Bill Verburg

If you want the coolest possible air stick, w/ a stock air box.


Notice where the intake is in relation to the grill opening. this is a transplant but stock isn't too different.


There is also a factory elbow that goes right up to the grill.

When the side of the air box is drilled you are ingesting heated engine compartment air.

When a cone is used that is even worse in this regard as all of the air comes from the relatively warn rear spaces.

Most of the whales have numerous small scoops that are pressurized at speed further enhancing cool air delivery.

GT3s actually have a nice big scoop and a sealed cool air intake tract.

Lorenfb

Let's not waste time and money on these so called "performance" mods without
some real performance data, and not by using those mickey mouse G-Tech boxes
for making comparisons.

As the saying goes, "There's always another sucker to buy a hyped performance
product or idea." Check out this web site (www.systemsc.com) on the Technical and
Problems pages for some insightful info about performance chips. Also, check out
Andial's web site (www.andial.com) on the FAQ page Question #2.

Have Fun
Loren
'88 3.2

lightisright

I had drilled three 4" holes in my airbox lid. More noise, not sure about more power. After I got tired with the noise I epoxyed the plugs back in (used a hole saw and kept the plugs, was thinking that day....). Definately all noise, no power. Just look at where the air goes after pass through the air filter, it goes into an even smaller area horn of the mass air flow sensor.

I also put on a cat bypass pipe, very nice improvement in power. But that I too removed, at least for the winter. The hydrocarbon filled exhaust would get sucked into the car by the heater when at a stop.

Brad

Lorenfb

Didn't mean to be so strong on my post, but there are a lot of flaky mods
out there. From the standpoint of chips, as Steve has said on another forum,
"Don't group all chips in the same category". I agree!

Good Luck
Loren
'88 3.2

Chris Picklo

You are right Lorenfb - many of the mods don't do much. But as far as the intake goes, you probably wouldn't notice a better intake unless you had headers coming straight out of megaphones.

The stock intake is better than the stock exhaust, and therefore not much benefit to change the intake and not the exhaust. The other way around you'll see an improvement, partially due to the stock configuration if you go to SSI's/headers.

The 911's have great air flow at speed in the engine compartment - so if you are driving the intake air will remain to be "cool air". I believe it's something (along with oil cooler) to be of more concern with the modified turbos.

I have a decent exhaust on my 3.2, and I noticed better throttle response after adding a (used) cone filter. Power, not sure about that...


cdp

Chris Picklo

Lightisright: You are getting exhaust through your heat? May need to replace your heat exchangers...

Lorenfb

Here in CA changing the exhaust is "bad news". Smog stations will "get" you.

Have Fun
Loren
'88 3.2

lightisright

Chris: No, not getting the exhaust in the heater ducts that way. Sitting at a stop sometimes, depending on how the breeze is blowing, the exhaust will come out the tailpipe and blow under the car. The intake for the heater air is back there and you can smell the exhaust. The other thing I didn't like was having my pants smell after scraping the snow/ice from the windows. My old '82 RX7 did this too (full racing exhaust, no cat) but I was back in college then.....

lightisright

In Ohio, you have to get your car e-checked every two years. Plus you can do it a year in advance so essentially you can have 3 years of polluting the earth before having to do any retrofitting. BTW, when I had mine tested (stock) the guy did a visual look for the cat with a mirror. He started just in front of the rear wheel and moved FORWARD. The engine was even running at the time. Apparently there must be one up there because he marked down that he found it.....

r911

BTW, you want to evaluate the amt. of decrease in temp. you will (likely) get, but aren't done then. You need to calculate the pressure increase for that temp. decrease. The benefit will then be equal to or less than that -- the latter if the exhaust is controlling the engine's ability to pump air.

Chris Picklo

randywebb- I'm not quite sure what you are saying...

If it was in reference to my post, the 3.2 carrera (ROW only, of course) has a better intake than exhaust, due to the header/cross over pipe configuration. Therefore, intake mods don't help you as much, whereas you can leave the stock intake and improve flow by freeing up the exhaust.

lightisright: What do they do in Ohio now? I'm originally from Cleveland, may move back next year (not sure), and need to be prepared as my 911 is both track and street.

Thanks guys - cdp

Von Kiser

The Idea: I have always heard about the Porsche Race Team opening up their air boxes or drilling holes in them to get a cooler air induction along with more free flow but wondered if it would be a true improvement. I never would do it to my factory one simply for the fact that it was the only one I had. But since I had two(picked one up at a show)...I said what the heck?

The Result first: after making it and installing it (with the filter of course) all I can say is WOW! OK...honestly, I can't tell that there is any Horsepower gain or any seat of the pants performance...but what I can say is the sound you get is amazing! The car truly sounds like a race prepped Porsche! I am sure if we put the car on a dyno we may see .5 or 1 HP gain but nothing major or that you could tell. The best way to describe the result is "I was grinning ear to ear during the entire first test drive." Of course that goes hand in hand with driving our cars...period.

The Design : When I decided to do this, my first goal was to keep the rigidity of the air box as close to original to insure the seal was uniform. Secondly...I wanted it to look like a factory quality job and not just have holes drilled(not that holes are bad). I wanted to open it up as much as possible. I decided on going with three large triangle openings that followed the original design molds of the air box while keeping two diagonal supports for strength. Below I have attached a link that has a picture of the Original Air box on the left and the Modified one on the right.


--Von
1986 911 coupe

Von Kiser

The KiserStyle Airbox read review above.

r911

Chris, I gave a way to calculate the max. performance improvement one can get from this mod.

911pcars

It's not all ambient air temperature. One reason engines seem to run better during evening hours and when it's moist (rainy weather) is the amount of water vapor in the air and thus drawn into the engine. It's called latent heat of evaporation. As the moisture evaporates, it absorbs a large amount of heat. Same principle as used in A/C.

Sherwood