performance air filters suitable for a 944s
- Thread starter j4mou
- Start date
TK2015
New member
I looked at a number of cone type induction kits and an after market panel filter. With the under-bonnet temperatures being quite high, I thought that the cones would just be sucking in hot air unless I modified the front of the car to duct in cold air. I looked at getting a front panel with the four holes - as fitted to the 924 turbo but is would not have fitted without major surgery. In the end, I just went for the factory paper filter.
Wigeon Incognito
New member
Are the K&Ns not particularly suitable for our cars?
The reason I ask is that I have read some recent discussion elsewhere about such oil covered filters being a poor choice for cars with an AFM such as ours as the oil can slowly migrate into the AFM gunking it up.
Any opinions?
The reason I ask is that I have read some recent discussion elsewhere about such oil covered filters being a poor choice for cars with an AFM such as ours as the oil can slowly migrate into the AFM gunking it up.
Any opinions?
appletonn
New member
I think there is some credence in what you say there.
For me, the main benefit to these reusable type filters is the fact that you don't need to buy a new one ever again.....
The airflow improvements, and thus power gains, over the standard Porsche filter is minimal.
Any gain in power over the standard one, would be more than outweighed by the loss in power caused by the engine inhaling warm air from the engine bay, rather than the cool stuff from under the spoiler.
I like the idea of an intake kit for mine, but would need something that sucked nice cool air from beneath the bumper area. There are some kits that simply remove the turbo airbox and clamp a cone type 'performance' filter to the throttle body, but that is then just between the radiator and the turbo which cannot be good for cool air!
For me, the main benefit to these reusable type filters is the fact that you don't need to buy a new one ever again.....
The airflow improvements, and thus power gains, over the standard Porsche filter is minimal.
Any gain in power over the standard one, would be more than outweighed by the loss in power caused by the engine inhaling warm air from the engine bay, rather than the cool stuff from under the spoiler.
I like the idea of an intake kit for mine, but would need something that sucked nice cool air from beneath the bumper area. There are some kits that simply remove the turbo airbox and clamp a cone type 'performance' filter to the throttle body, but that is then just between the radiator and the turbo which cannot be good for cool air!
Nick,
I am unsure of the turbo's air filter location but I think it is in the engine bay rather than under the front slam panel like the S2. The advantage of the airfilter box /intake being under the slam panel is that it takes far more cool air as it is fore of the engine bay heat. It does however pick up some reflected heat bouncing of the radiator but that is minimal compared to engine bay heat.
Is it possible to fabricate a filter system for the turbo to sit in the same location as the S2 or will it have other implications on flow and engine dynamics?
I am looking at other filtration for my S2, a K&N panel is the obvious easy way to go, but I welcome others experience with cone type filters.[/i]
I am unsure of the turbo's air filter location but I think it is in the engine bay rather than under the front slam panel like the S2. The advantage of the airfilter box /intake being under the slam panel is that it takes far more cool air as it is fore of the engine bay heat. It does however pick up some reflected heat bouncing of the radiator but that is minimal compared to engine bay heat.
Is it possible to fabricate a filter system for the turbo to sit in the same location as the S2 or will it have other implications on flow and engine dynamics?
I am looking at other filtration for my S2, a K&N panel is the obvious easy way to go, but I welcome others experience with cone type filters.[/i]
xenon
New member
And probably the best too. As well as the cooler position of the filter on the S2, the airbox is also designed as a resonant chamber and is supposed to help flow. I'm not convinced with cone types.
That said, the airbox cannot be resonant across the entire rev-range so it might be rubbish, but I read it in the Peter Morgan book or the Porsche manual or somewhere.
The 968 filter box is in the same place relative to the engine as the S2 but it does not have the same protection from engine heat. It responds well to modifications to it that allow more air to flow through. I can't see a reason why the S2 will not respond in the same way, but as yet I have not tried it. I have had a K&N in previous S2s but have to admit they made no discernable performance difference other than intake noise. However I am now seeking any extra power I can so am prepared to try almost anything.
The other fact to consider along with air temperature is that you need smoothly-flowing air where possible. Sucking in turbulent air is not as desirable as taking air from somewhere less turbulent.
The S2 air intake under the badge panel struck me as quite a clever bit of design - using what was previously an un-used bit of space (although I understand that on the turbos there is an intercooler in there, which may prevent the mounting of a turbo air intake there.)
The S2 air box can be modified - see photos here:
... four big holes in the front of it (with a paper filter behind.) This method has worked well with Golfs I have owned, and is known to work well with 968's, but the result on my S2 wasn't fantastic. It did feel more powerful, but not much, and changed the mid-range throttle response for the worse (slightly). I did it soon after buying the car and thus can't honestly remember what it was like before the work, but I do recall being almost slightly disappointed by it.
