Performance panel filter or CAI? Tell us what you use

[BottomScratcher]

There's a few references in this thread to CAIs being or not being insulated from engine bay heat.. are we counting CAIs such as the Carbonio or the new VARDesign ones which use a sealed carbon box and only draw air from outside as sufficiently insulated or is a whole lot more insulating needed? Just curious..

The boxes that connect to stock induction hoses may be partially insulated from engine heat, but everything between them and the intake manifold isn't. The moment you pull up at a set of lights the under bonnet temp shoots to 60C+.

I mentioned a unit I had on an old Bimmer. The hoses were insulated, and when the bonnet closed it came down on seals on the top of vertical insulation panels that sealed between the inner wheel arch of the front guard and the underside of the bonnet, so totally isolating the already insulated filter box from the rest of the engine bay. Afterall the whole idea is get cold higher density air into the manifold. The spaces under bonnets today don't allow what I've tried to explian to be done.

There's a pic here, http://www.bimmerwerkz.com/forum/5-series-e12-e28-e34-e39/cold-air-intake-5312.html that gives the idea.

It's OK for track, or long distance, but is more efficient when the car is moving. Like any insulation, once the R value has been reached then the insultion is no longer efficient. For city driving I don't see any benefit from CAI's or panel filters, and even on the open road I don't consider spending money to mod one component of the intake system, but leave everything else on the intake side and the exhaust stock standard to be worthwhile in attempting to achieve perfomance gain.

[Weekend-Warrior]

Yep, swept volume and agree with most of what you wrote.

But the exhaust won't be atmospheric pressure since there's a back pressure. To reduce this you change the exhaust.

Agree a replacement panel filter won't do much. However what I was arguing was restrictions like resonators, bends, snorkels, the airbox itself, etc.

Have a read of this and see what you think.

http://www.autospeed.com/cms/article.html?&A=111369

[andymarc]

The boxes that connect to stock induction hoses may be partially insulated from engine heat, but everything between them and the intake manifold isn't. The moment you pull up at a set of lights the under bonnet temp shoots to 60C+.

I mentioned a unit I had on an old Bimmer. The hoses were insulated, and when the bonnet closed it came down on seals on the top of vertical insulation panels that sealed between the inner wheel arch of the front guard and the underside of the bonnet, so totally isolating the already insulated filter box from the rest of the engine bay. Afterall the whole idea is get cold higher density air into the manifold. The spaces under bonnets today don't allow what I've tried to explian to be done.

There's a pic here, COLD AIR INTAKE - BMW Forum - BimmerWerkz.com that gives the idea.

It's OK for track, or long distance, but is more efficient when the car is moving. Like any insulation, once the R value has been reached then the insultion is no longer efficient. For city driving I don't see any benefit from CAI's or panel filters, and even on the open road I don't consider spending money to mod one component of the intake system, but leave everything else on the intake side and the exhaust stock standard to be worthwhile in attempting to achieve perfomance gain.

Here s the pics from that site

[Weekend-Warrior]

That's pretty average... a real airbox should be air tight from air within the engine bay.

If we want to look a Bimmers, check out the puppies on this thing...

Member frankenauto perfect V10 M5-powered BMW M3 E30 is now ready - BMW M5 Forum and M6 Forums

[andymarc]

Well this is the CAI i'm thinking of getting since my paper filter needs replacing and well... figured why not!
Dont know much about them but i like the fact its still enclosed and looks pretty good too.

[Dutch77]

If we want to look a Bimmers, check out the puppies on this thing...

Member frankenauto perfect V10 M5-powered BMW M3 E30 is now ready - BMW M5 Forum and M6 Forums

Now that's an intake!

re: comments above in relation to my query - thanks, and yep get where you're coming from. I guess my mod path if/when I ever get there would also involve dump pipe and tune, and I feel confident then that there will be some benefit (particularly if it is acquired cheaper on a package deal).

[BottomScratcher]

[QUOTE=Weekend-Warrior;921660]That's pretty average..[\QUOTE]

when I did mine in 1991 it was cutting edge.

.. a real airbox should be air tight from air within the engine bay.

I only meant to post one pic. Don't know what happened there. Air tight was supposed to be achieved by the rubber seal that the bonnet came down on. I tend to think of it as experimental .... just like those made today . If F1 teams (who apparently think resonance can be used beneficially) struggle with it on their budgets I'm leaving it well alone.

Haven't read your link yet, but I most certainly will. Thanks.

And of course you're right about back pressure in a stock exhaust, which opens up discussion about airflow and valve positions and scavenging unburnt fuel in exhaust gasses. Maybe later. Now, it's beer o'clock!

[Dutch77]

Came across this comment direct from an APR representative from the USA on the golfmk6 forum:

"It sounds like power vs cost is your biggest concern and I have to tell you the best route to go is the APR Stage 1 ECU upgrade + Carbonio Intake. This will actually get you more power than the Stage 2 setup with downpipe + stock intake.

The intake is a huge restriction on this engine and we have seen removing this restriction really opens up the top end. We are seeing rather large jumps in power with just the intake over stage 1 so given it's cheap price, I think this is your best option."

[dArK5HaD0w]

Came across this comment direct from an APR representative from the USA on the golfmk6 forum:

"It sounds like power vs cost is your biggest concern and I have to tell you the best route to go is the APR Stage 1 ECU upgrade + Carbonio Intake. This will actually get you more power than the Stage 2 setup with downpipe + stock intake.

The intake is a huge restriction on this engine and we have seen removing this restriction really opens up the top end. We are seeing rather large jumps in power with just the intake over stage 1 so given it's cheap price, I think this is your best option."

in the US, the mk6 gti has a different engine to what is supplied to the european & rest of the world.
they get the CCTA & CBFA engines, while the rest of us get the CCZ.
the CCZ has a different mechanical structure to the US variants.

surely that will make a difference to the intake characteristics?

if the same applies to the CCZ, then that good news indeed, as i'm tossing up between a full apr exhaust, or just the downpipe with the intake.

[Dutch77]

Very true, struggling to find what the mechanical differences are though.

Is the APR downpipe still a different length to stock? (If I go downpipe only, I'm not interesting in cutting pipe)

I'm in the same boat though, tossing up between two intake options or skipping it altogether and also tossing up between full TBE or downpipe only - any catback I select would be 2.5 only, don't want anything too loud, just a step up from stock. Under any of these options still doing the tune, just deciding between two brands still. Decisions..