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Man, ain't the under bonnet heat of a turbo engine pretty extreme?

I had cold air intake ducting made of nylon duct pipe insulated with foil tape and also used 50mm PVC vent pipe. The heat has collapsed the PVC pipe and the insulated ducting has kinked. Not really wanted to give away the turbo inside but may just cut a few vents in the bonnet. There is room for a flat fan to hang off underside of bonnet. The blanket aint there for noise - its there to stop the bonnet paint burning!!

What have others done? Is main reason for post..

An STi equipped Brumby I have seen has bloody holes drilled all over the front rad mount and did have the bonnet raised at windscreen with washers to let heat vent (but owner thought it looked off so reverted back to slim lines.

Got new plans and foil hose for next air intake.

just wondering... why are you bothering with a custom cold air intake?

The factory airbox draws its air from the wheel arch which has a nice cool supply of air.

Please post a pic of your current setup, cos i am having a hard time imagining what it looks like

Most OEM turbo systems are swarthed in heat shields to lessen the effects of radiated heat , a lot of engine transplants don't have the shields and fry things around exhaust components .

A nude turbo/manifold/dump is a great radiator of heat . By the way this heat loss costs you power because keeping the heat in the exhaust gasses makes them want to apply their thermal expansion across the turbine and to atmosphere via the exhaust system .

You can do a lot worse than to make your own heat shields if you don't have the factory ones or through modding no longer fit .
Late Ford sixes use an aluminised matting that makes great shields and i think you can buy the same material from the aftermarket .
You can also buy those turbo blankets or "beanies" that fit around the turbine housing to keep in the radiated heat .

I know some people have hysterics at the thought of insulating heat inside a turbo system but manufacturers race teams do it and road cars have it too . Heat energy is fuel energy , don't waste it heating engine bays .

Lastly you can make effective shields out of even thin mild steel sheet , the shield and the air gap make really good insulators .

A .

I to would be keen to see the system.

I agree that the standard air box has a good cool air pick up point. I just enlarged mine to 3” (I can take a picture if you like) and it still picks up from the same place. I have used some thick rubber tube and not ever had an issue. I’ve heard that pvc should work so if yours has melted what does it run near?

In terms of the heat blankets/wrap (I have not used 1) however there is a significant amount of writings out there that they encourage corrosion once they get wet (I would assume that race teams would often replaces these items).

My 2c.

I'd like to show you but have upgraded PC from a 2000 chassis with Win ME to a 2007 box with Win XP Pro and the new card reader software is causing grief and also upgraded pic taker...get the drift? Got no pics on file

The factory air box and AFM is resting at the moment just sitting there while an upturned VN style air box sits where spare tyre used to be up against the curve of the firewall to feed the LPG mixer. The panel filter faces up. Thjinking discreet 25mm holes drilled in bonnet near the hole underside of the reinforcement double skinned bit

My exhaust fella says it is the heat shielding like on the crossover pipes below turbo is what causes them to crack - need to find a happy medium there eh ?

The PVC had an elongated slot cut into it for air delivery sideways and the slot has closed due to droop. This bit runs along the front of air box in spare wheel well. All other heat shields are in place

Dunno what happened there.... half my post disappeared ?!


As I have the VN air box in the spare wheel well I saw that to simply enclose the spare wheel well with thick cardboard as an extension of the firewall (huh, cardboard firewall , huh) in a very temporary way as a prototype .Anyway, separated the engine air from air box and cut two 30mm dia holes in bonnet just above the rectangular holes at the back underside of the bonnet thus supplying fresh air to the new cavity. I have got two holes on top possibly draw someunwanted attention....BUT have got a temp sensor on the air filter element and cruising speed can get air temp down to about 40' C on the element when outside temp in the weather bureau measuring box is about 35' . Next I will be filling the cavity floor with ice !!

Ice brick in the air box?

Gotta say I am convinced that to keep nice cool air going in and ensuring the EGR is hooked up and working has contributed to my fuel consumption improving consistently by 1.2l per 100km or the quality of LPG has improved for the time being, possibly due to the heat of the summer , the makers may be altering the blend propane and butane? To get that mark out of LPG is going pretty well. Got it down from 15 to 14.5 to 13.3. Think it was doing 10.5 to 11 litres per hundred on petrol....I can subtract, actually improved by 1.7l from start by attending to mixtures by tailpipe analyser to get the first drop. Saw air temp this morning drop from over 50' while sitting for an hour in the sun after a 15 min run, dropped to 31.6' .

1. change the pipe material from pvc to metal/alloy/stainless etc

2. or use the oem set up (preferable)

yeah without photo's it's hard to say but i knew a bloke with an sti 2 door that got more power using a cold air ducting system to his oem air box than a pipe and pod system filter

steptoe wrote:Man, ain't the under bonnet heat of a turbo engine pretty extreme?

yeah, I have been thinking of what to do with the heat as well, mine is pumping out large amounts of heat. I think I might be a bit shocked at what the intake temps might actually be.

I have a scoop on mine that lets out some of the heat, but I am also thinking about heat wrapping a few parts off/around the turbo.