EVO Intake discussion I had with a mechanic. - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Dragonwind · 08-04-2009, 12:09 PM

I just wanted to make an observation I had with another mechanic. I was talking about headers and he saw that I have mentioned I had an EVO intake. He was saying I should put the stock one back in as soon as possible to prevent further damage to the engine. When I asked why it was because of the vast amounts of hot air. This would make sense but the EVO came with a shroud to block it off from the engine bay and I went a set further and sealed all the gaps less a tiny drain hole for water.

Now I've been running with this in the car for a year and a half with no issues but that got me wondering if anyone here has real data on if these make a difference or really do more harm than good. My old box was damaged so that was the main reason I replaced it. A used factory box is cheap so I can always go back if they really aren't that good.

Thanks
Chris

Boxtaboy · 08-04-2009, 12:21 PM

Well, the factory intake is, as you know, already a fully sealed cold air intake, and if you install the EVO kit, I'm not sure it fully blocks off all the air from the top, as the engine cover may not seal fully well against the rubber piping. Did you cover the top of the EVO, like this guy did?....

jmatta · 08-04-2009, 01:14 PM

I would really question the mechanic's opinion...harmful to the engine? Even if there were a small air leak, it is nothing compared to the air the 997 cup cars and RSRs pull in with thier setup.

The air would be warm, not hot anyway; even if it were pulling some in. I've had an Evo Hi-Flow on my car for the last four years, without issue.

eightsandaces · 08-04-2009, 02:05 PM

I think the mechanic is wrong, it may well be that the hot air negates any hp gains but I see no reason this modification would harm the engine.

PS I am however worried about jmatta making the 666 post in this thread.

Adam · 08-04-2009, 02:06 PM

Your mechanic doesn't know what he is talking about. I don't think there is much, if anything that is gained by the EVO intake, but warm intake air doesn't damage the engine.

jmatta · 08-05-2009, 07:15 AM

I don't think there is much, if anything that is gained by the EVO intake

I tend to agree; a couple HP, if any?

But the sound is pure intoxication!

PS I am however worried about jmatta making the 666 post in this thread.

Follow me!!!

Jaxonalden · 08-05-2009, 06:42 PM

I'd like to know where your mechanic came up with the notion that sucking in hot air was some how damaging your engine? Education is a wonderful thing.

The only thing the hot air is doing is cutting down on the power your engine is making. Hot air (O2) molecules are expanded and you get less of them in the cylinder on the intake stroke. That's why the trick is to draw in the coldest air possible, in which the same O2 molecules are closer together (dense). More O2 + more fuel = more power.

That's the reason nitrous oxide (N2O) is such a great (and cheap) power adder. It's molecule is made up of 1 nitrogen and 2 oxygen molecules. During the combustion process the N2O molecule is broken down and the O2 is released. That added O2 combined with extra fuel that's injected produces allot of power. It is hard on the engine though.

I also have an EVO intake installed on my car. A properly installed and properly maintained EVO system will not damage your car and will provide more airflow into the engine because it is not as restrictive as the stock intake.

roadracer311 · 08-06-2009, 08:22 AM

Quote:

Originally Posted by jmatta

I would really question the mechanic's opinion...harmful to the engine? Even if there were a small air leak, it is nothing compared to the air the 997 cup cars and RSRs pull in with thier setup. .....

I don't think the 997 intake, in that photo is drawing air from the engine compartment. I think the rubber boots probably connect to the outside world when the hood is closed. The hood probably has some ducting that fits into those rubber boots, otherwise they wouldn't have clamped the rubber boots on there.

turbo23dog · 08-06-2009, 09:28 AM

I don't support or deny what the mechanic said, but one thing I'd like to add is that increase in temp of the intake air will raise the threshold for engine detonation. Turbocharged engines normally have an intercooler set up to aid in cooling intake air to make more power which is related to reducing odds of detonation.

Most newer cars have knock sensors that automatically adjust engine management when the knock sensor is triggered that would prevent dammage.

JAAY · 08-06-2009, 09:34 AM

Get a scangauge tool. Plugs right into the obd2 port and you can watch all kinds of things, including air intake temps. I had a cone filter on and while driving I was getting 86deg fh. on a 80 degree day but while stopped I was getting high 120's. With my stock box back in on a 88 degree day I was getting 88-90 degree temps and while stopped I was only hitting 105 and that was stopped for a long time.
KISS Keep It Simple Stupid and stay stock with a drop in filter. There is plenty of noise if that is what you are after if you desnorkle.

My .02

Jaxonalden · 08-06-2009, 03:30 PM

[QUOTE=turbo23dog]I don't support or deny what the mechanic said, but one thing I'd like to add is that increase in temp of the intake air will raise the threshold for engine detonation. Turbocharged engines normally have an intercooler set up to aid in cooling intake air to make more power which is related to reducing odds of detonation.

Most newer cars have knock sensors that automatically adjust engine management when the knock sensor is triggered that would prevent dammage.[/QUOTE

Detonation is caused by crap gas in high compression, turbo and supercharged engines. It has NOTHING to do with intake air temp. The intercooler in a turbocharged engine is NOT related to reducing the odds of detonation.

986rgt · 08-06-2009, 04:49 PM

Quote:

Originally Posted by Boxtaboy

Well, the factory intake is, as you know, already a fully sealed cold air intake, and if you install the EVO kit, I'm not sure it fully blocks off all the air from the top, as the engine cover may not seal fully well against the rubber piping. Did you cover the top of the EVO, like this guy did?....

Hey Rich, you pimpin out pics of my engine bay?! Sweet!
I would take what the mechanic said as a grain of salt as the EVO intake is a negligible gain in engine performance without headers, chip, high flow cats and exhaust. All itreally does is give tha car a real nice sound. I also found that the way the engine delivers the power has changed, no dyno charts to back this up, but its my seat o pants feeling.

Steve

Boxtaboy · 08-07-2009, 08:38 AM

Quote:

Originally Posted by 986rgt

Hey Rich, you pimpin out pics of my engine bay?! Sweet!
I would take what the mechanic said as a grain of salt as the EVO intake is a negligible gain in engine performance without headers, chip, high flow cats and exhaust. All itreally does is give tha car a real nice sound. I also found that the way the engine delivers the power has changed, no dyno charts to back this up, but its my seat o pants feeling.

Steve

Ha, yeah, you're the first person I've seen who's rigged up a top cover for their EVO intake. Not that you could hear it over the GHL!