Top Tips For This Summer?

[JonnoHR31]

yer somethings obviously not right, especially if it only started doing it after an ecu change. just saying its possible

[paulr33]

so yeah to summarize the nissan RB is setup resonably well to handle high temps

the main things are plenty of water, good oil and good amount of oil and basics 101

no need for aftermarket caps, different water pipes, cooling panels etc

these usually add zero benefit, and in a lot of cases make it worse than OEM stock

nissan would stress test the ass out of the OEM gear to ensure it is acceptable, so you shouldnt need cooling panels etc

i think on dezz's car we saw worse water temps with a cooling panel fitted on his GTST, so he took it off

likewise aftermarket radiator cap on bassjunky's car caused the radiator core to explode (sure 3 minute burnout) but a stock would have just blown and pissed water everywhere

so more often than not, dont need the "marketing mods" that you see

80deg is ideal watere temp and the ECU (at least the powerfc does in defaults) will always richen up a touch to get to 80deg and stay there

[R31Nismoid]

can run below thermostat temp if theres not enough heat being produced to heat the coolant in the engine enough. its rare but does happen, my car for example has a 76.5C thermostat but doesnt got over 70C in the top hose on cool nights (or even most days for that matter), and no thernostat isnt stuck, works properly

my GTSR does the same.

factory thermo, never gets above 72 on a 25 degree day unless I'm absolutely up it for 5-10mins.

on sub 25 its 69-70 average. so definitely possible.

that's using a race radiators item, stock clutch fan/shroud

[Rolls]

My advice for summer is to get lots of heat soak driving around in traffic then rev out 3rd gear on a 35c day with someone in the car with a knock sensor and knock ears listening to the engine. If it pings, pull some timing and you've probably just extended the life of the motor by 50%, most aftermarket tunes that haven't been tweaked will ping in this situation. Any decent tuner should spend the 1 hour required to do this if you ask, I personally got it done for $50 but I would expect most tuners would charge at least $120/h.

The other thing to do is set up ignition vs coolant temp trim tables, basically if it gets real hot just pull loads of timing out, once again it'll probably save the motor if you thrash it on a hot day. The next thing is to get a large aftermarket radiator.

Anything else is a waste and a false sense of security, pinging is far worse than overheating the motor, and you can get pinging well before it overheats.

Edited December 30, 2010 by Rolls

[GTRNUR]

Dont go too big on the radiator though. Look at the standard R34 radiators. They are barely 20mm thick, and the secret here is that while they are thin and dont hold a lot of coolant... they do allow the airflow to keep moving fast through the radiator.

Next on the list would be the clutch fan. Make sure it actually works. They are supposed to roar and move a shitload of air, and not start to slip until 4000 rpm.

An interesting side note... The nismo intercooler ive just purchased has huge air gaps, I presume to keep the air speed up through the cooling system. The Nismo radiator that matches it is 35mm as well, where as most common after market cores like the PWR are 40mm.

Cooling panels do work as well. Mostly they reduce the rate that heat soak sets in when you are stuck in traffic.

The addition of a greddy air seperation tank is also a good investment. It connects to the air bleed on the head and radiator and draws air from these two high points of the cooling system. A 3rd hose connects to a T piece in the bottom radiator hose to create a suction point connected to the bottom of the air seperation tank. This creates a whirlpool in the seperation tank, drawing air from the engines cooling system. As the system pressurises the air is forced into the overflow bottle. Then when it cools again, coolant is drawn back into the cooling system again. They work a treat!

I envy you guys and your 25 degree summers. 38 degrees in the sun up here in summer, and a cool night is lucky to drop below 30 degrees after 8pm at night!

[R31Nismoid]

For a modded GTR, most of them need a tri-pass rad though to stay cool.

Especially 34's it seems.

Snowy was having issues in the Vic climate with various radiators, put the PWR tri-pass in, temps under control.

