robjnr said:

Maybe I'm wrong about the turbulence making colder air, I did read somewhere about it but can't find it now. I disagree about the airfeed not doing anything, standard pipe isn't getting any air directed to the filter, the pipe I've put in IS directing a good source of cold air, but you still think that it's doing nothing?

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I'm not disagreeing that the airfeed is not doing anything, but I am as of yet unconvinced there is a real benefit in objective terms.

Please, you do not have a good source of cold air. The air is not cold it is ambient temperature. So saying you have a cold air feed is a nonsense. No offence meant.

Lol, so what is a cold air feed? It IS getting more air and colder air than the standard air intake pipe, all you got to do is look at the position of the original pipe, me and a mate did a test on another car with and without a cold air feed, and driving along at reasonable speeds reduced the intake temp by 15 degrees. Although it was a 4" pipe

What you are saying is:

By swallowing air from the very front of the car, the ambient air is not contaminated by any heat in the engine bay, and the air is being 'pushed' into the intake rather than, a virtually stale air blocked by parts around the intake.

• Ambient Air in front and proportional to mph...
  
• Engine bay potentially contaminated (Warm) air entering intake at regular intake presure (Air would be approx 0mph, out of the vacuum of the intake)

Hope this helps!!!

robjnr said:

Lol, so what is a cold air feed? It IS getting more air and colder air than the standard air intake pipe, all you got to do is look at the position of the original pipe, me and a mate did a test on another car with and without a cold air feed, and driving along at reasonable speeds reduced the intake temp by 15 degrees. Although it was a 4" pipe

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There is absolutely no such thing as a 'cold' air feed. It is ambient air. The air isn't cold it is of ambient temperature, if this is the temperature of the air outside it is ambient temperature.

Do you think a difference of 15 degrees will make any difference at all?

trackdayqueen said:

There is absolutely no such thing as a 'cold' air feed. It is ambient air. The air isn't cold it is of ambient temperature, if this is the temperature of the air outside it is ambient temperature.

Do you think a difference of 15 degrees will make any difference at all?

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But they are called cold air intakes, evan though it is taking in ambient temp, (well it's not truely ambient as when you are moving the air is colder.)

20% rise in under bonnet temps can rob you of 3% power, so i'd imagine lowering the temps will gain you some power.

Re: Cold air feed for standard airbox UPDATE!!

Today i checked the pipe to see if it was still ok and i found that the pipe doesn't fit properly becuase a bit of the bumper that annoyingly sticks out was making a crease in the pipe which obviously wasn't good.

So... i came up with another way of directing air towards the standard intake pipe

I used some material that i had in the garage and made a deflector so the air hits it and flows straight into in line of the intake hole to give it some sort of air source



With out the side on


with sides on




Ok i'm no fabricator, but it definately serves a purpose

I bet that you can have the bumper off and on quicker than an F1 team changing the front wing!

It looks like a reasonable bit of fabrication to me - and well done for persevering despite the detractors

LeanMeanRacing said:

I bet that you can have the bumper off and on quicker than an F1 team changing the front wing!

It looks like a reasonable bit of fabrication to me - and well done for persevering despite the detractors

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Haha it was definately quicker this time around i can do it in under 10 mins now.

I support your research... but..!

Would this not reduce the air flow to the radiator?

Plus, you seem to have a lot of damaged fins already on your rad (towards the centre) was this accidental bumper removal damage, or just from road use?

By the look of your pictures, the intake is right behind the honeycombe grill. Can some of the honeycombe sections not be drilled out or parts of? Maybe some sort of mesh to reduce debris? Hard to get it to look good though i guess...

Just thinking out loud..!

pdtrewern said:

I support your research... but..!

Would this not reduce the air flow to the radiator?

Plus, you seem to have a lot of damaged fins already on your rad (towards the centre) was this accidental bumper removal damage, or just from road use?

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Yeh not anything to worry about though Damage to the fins was caused by previous owners, that's the reason the front grill was cracked. Must of been a bird or something because the aircon rad was pushed back.

I had another go at cutting the honeycombe grill today but it is difficult to get it to look good, also there is another bit of plastic behind the honeycombe which is part of the bumper which I don't want to start cutting holes in.

robjnr said:

But they are called cold air intakes, evan though it is taking in ambient temp, (well it's not truely ambient as when you are moving the air is colder.)

20% rise in under bonnet temps can rob you of 3% power, so i'd imagine lowering the temps will gain you some power.

Click to expand...

They may be called 'cold air intakes' but that is not technically correct as we know for obvious reasons.

I don't think cars register windchill. The air is not colder when you are moving it is the same temp it is, ie ambient temperature no matter what speed the car is doing.

So a 20% rise (if this is indeed correct?) in underbonnet temperature makes no perceivable difference to power given your figure of 3%.

The trouble is you can't lower the temps below ambient temperature. So as you can see it would seem there is very little to gain.