On the plus side, it did produce a good 219.6bhp at the last Weltmeister day, so something is going well in there. The engine is otherwise stock.
Peter - I'd be interested to hear what else you have done to get more oomph out of yours. I too am considering a K&N filter, but have yet to persuade any american friends to buy one for me and send it over! (They are less than £25 out there ... )
Oli.
The S2 air intake under the badge panel struck me as quite a clever bit of design - using what was previously an un-used bit of space (although I understand that on the turbos there is an intercooler in there, which may prevent the mounting of a turbo air intake there.)
The S2 air box can be modified - see photos here:
... four big holes in the front of it (with a paper filter behind.) This method has worked well with Golfs I have owned, and is known to work well with 968's, but the result on my S2 wasn't fantastic. It did feel more powerful, but not much, and changed the mid-range throttle response for the worse (slightly). I did it soon after buying the car and thus can't honestly remember what it was like before the work, but I do recall being almost slightly disappointed by it.
On the plus side, it did produce a good 219.6bhp at the last Weltmeister day, so something is going well in there. The engine is otherwise stock.
Peter - I'd be interested to hear what else you have done to get more oomph out of yours. I too am considering a K&N filter, but have yet to persuade any american friends to buy one for me and send it over! (They are less than £25 out there ... )
Oli.
Oli, the mods you have done to your airbox are similar to the ones commonly done on 968s. The downside is you can reduce mid range torque by doing what you have done, by the sounds of it this may have happened to yours. As you said though you are making a good top end hp figure and that is also commensurate with the airbox mods (If anything your hp is a tad higher) so it may well have made a positive difference.
As for other mods I will be doing, to early to say yet, but I have improved my 968 with head work and decent mapping, the S2 is used for Hill Climbs/Sprints and trackdays and will probably end up being seriously lightened, crank flywheel etc as well as headwork. Early days and budget not seen, let alone past by the management.[
] [][]
As for other mods I will be doing, to early to say yet, but I have improved my 968 with head work and decent mapping, the S2 is used for Hill Climbs/Sprints and trackdays and will probably end up being seriously lightened, crank flywheel etc as well as headwork. Early days and budget not seen, let alone past by the management.[
] [][]Peter,
I took the inspiration from this:
http://www.968engineering.com/pdfs/airboxmods.pdf
... which is pretty much an account of the same thing done on a 968 (you probably know this document.) Having said this, I don't know of anyone who has done something similar with an S2. (I also removed the small clip-in duct on the inside of the air box, which is visibly absent in the picture.)
Yes, I think it may have affected the mid-range torque slightly. The big difference was to the 'engine' note (intake noise) - it became flatter and much more dull. I do recall however that it pulled much harder for a given throttle movement - you needed to push the pedal a lot less in any given situation to get the same acceleration. I *think* it may have made it a smidge more economical as well.
Headwork appeals, but is very expensive and my S2 is a daily driver. Peter Empson had (I believe) good results from the headwork on his S2 engine (in a lux.)
I have yet to experiment with chips or with removing the middle silencer, both of which are meant to make a big difference.
All the best with your S2 and hillclimbing - it must make a pretty good hillclimb machine!
Oli.
I took the inspiration from this:
http://www.968engineering.com/pdfs/airboxmods.pdf
... which is pretty much an account of the same thing done on a 968 (you probably know this document.) Having said this, I don't know of anyone who has done something similar with an S2. (I also removed the small clip-in duct on the inside of the air box, which is visibly absent in the picture.)
Yes, I think it may have affected the mid-range torque slightly. The big difference was to the 'engine' note (intake noise) - it became flatter and much more dull. I do recall however that it pulled much harder for a given throttle movement - you needed to push the pedal a lot less in any given situation to get the same acceleration. I *think* it may have made it a smidge more economical as well.
Headwork appeals, but is very expensive and my S2 is a daily driver. Peter Empson had (I believe) good results from the headwork on his S2 engine (in a lux.)
I have yet to experiment with chips or with removing the middle silencer, both of which are meant to make a big difference.
All the best with your S2 and hillclimbing - it must make a pretty good hillclimb machine!
Oli.
appletonn
New member
ORIGINAL: PJS917
Early days and budget not seen, let alone past by the management.[
[
][][]The turbo airbox sits off centre to the right of the centre line of the engine bay, directly in front of the bonnet slam panel, with a 'snorkel' pipe running off to the right down towards the front corner of the wing - from wher it should collect some nice cool air.
What i really need to do, is remove the exisiting air filter but leave the box in place and somehow fabricate a cone type arrangement to fit on the end of the snorkel...
Or something like that...[8|]
I need to get my A/C condensor swapped out tonight, so that I can get back driving the thing and check my boost levels properly.
Even on my drive-on ramps, there's still not much room to get underneath it[8|][
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