Intercooler Pipe Sizings

[Firestar_3x]

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

 

[Firestar_3x]

what's the maximum power you are after?

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.

No, it wont cause any problems.

Cheers

 

[Firestar_3x]

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

 

[Firestar_3x]

Forge Motorsport, used them in the past and the service / quality is fantastic

http://www.forgemotorsport.co.uk/content.asp?inc=product&catalog=siliconhoses

 

[Firestar_3x]

Ah good news, cheers Andy

 

[Firestar_3x]

Wait a minute, MAP sensor before the throttle?

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.

Guess he meant MAF on a 1.8T?

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)

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 (even with the ic).

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

 

[Firestar_3x]

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?

 

[Firestar_3x]

Yes i did just ask that, i've never heard of a MAF on the pressurised side of a turbo system, affraid i can't know everything all the time, just most

Yes they are usually on the intake manifold, not got an issue with this, but this is clearly called a MAP sensor, so whichever fool at Bosch / VAG / Forge / ECS Tuning should clearly be shot.

http://www.forgemotorsport.co.uk/content.asp?inc=product&cat=260401&product=FMMAPT

http://www.ecstuning.com/stage/edpd/pagebuild_v2.cgi/?html=learnmore.html&productID=9611

MAP - The MAP sensor is located in the OE SMIC end tank. There are two different sized MAP sensors, and VW didnt make the transition based on years but cars from all years might have either the small or large version (rumor has it the small version didnt come around till ~2003). When your upgrading your intercooler to a larger SMIC or FMIC and need to specify which MAP sensor your car is running the only fool proof way to check which sensor your car has. If you are making custom piping and need a MAP sensor flange check out 42nd Draft Design for a universal solution.
Rule of Thumb appears to be:
2002 and earlier cars = large MAP
2003 and later cars = small or large MAP

I know the location of my MAF its just by the airbox on the non pressurised side of the system, i'm talking about the pressurised side of the system hence we are talking about intercoolers.

 

[Firestar_3x]

 

[Firestar_3x]

Well yeah, especially as thats the load measuring method on the VAG 1.8T

Yours may be different as you have alluded to, but thats certainly in a charge pipe.

Thats the MAF and its not in a charge pipe, the picture you've posted is the output from the airbox to the turbo intake, see ere.

Charge pipe coming from the intercooler to the throttle body can be clearly seen at the front of the engine, only charge pipes that exist that high up in a 1.8T are for the diverter valve.

 

[Firestar_3x]

Its a case of JohnnyCoupe vs the world then, whilst i agree its not in the Manifold so its name is somewhat strange thats what everyone is calling it including the people who design and make the dam thing, if i hadn't called it by that someone would have pulled me up on it.

This low level analysis is all irrelevant anyways, the semantics about what a pressure sensor is called depending on its location in the system doesn't matter, what does matter is i got the information i needed so i could order the parts for the weekend.

Also the quote about the sensor was simply to identify its location to youselve and to show i'm not seeing things (again)

 

[Firestar_3x]

Fantastic clamps, i've got a full set for my install

 

[Firestar_3x]

Always been happy with Forge, they knew i needed the bits for the weekend so they sent them on a pre 9am service via ups even though i'd only paid for 1st class Royal Fail!