Engine bay cooling

[Tophler]

Now as many of you probably know, our engine bays get extremely hot. Even things like the intercooler piping heats up to the point its too hot to touch and in turn heats up the air inside them and when the ECU detects the heated air it pulls timing out of the tune and decreases power. I have also noticed that my COP setup gets extremely hot too which can't be good for the coils.

What the aim of this thread is, is to see what we can do to cool the entire engine bay down and vent the excess heat out. The obvious first thing to do is put a vent in our bonnets but the ones from topstage etc are non-adr approved and may not crumple in a crash. The excess force in a crash will make the bonnet snap off the 4 bolts holding it and guess where its going to slide back to?

Assuming no-one on here wants to be decapitated (absolute worst case scenario, they may also splinter into a million tiny fibreglass bits) there must be some other ways of decreasing the heat in the engine bay. Maybe installing an evo vent in our stock bonnets could be an option? From my research (only reading up on what other car guys have done) putting in bonnet spacers is a complete waste of time but i wouldn't mind doing my own experiments with this down the track.

If anyone else has some ideas feel free to share

 

[pretzil]

Might need to try to chase the heat sources instead of trying to cool them, mainly the exhaust pipes inside the engine bay. Ceramic coated exhaust manifold and dump pipes would have to have a significant effect of the heat pumped into the engine bay.

As for intake air temps, you could Insulate any hardpipes you have: http://www.autospeed.com/cms/article.html?&title=Insulating-the-Return&A=109587

 

[6A13TT TYPE S]

vented bonnet is by far the easiest.
putting an evo vent into a stock hood never looks quite right as the evos have alloy bonnets so you cant weld the evo vent into the stock bonnet, and with the heat behind the hood it seems to always crack the glue/bog used to seam the two materials together. not to the point where they come apart but its just not a nice soloution.

I have a fiberglass "monster style" hood sourced from Speedfactory which has the proper lip in-front of the vents to create a low pressure zone above the vents at speed to drag hot air from behind the rad out.

(not my car but the same hood)

but in a crash I'd be very suprised if a bonnet went through your windscreen instead of being deflected up and over the car.

short of a hood, there isn't much more you can do other than insulating all the pipes and adding heat sheilds in as pretzil said. heat is what you have to live with in a compact engine bay with two turbos.

 

[d3ck5]

hahaha autospeed, by far the best website of its kind back in the day.

speaking of which, this topics reminds me of an article they wrote about under bonnet temps

http://www.autospeed.com/cms/article.html?&A=2159

basically, extraction vents work (they did on my other car) and the monster bonnet looks the goods. Ive actually emailed speedfactory about them by never received a reply.

i also emailed andysautosport and got a prompt reply about postage that scared me. even after a 5 bonnet group buy.

 

[6A13TT TYPE S]

my Monster one cost me 700NZD. just FYI

 

[Quintenperren]

This is what I plan on doing, fl bonnet with evo 5 vent

 

[pretzil]

hahaha autospeed, by far the best website of its kind back in the day.
speaking of which, this topics reminds me of an article they wrote about under bonnet temps
http://www.autospeed.com/cms/article.html?&A=2159

Yeah, I read that a while ago, managed to snag my own magnehelic gauge on ebay for $10 too , haven't got around to using it yet though.
Bought abs plastic to do the flat undertray thing, went halves with a mate and did his R32 gtr last weekend, need to pull it back off to get a baseline pressure reading.

 

[Tophler]

So ideally we would ceramic coat all piping in the engine bay; and install a carbon or fibreglass bonnet. Shame us aussies are restricted to using topstage for our bonnets and they only do the evo vents, they don't do the side one which would be idea for a CAI

 

[Guest]

how much did the abs plastic cost

 

[Tophler]

But youd wanna install dzeus clips for doing any work under the car so you don't have to pull bolts out every time. Looks great though, wouldnt mind doing that to my ride

 

[whats_doing]

CERAMIC COAT ALL THE THINGS!!!!!!!

