R33 GTSt Intake Temperature Tests

[rb25]

Recently I performed some intake temperature tests. They are not dead acurate but are atleast an indication of when heat soak is affecting your engine. I used some digital thremometers from jaycar for the tests.

The car: 1993 R33 GTSt, 3" turbo back exhaust, 8psi (stock) boost, stock intercooler, pod filter with cold air partition (95deg neoprene heat shield).

Ambient temperature: 17degC

1st Test: Cruising at 110km/h

Pod = 15deg

AFM = 15deg

Engine Bay = 35deg

2nd Test: Stuck in traffic (45km/h max.) (heat soak had set in)

Pod = 35deg

AFM = 37deg

Engine Bay = 55deg

3rd Test: On boost hill climb and high speeds

Pod = 14deg

AFM = 12deg

Engine Bay = 33deg

4th Test: Heat Soak

After pulling up at a set of lights from cruising at 110km/h, it took 3 minutes to reach full heat soak as shown in the 2nd test. It took 7 minutes of driving at 110km/h again to fully get rid of it.....

5th Test: After idle for 3 mins

Pod = 40deg

AFM = 43deg

Engine Bay = 60deg

[sweetr33]

dude thats amazing. Hadnt seen heat figures before. good work

[Guest RedLineGTR]

goood stuff...i know it will be helpfull

[Guest Robo's]

So you have a heat shield. Is it any improvement over just a normal pod. I do feel some draft from the fan at idle straight from the fan, obviously not good.

[predator]

pod filter with cold air partition (95deg neoprene heat shield).

rb25 - do u have a cold air intake?? e.g. a tube rigged from somewhere front of your car to feed your partition steady supply of cold air? Of course, not much use at idle.

*Very* interesting results, about time somebody got scientific on this

Those that take their skyline to the strip should take note. Obviously sitting there idling as you wait to get your run (can be 20mins), gradually moving forward - its just like traffic unfortunately. Even if u regularly turn your engine on and off heat soak is going to set in and its going to effect your times.

A suggestion: Can u at all do plenum temperatures? Obviously you've got some good before intake results, but the most important thing is the actual temps going into your engine..

[Sil8ty]

rb25: good work.. Where did you get the heat shield from?? As i cant find any thing anywhere.. Must be looking in the wrong places??

[benm]

Interesting results...

Now all u need to do is *borrow* someones carbon fibre bonnet with the vents in it and see how much of a difference it makes (obviously weather and traffic conditions would be hard to keep accurate).

[kjb_r33]

temps after the intercooler would be interesting.........

you would finf that uner boost they would be hotter than under bonnet temps..

[sewid]

Interesting. The people driving around with pod filters but without partitions should take note of the air temps they are sucking in.

What thermometer model did you use?

I tried to buy thermometers from Jaycar 2 weeks ago to perform similar testing with my own partition (http://www.endusk.com/skyline/caip/caip.html) but the dumbasses couldn't find where in the shop they put them.....

When I get some I will add some notes on the temp differences between using just neoprene and using aluminium + neoprene stuff + sealing rubbers.

[rb25]

I forgot to mention that without a duct forcing air into the partitioned area the heatsoak reduced at 60km/h and above, even in traffic.

predator666: I dont have a duct rigged up to it at the moment. I will do some plenum temps very soon (end of this week/early next week)

Sil8ty: I got the heatshield from Century Foam and Rubber. It's about 8mm thick, sort of like neoprene and has a reflective foil on one side. My partition cost 2 hours of time and 4 dollars.

kjb_r33: I've been informed that the clutch fan on the engine from the factory is excellent in its efficiency and i think that at high engine speeds it pulls alot more fresh air int the engine bay thus making it cooler.

sewid: boxhead has a similar partition (made from metal) and it gets red hot. Metal partitions in my opinion suffer from heat soak and would lengthen the times to get the intake temps down.

I've posted a pic of my setup below. I know its rough, but it seals to the bonnet and the top of the wheel arch and right up to the back of the headlight and it works really well.

[king_kw13]

nice setup. do u find this setup works much better in terms of airflow and temperatures to a high flow panel filter in a standard airbox?

[hippy]

have u thought about shifting the bonnet up slightly higher so its on an angle?? should allow more air to flow a bit better??

[king_kw13]

hippy wont u get a gap in the front b/w the light and bonnet?

[sewid]

Originally posted by rb25

sewid: boxhead has a similar partition (made from metal) and it gets red hot. Metal partitions in my opinion suffer from heat soak and would lengthen the times to get the intake temps down.

I have thought about that as well. Now the aluminium is insulated with foam it gets warm but never hot/red hot/too hot to touch.

To solve the problem of getting the heat out of the aluminium i was thinking of thermal epoxying on some aluminium heatsinks on the cold side.

I dont know if this would worsen the problem of heatsoak however in the long term or increase the effective heatsoak time to beyond average lenght of time spent stopped thereby negating it.... Only way to find out is to experiment.

Or could just remove the headlight and poke the pod out the front

[hippy]

not really .. its only very small .. this is very easy to do and won't damage anything at all i dont' think .. u will find this sorta stuff on alot of drift cars ...