[urq] AAN or 3B swap

[David Glubrecht]

That is what I thought the concern was, but being as how a turbo is not a positive displacement devise, I don't see how it could have much of an effect.  I suppose it could affect where the turbo is in the compressor map while spooling up, but in practice (in an extreme case) Huge volume and old school turbo motor (MC) that is known to have significant lag, I do not see any effect.   I mean this vehicle really does have about the same post compressor intake volume as a remote mount turbo.
 Perhaps it might have a noticeable effect on a newer motor with minimal lag.

This is somewhat academic, as I can't/won't change this vehicle and will try to minimize the 3B UrQ anyway.  
But I do want to understand the significance of this.


  David Glubrecht
  



Intake tract length is a major factor in turbo lag. The turbo has to work to compress and maintain pressure on the intake volume, and the larger it is the longer it takes. It's not the end of the world, but it's desirable to minimize it. 
On Feb 2, 2014, at 4:13 PM, David Glubrecht <daveglu at hotmail.com> wrote:




Another 3B swap here.  Will definitely be doing the 3B as I have two of those and no AAN's.
I also plan on going stand alone with the adaptronics 1280 and this will run COP.
While I feel free and able to modify mostly anything I want, intake track length is only a concern due to room constraints.
I was concerned a little on my last project about intake track length (volume) as it is very long/large.
This is a MC running CIS with 3' cis to turbo, 2' turbo to intercooler, large intercooler, 3.5' intercooler to intake. All plumbing is ~2.75id.
 I have not seen anything with this much post airflow meter volume and was concerned, but I have not noticed any adverse effects.
What is the concern with intake volume?  


  David Glubrecht


> I do believe the AAN is a better engine, but the AAN can require a lot of fabrication to install. I personally would go with an ABY (late S3) or ADU (RS2) sourced from Europe, or installing an SQ style intake on the AAN that moves the throttle body to the front of the engine. This should minimize the required modifications and also minimize the length of the intake path.