Underbonet & Intake temps

[Classique71]

Im a big fan of ceramic/HPC coating - all my intercooler and intake piping was donr with HPC inside and out - and its lucky to brek 20 degrees if that while driving - I have an airtemp sensor close to the throttle body to monitor the intercoolers effectiveness , so far , so good ..

Though yeah - getting the extractors coated and wraped would be a start - make your intake iiping a littl longer into the corner - and SHIELD the pod with some insulted metal or airbox , and this will help too

venting in the bonnet helps suck the heat out ( i have a group a vent on the GT4 - Extremely effective ) so anyway you can assis to get the airflow around the motor , and the hot air out - is a good thing ..

Cold air inductions into the airbox is easy too - PVC or flexi pipe is your friend

ill be making a custom airbox , for the gt4 as soon as it arrives back , so this thread might be a good place for people to add their ideas

im using stainless for the box , insulated inside with foil board ( reflctive house insulating foam ) and plumbing back a caoi from under the arch/front bumper or from behind the light - or both!

should have a jig done soon

[takai]

Stainless for the box... use alloy, much easier to work with imho.

[Alchemist]

Getting the extractors HPC coated would be nice, but a little more $$$ then I am planning on spending on this. I can do the shield, box and piping pretty cheaply so we'll so how that goes. At least they are heat wrapped, it's a start...

[CrUZida]

Get a price on HPC'ing.

Last I was told it was $16ish per metre - since we don't need the uber coating ($50ish/m)

[AndyTTR]

Interesting discussion. This arvo I picked up an inside / outside thermometer from work to measure the temperature of my intake. With the ambient temperature ~23 degrees it measured ~22 (?) when the car was moving and ~26 when stopped at the lights. After the car had been idling for a while the temperature rose to around 40 degrees when the thermofans kicked in!

The intake manifold on the gen 3 is a bit silly in that it sits on top of the rocker covers. It gets quite hot. Is there anything i could do to reduce the heatsoak into it? HPC coating maybe?



This is the dodgy heatshield I made up to pass the vicroads inspection, hasn't really made much difference to the performance. I've got ducting running from the grille to the opening at the end.


Another thing I've seen done to improve under-bonnet ventiliation is to put spacers between the bonnet and hinges. Supposedly the vacuum generated at the base of the windcreen while the car's moving sucks out the hot air or something? Has anyone tried this? A customer at work also suggested running a bit of sheet metal over the top of the radiator to duct the air that gets between under the front of the bonnet down toward the intake? What else have you guys tried?

Sorry for the long post, I've been thinking about this for quite a while.

[BeRad]

yer ive tried washers dont think it helped just made the car look like something out of fast and furious,

my pod is down near the bottom of the radiator so escapes most heat and no it doesnt get muddy and wet as its not behind the wheels

[BlackSupra]

You'll see the biggest gains from the airbox + cai though.

Well you will see the biggest gains by replacing the metal pipe with the factory plastic one actually. (yes i know you cant fit it in there with the extractors)

I dyno'd my 2jzge in similar conditions on the same dyno and the airbox made 0.2rwkw less than the pod filter but the car ran much healthier in the summer time with reduced under bonnet temps thats for sure.

Factory JZA80 has a CAI above the radiator into the aribox which should be adequate.

If you wanted full house, you would be looking at 75-100mm piping to the front bar up into the aribox, problem is, it is IMPOSSIBLE to plumb a pipe of this size into a JZA80 airbox and still have it function, with access to removing the filter. If you want this, custom airbox is the go.

Another beauty of the factory airbox is that is the position of the air temp sensor, rather than the super hot pipe.

Best option is to ceramic coat extractors and the crossover pipe.

Then remove the coolant line to the throttle body, that will help in summer

[4DaDrift]

Edited post!

[petespipes]

Its a real science moving air through the engine bay.Myths abound.People install scoops and vents in exactly the wrong places and even around the wrong way.
Well designed vents are great as are the undertrays extending back under the engine from the base of the radiator which is designed to force more air through the "radiators"
A related topic I came across recently was coolant temps.When researching 1j thermostat I found it starts to open at 82c from memory,was fully open by 92c,the smart guys were saying to set the thermos by thermometer to turn on around 98c with the logic being that the engine runs best hot with cool inlet temps.
point is its not simple,most think keeping the radiator cool and keeping inlet temps cool are co joined but obviously not.
The trick with lifting the rear of the bonnet? I removed the rear sealing rubber to allow air to escape at that point.The result was an immediatly fogged up screen with hot air flowing over a cold screen at night.I guess there is a reason for the excellent quality rubber seal I hastily re-installed.Thats enough from me.Cheers.Pete.

[steve_t647]

Why do you not just push the pod through in front of the wheel arch, ready made box but it will pickup some dirt ets thrown about by the wheel. I did that on an EVO and apart from a monthly pod filter clean and oil it was all good even in the wet (high enough)

[steve_t647]

I did the bonet lift trick but you get oil and other crap in the heat and if it rain's you can get streaky windows. I ended up removing the seal at the leading edge of the bonet and ducting air in from the front of the car. When idleing you will get hear soak mine was an evo and ran launch control and antilag (switchable for on road) so the fan's were on all the time when stopped the bonet vent's do help on the evo's for rad temp.

[Rodger]

Another thought on reducing the under bonnet air temps.

Has anyone tested the general enginebay air temps without the thick layer of sound deadener on the inside of their bonnet?

Could it be possible this is acting like a blanket and trapping all the heat in, adding to all this?

Regards

Rodger

[oldcorollas]

Another thing I've seen done to improve under-bonnet ventiliation is to put spacers between the bonnet and hinges. Supposedly the vacuum generated at the base of the windcreen while the car's moving sucks out the hot air or something? Has anyone tried this? A customer at work also suggested running a bit of sheet metal over the top of the radiator to duct the air that gets between under the front of the bonnet down toward the intake? What else have you guys tried?

Sorry for the long post, I've been thinking about this for quite a while.

the base of windscreen is actually a high pressure region, which is why trearward facing scoops near windscreen are used for intake to engine... higher than ambient pressure
ideally you want to create low pressure under the engine bay and suck the air out from down there.... it is also a much larger open area than just a thin crack around the bonnet.

the HSV intake (can't remember which model) had a long thin intake that sat above the radiator to get the air you mention... as long as you don't want that air to actually pass thru the radiator, you may as well use it for intake.

[steve_t647]

Hi I would not recommend removing the shield onthe bonet in a turbo car I had to put mine back after repainting it three times in a year. The manifold temp cook's the paint even with evo vent's in the bonet

[Rodger]

Steve_t647

I agree it does save the paint on a turbo car especially if the turbo is up nearer to the bonnet.

But is not Alchemists Car an N/A motor?

All I can see is a big insulating blanket lying across the top of the enginebay so I thought I'd ask the question.

Us old school car owners dont have this issue.

Regards

Rodger