BMC CDA (First thread)

[Alun]

Hi all,

After spending 6 months visiting this excellent forum I dicided it was about time I started a thread.

Recently I purchased the BMC CDA for my 3b and after removing the original air box I found the cone and intake pipe were way to big (even just with the cone fitted I couldn't close the bonnet). So after refitting the air box I took the unit back to the supplier who then called the BMC head office. They looked into it and said that the only S2 they new that had the unit fitted was in Italy. They have decided to send a smaller model with different intake pipework which will arrive tommorow. (Will keep you posted on the results) and more info on the car in Italy.

The main problem with this unit is that our MAF's are facing into the bulk head and therfore the intake pipe needs to turn 180 deg using up more vital space.

Cheers
Alun.

[s2avant]

What part number did you have? Wa it the 200mm or the 250mm filter? I'm planning on ordering one of these in the next couple of weeks (I have heard nothing but good news about them so far and am waiting for Graham Goode to let me know which one BMC say to fit) so am very interested in any problems with fitting.

I was concerned about the 180 degree turn needed for intake hose. BMC list a kit for the A100 S4 which has a very similar MAF arrangement (albeit with a bit more space to play with). That kit has a hose between the MAF and the filter housing. They also do a kit that bolts straight to the MAF (which I was going for)

Does the filter sit at an angle so that one end is too high?

Ben

[Alun]

I went to a local motor factors and he spoke to the main dealer and they sent the recomended unit. The cost was £175 that inc vat. When i went to collect the part he told me they gave him the wrong price and they had actually sent the larger recommended cone which should have cost £215 but as it wasn't my fault and he didn't charge any extra.

The cone fiitted directly on to the MAF but was too long and sat on the wheel arch area hence the boot not bieng able to close. The intake pipe was made of a light alloy and wasn't all that flexible or long enough to reach the front of the car. The new one that is arriving tommorow is supposed to be 6 inches shorter and has a longer more flexible hose will let you know what happens.

I will get the part number of the unit tommorow if it fits.

The motor factors recon that it's the best air filter on the market at the moment and its good for standard and high powered engines. One of its advantages is it isn't affected all that much by heatsoak.

Cheers
Alun

[s2avant]

They do two lengths that fit directly onto the MAF. One is 200mm and the other is 250mm. The A100 S4 kit uses the 200mm long one and as they have the same engine this would seem to be the right one for S2's as well.

The intake hose they list is only 600mm long so by the time it has looped round back past the filter there isn't going to be much left to play with. It may need a longer hose making.

The heat soak issue is one of the main reasons I was looking into this (and the fact that an RS2 airbox is now about £300!!). I'm told they don't make the roaring noice you get from some cone filters either which is another plus point as I want to retain my stealth appearance (if I can be stealthy with big red callipers with porsche written on them )

Ben

[Alun]

Ben,

Made a mistake with the Shorter unit it will be 6cms shorter but i am still dubious as to whether it will fit. One idea I had was to replace the turbo to MAF hose with a custom job routed down towards the IC where there is a bit of space to put the cone then the intake pipe can be routed to the front of the car. The only drawback is the MAF connections will have to be extended and the MAF will be difficult to access. Any thoughts?

Alun.

[s2avant]

That's one solution. Extending the MAF connections shouldn't be a problem bit it could make things tight if the MAF needs cleaning or replacing though.

A custom MAF to turbo hose could be used to change the angle of the air box. I haven't taken my airbox out yet so I don't know how much space there is to play with. If the BMC was moved slightly nearer to the engine the hose could run down by the wing and into the opening behind the headlight where the standard airbox feeds from. Perhaps the standard MAF to tubo hose could be rotated slightly.

Ben

[Alun]

Tried to rotate the hose but the restricting factor is the small tee on the engine side.

The problem is due to the design of the original air box the MAF sits in the middle of the available space left once the air box has been taken out. (By the way anyone know how to put the original clips back on the wing side of the air box once refitted.) Maybe a shorter custom hose needs to be looked at if the CDA dosn't fit tommorow.

Alun.

[horvathg]

Hi Alun,

put in a photo when finally fitted plz.


thanks

[Alun]

Gabor,

Will take some photos tommorow and post them in the evening.

Alun.

[Stick Insect]

Originally posted by Alun
(By the way anyone know how to put the original clips back on the wing side of the air box once refitted.)

Alun.

I use a pair of fine nosed pliers and a screw driver to fasten and loosen the clips.

David

[Alun]

The BMC CDA arrived today and after some work was finally fitted. The Cone is the 200mm one and needed some extra exhaust ducting to make the 180 deg turn. I have noticed a considerable power increase between 2 and 4000rpm but sometimes the power delivery is a bit lumpy between 4 and 7000. My initial thoughts are that the ECU is reading the increase in air flow and adjusting the boost.

The induction roar is not too loud and makes a nice whooshing sound when floored also it sounds like a dump valve when you change gear.
I am pleased with it and need to make some under bonnet mods to tidy everything up as the fitting in the pic is a temprory thing.


Alun.

[Alun]

Another one.

[Alun]

Last one.

[Stick Insect]

Sorry for my ignorance, but....
isn't the MAF on the inlet side of the air filter, I can't tell which hose goes to the turbo and which goes to fresh air.

David

[dan_b]

Where does that curly fat silver hose go?!

Looks huge. Sounds like it's done the trick too, more power, better noise.

I'm not doing any more mods...