[Mk2] [Generic] Fitted my BMC CDA Filter (With Pics) - Do You Have One ??

[mark.pt]

hi all

just removed my k&n filter from my 93n/a and replaced it with a bmc cda filter.

liked the k&n but hated the fact water could be absorbed into the foam when in a heavy downpour as its located beneath the bonnet vents.

now to fitting the bmc cda

couldn't wait to fit until i opened the box and saw the size of the thing and released there was no way it would fit straight onto the throttle body.
luckily i work at a motorcycle company so i had two small 45 degree stainless pipes welded to angle the box into an open space.
i used some 63mm samco hoses to join everything together and hung the filter with the supplied bracket and then placed the intake hose to the side vent to draw in cold air.

All this took about 1 hour.

The sound is different to the k&n and it also feels like there is more "go" at lower revs.

Overall i'm really happy with the product and performance and would recommend to others.

Any opinions from people with this kit would be interesting as i couldn't find many people with these fitted.

PS - If any of you have a sportsbike then contact me as I work @ Harris Performance and will do my best to get you a good deal on parts.

regards mark

[Greddy-Matt]

[mark.pt]

ha ha good reply

will try and get some up asap

[Greddy-Matt]

Nice one, I assume this is the carbon coated "canister" style one?? Always been interested to see how effective they are! Will the canister heat soak at all?

[mark.pt]

yes its the carbon coated one mate

as its only been on a week i haven't done any long runs yet, but the box doesn't seem to get hot anyhow

i thought the standard air box gave good low power but seemed limited at higher revs

the bmc improves performance at higher revs compared to standard and you don't have the problem with the k&n of drawing in hot air when the engine is warm.

[mark.pt]

pics

[tomwoodis]

I've not had one fitted to an mr2 as I have a tubby and in my case it wouldnt make a huge amount of difference however.......

I had one of these fitted to my previous car (106gti) and the difference over a bog standard K&N was definately noticeable.

Whether this is down to the point you have already made about not sucking in hot air like the K&N would or not or something to do with the design itself i dont know - definately worth the money though I reckon.

What made me most interested in it when i was looking at them before is that the claim they can make a pressure drop /suction type effect by getting the air to spin in a vortex type motion. Apparently this is significant as it helps flow more air - in the end who know but it definately works and is a real looker

[Spittinflames]

Whether this is down to the point you have already made about not sucking in hot air like the K&N would or not or something to do with the design itself i dont know - definately worth the money though I reckon.

:

Wouldnt the standard airbox do just the same? Perhapes buying just an aftermarket panal filter and slapping it in the standard airbox???

[mark.pt]

Whether this is down to the point you have already made about not sucking in hot air like the K&N would or not or something to do with the design itself i dont know - definately worth the money though I reckon.

:

Wouldnt the standard airbox do just the same? Perhapes buying just an aftermarket panal filter and slapping it in the standard airbox???

the standard air intake system will draw air from the side vent (thus eliminating air being sucked in from the hot engine bay) but its far more restrictive compared to a k&n or bmc cda.

[Spittinflames]

I've never seen a standard airbox on a 2 so i really cant comment on how restrictive they are, Wouldnt it be the filter thats the restrictive bit? Take that out and replace with a K&N panel filter and your half way there.

I know on some of the other cars i've had they put in a silencer section, would that be the restrictive bit? If it is then i'm sure it couldnt be that hard to simply keep the standard airbox, lead a pipe from the side scoop to the standard box and replace filter with aftermarket one.

I've seen tests before where cone filters actually reduce hp, over a standard box, only by 1 or 2hp.

Sorry to go slightly off topic as i know you want to show your new toy off but to me it looks like we've gone full circle...... Closed in airbox (standard) rip it off replace with expensive cone filter.... rip it off replace with aftermarket enclosed filter. Do you ever get the feeling we are getting royaly shafted with all these gizmos.... or is it just me.

Looks nice anyway mate

[mark.pt]

I've never seen a standard airbox on a 2 so i really cant comment on how restrictive they are, Wouldnt it be the filter thats the restrictive bit? Take that out and replace with a K&N panel filter and your half way there.

