Intercooler Pipe Sizings

Firestar_3x

Firestar_3x

Firestar_3x

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Quick question for the engineering people amoungst us, some details first :

KO3's turbo @ 21ish psi
51mm turbo outlet size
63mm throttle body inlet size
51mm inlet and outlet on intercooler

If i had a turbo outlet pipe size of 51mm running to the intercooler, through the core to a 51mm outlet pipe, then this 51mm pipe expanding to a 63mm pipe, just before the throttle body, about 20cm long to house the MAP sensor would the increase from the 51mm to 63mm pipe after the intercooler cause me boost problems?

I'm trying to figure if its best to stick with 51mm piping through the system or if an increase to 63mm before the throttle body is acceptable?

Cheers Chaps :)
 
ineed2upgrade said:
what's the maximum power you are after?
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On this turbo setup i think i would be doing well to get anything over 220bhp, in the future i want to slap a bigger turbo on and perhaps get 260 - 280bhp.

Really wanted to know if the extra volume to fill going from 51mm to 63mm was going to cause excess turbo lag issues.

Orange Peel said:
No, it wont cause any problems.
Click to expand...

Cheers :)
 
best book to read on this subject is "forced induction performance tuning-a graham bell". from this book it states that a 2" od pipe is good enough for 255bhp but you have to take away 5% power for every 90 degree bend or 3x30 degree bends.if you are later going for 260bhp+ you could go to 2 1/4" as that can support upto 345bhp.this is obviously all in theory as it doesnt take into account inlet temps and how efficient your intercooler is etc etc.
go buy the book,its a great read:)
 
Cheers for the info fella, will buy that, when i was doing the supercharger project for the Mazda i read bits out of the corky bell book but didn't need to cover boost pipe sizes and capacity etc, would have read that but i'm in work and need to order the parts today so i can crack on with this at the weekend :)

Everything in this project is pre made sweeping alloy bends, the only addition i need to make is the MAP housing due to my version of the 1.8T having one :)
 
Interesting.. 5% loss per bend seems quite high :eek:

I'm (hopefully) building my pipework on Friday, I'm using 2.5" Stainless to the inlet manifold from the intercooler, and 2" from the turbo to the intercooler.

Out of interest.. where are you sourcing your silicone from?
 
try pirtek for silicon hoses,miles cheaper than getting a purpose designed one but make sure its high temp/pressure stuff.
the corky book isnt bad but most turbocharging books are of american origin whereas the a graham bell one is english so relates more to our engines and is VERY comprehensive
 
I couldn't detect any extra lag when I fitted my front mount. I used 2.5" (63mm) pipework.

That was on the little T25 too. It hit full boost (12psi) by 2500rpm on the front mount, exactly the same as the stock IC and much shorter pipe run.
 
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there are several bends in my intercooler pipe work also varying diameter sizes i cant say i have noticed any increase in lag :). I think the air is moving that fast lag isnt really affected.
 
Clarkey said:
Wait a minute, MAP sensor before the throttle?
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Erm yes why not, its to measure boost in the intake pipes before the throttle plate, no doubt its got another one in the manifold someplace.

Jonnycoupe said:
Guess he meant MAF on a 1.8T?
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No, why would i have a MAF in a boost pipe? The MAP's current location is the top of the sidemount intercooler (outlet side), fitting a front mount means i need to move the sensor out of the intercooler into the boost pipes (just before the throttle body)

austinpowers said:
Isn't 21psi pushing the efficiency rating of the little K03? Thought they were good up to around 17-18, then you're blowing hot air :p (even with the ic).
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Its right on the edge and thats max boost it see's in the rev range, doesn't hold that till the redline, mines got a different compressor wheel to a KO3 (Being and S), its more of a hybrid between a KO3 and KO4 :)
 
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Firestar_3x said:
No, why would i have a MAF in a boost pipe? The MAP's current location is the top of the sidemount intercooler (outlet side), fitting a front mount means i need to move the sensor out of the intercooler into the boost pipes (just before the throttle body)
Click to expand...

You can have a MAF either side (differing types I guess). If on the boost side, its called a blow through MAF as opposed to a draw through on the intake side. Never really found out the positives and negatives of the blow through in comparison to a draw through. Jonnycoupe may know though.
 
Never heard of a MAF on the boost side, but tbh i've never read or looked about the subject.

My MAP sensor also seems to be called a Thrust Sensor on various other sites, not sure what thats about?
 
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