Air-intake mushroom filter

[VR4Kaos]

as some may knoiw i got a hks pod mushroom filter that is highly hated by fellow members well im finaly looking to replace it thinking of this
http://cgi.ebay.co.uk/Mitsubishi-Evo...item4cefbac192
is this any good if not can one be recomended or even twin ?
want to sort this issue before eurospec RR day init

[Wodjno]

That will just gave same effect as an unshielded mushroom filter.. Your best bet would be to get hold of a standard airbox and updated panel filter for now.. And then if u want to, you can then look at moving battery to boot(or turn it sideways) And making ajnew air box and intake there.

[PaddyB]

You'll still be sucking in hot air => bad (unless you've got a cold air feed).
Accepted wisdom is the std airbox can't be beaten (unless you've got a cold air feed).

btw. I have one spare (actually 2) - £20 & it's yours
I have a panel filter too that I'll throw in for that price but I've no idea if it's any good.

[VR4Kaos]

You'll still be sucking in hot air => bad (unless you've got a cold air feed).
Accepted wisdom is the std airbox can't be beaten (unless you've got a cold air feed).

btw. I have one spare (actually 2) - £20 & it's yours

ill have it off ya mate asap only need box already got scoop

[Gowf]

Just out of curiousity. Has anyone actualy got any true impartial scientific proof for the 'shroom filter being pants other than hearsay and conjecture?

Has anyone had their car on the dyno with stock air box, then with 'shroom?

Id be interested to know, as clearly from stock my engine must have been far exceeding the factory power!

[Wodjno]

I would advise getting one of these also ...

http://cgi.ebay.co.uk/HKS-REPLACEMEN...item3f005b0f61

Or a Piper cross or K& N Compatible etc

[John TheAntique]

I've got a Blitz sonic ( you can make it whistle ) and it doesn't seem to make any marked difference.

[John TheAntique]

Found it

[bradc]

We've had multiple dyno results in NZ with pods that have shown a reduction in power and a richening of fuel maps.

[Gowf]

ok, thats not what i asked brad. Do you have results from the same car on the same day, at the same time of day, on the same dyno, with nothing changed but the air filter?

[Wodjno]

ok, thats not what i asked brad. Do you have results from the same car on the same day, at the same time of day, on the same dyno, with nothing changed but the air filter?

Well theres a RR Day not to far away.. So let's get the Raw Data on the day..
Sure there'll be someone with a Mushrrom there on the day that can do a swap over
Or we can sort 1 out

[Turbo_Steve]

Gowf -

Nothing quite that imperical, however several people who have had issues with fuel cut have removed the pod and gone back to a panel to find the issue resolved.

I've also seen mine use significantly more fuel over several months with a pod than with a box, doing the same journey day-in day-out.

Once you're into ECU territory, it stops being an issue as you're modifying the maps to suit the stuff you've got fitted, but if you're on the standard MAF and ECU there seem to be some issues with accuracy.

And, as I keep on saying over and over, it's got feck all to do with hot air.

[AlanDITD]

yeah can someone cant do it at eurospec on the day...or even a few cars do it as one may be differnt to another.

All the hear say around this just gets on my nerves...no one knows **** as far as im concerned when it comes to pods and panels and standard boxes and power gains and power losses....not one person that claims a power loss can back this up scientifically!

The position of the pod will be vary the results possibly...pedro was mean to send me my old pipe work if he could send it to a member thats going to the RR day they can use that. Im convincied it works well but would be interested to see the dyno results!

So pppppppppleeease someone do it to settle it either way.

[Gowf]

yeah can someone cant do it at eurospec on the day...or even a few cars do it as one may be differnt to another.

All the hear say around this just gets on my nerves...no one knows **** as far as im concerned when it comes to pods and panels and standard boxes and power gains and power losses....not one person that claims a power loss can back this up scientifically!

The position of the pod will be vary the results possibly...pedro was mean to send me my old pipe work if he could send it to a member thats going to the RR day they can use that. Im convincied it works well but would be interested to see the dyno results!

So pppppppppleeease someone do it to settle it either way.

This is my point exactly. There has been far too much chat about it, but no true data aquisition in any form of impartial way.

I know there has been indepth talk about disruption to the air flow causing indiscrepencies in the vorticies that are then created, but it does need some form of results to prove the theory. I fully agree with you though steve on the hot air front, as surely you would fuel less if it was heating the air significantly?

But my point is, was mine the only success story of a 6a13tt with one? And out of curiousity, if its creating more issues with fuel cut, is that not down to it flowing more air?

[Wodjno]

Don't even need to go as far as swapping over to a pod or shroom filter

I'm sure if we just took off the snorkel and front part of airbus off it would give pretty much the same results.. Filter should stay where it is as its being sucked not blown But a bit of Gaffer tape will hold it secure while not on throttle..

[Gowf]

Yeah but as its a different shape to the mushroom filter it will have an influence on the flow as it hits the maf, which is the basis of the arguement, so would be best to swap

[Turbo_Steve]

I agree there is nothing empirical, but I think there is enough anecdotal to know that the reading is different: if the pod actually allowed more flow, it would surely manifest itself as higher boost, no? People running the exact same boost target are seeing fuel cut with a pod, and none without.


I am not disputing that it may not make a significant difference in the midrange, but it absolutely categorically changes the load point approaching fuel cut.

Mine didn't feel any different at all going from one to the other (Pod > Box)...so much so that I was dissapointed. However the cars overall fuel economy was improved by 2mpg (increased to 17mpg from 15mpg. Epic.). What that only proves is that MY filter was a problem.....maybe it was dirty.

I'd be very interested to see someone do a couple of runs with Evo scan, if they've got it?

I'd be even more interested to see what some pipework will do, as positively pressurising the airbox is always a big win.

[Gowf]

I am agreeing with all this as there are sound arguements for it. But the extra air flow going through the maf at certain engine speeds are what cause the fuel cut no? Surely in upping the boost it is sucking more in through the maf, and thus this air flow is out of the region it want to see. By that logic if a pod is causing fuel cut then surely it is allowing comparitively more flow. And yes, unfortunatley more flow does mean more fuel, so for the same values you would be using more. So i do agree that it may be detrimental in some respects, but as an outright better filter then yes it could be, but as you say, as it will have changed the VE then you should map accordingly to get the most out of it

[VR4Kaos]

swapped back from mushroom filter to original stock air box and omg what a differnce in excelleration responce its huge ! thank you Paddyb rep is on its way to you mate for supplying and fitting the niggly thing lol

[Turbo_Steve]

But the extra air flow going through the maf at certain engine speeds are what cause the fuel cut no?

That's the bone of contention, right there: users running specific boost change filters, get the same boost but do/don't get fuel cut.

I believe these filters can offer a significant performance increase: unfortunately I believe you need to remap to take advantage of it.

I guess the most concrete proof would be to find a way of measuring the flow through the MAF sensor on a bench, then try a cone filter, and then a cone filter with a stabilising mechanism.

The primary cause of the issue seems to be that most MAF adaptors actually funnel the airflow towards the centre of the MAF. As this is a "tuned pipe", this effectively increases the airspeed by reducing the diameter, causing it to over-read.

Again, I have no proof at all, but if you look at the MAF, and an adaptor, it starts to become clear.

I suppose the best thing to try would be to drill a hole in a V6-24 airbox and fit a pod to it and chuck a baffle inside, then fit the whole caboodle to a VR4 and see what happens: the baffle / box arrangement should mean it sees normal airflow but without the restriction of the MAF adaptor OR factory airbox?