ajh Posted March 26, 2012 Share Posted March 26, 2012 Has anyone seen installing a Mantec "mushroom top" type raised air intake on a 200TDI have an effect on turbo boost pressure? My boost seems to top out significantly lower with the intake system sealed up than if I remove the top from the filter housing which leads me to believe the system is too restrictive as-is. Without mounting a series of pressure gauges to determine where the bottleneck is I'd love to improve the airflow as I believe it's affecting my mileage and performance. (I gained about 10kph by pulling the air-cleaner top off). Quote Link to comment Share on other sites More sharing options...
zardos Posted March 26, 2012 Share Posted March 26, 2012 Southdown and Safari both use a directional scoop which produces a ram air effect when driving forward, I think that a lot of other vehicle air box inlets are also forward pointing, where as a mushroom top does not produce a ram air effect. I'm not an aerodynamics engineer but other shapes could produce the opposite and hinder air from entering the inlet. If you are worried about performance and mileage swap to a forward point scoop. Quote Link to comment Share on other sites More sharing options...
mmgemini Posted March 26, 2012 Share Posted March 26, 2012 If you are worried about performance and mileage swap to a forward point scoop. Proffessor Kamm theory says different Quote Link to comment Share on other sites More sharing options...
zardos Posted March 26, 2012 Share Posted March 26, 2012 Proffessor Kamm theory says different Enlighten me? Google only turns up Kammback body style relating to aerodynamics Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 26, 2012 Share Posted March 26, 2012 Southdown and Safari both use a directional scoop which produces a ram air effect when driving forward, I think that a lot of other vehicle air box inlets are also forward pointing, where as a mushroom top does not produce a ram air effect. I'm not an aerodynamics engineer but other shapes could produce the opposite and hinder air from entering the inlet. If you are worried about performance and mileage swap to a forward point scoop. From what I've read you'll not gain any significant ram air affect below 100-120mph. Also "ram air" affect would necessitate a widening of the opening, not narrowing, i.e. a reverse funnel. This needed to slow the airflow and cause the pressure to rise and increase the air density. A funnel, or narrowing of the opening will speed up the air flow and reduce density doing the opposite of ram air. Quote Link to comment Share on other sites More sharing options...
zardos Posted March 26, 2012 Share Posted March 26, 2012 Yes Chicken, Ram air effect is low, some numbers found e.g. 1% pressure increase at 76mph or 0.15psi boost. The widening is provide by the larger size of the air filter housing usually. But add to it a negative of a possible venturi effect of a mushroom top Quote Link to comment Share on other sites More sharing options...
zoltan Posted March 26, 2012 Share Posted March 26, 2012 I think Mr Reynold's theories might be more useful to your quest Quote Link to comment Share on other sites More sharing options...
tuko Posted March 26, 2012 Share Posted March 26, 2012 The hose that clamps on the air filter housing is normally disconnected on my truck and only hooked up when offroading. Is this a possible option for you ? I carry a 7 mm wrench to tighten it up which only takes a few quick minutes. Quote Link to comment Share on other sites More sharing options...
Landrovernuts Posted March 26, 2012 Share Posted March 26, 2012 I have a mantec raised air intake with a mushroom top on a 4.2 V8 and have not noticed any noticable performance drop, or drop in fuel consumption. I know there must be due to the air restriction, but I would have though it would be negligable on a 200 tdi. Were Mantec raised air intakes with mushroom tops not used by LR as genuine parts, if so I would have thought they would be fine? Toby Quote Link to comment Share on other sites More sharing options...
ajh Posted March 26, 2012 Author Share Posted March 26, 2012 That's what I thought, I guess fitting a vacuume gauge between the airbox and turbo and testing various configurations is my best bet. My gut is telling me the limiting factor is how it connects to the side-vent and that a larger opening there would make a difference. You cannot add that much tube length without increasing drag on the inlet air for sure; I suppose I'll do the tests and try to get around to publishing the results. I do know my boost pressure peak goes from 15psi with it all connected, to 20psi with the airbox top removed, which is significant (boost controller) Quote Link to comment Share on other sites More sharing options...
specialbikejames Posted March 26, 2012 Share Posted March 26, 2012 This has been done to death on the forums, I think the general consensus is that there is f' all difference. Maybe fitting a snorkel to your V12 Ferrari 599xx may restrict the engine, but a shonkey mid nineties Land Rover diesel fitted in a housebrick Defender will make no difference in the real world. There's a chap on one of the forums (maybe Devon 4x4) who lives in the Middle East somewhere who posted up some curves from a Dyno with a snorkel fitted and removed. Quote Link to comment Share on other sites More sharing options...
ajh Posted March 26, 2012 Author Share Posted March 26, 2012 I'm certainly seeing a difference. Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted March 26, 2012 Share Posted March 26, 2012 I have the plastic, mushroom topped Mantec RAI on my 200 and I can't really say that it made any difference at all to performance. Mo Quote Link to comment Share on other sites More sharing options...
Happyoldgit Posted March 26, 2012 Share Posted March 26, 2012 Got a Mantec RAI on my current Puma and can't say I noticed any before and after difference at all. Quote Link to comment Share on other sites More sharing options...
Chicken Drumstick Posted March 26, 2012 Share Posted March 26, 2012 I'm certainly seeing a difference. In performance and feel of the engine or just in boost readings? I do know my boost pressure peak goes from 15psi with it all connected, to 20psi with the airbox top removed, which is significant (boost controller) Not sure how much affect this might have, but it's worth remembering psi and boost is a measure of resistance and not flow. So even though you where seeing 20PSI, is it actually flowing more, or is it more restrictive and flowing the same? Quote Link to comment Share on other sites More sharing options...
Daan Posted March 27, 2012 Share Posted March 27, 2012 I dont think the top makes a big difference, but the pipe diameter does. From memory, the standard Mantec snorkels are 2.5", where your intake pipe from the aircleaner is 3". So anything smaller than 3" upstream from the aircleaner looks like choking the system to me. I always ran a 3" snorkel so cant comment on what the difference would be for 2.5" vs 3", but it just doesn't look right to me. Daan Quote Link to comment Share on other sites More sharing options...
Maverik Posted June 28, 2017 Share Posted June 28, 2017 Just to link back to some testing I've just done, pretty basic, but tells you something... https://forums.lr4x4.com/topic/49267-diamond-in-the-rough/?page=16#comment-886743 Quote Link to comment Share on other sites More sharing options...
Cynic-al Posted June 28, 2017 Share Posted June 28, 2017 I thought the purpose of the mushroom top was to separate the dust and dirt out like a vortex filter would do on a fish tank? Like a tractor top does but it just slings it out the side rather than collecting it in a tub. That has to use some energy right? Quote Link to comment Share on other sites More sharing options...
dangerous doug Posted June 28, 2017 Share Posted June 28, 2017 Holy thread revival batman! Quote Link to comment Share on other sites More sharing options...
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