But What i'm trying to say is the standard intake has no 'direct' air source. You can't really rely on gaps through the bumper as a source of air. You got to admit that having direct air pointed towards the intake is better than no air?

robjnr said:

But What i'm trying to say is the standard intake has no 'direct' air source. You can't really rely on gaps through the bumper as a source of air. You got to admit that having direct air pointed towards the intake is better than no air?

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Well of course air pointed towards the air intake is better than no air at all, but clearly it is not the case that there is no air at all, because if that was the case, the car wouldn't run.

Of course you can rely on gaps in the bumper etc as clearly that's all that is needed.

Whilst I agree, it does seem odd that there is no obvious air source for the intake, obviously there must be enough airflow as it's not like the car struggles at high revs for example.

As I've said before, due to my intake piping falling off, I ended up with an open airbox. I found that the car sounded meatier, but there was otherwise no perceived difference to the performance that I noticed. When the dealer fitted new intake piping, it just went quieter again.

Though what you have done will certainly do no harm, I'm not convinced that it is worthwhile going to the effort of doing it. Also I'm not convinced at some of your understanding of the issues etc. No offence is meant and I'm not trying to rile you, honestly. Temperature of the intake air is not a factor, I guess what you are getting at is airflow, but we don't really have evidence (that I'm aware of) that there is a restriction of airflow to the intake in the OEM position.

Maybe I'm missing something? An engine has four parts to the combustion cycle - the first of which is 'suction': the piston moves down in the cylinder (driven by whichever other cylinder is in the power stoke), and sucks air in. So, it is able to draw air in just like a vacuum cleaner. It doesn't need a direct, clear path to the air in front of the car: it can suck it in from the area around the intake, even when it appears to be hiding behind the grille. There are many, many 'gaps' around that area that allow more air in to replace that sucked up by the engine's induction phase...

Herts Hillhopper said:

Maybe I'm missing something? An engine has four parts to the combustion cycle - the first of which is 'suction': the piston moves down in the cylinder (driven by whichever other cylinder is in the power stoke), and sucks air in. So, it is able to draw air in just like a vacuum cleaner. It doesn't need a direct, clear path to the air in front of the car: it can suck it in from the area around the intake, even when it appears to be hiding behind the grille. There are many, many 'gaps' around that area that allow more air in to replace that sucked up by the engine's induction phase...

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Your right it doesn't 'need' a direct path of air, but...... the more outside air you get to it the better it is! Anyone can work that out.

TDQ: Like i've said before when i took my intake pipe off it was louder (which doesn't mean that performance has increased), i noticed that it felt quite sluggish, i just kept thinking how much hot air it was sucking in from the engine. Soon as the pipe went back on it felt alot sharper.

robjnr said:

TDQ: Like i've said before when i took my intake pipe off it was louder (which doesn't mean that performance has increased), i noticed that it felt quite sluggish, i just kept thinking how much hot air it was sucking in from the engine. Soon as the pipe went back on it felt alot sharper.

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It's interesting you say that, because I had two weeks driving around with no induction piping and didn't notice any difference. Maybe it was the placebo effect of you thinking about the hot air?

I've run cars before with a cone filter directly on the throttle body and noticed no ill effect compared to a longer intake that took air from ambient outside temps.

Seriously, I can't believe you think that running an induction kit straight off the throttle body will have no effect to performance! It's been tested and proven so many times.

My first car was a 1.2 Clio with a whooping 60bhp and I had a green induction kit bolted right onto the throttle body, sounded good and in my head I thought it was doing wonders for the car... That's until I had a little play with the exact same car as mine, I Evan think it was an old lady driving, and she just pulled away easy. So then I bought a green replacement filter and the difference was quite noticable.

robjnr said:

Seriously, I can't believe you think that running an induction kit straight off the throttle body will have no effect to performance! It's been tested and proven so many times.

My first car was a 1.2 Clio with a whooping 60bhp and I had a green induction kit bolted right onto the throttle body, sounded good and in my head I thought it was doing wonders for the car... That's until I had a little play with the exact same car as mine, I Evan think it was an old lady driving, and she just pulled away easy. So then I bought a green replacement filter and the difference was quite noticable.

Click to expand...

Some engine bays are pretty well ventilated, that was the case on my MK1 MR2. It's not the case on every car and it depends upon where the throttle body is etc. So you can't make a sweeping statement saying that it will affect performance if you put a filter straight on the throttle body without knowing what car it was.

It is less critical than you think in all honesty.

There's only one way to find out!...

Seriously though, a back-to-back rolling road or V-box session is the only way that this is going to be proved one way or another. The placebo effect is always going to get in the way of the hard facts.

However, robjnr's modification has cost him nothing and it's good to try out these theories for real.

I wasn't using this forum when the 100HP induction kit thread was 'live' but I have now read it and all I can say is

Right, where's my hole saw? I'm going to ventilate that bumper for good!