Cold air question...

[Chaz243]

This may have been talked about in the past; but here goes... I was looking at the airbox on my 08 MS3 and thinking about the mods everybody has discussed... I took the lower box out and zip-tied the filter like so many other have described... Then I thought about the amount of heat that would be simply sucked out of the engine compartment and decided I didnt like the idea... I did take it for a ride; with no significant difference in sound or power to me... While I was putting it all back together; I noticed the battery box vent coming off of the ram air ducting for to intercooler...

This led me to the question: has anyone ever tried to tap off of that ducting to supply a forced cold air stream to the filter???

It seems that it would be easy enough and could only help... I will post info as I go, but this mod is on my drawing board... I am going to remove the ducting from the hood; make a template for the piping I will need to make by laying it up using the battery vent as a reference point... This will supply cold air directly from the ram air vents in the front grill into the top of the airbox just like the batt vent... I may even work on a little C/F wickerbill for the grill vents to farce in a bit more air... I think I will put the bill above the vents to catch overflow air that would normally just run over the hood... Again, a picture will speak a thousand words... A good outcome after this mod will speak even more... I work in the aviation industry so this kind of stuff is available to me all day... I will get back with updates as I go... Should be interesting...

Once again, I may be wasting my breath here; I just wanted to share the idea...

 

[intak3_bLkMs3]

i did that with my air box before my cobb sri came in i actually noticed a good change in sound not much but enough to hear the bpv... and dont mean to base on you but it all go's through an intercooler ne ways dude shouldnt see a whole lot of difference

 

[Chaz243]

Well, what I am looking for is a good cold air charge that doesnt draw from the engine compartment... I am talking pre-intercooler air... The air that goes into your filter is drawn form inside the engine compartment unless you go aftermarket and relocate the filter...

 

[PCspeed3]

So does the battery absolutly need that air? Or could you just shorten the battery duct and aim it towards the intake?

 

[Chaz243]

Good question... I assume the batt box is being purged so fumes do not build up... I doubt that cooling is the point of venting the box...

 

[15min5k]

Well, what I am looking for is a good cold air charge that doesnt draw from the engine compartment... I am talking pre-intercooler air... The air that goes into your filter is drawn form inside the engine compartment unless you go aftermarket and relocate the filter...

When the car is in motion (i.e.; when it's moving) the air in the engine bay is extremely close to ambient temps making it pretty much a waste of time to fit a long metal tube under the engine bay (Metal tubing also conducts heat). A good SRI is all you need for this car with it being turbo charged and all. The intake air in a turbocharged car gets heated by the turbo before it makes its way into the engine and then cooled by the intercooler. In an N/A car the process isn't exactly like this and the reason a CAI yields slightly better results for those applications.

 

[Chaz243]

When the car is in motion (i.e.; when it's moving) the air in the engine bay is extremely close to ambient temps making it pretty much a waste of time to fit a long metal tube under the engine bay (Metal tubing also conducts heat). A good SRI is all you need for this car with it being turbo charged and all. The intake air in a turbocharged car gets heated by the turbo before it makes its way into the engine and then cooled by the intercooler. In an N/A car the process isn't exactly like this and the reason a CAI yields slightly better results for those applications.

Very good points... After thinking this over a bit and pulling all the good points from the posts in this thread; it looks like the only advantage would be getting better flow from the stock airbox... I dont like the idea of drilling and hacking the box, and I already ruled out the zip-tie technique... Even with a SRI you may gain some advantage by piping in outside air... I understand what you are saying about the "car in motion", but I cant see the inside of the engine compartment being that close to ambient... The way everything is laid out, the air coming in is forced through the radiator; this has to deliver not much more than hot air to the compartment... Considering that the heating of the air going through the turbo is caused more by the compressing of the air; doesnt it make since that cooler air would provide a denser charge?

I would think a cooler intake air would equal a more efficient turbo...

 

[phantom6294]

<snip>Even with a SRI you may gain some advantage by piping in outside air... I understand what you are saying about the "car in motion", but I cant see the inside of the engine compartment being that close to ambient... The way everything is laid out, the air coming in is forced through the radiator; this has to deliver not much more than hot air to the compartment... Considering that the heating of the air going through the turbo is caused more by the compressing of the air; doesnt it make since that cooler air would provide a denser charge?

I would think a cooler intake air would equal a more efficient turbo...

Shameless plug of my own thread regarding IAT and BAT with the stock exhaust. Don't yet have an SRI or CAI for comparison, but hope for that to come soon.

 

[60181]

not sure if our cars "need it" but heat from engines are what degrade batteries pretty fast, so I'm sure it helps. Personally, I wish they would have mounted it under the back seat somehow as many cars do.

So does the battery absolutly need that air? Or could you just shorten the battery duct and aim it towards the intake?

 

[15min5k]

Very good points... After thinking this over a bit and pulling all the good points from the posts in this thread; it looks like the only advantage would be getting better flow from the stock airbox... I dont like the idea of drilling and hacking the box, and I already ruled out the zip-tie technique... Even with a SRI you may gain some advantage by piping in outside air... I understand what you are saying about the "car in motion", but I cant see the inside of the engine compartment being that close to ambient... The way everything is laid out, the air coming in is forced through the radiator; this has to deliver not much more than hot air to the compartment... Considering that the heating of the air going through the turbo is caused more by the compressing of the air; doesnt it make since that cooler air would provide a denser charge?

I would think a cooler intake air would equal a more efficient turbo...

A few members have posted data logs with IAT temps: CAI vs. SRI and the difference was not notable. Also, many members have had both on their cars including myself and neither intake types out preformed one or the other as far as butt DYNO and real life DYNO’S are concerned. The only real difference noticed was that with the SRI throttle response was slightly better and you can hear air getting sucked into the turbo more along with more BPV noise which is pretty nice if you like that kind of thing. I have yet to see any hard evidence that a CAI is worth the money over a SRI in this car (MS3) Just my opinion.

 

[Chaz243]

This is the type of info I am looking for... I want to know if any of it will be worth the buck... I am not looking to eek every once of HP, just that seat of the pants feeling... When I want to go REALLY fast I prefer two wheels anyway...LOL