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when i got back from a drive earlier i was under the bonnet doing my routine checks as you do and started thinking about the heat that was in the boost pipes, airbox and all the pipework onwards from there and was wondering how much of the heat will have been generated by the flow/friction of air inside the pipes and how much was heat soak from the engine bay temps as the car was parked up with no airflow..leading me onto the idea of some home made pipe covers and heatsheilds especially round the turbos + downpipes and insulate the airbox and intake as best as possible form the radiated heat or is the majority of heat from the air flow itself and would i be then trapping the heat in making the intake temps rise even further? i have a load of glass cloth blanket that i use in the furnace building industry which will be identical if not better than some of the stuff motorsport places selling. any thoughts on the idea??? i was maybe thinking of bonding it to some aluminium foil with the special fireproof glue thats used with the cloth to make rigid heatshields too and can make all sorts of shapes like doing fibreglass work. i have plenty if anyone wants to try something like this???

anyone thought about bonnet louvres to expel the heat?

Cossymad put some louvres in his 500+bhp RS4. Don't really think the under bonnet temps upset our engines when they are on the move.

after testing different heatsheilds the majority of heat up is after the car has been sat a while, i've sheilded my airbox from the manifold thats very close but apart from that the pipes and stuff feel quite cool if checked immediatley, while on the move the temps are fine

s4marsh wrote:after testing different heatsheilds the majority of heat up is after the car has been sat a while,

Agreed. I have phenolic spacers fitted under my inlet manifold. After a drive, the inlet manifold and Y-pipe are cool to the touch. Give the car 5 minutes to rest with the bonnet closed and you could just about fry an egg on them.

im sorry but basic engine tuning says the cooler the charge temp the more power created, the pipes cool dude to the intercoolers doing there job but heat soak will still happen, and is a problem on all turbo charged cars, i would bet if you went out without a bonnet there car would feel like its on rocket fuel, i have tuned lots of turbo charged cars and they all suffer from it, a cooler bay and lagged boost pipes is on my list of things to do and ill try and do maf readings before and after if anyone's interested, on my last car by reducing the charge temp by something like 10 degrees gave me 30bhp and 50Lbs torque and on a 2litre engine that's massive!

thats a health gain, i'm on the look out for bigger intercoolers now or water injection possibly

s4marsh wrote:thats a health gain, i'm on the look out for bigger intercoolers now or water injection possibly

both with methanol and lagged pipes and your laughin!!