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-   -   DIY - Cosworth Cold Air Intake install (https://www.team-bhp.com/forum/diy-do-yourself/161695-diy-cosworth-cold-air-intake-install-2.html)

Reading books is old school now, believe in practicality.
https://www.youtube.com/watch?v=xwNtjKT_1cA

In a way it does, when the engine is making less torque it tries to compensate with more fuel. In older carburetted cars, one modulated the throttle pedal to achieve the same effect.

One very simple example, a car usually runs better (and takes in less fuel) on a colder day than on a warm one, for similar day (and let aside different days, one can look at how a vehicle performs during the colder part of the day versus the warmer parts).

Anyway, how much was the difference in 0-100kmph acceleration times prior to the installation compared to now.

Yours is a turbo car, the video you posted above is of a naturally aspirated car. You should have posted this video

https://www.youtube.com/watch?v=gCi2yo4UqPI

Btw your setup is not a "cold air intake", its just a pod filter inside the engine bay soaking in the heat, no matter what the manufacturer calls it as.

This is an example of a proper cold air intake similar to the one in that S2000 video you posted.


PS: On a turbo diesel you will get very minimal gains if any with pod filters, air supply is not the limiting factor on a stock turbodiesel.

Dear Allien936,

For a moment here let's assume, for the sake of discussion, that what you've achieved is a Cold Air Intake.

Now, remember that you have a 1.4 TDI engine which is Turbo Charged. It means that the air that enters through the Air Filter is passed through the Turbo Charger where it is going to be compressed. I deduce that you hate reading text books, but I urge you to search your very practical internet to find out what happens when you compress air(or for that matter any compressible fluid). Well, guess what, it heats up! What it means to you is that whatever temperature difference you achieve with your CAI is quickly and quite positively negated the moment the air passes through the Turbo-Charger, simply because it is going to heat up when it is compressed. Don't you think now that a CAI for a Turbo-Charged engine is as useful for performance gain as a big, multi-barrelled, chrome plated, bolt-on, after-market muffler tip?

As an aside, what helps in Turbo-Charged engines is not cooling the air before reaching the turbo-charger, but cooling the compressed air after it leaves the turbo-charger. And that, my friend, is where an Intercooler comes in handy.

Sorry, but I dont understand what you are saying at all. Less torque gets compensated by more fuel? Please note that in a modern car with fuel injection, if you push the righ pedal, more fuel will be introduced into the engine just as with a carburretted engine. How is different but pusing the right pedal gets the same result, more fuel.

I doubt very much any of us can tell the difference between the performance on a hot or cold day of our cars. If anything a modern car has a whole host of sensors and clever electronics that minimize the effect if any at all.

You are confusing, running better, using more fuel, and fuel efficiency. These are three completely different things. On a car fuel efficiency is typically measured as unit fuel per unit of distance. As I mentioned before the cold air inlet (as pointed out by several this one isn't one) or the free flow filters effect is most noticeable during acceleration. But you cant use the above definition of fuel efficiency during acceleration at all, you need to come up with something else.

Your engine needs a certain ratio air/fuel to run properly. That is controlled by various sensors and the ECU and maybe a few more bits of electronics. Putting a cold air intake and or different filter on your engine isnt going to make a whole lot of difference to any of that. As I said before I doubt you will see the difference, although in theory there is some advantage to be had. Actually, from a theoretical point of view it could actually make the FE worse. It really depends on the engine. What happens with cold air intake/free flow filter is you effectively shift the torgue curve a little bit downwards. So a bit more torque at lower revs. That by itself isnt necessarily more fuel efficient. Depends on many factors.

Jeroen

Jeroen

Any "better flow filters" will not make any difference in fuel efficiency. It helps the fuel to burn more efficiently on lower gears or during hard acceleration. The usual symptom is the black smoke from the exhaust, esp on a remapped or boxed car with more fuel injection at earlier rpms. Any difference in performance \ torque depends on how well the fuel is burnt and converted to energy.

Yes, by making the mixture Rich (within preset range)

The difference is, in a modern car, the electronics steps in by altering the Air-Fuel ratio as well ( which means you drive with a lighter foot compared to the similar situation on a carb).

Using more fuel and fuel efficiency are interrelated (a car running Rich will consume more from one running lean).

However, when I meant "Running better" I will admit, I was speaking more in terms of "Part throttle responses". When your car responds quickly on slightest inputs on the throttle (rather than a heavy push on the accelerator), many say that the car is running better, but it is probably better to say "responsive".

Right. I did not intend to bring up Fuel Efficiency either. It was brought into the equation by the thread starter, stating the usually marketed pitch by the performance parts brigade, that auto manufacturers have to design things for Fuel efficiency alone (in response to him having removed the air duct).

Not directly, but as a byproduct, of being able to stay in a higher gear at lower speed (though a person who has made the installation to hear the noise, would most likely to remain in the high rev zone).

I still dont understand what you mean, sorry


Carburators do the exact same thing, they introduce additional fuel during acceleration and thus change the Air-Fuel ratio. The amount of light footness is not specific to injection, but specific to the complete engine design

I don't want to get caught in semantics but if more fuel result in more power output (HP) it is actually an increase in fuel efficiency. Lean and rich can and does occur along the full range of an engine operating envelop.

The cold air intake or free flow filter doesnt fascilitate being able to stay in higher gear at low speed perse. It allows or tends to allow for better performance in terms of a bit of extra torque at the low end of the rev band. So, engine pick up tends to improve.

