air flow to airfilter - how to improve it?
Discussion
I have just replaced the inner wheel arches in the car after adjusting the bonnet the other evening and it got me thinking about how poor the airflow is to the airfilter....
The air cant get thru the wheel arches and it is only going to get thru the grille at speed. Once the engine is hot at lower speed the air is just going to be seriously hot and the engine must be gagging for air flow. As you can see below once the bonnet is closed the picture is pretty grim
just a thought but re the below...
the air pipe for the passernger internal fresh air vent is clear in this picture and passes right by the filter.... has any cut this pipe and used the air flow to create some sort of air box???
It never get used by the passenger anyway as on a hot day the roof is off!!!!
>> Edited by doddze on Thursday 28th July 22:19
The air cant get thru the wheel arches and it is only going to get thru the grille at speed. Once the engine is hot at lower speed the air is just going to be seriously hot and the engine must be gagging for air flow. As you can see below once the bonnet is closed the picture is pretty grim
just a thought but re the below...
the air pipe for the passernger internal fresh air vent is clear in this picture and passes right by the filter.... has any cut this pipe and used the air flow to create some sort of air box???
It never get used by the passenger anyway as on a hot day the roof is off!!!!
>> Edited by doddze on Thursday 28th July 22:19
Good point. On the V8S the standard filter is sideways over the top of the radiator, not quite as bad but still far from ideal.
I don't think there's an easy answer. What I've done in mine is duct round the rides of the radiator so the 'cold' side is sealed off from the engine bay, and then put the filter on the 'cold' side with the intake duct routed through the gap between the radiator and the plywood bonnet supports. It isn't completely ducted in yet but seems to be quite effective. In my case a combination of an 85mm duct and an extra wide radiator make this a tight fit, but with a standard rad and smaller diameter intake pipes it might be easier to arrange?
I don't think there's an easy answer. What I've done in mine is duct round the rides of the radiator so the 'cold' side is sealed off from the engine bay, and then put the filter on the 'cold' side with the intake duct routed through the gap between the radiator and the plywood bonnet supports. It isn't completely ducted in yet but seems to be quite effective. In my case a combination of an 85mm duct and an extra wide radiator make this a tight fit, but with a standard rad and smaller diameter intake pipes it might be easier to arrange?
Not sure how to overcome it on a V6 S but my filter now resides inside the near side wheel arch liner behind the headlamp. Believe me I spent ages with a remote temperature gauge monitoring where was best over lots of conditions.
I would suggest posssibily ducting some air directly onto the filter by some arangement from the LH side of the rad, use a temperature probe to see what effect it is having to perfect your ducting.
The drive for me was seeing the significant difference it made to the car on the RR, directly taking in hot air the V8S was losing around 30bhp
, incentive enough me thinks to sort it out.
Harry
I would suggest posssibily ducting some air directly onto the filter by some arangement from the LH side of the rad, use a temperature probe to see what effect it is having to perfect your ducting.
The drive for me was seeing the significant difference it made to the car on the RR, directly taking in hot air the V8S was losing around 30bhp
, incentive enough me thinks to sort it out. Harry
doddze said:
what did you use to build the boxing?
Everything, steel, aluminium, plastic, cardboard you name it. (Seriously, all those materials are in there somewhere.) It isn't going to win any prizes at a beauty contest, but it gets me cold air so I can move on to the next problem.
GreenV8S said:
Good point. On the V8S the standard filter is sideways over the top of the radiator, not quite as bad but still far from ideal.
I don't think there's an easy answer. What I've done in mine is duct round the rides of the radiator so the 'cold' side is sealed off from the engine bay, and then put the filter on the 'cold' side with the intake duct routed through the gap between the radiator and the plywood bonnet supports. It isn't completely ducted in yet but seems to be quite effective. In my case a combination of an 85mm duct and an extra wide radiator make this a tight fit, but with a standard rad and smaller diameter intake pipes it might be easier to arrange?
GreenV8S said:
Good point. On the V8S the standard filter is sideways over the top of the radiator, not quite as bad but still far from ideal.
I don't think there's an easy answer. What I've done in mine is duct round the rides of the radiator so the 'cold' side is sealed off from the engine bay, and then put the filter on the 'cold' side with the intake duct routed through the gap between the radiator and the plywood bonnet supports. It isn't completely ducted in yet but seems to be quite effective. In my case a combination of an 85mm duct and an extra wide radiator make this a tight fit, but with a standard rad and smaller diameter intake pipes it might be easier to arrange?
I struggle to get my standard 3" ducting around my standard rad. Infact I keep meaning to pay a visit to my local pipe benders to have a decent aluminium 90 deg bend made to get me around the radiator with out crimping the bendy tubing too much. Actually doing away with the bendy tubing all together would be a great idea if I could find enough parts to get all the way to the air meter.
I don't really see a problem with the filter being mounted upstream of the rad. It must get a good supply of clean air when you are on the move. I am not too worried about it ingesting hotter air when stuch in traffic, the exhaust manifold sees to that anyway.
If I remember correctly, has Pies managed to route his intake over the rad between the bonnet. If so, has anyone any pictures and will it fit mine / others.
Z
Built an airbox and ducted cold air into it from outside,into a K&N filter on a 2.0 Cav GSi I used to own.
It did make a big difference and then adding a chip racked it up from 130 to 155 bhp.
Often looked at the position of mine on the 'S' but don't want to increase the pipe length to the plenium.
Any modification to get cold air in would benefit of course...That counts for the entire engine really I would have thought!
It did make a big difference and then adding a chip racked it up from 130 to 155 bhp.
Often looked at the position of mine on the 'S' but don't want to increase the pipe length to the plenium.
Any modification to get cold air in would benefit of course...That counts for the entire engine really I would have thought!
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