CAI calculations and retraction

[grantwildbill]

question. if i run a pipe from the turbo out the hood with no restrictions .How much will my HP. and TOUQUE increase? I don't think it will be very much because the PCM CONTROLS THE HP AND TOUQUE OF THE ENGINE. Am i right 3barboost .Ifamx pipe gets him 12 more hp why go to s1?

[Ian-PT-GT]

Intake air smoothing, volume and density are the three most important thinks you have to do to increase overall performance.

Smooth air: this will make the turbo be more efficient in pushing air. this is achieved with smooth pipes and elbows

Volume: the more air you make available, the better the turbo will breathe and spool up faster. Achieved with big diameter pipes and removing restrictions ( silencers)

Density: dense air has more oxigen in it. IF you heat up the air it will loose it's density making less power. any boost over 8 PSI needs an aftercooler to make the air good for combustion and making power.

If you think that a metal intake tube will have the same effect as a composite plastic, you are wrong. then why do we have an IC after the turbo??? No matter how fast the air is going, if you run it thru metal, the air will heat or cool down trying to equalize itselfo to the ambient.

Yes the power increase is minimal at ambient temp but if you are drawing the air inside an engine compartment that is hot inside, warm it a little more making it go thru a metal tube that it is considerably warmer than the air, and then compress it to almost twice the ambient pressure. you will be realy making that IC less efective.

If you still think that warm air is the same as cold air, make this simple test: get two sauce bottles with the poping top put the same ammount of water in them, heat one of them for thirty secconds and place the other on in the freezer for the same time. close them tightly and wait a while. The one with the warm water will make the cap Pop when you open it. the cold one won't do anything...

when the hot air cools down it becomes dense again (compacting itself) creating a vac. because it is sealed it imake the famous poping sound.

Yes, the computer will try to compensate by reducing boost, but here is where the MBCs and the EBCs will help you... and you will produce the same power with less boost.

Ian

[amx1397]

Ian thank you I do hope every understands what you have said.
1. the smoother the pipe the better the air and increase power and mpg.
2. the plastic pipe, 2 1/4" will give you cooler air,
3. the 3" metal pipe being smoother gives you more air, which means the turbo doesn't have to work as hard to get air to it,and so much goes through it that it is cooler than the 2 1/4 plastic.
3. this allows the turbo to spool faster, and produce more power for less work.,
4. as shown by LAF doing this 3 to 4 times a week, from point "a" to point "b" 100 mph, after adding the amx1397 intake down pipe made the same run 3 or 4 times a week he now goes 110 from point "a" to point "b". wot the intire way but 10mph more Huh something works
5.what works, works, some like, some don"t, some own it, some don"t
again thanks Ian I think you put it in a way that shows everyone that a CAI does work some better than others.
6. and mine is the best.

[Jason_L]

quote:Originally posted by 3BarBoost

Generally speaking, the charge cooler is an efficiency device.

So if the ambient side is 80 deg F and the turbo outlet is 300 deg F - the efficiency is a fraction of the temp delta. So an 80% efficient cooler has an outlet temp of:

300 - [(300-80)*80%] = 124 deg

If you drop the inlet temp by ten

290 - [(290-80)*80%] = 122 deg

Not much, right? The heat transfer efficiency will move around a little, but not much

You are more likely to pick up more power from reduced restriction in front of the turbo, and therefore less wastegate is required to make the desired boost, so lower backpressure.

This was roughly how I originaly looked at it.. I'm going in circles Well, at least I qualified my statement with "If the post intercooler temps are lowered the same amount"... I should have figured that the one part I hadn't looked at yet would be the one to break my results

[Ian-PT-GT]

quote:Originally posted by Jason_L
[This was roughly how I originaly looked at it.. I'm going in circles Well, at least I qualified my statement with "If the post intercooler temps are lowered the same amount"... I should have figured that the one part I hadn't looked at yet would be the one to break my results

The aftercooler will reduce the temp by X ammount of Degrees but it won't lower the Boosted charge to ambient air temp. I think our ex-resident eng. 3Bar mentioned that the IC has a 80% efficiency. and he asumed that the intake air temp was 80*. that is incorrect because the air is sucked from inside the engine bay, compounded by hot pipes. In a warmer day, the I/C eficiency will be lower. This is the reason why you see high Boost levels in warm days, and Low Boost in cooler days. The PCM is correcting to keep "optimum Performance".

If we take control of the Boost controller with a CAI, you will increase HP.


One last example of hot air and how fast it can be warmed:

A hair Dryer is just a fan with three or four metal filaments that gets warmed, the air passes thru them in less than a second and it gets heated to over 100*... It gets wamed this fast with just a small contact area...

Ian

[Jason_L]

ian:
- I like your blow dryer analogy. But, I also think air flowing through heating elements vs a heated tube isn't really apples-to-apples. I haven't thought it out a whole lot though..

- I bypassed the WGA solenoid with my first MBC install

- I have a spreadsheet with all the various formulas for computing turbo outlet temps, etc.. After adding in an IC with an 80% efficiency, to get a 10 degree drop at the manifold it takes just shy of a 40 degree decrease in temp at the turbo inlet.

[03baggedturbo]

I wish I would have come on here earlier. I agree with 3 bar and have said this to many people.. Turbo cars with intercoolers it doesnt matter that much or as much the inlet temp because we have an intercooler and like 3 bar said if you decrease the temp by even 10 degrees then it only dropes the temp going to the motor by 2 deg. about...

ADAM