Do front mounted intakes cause a power drop?

[diceman]

Hi Guys

I'm expecting my new M400 in the next few days (:yum:)and had asked to have the air intakes mounted forward as per the original position on classics for extra silly sound effects.

Have just been informed that the factory don't like doing this and stated that you are looking at a 25-30 bhp power drop due to increased intake temps.

I can't really see this, as we already know that the intakes sit next to the intercooler which gets relatively little if any flow. Would forward mounted intakes get less cold air?

I know a few cars, 3rs and 400's, with the forward setup and hadn't heard this before.

Any ideas?

Cheers
Steve

[DanH]

Not heard of that either.

My car had them and I was happy with it, although it was a GT03.

[m12_nathan]

Was it your dealer informing you, or the factory?

[gizard]

Sounds like they just don't want to do it.

[joust]

In hot weather the area around the air intakes does indeed get very hot. There isn't much "inflow" from the sides due to the aerodynamics.

Having them down at the intercooler at least gets them away from the tubos which throw masses of heat upwards on the offside intake.

So, given the ECU will retard things when it gets too hot, I can believe the power loss (and indeed I feel it).

However, given everytime I've heard a factory person talking about it it's usually "****** hell, I hate it" probably both reasons (power loss and it's a pain to do) are true!

J

[Mr Noble]

Factory seemed more than happy to move mine forward for me, and they did a stirling job too.

Cant say I have noticed any power drop though!

[sjc]

Sincerely hope this isn't the case because i'd like mine done too, maybe Simon may like to confirm one way or t'other?

[Diceman]

Thanks for the input.

The dealership informed me what the factory had told them.

I'm sure as Joust says it has more than a little to do with the hassle factor of doing it rather than performance loss of that degree...

Thanks for the advice the other day by the way Justin.

[obes]

I'm going to wrap my intake pipes in some heat shielding, cos of the heat thing.

As one turbo is at the front and one is at the back, surely it's a bit 6 of one and half a dozen at the other isn't it? Maybe the best solution is front turbo intake at the front and back turbo intake at the back.....

[matt_fp]

The ambient temperature at the front of the engine bay is higher than in the IC box. Hence the air inducted is less dense, combined with the standard IC it is entirely feasable that cars with engine bay mounted filters are down on power compared to those with filters in the IC box. However, with the filters mounted in the IC box it disrupts what little ambient airflow there is through the IC.......... so, you can either have higher pre turbo intake temperatures and more efficent charge cooling or lower pre turbo intake temperatures and less efficent charge cooling. Of course it is possible to flush a pair of ducts into a suitable area (or take feeds from the existing side pods) and use these to feed a pair of carbon airboxes or similar which are mounted in the bay.

Best Regards
Matt

[jipsom]

Can't you fit a noisy BOV aswell, to give you even more Darth Vader growl?
(my knowledge is limited - I could be wrong)

[matt_fp]

You can indeed, and if you go for a valve which utilises a filter the sound is very similar to that of a car with bay mounted filters, albeit slightly louder.

Regs
Matt

[obes]

matt_fp said:

Of course it is possible to flush a pair of ducts into a suitable area (or take feeds from the existing side pods) and use these to feed a pair of carbon airboxes or similar which are mounted in the bay.

Sounds like a job for our resident Surgeon
....or are we getting a hint of a new F.P. upgrade !

[matt_fp]

obes said:

Sounds like a job for our resident Surgeon ....or are we getting a hint of a new F.P. upgrade !

Clue



Although we're not ruling out the possibility of a single larger airbox fed from the passenger side pod filtering the air for both banks/turbo's.

Regs
Matt

[alex s]

My little nephew has that on his max powered saxo !!
I assume you are getting one made specifically for the noble. BMC make some very nice carbon airboxes.
Would look nice as well, anything that can make the engine bay look better has to be worthwhile

[Diceman]

Thanks Matt for clarifying this.

It is interesting that temps are higher there, I was thinking that at a good speed those vents in the clam just behind the rear side windows would flow a reasonable ammount of fresh cold air. There isn't much in the way of exit venting though so i suppose the pressure in the engine bay is quite high and relatively little flow occurs.

have you measured temps in that area Matt?

I'm not really after the noise anyway.... honest

[adrian w]

sounds like someone needs to carry out some proper meaningfull data logging, the front of the engine bay is only hotter when the car is standing still, due to heat soak etc, as soon as you move the air flow improves. as for the rear intake position, take a look and on the right hand side you'll see a metal plate on the bottom. this is to stop the rear turbo melting the K&N filter.....................tell me this is good.

Adrian

[matt_fp]

Adrian,

We'll be carrying out extensive data logging over the coming couple of months as part of the development for our filter/induction upgrade. I'll keep you all posted on the results.

Regards
Matt

[silversix]

Diceman said:

I was thinking that at a good speed those vents in the clam just behind the rear side windows would flow a reasonable ammount of fresh cold air.

You'd be supprised how warm the air directly arround the car is. I was suprised when putting hand out of window you can feel warm air bleeding from radiator until you get about 6 inches out from the bodywork. And those opening aren't exactly "sticky out"

[diceman]

That's a good point, I was suprised how hot the air is just outside the windows.

Really like the look of the cold air induction kit, that plus the intercooler would make sensible safe mods. Would that screw the warranty though? They would probably make the drivetrain more reliable.. less chance of any det etc.