This is strictly circuit though, not street so a bit off the point but its not just about airflow

[DVS JEZ]

my 32 GTR on the street doesnt see over 74 in traffic and most the time at night it will sit at 62,

this is with stock rad, nismo low temp thermostat, trust oil cooler, i reckon the oil cooler helps keep the temps down ALOT,

on the circuit have not seen over 88degrees,

[l0WRB]

can run below thermostat temp if theres not enough heat being produced to heat the coolant in the engine enough. its rare but does happen, my car for example has a 76.5C thermostat but doesnt got over 70C in the top hose on cool nights (or even most days for that matter), and no thernostat isnt stuck, works properly

I have the same issue, after market alloy radiator stock thermostat and cap and it barely reaches 70 degrees even on hot days..dont wanna know wot it sits at on the highway and during winter

ive prob got a f*ked thermostat and stuck open.. never replaced it.

Edited December 30, 2010 by l0WRB

[JonnoHR31]

if its stuck open it'll take ages to get up to temp

[paulr33]

rolls has a very good and easy suggestion

[l0WRB]

it does take ages to get to temp, it barely moves off the cold line on my dash.. normally sits bout 2mm above it

[R32 TT]

Not to get too far of the OP's question. But I wanted to ask why you guys think fitting a slightly higher pressure radiator cap is such a bad thing?

(Assuming that the radiator and associated hoses are all ok of course)

The idea of raising the pressure is not so you can run your car past 110degrees and just have it keep going - it is to raise the boiling point across the entire cooling system. That means at the head and near the combustion chamber and at the turbo etc. ie, your temp gauge may be happily reading 85degrees where the sensor is, but it may be boiling its head off at the 'hot spots' in the engine where the real temps are when punching out 500hp. By raising the pressure, you lower the chance of boiling nearby the combustion chamber. If its boiling, the coolant isn't making contact with those surfaces properly and you not getting efficient cooling where you need it most.. no?

This is the same idea behind Redline Water Wetter - to reduce boiling at these points. The gauge reading 85 doesn't really tell the whole story does it?

[Rolls]

That is certainly interesting information R32 tt, thanks for the post.

[NISSAN GTR]

Dont go too big on the radiator though. Look at the standard R34 radiators. They are barely 20mm thick, and the secret here is that while they are thin and dont hold a lot of coolant... they do allow the airflow to keep moving fast through the radiator.

Next on the list would be the clutch fan. Make sure it actually works. They are supposed to roar and move a shitload of air, and not start to slip until 4000 rpm.

An interesting side note... The nismo intercooler ive just purchased has huge air gaps, I presume to keep the air speed up through the cooling system. The Nismo radiator that matches it is 35mm as well, where as most common after market cores like the PWR are 40mm.

Cooling panels do work as well. Mostly they reduce the rate that heat soak sets in when you are stuck in traffic.

The addition of a greddy air seperation tank is also a good investment. It connects to the air bleed on the head and radiator and draws air from these two high points of the cooling system. A 3rd hose connects to a T piece in the bottom radiator hose to create a suction point connected to the bottom of the air seperation tank. This creates a whirlpool in the seperation tank, drawing air from the engines cooling system. As the system pressurises the air is forced into the overflow bottle. Then when it cools again, coolant is drawn back into the cooling system again. They work a treat!

I envy you guys and your 25 degree summers. 38 degrees in the sun up here in summer, and a cool night is lucky to drop below 30 degrees after 8pm at night!

My 34 sits on about 87 degrees most days , maybe 93 when it gets hot at 36 degrees ,

the thing that i find frustrating is only being able to flush 2 litres of water out he radiator at a time when changing coolant . any easier way

Edited December 31, 2010 by NISSAN GTR

[jrm]

My 34 sits on about 90 degrees most days , maybe 93 when it gets hot at 36 degrees ,

the thing that i find frustrating is only being able to flush 2 litres of water out he radiator at a time when changing coolant . any easier way

Seems about the same with my R34 (GTT), with GTR MFD fitted. Normal days, it'll sit 70-80C, warmer day (like yesterday 35C+) it was hitting 90-95C (especially when idling/stopped temperatures would get higher - 96-98C - and quickly drop when moving again). I've only recently replaced the termostat & waterpump and the radiator was flushed semi-recently - so everything should be spot on. Mind you - factory gauge doesn't move (I'm told it wont until it breaks well past 100C).