 

[pretzil]

But youd wanna install dzeus clips for doing any work under the car so you don't have to pull bolts out every time.

We had to get creative to space down the tray, Long bolts with aluminium tube spacing the plastic from the bolt holes.
I wish we had shitloads of M6 thread holes facing down under our cars like this did.

 

[Badger]

my Monster one cost me 700NZD. just FYI

Heh with my Monster hood you can definitely see the heat waves coming out of the vent

 

[whats_doing]

CERAMIC COAT ALL THE THINGS!!!!!!!

I am seriously contemplating ceramic coating all of my exhaust housings/dumps/front pipes/IC pipes.

 

[pretzil]

IC pipes would be a waste of effort, once the others are done there will be no heat left to get into them...

Also, look into the autospeed article on insulating the intake plenum from the engine.

 

[d3ck5]

anyone up for a monster bonnet group buy??

has anyone made contact with speedfactory lately? I emailed a couple of weeks ago and nothing.

 

[Tophler]

I do like the monster bonnet... pending price but we'll see. if they can compete with the topstage pricing im in

 

[jungle]

vented bonnet is by far the easiest.
has the proper lip in-front of the vents to create a low pressure zone above the vents at speed to drag hot air from behind the

View attachment 23033

(not my car but the same hood)
.

Great picture!!

 

[slickd1]

I've been doing a lot of looking into this with Trotty and some convos with Steve et al.


Temperatures a big problem, price is also an issue with me. The best bang for buck solutions I've found so far is:

· Insulate the intake from the radiator (lots of radiant heat here, and conductive heat through the intake itself. The airbox acts as a spacer, and flow also slows as it hits the larger volume box)

· Remove the coolant loop through the throttle body (we’re literally running hot coolant through the throttle body, Trotty mentioned that there is a wax pellet and this allows us to have a higher idle when cold, so you may loose this function) but need to confirm with both kinds of throttle body.

· Include at least one phenolic spacer in the gasket setup leading to the intake manifold (The intake manifold is large, has a big surface area, slow, dense airflow sits above the block and rear exhaust manifold getting radiant heat from them both, it also is a very effective heat sync through the stock steel ‘highly conductive’ gasket sucking heat from the entire block and distributing it to the intake air)

· Heat shield the underside of the intake manifold

· Insulate the exhaust manifolds, dumps, and the top section of the downpipes. (best cheap way to do this is to remove the heat shields, give them a paint, #baybling, use the cheap exhaust wrap and with a lot of fiddling as neatly as possible wrap the crap out of it all, each exhaust manifold tube separately with no gaps, and follow down around the turbos as far as you can down the front pipe, do it in sections and use steel cable ties so it’s still easy to pull bits off if you have to. Be careful you don’t interrupt the operation of your waste gate actuator. Replace the stock heat shields over the wrap.)

· Needless to say, big intercooler.

· Vented bonnet in the negatively pressurised area in the centre front of the bonnet.

· A full under tray will provide initially less cooling, but greater downforce, venting the rear of the under tray creates another negative pressure port for the engine bay increasing intercooler flow and pulling some more hot air down and out of the engine bay.

· Fix the front bar, to fit the Jap numberplates we have a large section of the centre of the front bar blocked off (more prominent in the PFL), get a slimline numberplate, mount it up on the bumper, cut out the block of plastic behind the existing plate, you’ll need to replace the grille with something that flows at least as well as stock (which is quite good) so if it’s the aluminium universal anodised stuff then make sure it’s a very open weave version.


That’s where I am at the moment, if you can afford it then ceramic coat all the things.

 

[VOLK]

No wax pellet in my throttle body, just an empty space in that coolant chamber. Not sure if ours have them at all. It's an older, rudimentary cold start idle method commonly seen on old DSM stuff. I believe our cars rely on the idle solenoid alone. Would happily loop the coolant lines and cut out the TB.