Power enhancement by cool-air-intake on AR 3.0 V6 ?

[quick_andreas]

Hi all,

I wonder if anybody of you has made modifications in the engine-bay to get the air to the air-filter from a "cooler" place than the original place. Lately on an airplane with a 80 hp Rotax-engine we made a similar modification, i.e. sucking from outside instead of inside the fowling, which increased the horsepower to about 96 hp, as the manufacturer states. At least it is a very noticable increase.
My AR 3.0 V6 has an K&N-Filter just behind the firewall, not far from the exaust-manifold. Without having measured the intake-temperate I "feel" that there is a bif difference in torque at lower revs between cold engine and hot engine. Anybody made experience already? Otherwise my next step (from April on) will be temp-measurements to get this quantified.

Have fun,

Andreas

[Stratos]

Andreas,

This was something I was intending to do on my car over the winter, but lack of time means it hasn't happened.

I'm fairly sure you would get an increase, although how you would ever quantitify it, I don't know.

[rutthenut]

This is something that you 'should do' when looking for best (and consistent) power from the engine installation.

Just because you should do, doesn't mean that I have though!

A 'cold air box' is a sensible method, but sometimes you can get improvements just by mounting panels to isolate the hot areas of the engine bay from the region of the air filter and air intake.

Note that a 'ram effect' intake is different to simply providing for a large amount of cooler air. If you have effective ducting from a forward facing intake, the air pressure will rise as speeds increase. This isn't something that your ecu will be set up for, so it is not necessarily a good thing.

As an area for modification, ensuring that cool air can get into the engine bay is good. Also consider that the hot air needs to get out from the engine bay. Forcing speed-sensitive air pressure changes direct into the intake/air filter isn't going to be so useful. Maybe that's not true if the engine management system can tell the difference though.

A couple of panels around the back and side of the air filter region may help the engine to get cool air at the intake, but their size, shape and position would really depend on the layout of your own installation.

Trunking from the side vents of the rear panel may help a bit too.

Not that I'd expect any major differences in power output, but if the current installation does take pre-heated air then it will definitely result in some form of improvement to get colder, higher-density air to the intake.

Another option I've seen is to mount a radiator fan to the underside of the rear panel - above the engine - to extract hot air from the engine bay. Personally, I don't think that's really necessary, but for a car that may spend a lot of time in slow or stationary traffic it might help reduce engine bay (and engine) temperatures a bit. It's not something aimed at increasing power levels, more for avoiding potential cooling problems. And at the expense of a bit more wiring and (minor) weight penalty.

[chris.richard]

I'd be cautious extrapolating from an aeroplane to a car - lower air temperature at altitude, greater ram effect from higher, non turbulent air velocity.

An ECU will notice the greater airflow from the ram effect - the greater pressure difference between intake and plenum will result in a higher airflow through the meter.

I was looking at potential solutions to this the other week when I had the rear bodywork back on. The inside of the side intake is obstructed by the upper diagonal member and the top chassis rail, so there is no room for large bore ducts, The best I could think of was some baffle plates to try to direct the flow in the desired direction.
Marcus's Castrol colours turbo engined car has a couple of added intakes under the roof spoiler, but to work well, they would have to be ducted into the engine compartment, rather than just opening into the space below the louvres, which is a low pressure air extraction area.

[rutthenut]

Originally posted by chris.richard
Marcus's Castrol colours turbo engined car has a couple of added intakes under the roof spoiler, but to work well, they would have to be ducted into the engine compartment, rather than just opening into the space below the louvres, which is a low pressure air extraction area.

Besides the easily visible air scoop/intake under the main roof spoiler, at the top, he has also fitted some clear perspex-type panels to the sides of the spoiler. These will help duct air into the side vents of the rear panel.

Still doesn't get it exactly where it is wanted, but this is likely to be nearer the air filter assembly - and looks quite discreet too.

I think Colin Artus has ducts from each side vent to the airbox assembly for his intake system on his 308-engined racer.

[Stephenos]

OK Andreas, late as I am... I'll chime in on this one,
It is a known fact that cooler air will produce more H.P. (Cooler means denser, therefore more molecules per any given unit of measure as previously stated.)
Ever noticed how your car (or motorcycle) seems to run better, have crisper throttle response, on a cool fall evening as opposed to a hot summers afternoon when it seems very sluggish? Racers know this, that's why all but the production based classes use some form of ducting, ram air or cold air box.
It was used as a big sales pitch on muscle cars of late sixties and early seventies. Cars like the '69 Firebird Ram Air 400, 70 Chevalier 454 and Road Runners. With their air filters sealed up against the underside of the hood, (oh BONNET for you blokes) and then with pop up hood scoops or reverse cowl induction feeding them. Any means they could use to get cooler outside air into the intake tract.
Funny though, the other side of this equation is cooler fuel. But few people seem to pick up on this side of things. Drag racers have been doing it for years with the use of a "swirlpot". As it sounds, it's a pot or can that the fuel line winds around. It's filled with "dry ice" and will super cool the fuel.
(A little trick we use to use was to fill areas of our race bikes air boxes with chucks of dry ice to help cool the intake air as well as the underside of the gas tank. Worked great for short sprints.
(Oh and it's -25c here in the Great White North. Just got our power back. Ice storm last night, blowing snow now....)
Here is a photo of a cold air box on a racing Stratos. Might not be practical for your street application but it does work.

[John]

Stephenos,
any more details about the car in your picture? It looks interesting. A previous thread was asking if any cars were located in Canada.

[Stratos]

Stephanos,

Any more pictures of that airbox. I'm intrigued how the hoses carrying the air from the side vents makes a seal against the box.

This was the sort of thing I was planning on adding to my car this winter.

[Andrew Way]

I thought I recognised that picture.....

http://www.allferrariparts.com/cars/mccstrblu.html

Andrew.

[rutthenut]

Originally posted by Andrew Way
www.allferrariparts.com/cars/mccstrblu.html

The site also happens to list a spare 'chin spoiler' for sale, along with bodywork parts (which are available elsewhere, as we know).

I'm intrigued as to the 'adjustable rate' quick rack - unless that means the steering arms have alternative mountings in them.

[x19er]

I have talked to the owner of AllFerrariParts a few times. It seems he wants little to do with replica owners. It may be difficult to get him to sell you the parts. He does have alot of stuff, though.

[Stephenos]

Sorry, I have no other info on this car or the air box shown. Nor do I know of any Stratos (real or replica) here in Canada.

This is as close as I get right now, me in my "virtual" Stratos competing in Finland

[John]

COOL! What game is that?
I think a few of us have got "virtual" Stratii in the garage.

[Stephenos]

Rally Trophy. It's like Grand Prix Legends, only for rally.
I had to use a "cheat code" to unlock the Stratos as I don't have a lot of time to play full seasons.
I find it's a very difficult race sym. I suppose much like the real car. The Stratos does have great sound in this game compared to Colin McRae II. but I have more fun with CMII.
Check it out at:
http://rally.jowood.com/

[Stephenos]

Here is a link to a photo of another group 4 car's air box.
http://www.carclassic.com/images8/DG67/L-DG67-6.jpg

And yet another link. This one shows hoses but they're not connected to anything.
http://www.carclassic.com/images4/DD12/DD12-7.jpg
I'm not sure about the shoes in the photo either. Maybe this car has real "sole" ;)

What you really need is to see the underside of a group 4 car's rear deck lid. Showing how they route the air to the snorkels on either side of the air box.

I'm still searching....

[chris.richard]

That is definately a home made box!