I'm guessing this isn't that unusual, but I'm pondering fitting a larger radiator to try and lower my temperatures for those warmer days like we get in Adelaide.

[Moodles2]

Not to get too far of the OP's question. But I wanted to ask why you guys think fitting a slightly higher pressure radiator cap is such a bad thing?

(Assuming that the radiator and associated hoses are all ok of course)

It's a bad thing because pressure is pressure, rubber expands and (and overtime will swell) under pressure.. it can only expand so much until the least path of resistance is the area where the hose is physically clamped to the cooling system which forces the hose to blow off (even if the hoses are really clamped down, the next path of least resistance is the hose bursting), and from first hand experience at the track it's always the lower hose which is in a pig of a location with GTRs (R32s at least), you're not going to be able to reconnect it with the enginebay still hot, even with it cool it's still a difficult job with everything else in the way. Also because hoses decay from the inside out, outside observations are useless.

The factory OE rad cap is designed around the fact that (1.2bar for turbo apps, alittle under 1bar for N/A apps) this pressure is safe for the hoses to be securely clamped down.

[R32 TT]

It's a bad thing because pressure is pressure, rubber expands and (and overtime will swell) under pressure.. it can only expand so much until the least path of resistance is the area where the hose is physically clamped to the cooling system which forces the hose to blow off (even if the hoses are really clamped down, the next path of least resistance is the hose bursting), and from first hand experience at the track it's always the lower hose which is in a pig of a location with GTRs (R32s at least), you're not going to be able to reconnect it with the enginebay still hot, even with it cool it's still a difficult job with everything else in the way. Also because hoses decay from the inside out, outside observations are useless.

The factory OE rad cap is designed around the fact that (1.2bar for turbo apps, alittle under 1bar for N/A apps) this pressure is safe for the hoses to be securely clamped down.

Yep, appreciate what you are saying, more pressure, heat, what ever is always more strain on components - but hey that applies to everything we do to these cars doesn't it - especially when you hit the track. Interesting that you point out that the turbo app uses a 1.2bar while the NA uses under 1bar. That to me shows that Nissan determined that the turbo which produces more horsepower and has hotter 'hot spots' requires more control over boiling points at localalised areas in the engine.. but both NA and Turbo probably run at around 85 degrees around town. You wouldn't see the difference on the gauge.

Lastly, aftermarket radiator caps are what.. 1.3bar? hardly a massive pressure then. No one is suggesting using 2bar caps. If this small increase in pressure is enough to blow off a clamp then possibly your hoses and clamps needed looking at already ?

Bottom line is I agree that putting a higher rated cap on your car isn't going to change it from being an overheating car to a cool running car - but that is not its purpose. I also agree that if its near stock hp and stock radiator hoses that could be years old, I probably wouldn't put one on for street use. Just pointing out that the raised pressure does serve a purpose and maybe shouldn't be overlooked by the OP who is knocking out 500hp.

[Moodles2]

I remember someone at a Mallala trackday kept having his silicone hoses (the lower one) blowing off on at least 2 seperate occasions (autobahn888 ones iirc) no matter how hard they were clamped down, so it would seem silicone hose might be harder to clamp down due to it's slipperyness, probably not a good combo with a higher rated cap

[KiwiRS4T]

I remember someone at a Mallala trackday kept having his silicone hoses (the lower one) blowing off on at least 2 seperate occasions (autobahn888 ones iirc) no matter how hard they were clamped down, so it would seem silicone hose might be harder to clamp down due to it's slipperyness, probably not a good combo with a higher rated cap

Pipes shouldn't blow off if you use a swaging tool to create a ridge like a crox tool does or a row of dots of weld right round and use two clamps per join!

[Bond]

Was 40 in melb yesterday and my 33 was sitting at around 102 deg with A/C but the factory gauge still showed just under half!! With A/C off it would sit around 94 (both times just cruising). Clutch fan is in good nick and rad seems fine!