I know on some of the other cars i've had they put in a silencer section, would that be the restrictive bit? If it is then i'm sure it couldnt be that hard to simply keep the standard airbox, lead a pipe from the side scoop to the standard box and replace filter with aftermarket one.

I've seen tests before where cone filters actually reduce hp, over a standard box, only by 1 or 2hp.

Sorry to go slightly off topic as i know you want to show your new toy off but to me it looks like we've gone full circle...... Closed in airbox (standard) rip it off replace with expensive cone filter.... rip it off replace with aftermarket enclosed filter. Do you ever get the feeling we are getting royaly shafted with all these gizmos.... or is it just me.

Looks nice anyway mate

understand what you mean by getting shafted but i got a good deal on the kit thats why i decided to replace the k&n

i think each standard intake system varies but the standard mr2 one is quite long and replacing it does free up the higher revs (thats what i experienced anyhow)

[Greddy-Matt]

Do you ever get the feeling we are getting royaly shafted with all these gizmos.... or is it just me.

Not just you I agree! I went for a standard box, panel filter and more importantly removed the big tank! That way you can run an air feed directly into the air box, felt much better than either the K&N or standard box...

looks very nice chap, how does she sound now?

[Greddy-Matt]

Dp

[mark.pt]

Do you ever get the feeling we are getting royaly shafted with all these gizmos.... or is it just me.

Not just you I agree! I went for a standard box, panel filter and more importantly removed the big tank! That way you can run an air feed directly into the air box, felt much better than either the K&N or standard box...

looks very nice chap, how does she sound now?

sounds different to the k&n and screams when u get to 4.5/5k rpm

when driving at low revs and cruising at 60-70mph its quite quiet

[nikk1877]

So they really do improve low down response - good. Cos I lost all mine when i fitted an HKS intake.

It's claimed that the CDA delivers air under slight pressure to the engine, just like the factory airbox (wich is good for low down torque as the engine is not having to work for the air) but still have the high flow qualities of a direct cone filter( which is good for noise and higher rpm's)

Best of both worlds - just hope it works well with a Beams engine.

[teccyjim]

Will the canister heat soak at all?

It will be considerabley less than any metallic material. It's not immune to it as the heat source (the engine) is running however the properties of carbon fibre are such that it will not 'absorb' and 'trap' the heat such as aluminium would for example.

A good example of this would be 2 identical motorbikes, 1 with a stainless steel exhaust can, the other C/F. Ride them until the engines are at normal temperature. If you put your hand on the carbon fibre exhaust, it will be warm (and will cool quickly). Put your hand on the stainless one- you will stick to it!!!

"Carbon fibre composites have very low thermal expansion coefficients, making them dimensionally stable at a wide range of temperatures"- straight out of my aircraft structures notes!!!

Jimbo

[RST]

It's claimed that the CDA delivers air under slight pressure to the engine, just like the factory airbox

.... so how does the stock box deliver air under pressure? I can't see that personally and I asked a few tuners about that theory before, nobody I spoke to agreed with that.

[teccyjim]

(Jimbo gets " theory of flight" manuals out!!!)

If you can accept that an aircraft develops lift via its wings using an aerofoil shape, accelerating air over the top of the wing which also has the furthest distance to travel (rest of the air goes under the wing) then youre half way to understanding.

If you also accept (look it up if you wish!!!) that as the air is accelerated over the top of the wing its pressure is REDUCED. Fact. Like the weather, high pressure wants to be where low pressure is. This higher pressure under the wing is in effect trying to 'push' through the wing to reach the low pressure area or a vacuum type void above the wing.

How is this relative to the CDA? If you ACCELERATE the air flowing the through the unit the pressure will REDUCE. I think BMC are claiming that they are producing a system where by more airflow (volume) is introduced per second than a normal system. The fact it delivers the air 'under pressure' is kinda irellivent from a marketing perspective, the increased flow is what matters but it's a fact of nature you cant have increased flow without a reduction in pressure!

Still with me?
Jimbo

[mark.pt]

looks like ive started a debate

[RST]

Jimbo,

I'm not digging my fluid dynamics notes out either but as far as I can remember ....bernoullis equation. You're spot on.

Nick,

Remember I was explaining about this that night in Falkirk?