Extra heat extraction/control modifications

Discussion in 'Technical' started by Sketchy, Dec 8, 2016.

  1. Sketchy

    Sketchy Sick to the power of rad

    It's no secret that underbonnet heat is a major killer of Z32s roasting pipes, lines, radiators etc.

    Will have at least one z32 back on the road shortly and I'm turning my thought process to controlling this heat in the most value for money fashion to ensure I don't have to get back under the bonnet anytime soon.

    Initial ideas on top of a bunch of heat wrapping I've already done include:

    • spacing the rear of the bonnet up slightly drifter style
    • vented nose panel
    • radiator cover panel between rad and front rad support
    • cover panelling in front end to channel air through front mount and rad
    • cutting a vent into the bonnet behind the radiator

    This is assuming my cooling system is all up to spec first of course. Radiator, pipework, water pump all look great, will be using quality coolant.

    Anything else that's been tried and works I haven't thought of?
     
  2. rob260

    rob260 Administrator Staff Member

    Ducting the front mount was one of the most effective improvements I've made.
     
  3. MagicMike

    MagicMike Moderator Staff Member

    Anything to get the cold air in and the hot air out.
     
  4. rob260

    rob260 Administrator Staff Member

    Pics here http://www.aus300zx.com/forum/showthread.php?t=327924 if you're interested. Mike is bang on; increase pressure (ducting etc) where you want the cold air in and reduce pressure (vents etc) where you want the hot air out.
     
  5. JamainexD

    JamainexD Member

    Nissan was very smart and designed a cooling vent that would appear after 20 years. It's called the broken passenger side window cowl. :rofl:
     
  6. Chad_

    Chad_ Well-Known Member

    ye best way as mentioned, just duct your fmic and if u can duct behind it going to the radiator , then vent the bonnet... cold air in, hot air out...
     
  7. Sketchy

    Sketchy Sick to the power of rad

    This is my thinking, hence simple stuff like spacing the rear of the bonnet to take advantage of the low pressure vortex normally present at the base of the windscreen. DOT/police tend to not like it because it increases the likelihood of oil being smeared across the windscreen in the event of an engine malfunction but I figure if that happens you have bigger dramas.
     
  8. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    You dont need to space the bonnet just remove the rear rubber seals .
    That and a vented bonnet behind the radiator will make a difference with extracting heat out which is the biggest problem of the engine bay .

    .
     
  9. Fists

    Fists Well-Known Member

    I'm not a huge fan of venting the bay right at the back of the bonnet as all the hot air you let out there goes straight into the cabin if you have the fan/AC on (deleting the AC is another great boon for your cooling system).

    As for adding forward bonnet vents they're good for radiator temps but beware they will probably reduce airflow around the engine and plenum allowing more heat-soak in other components. So venting at the back of the bonnet is probably better, wait... engineering cars is hard.

    Ducting to cowled vents in the fenders would be a cool solution, not really quick and easy though.
     
  10. rob260

    rob260 Administrator Staff Member

  11. Fists

    Fists Well-Known Member

  12. rob260

    rob260 Administrator Staff Member

    Yeah that's it! I'd never fit such a thing, but props to Greg for testing it properly
     
  13. Shane001

    Shane001 Well-Known Member

    For the V6 Z32, would you be better off running vents up the side of the bonnet, rather than down the middle?
     
  14. MikeZ32

    MikeZ32 das Über member

    Commonly noted venting above turbos would be best since there are no electronics there and the biggest source of heat in the engine bay.


    Very interesting, what sort of improvements in temps? If only a few degrees, as there's a lot of wiring at the back of the engine, just in case it's raining would rather have them there.
     
  15. SrAfciGeR

    SrAfciGeR Member

    Do you mean venting cabin air inlets in to fenders?
    Good idea... but yeah not easy
     
  16. BLACK BEAST

    BLACK BEAST SLICKTOP TT R-SPEC

    Very interesting, what sort of improvements in temps? If only a few degrees, as there's a lot of wiring at the back of the engine, just in case it's raining would rather have them there.[/QUOTE]

    Havent tested temps .
    Just putting your hand at t the back of the bonnet you feel the heat coming out as well as the reverse vents over the radiator.
    Never had a problem with water and eletricals even hosing and washing the car .

    If your emgine runs hotter than normal obviously your under the bonnet temps will be higher .

    I run extremely cool for my power level due to my setup and ducting

    I struggle to hit 100 degrees oil temps at constant WOT and drops in secs to 90 off the pedal

    Water struggles to hit 90 at WOT and drops quickly to 82

    A good ductied setup with the bonnet mods I have works well

    .
     
  17. chewy

    chewy Active Member

    HPC Extreme coating the exhaust manifold and turbos

    is the single biggest reduction in under bonnet heat. I hpc coated everything and noticed a huge difference in under bonnet temps.


     
  18. JamainexD

    JamainexD Member

    Kym who runs the Australia Z32 300zx Buy/sell page on FB has that exact bonnet in storage, still in yellow.
     
  19. QLDZDR

    QLDZDR ID=David

    Not sure if you could drive around QLD with such an obviously Fiberglass bonnet it would attract the QLD HEAT but it looks like it would let the engine heat out.

    [​IMG]
     
  20. MagicMike

    MagicMike Moderator Staff Member

    Not so obvious, because it is a modified stock bonnet ;)
     

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