's not a switch that's either fully open or fully closed. If the coolant coming into the block is too cold then the thermostat shuts slightly, restricting how much enters the engine. So the engine is always getting just enough coolant to keep it at operating temperature. Your radiator will never be so efficient at cooling that the thermostat can't keep up (unless the thermostat is dicky).

[Checkbuzz]

Oh i know how a thermostat works thanks...

The problem with your logic is it doesn't account for the fact that the thermostat actually starts opening at a lower temperature than the optimal running temperature of the engine (usually about 30f lower) therefore if the radiator is too big for the system it will never get up to that optimal temperature.

That is why people in colder climates have to use a radiator cover (usually a piece of cardboard) on an otherwise healthy cooling system to reduce airflow through the radiator (i.e. reduce it's efficiency) in cold weather so the engine gets up to normal operating temperature.

Yes but that is how thermostats are designed to work; the amount they open varies, it's not a switch that's either fully open or fully closed. If the coolant coming into the block is too cold then the thermostat shuts slightly, restricting how much enters the engine. So the engine is always getting just enough coolant to keep it at operating temperature. Your radiator will never be so efficient at cooling that the thermostat can't keep up (unless the thermostat is dicky).

[Hanaldo]

Oh i know how a thermostat works thanks...

The problem with your logic is it doesn't account for the fact that the thermostat actually starts opening at a lower temperature than the optimal running temperature of the engine (usually about 30f lower) therefore if the radiator is too big for the system it will never get up to that optimal temperature.

That is why people in colder climates have to use a radiator cover (usually a piece of cardboard) on an otherwise healthy cooling system to reduce airflow through the radiator (i.e. reduce it's efficiency) in cold weather so the engine gets up to normal operating temperature.

30d? You think thermostats start to open at 30 degrees below their operating temperature? So my 82 degree thermostat starts to open at 52 degrees? Rubbish. They do open earlier, but only a few degrees, and only very slightly. Having a bigger radiator will not affect this in the slightest, especially considering the water in the radiator will never be below ambient temperature regardless of air flow or road speed. The radiator is removed from the equation until the engine is at operating temperature. Find me one source that tells you differently and backs up your theory.

For the record, I'm originally from Germany so I go back to visit my grandparents quite often. They have never had to cover their radiator at any stage, and where they live (Kiefersfelden) it often gets well below negative 10. It would take some extreme cold for that to be necessary; maybe it gets that cold in Canada, I'm not sure. But it has certainly never been an issue for them in Germany. It would probably be more necessary on a diesel engine than a petrol engine.

[Marlin]

Someone's been watching Ice Road Truckers! ! ! !

[fatz]

yea i went back to a stocker

china alloy doesnt like my car

[iplen]

Only issue I had was the location of the overflow and and the size of it, my fan went to town on my JJR radiator and still didn't hole it. Will be replacing eventually, probably with another JJR one.

[boostn0199]

Hrmmmm I think im just going to go the koyo one to be safe when I decide to buy one.

[Checkbuzz]

I said 30f not c ...and radiator temperatures can be below ambient due to air flow cooling effect.

Germany is a really nice place I really like their bier - chilled of course!

I'm from Canada so have seen a bit of cold weather myself.

30d? You think thermostats start to open at 30 degrees below their operating temperature? So my 82 degree thermostat starts to open at 52 degrees? Rubbish. They do open earlier, but only a few degrees, and only very slightly. Having a bigger radiator will not affect this in the slightest, especially considering the water in the radiator will never be below ambient temperature regardless of air flow or road speed. The radiator is removed from the equation until the engine is at operating temperature. Find me one source that tells you differently and backs up your theory.

For the record, I'm originally from Germany so I go back to visit my grandparents quite often. They have never had to cover their radiator at any stage, and where they live (Kiefersfelden) it often gets well below negative 10. It would take some extreme cold for that to be necessary; maybe it gets that cold in Canada, I'm not sure. But it has certainly never been an issue for them in Germany. It would probably be more necessary on a diesel engine than a petrol engine.

[HEKT1K]

For a track drift car, currently after going hard for maybe 15 min temps starting to go mid 90s to 100 so i wanted something that can cool more so im looking for somwthing suitable for track and by what you guys say this is a cheap replacment for a daily streeter. So i should look at the blitz?

Try Nengun for the Blitz rad... much cheaper

EDIT: Is it just me or has delivery pricing increased drastically? I remember looking on Nengun a few months ago and it was significantly cheaper than now

[wolverine]

and radiator temperatures can be below ambient due to air flow cooling effect.

No.

[boostn0199]

Yeah i was cosidering blitz aswell but no ones given me any reviews on it would like to have someone input thats used one.

[Hanaldo]

I said 30f not c ...and radiator temperatures can be below ambient due to air flow cooling effect.

Germany is a really nice place I really like their bier - chilled of course!

I'm from Canada so have seen a bit of cold weather myself.

Yeh 30 degrees Fahrenheit is about -1 degree Celsius lol (as I'm sure you know being you are from Canada). So if a thermostat opens 30f below operating temperature then that is 1c below operating temperature.

It is impossible for a standard heat exchanger (radiator) to bring water below ambient temperature. That would require a thermodynamic refrigeration cycle, eg. the vapor-compression refrigeration air-conditioner in your car. Wind chill has no affect on a radiator unless the temperature of the water is above ambient temperature. If you parked a car with a cold engine out in a freezing cold wind, the water in the radiator would not drop below ambient temperature. However if you warmed the car up first and then parked it in the same wind, it would cool down to ambient temperature quicker than if there was no wind. It would never go below ambient temperature, it's impossible.

Off topic, I've always wanted to go to Canada! Intend on doing a year-long working holiday over there at some stage; snowboarding being my main activity

[Blitz]

Yeah i was cosidering blitz aswell but no ones given me any reviews on it would like to have someone input thats used one.

I looked at the Blitz and HPI radiators side by side, and the build quality on the Blitz was not that impressive - the HPI on the other hand was excellent, really nice welds and well made overall.