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FN2 Gruppe M - restriction.

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15
Hi,

I have a Gruppe M fitted to my FN2 but have been told these can be restrictive. Can anyone tell me what is restrictive about them please as I thought the ram air affect would be better than a cone just sucking air in and the cone surface area is much bigger than the OEM panel filter.
Is it because of the smallish gap from the bonnet scope to the air box? Air box size?
Would a second air feed into the box remove this restrictiveness if it is restrictive?

Thanks for any answers and advice.
Cheers
Dave
 
Who said it’s restrictive?

Hi,

TDI North, in a discussion about supercharging. I heard it was only good up to 250 bhp as well from elsewhere? Not seeing how ram air apposed to sucking is restrictive unless it's the diameter of the inlet track.

Cheers
Dave
 
Ram air effect doesn’t really work until at very fast speeds.
Not aware of how the FN2 design is, but any air intake that has sharp or multiple bends will effect the air flow, as well as the size.
Ideally you want the air take in a cool area with the pipe work as straight as possible. That’s why these long arm intakes with the filter behind the front bumper perform better as the filter is out the engine bay and pipe routing is less restrictive.
 
Here's my latest, straight pipe, heatshield and I've got a fog light caf already fitted. Great filter too.
 

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Ram air effect doesn’t really work until at very fast speeds.
Not aware of how the FN2 design is, but any air intake that has sharp or multiple bends will effect the air flow, as well as the size.
Ideally you want the air take in a cool area with the pipe work as straight as possible. That’s why these long arm intakes with the filter behind the front bumper perform better as the filter is out the engine bay and pipe routing is less restrictive.

Thanks @Lewisgame, the FN2 has an under bonnet scoop feed from the front of the car from above the grill and slam panel, the scoop then (when bonnet shut) connect to the air box with a large K&N cone filter in it which runs the usual course of the standard air feed.


Here's my latest, straight pipe, heatshield and I've got a fog light caf already fitted. Great filter too.

Think I've seen that somewhere before :)
 

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