sebastian944

I've seen people put the cone filter in front of radiator or belts or near the left headlight. What is best? I've also heard that the stock porsche intake is way better than the cone filter or so my mechanic says.

Just asking, I have a autothority maf and the cone filter is at the headlight.

CarbonRevo

I personally have mine behind the left headlight. Its a tight fit with the stock coolant tank. I plan to put it through the fender though, as my car started losing power when going flat out through 4th gear. It really starts sucking in hot air if your going from 0-100...and I don't like that.

The stock paper filter IS better at filtering then the K&N, regardless of what they claim. True, the K&N DOES make more power, but this is because of how less restrictive it is. It has less paper element, which is how it is this way. It relies on oil to catch dirt, where as a paper doesn't. But unless your running the stealth Vitesse MAF, your kind of forced to run a K&N.

I would NOT do behind the radiator though as that's a place where air thats just been heated up by the radiator flows to.

toddk911

As Cory said, the best is to route through the fender hole behind the headlight and wrap paper filter around the pipe or get a smaller cone style that will fit most of it through the hole at the fender.

This way you are pulling in mostly ambient air which will always be MUCH cooler than under hood air.

LESS cooler air makes more power than MORE hotter air.

I.e. you will make more power flowing 250cfm @ 50 degrees than 350cfm at 100 degrees, etc.

toddk911

https://rennlist.com/forums/944-turb...-intake-3.html

APKhaos

So, anyone figured a way to get a pipe from the stock AFM to anywhere BUT behind the intercooler?
I've got a K&N cone on the AFM, but it drives me crazy that its sucking hot air from the IC. Can't see how its possible to run a large enough dia pipe from the stock AFM to the fender on either side.

Maybe the best compromise is to put the stock airbox back. Its a trade off between getting cooler charge air and taking the hit on slightly more restrictive flow. I'm stuck with PCA Stock class rules, so can't change the AFM or the JPipe, dammit!

Darwantae951

I'd go with your idea of re-using the original airbox. The change in intake air temp should cancel out the restrictions of the stock snorkel.

CarbonRevo

You could maybe run a metal j pipe off the turbo and hook the AFM to that pipe, then run a pipe from the AFM through the fender hole and put a filter down in that area.

See what I'm saying?

APKhaos

Great idea, but PCA Stock rules don't allow any change to the J Pipe, which means we're stuck with the location of the AFM.

CarbonRevo

Could you rotate the stock j-tube 180 degrees so it and the AFM now sit behind the headlight? May have to run a SFR coolant tank, if allowed.

TurboTommy

Well, that's not really true.
Air flow, actually, takes precedent over temps.
If, for an example, an engine can use 400 cfm at full power, any restriction in the inlet tract that causes a pressure drop, when the engine demands this cfm, will cause quite a drop in power. Colder air can recover that, but it has to be a lot colder; extremes you would rarely see.
Density is king. Flow losses cause pressure drops. Less pressure loses density quicker than colder temps can recover.
Of course, if you restrict your inlet a bit, but this flow threshold is still above what the engine needs, then no problem.

ehall

I've run both stock airbox and a filter in front of the belts, on exactly the same car, temps etc. The turbo spooled a bit over 500 rpm sooner with just a filter in front of the belts.

APKhaos

That's a great data point. I'd suspected that teh stock box and snorkel thingie looked like a ton of restriction, and that confirms it. I suspect its within the rules to mod the stock airbox by replacing the snorkel with a thumping big pipe into the fender area. That might help a bit.

toddk911

It seems like with the PCA rules you really are in a tight spot (no pun intended).

If the J boot can be in the same location, but turned in a different orientation, then you might be able to get something over to the headlight/fender hole.

If the J boot/AFM can not be moved or re oriented then the only other way to get outside air is the stock air box or hood modifications, which probably are not allowed.

toddk911

wow!

Then I guess the stock box/snorkel is REALLY restricting the flow.

I ran the cone in front of the belts with the stock afm and could certainly hear the turbo spooling a lot more.

toddk911

The numbers I used were just an example, not taken from real data.

However, the concept was taken from real data. I read a dyno comparison some time ago of cold air intakes and the ones that were more accessible to outside air produced more HP than those that flowed more cfm but not directly from ambient.

There is a point where that is not true; 500cfm more will certainly make more power even if it is hotter air.