BMC CDA Induction Kit - CAF or No CAF?

[bigup7]

fitted a bmc cda this morning, unbelievably tight fit, anyway managed to get it fitted and was just wondering what the general concensus was about the CAF? should i use one or leave it open?

if i use the CAF, am i supposed to take out the stock CAF and position the BMC CAF in its place?

Thanks

 

[Chris n nic]

All I know is when I had mine mapped on the rollers it made a massive difference when the filter was bent upwards to allow the cooling fans air to hit it. It made it quieter but I got a caf as soon as I could

Chris

 

[bigup7]

Thanks mate.

Any more views on this?

 

[Craigus]

If it is just sat open in the engine bay, it will be Heatsoak galore. Will be no different from a £20 cone filter. I would get a cold air feed on there, depends how you want it though, I like the look of them coming out the front bumper.

 

[ripp]

Hi,

I'll get the CDA myself in a few days, and for now I'll keep the standard elbow, and thought I could squeeze a short caf to the front grilee near the headlight, as in the pic bellow. Has anyone tried it? I don't think it will draw in hot air once the car on the move. the other option is just behind tthe headlight as the maxogen draws air in, is there any point in making the routing longer and twistier to the grille or the foglight instead of the two ideas above? thx!

 

[ripp]

went outside and took some pics. removed the airbox and placed a 76 mm caf just to see how it fits.
this is the the place the caf ends, and the red arrows point to the nearby air sources:

again the spot where the caf ends, and the OE airbox bracket which will be removed:

view from above, with the front grille lifted up to see where the caf ends:

view from the front-left of the caf opening towards the grille:

this is the aprox length of the CDA (160 mm- CDASP-08) and the space left in front of it, for the caf to go straight ahead as above:

 

[ripp]

this is the space for the air to come into the caf, it's not that much, but when on the move I'd imagine there won't be any lack of air:

the caf from the CDA is 70 mm, so it won't be that squeezed like the 76 mm one in the pics. I'm also thinking to place some heat insulation between the upper corner of the radiator and the caf, maybe the whole caf even.
Does the above setup seem ok or should I just go behind the headlight for the air source (like the maxogen does)?
you can see here the curved metal plate in which the second air feed from the OE airbox fits to, and the fact that it guides some air from the grill (yellow line is the limit of the plate in this pic)

so there should be a decent cold air source behind the headlight also.
As I said in a previous post I intend to make the caf as short and straight as possible.

 

[James28]

looks like you've done your research!

 

[Dave..]

How cold are people expecting this air to be? and how hot do people really think the air is in the engine bay of a car doing 40mph?

All your doing is sticking a pipe on the end of your filter, creating another half meter of tube that the car has to suck air through.

 

[ripp]

if going to get the caf near the headlight behind the grille, it will only be like 10-12 cm of tube I imagine, just a little help to get near the colder air in front. maybe in the future will leave the box with no caf, if I'll manage to make some heat shields. or leave it like above and wrap the caf in some insulation

 

[Ste666]

I might be wrong here cause i can't find the thread to confirm it but i'm sure jms did research into this and there was something about the best results being from no caf pipe as it allows air to be drawn in unrestricted and as the main heat source(exhaust manifold) is at the rear of the engine bay then air entering the front grill is still cold enough.

I took my caf pipe off yesterday from my standard airbox (after advice on here) and as this bypasses the AV it sounds so much better now. gives a real deep growl when you plant the right foot, feels quicker too but that could just be the way i feel it going by the sound.

But as i said i might be wrong here

 

[Craigus]

The best setup is the standard one.

That CAF will make no difference.

 

[Dave..]

if going to get the caf near the headlight behind the grille, it will only be like 10-12 cm of tube I imagine, just a little help to get near the colder air in front.

What cold air?

 

[ripp]

colder than the air in the engine bay, not by much though, as the car is on the move mostly but if the caf is short and the air drawn in a little cooler then what's the harm?

 

[Dave..]

The harm is where you stick a length of pipe on the filter, adding to the friction that the engine has to combat to get air into the cylinders.

I don't think people realise the difference in the volume of air between 20 and 40 degrees makes f**k all difference in regards to "performance". That's my main gripe.

 

[Craigus]

^^ This.

In comparison to the extra strain from having to suck air through another half foot of pipe, the temperature makes no difference.

 

[ripp]

so we all should run CDA's with no caf's? I thought the general opinion was that it runs better with a caf, many said they felt improvement with the caf fitted. will make some test runs when the moment arrives with/without a caf

 

[bigup7]

from what i have read using a filter with a CAF will only allow the air coming through the CAF so its restricted

whereas if there is no CAF your allowing the filter to suck air from other areas too.

if that made sense!

ive had the CAF on my BMC for a few days now, seems ok, il try it without and see if i notice any difference.

 

[Craigus]

Basically, the air temperature difference in the engine bay and from air being sucked in from in front of the car is not going to have any affect.

The ONLY benefit from having an induction kit is the noise.

If you want performance, put the standard airbox on with a ITG panel filter.

 

[bigup7]

If you want performance, put the standard airbox on with a ITG panel filter.

thats what i have come from and im sure i have noticed better throttle response with the BMC, could be placebo though.

but must admit the noise of the BMC is pretty good!

 

[Craigus]

Probably is placebo, but I do like the noise too, glad you are happy with it.

 

[ripp]

I am running ITG panel at the moment too, but after the CDA I'll do the mathched inlets plus a remap and hope to see gains from these mods. (milltek cat back on aswell)