Alternate (lower cost) idea for cold air intake..

[eliot]

I'm purchasing a 'carb hat' for my twin turbo conversion and it occured to me that these would be ideal for you Ultima chaps who want to cold air intake.

www.auto-nomics.com/cgi-bin/showresults?q=everything

Basicly get a carb hat, some 3" ducting and a filter and route in down near some nice cold air.

Ive got an inlet air temp sensor inside my traditional top mounted air filter and it sits at 50'c regardless of road speed, due to it sucking all that hot air from the exhausts.

Eliot.

[chuntington101]

good idea! have seen loads of these carb hats used on supercharged Chevy's and never thought of using them like that! ATI (the makes of procharger) do a comp version that looks good for use like this.

Chris

[davefiddes]

Once my EFI conversion is up and running (or I at least have the IAT sensor in place) I was wondering about getting a filter top for my K&N filter. Wondered if any of the cool air coming from the air scoop on the top of the GTR could be persuaded to just go into the engine instead of just acting as general cooling air...

[ultimasimon]

This is something I have been thinking about too. One thing though, you do not want to force air into the carb as it will have a negative effect on fuelling at different speeds. The trick would be to allow cold air to be drawn in but without pressurising it.

I am thinking along the lines of a circular ally intercooler that could be fitted inside the air filter assembly of the large K&N type filters, and connected directly to the cars AC unit. The unit would use the standard filter on the outside of the filter assembly but the core would be made up of thin guage ally pipes to form a heat exchanger matrix. You could then charge cool your intake air. The standard ac pump is more than big enough for the job but you would have to increase the size or density of the ac rad and it would have to fan driven. To this you would need a guru ally welder but it is possible.

[eliot]

ultimasimon said:

. You could then charge cool your intake air. The standard ac pump is more than big enough for the job but you would have to increase the size or density of the ac rad and it would have to fan driven. To this you would need a guru ally welder but it is possible.

Are you sure the gains wouldn't be outweighed by the drag of the a/c pump running all the time?. Cant see the point, when its easier to just duct ambient air into the car, rather than sucking red hot exhaust air in and them using the engine to cool it back down again.


>> Edited by eliot on Friday 28th January 14:37

[ultimasimon]

Probably not on a normally aspirated setup. When running the car on a hot day I had the ac on anyway so maybe it would help give a bit back. The original idea came to me when I was upping boost on my 300ZX, searching for that maximum advance curve before detonation comes in. The differences during warm and cold days was substantial - less so on a na setup. But we know there are bigger gains to be had on forced induction.

A lot of the pro ricers are now using a c02 bottle running through a similar alloy setup which just dumps the spent gas to atmosphere.

I think if I were to 'grab' some fesh air then it would be via some form of mild scoop picking up air from under the chassis but I am no aero expert and no idea what the effect would be on the cars stability.

I like the idea of a remote 'pickup' point that is away from the top though.

[chuntington101]

you will not see a gain running that system N/A, and i dout you would with FI. you see that the old rule "you dont get anything for nothing" applies! the energy requiered to compress the gas will be greater than the energy that you get out (ie in cooling the intake). also you will be increasing the density of the air and thus reducing the presure (increasing the vacum) even further, thus increasing pumping loses. there is a guy on a US forum that was think of using the remains of the A/C coolent (ie affter it has been through the cabin cooler) and this may give some gains on his turboed unit, but only marginal. there is a kit out that will reduce the temp of your intercooler by spraying N2O onto it. these kits work well for drag racing but on the open road the N2O runs out too quick. and your better off using it to cool the intake direct as then you see the power gains from the N2O to!

for N/A your best to direct cold air straight at the carb/intake. if you have injection then its even better if you can positive presure in the intake (achived at speed). there is a kit made for the elise thta gives you about 5% more power at 100mph thanks to presure in the intake! its like turbocahrging for free!

thanks Chris.