Yes, the sound at high revs does improve (although not everybody would agree on that, for instance my wife doesn't like engine reving, no matter how it sounds)

Jeroen

On a carb'd vehicle, one has different circuits inside the carburettor for different driving scenarios, you have the power circuit, you have the idling circuit, the starting circuit and in some cases an accelerating pump and much more. Each of these circuits can actually be tuned (based on the carb design) to run a different air-fuel mix. Then you can choose to have different Jetting in order to fulfil your specific driving needs (light foot responsive or top end power etc). But once setup the vehicle actually operates within those specifics.

When you press the throttle, it opens the butterfly valve and depending on how much it is open, air is allowed progressively freely to pass and a proportionate amount of fuel is drawn out by the suction created by the air (as well as the pressure in the float) as it passes the venturi to atomise and the final mixture thus enters the inlet manifold and then the combustion chamber. In this, the right foot actually might only be controlling the butterfly valve, which controls the air path (and indirectly fuel), but the air-fuel ratio remains same for a specific tuning (you can opt to set it lean, or rich or even just off stoichometric for a balance - nothing to do with the engine design as such)

In a computer controlled fuel injected vehicle, the tuning happens on the go, the injections do not depend on the air flow, but injectors being controlled by the computer depending on the throttle position. The Airfuel ratio is controlled by the computer.

In older high-end cars, you would have a lever beside the steering to change the airfuel mix, you made it rich, if you saw that the car was not responding enough. But with cars that did not have that feature, you would have to depend on pushing the throttle a little bit more. But on modern computer controlled cars, you will have the processor do it for you, without you feeling or knowing that the processor did that for you.



Yes, Torque helps acceleration at low rpms. So if you are cruising at a lowish rpm, to overtake another vehicle, you will probably be able to do it with just a twitch of the accelerator (without needing to downshift to a lower gear). That is the benefit of low end responsiveness.

Although, as I pointed earlier. it might also affect the top end, hence absolute acceleration numbers, like 0-100 (which will require visits to the redline) might actually turn out slower.

To add a few things. The air fuel ratio does not remain the same. This is the big problem with carburettor. By the very nature of its design it is limited. As you point out it has several design charaterestics to deal with different scenario. E.g. idle, accelerate etc. But an engine is used dynamically. If you stomp on the accelerator whilst driving at a steady pace as you want to accelerate, the mixture will go way to rich initially as you pump in more fuel. Once you keep your foot steady it might catch up, but as you lift of, the mixture is likely to go lean. etc.

Your description on how things work with fuel injection is to simple. Certainly the amount of fuel injected is not only depended on the throttle position and the amount of air is measured constantly by the air mass flow meter.

But to your point injection system do adjust the so called fuel trim constantly based on a large number of sensors. In the air inlet, exhaust (e.g. O2 sensors) and various sensors on the engine.

If you have an OBD analyser that can handle some live data you are very likely to be able to see the fuel trim at work.

Here is a good reference to it:
http://www.obd-codes.com/faq/fuel-trims.php

Jeroen

Yes you are right mostly! Only difference is, that the accelerator only directly controls the airpath (across the venturi) by means of the throttle body/butterfly valve. The velocity of the air passing controls the amount of fuel being sucked out by the applicable nozzle. So when you rapidly open the throttle (stomp on the gas pedal) you have a rapid gush of air (only - Lean) into the engine, suction of fuel takes a "delta" delay and one might experience a mild "miss" for a fraction of a second. Similarly, when you
lift off suddenly you have a sudden "rich". Usually starting circuit is set quite rich.

But beside that, you are correct that you do have a perceptible transition between various driving modes. But then, its quite fun actually once you get the hang of it. Like say, you tune it for low end responses, the vehicle responds to part-throttle inputs more than a pedal to metal shove and vice versa. The experience itself, of understanding your vehicle and then working around it, is phenomenal!

True, I was just simplifying things, there are various other sensors and factors that the processors use to calculate the fuel injection.

However, although this is a very good discussion, I guess we are both being guilty of hijacking and digressing from this thread!

No, that is not correct. When You press the accelerator you open the butterfly but you also, on most car engine carburetor inject (pump) extra fuel in. So next to what the Venturi draws, additional fuel is mechanically entered into the mixture. Thats why the mixture goes rich, not lean. Trying to accelerate with a lean mixture tends to be not so successful!
Jeroen

Thanks for detailing out your install allien936!

Clearly there's mixed opinions here on:
a) Whether the product is what it claims to be
b) Whether there'll be a net gain or loss in power
c) Whether it's doing the best it can in this current set-up

Great suggestion. This is probably the best way to truly test this setup (or at least the "cold" part of it).

I agree with what you've said about the intercooler, but I think you've overlooked something in your statement above.

It's not that the turbo compresses are to a 'pre-defined' pressure (or temperature) and not any more or less than that. It just compresses air. So if you feed it air that is already dense (cold), your overall end result will be better than if you start with air that is warmer.

1) My OBD2 scanner from some cheap china website works fine on a Skoda Superb (1st gen) V6 TDi, so hoping any skoda should hand out readings from a OBD2 scanner.

2) IMO that is Surely not how a CAI should be fit (I cant comment if the blue cosworth thingy is just a filter?) - but the intake point should be way ahead of the engine, closer to the road because all the air going around the front bumper isnt doing any good - one needs to capture the source either through the slats or point to the ground (in case a large IC+plumbing blocks the way).

Just to confirm the OBD2 scanner can be used as a basic test to confirm if the CAI actually makes any difference, I had tried it out few months ago on a stock Figo (2014) and mine (2010).
Mine has a BMC Conical filter enclosed with an extended intake pipe to the front grill . Both the cars were fired up the first time for the day, in the same building and revv'd to the same rpm and it was done to check the difference in intake pressure more than the temperature.
I have to also mention, the stock Figo was fired up and left in idle for a while and some revving as well before the readings were taken.,(coolant temp difference) which can also be a reason the intake temp reading was high.

The first screenshot is of the stock Figo.