Which Y pipe has the smallest diameter piping and collector. Currently running the Nismo Y pipe and I believe its 2.25 to 3" at the collector. Nismo makes too much noise at the flexpipes when its frayed/scratched. I need as much backpressure as I can after the cats without using the stock Y pipe. thanks

 

You sure you want to do that with boost? Maybe get a new y-pipe that has sufficient flow and get a resonator welded on to make it quieter?

 

tanabe?

 

Reasoning? Just out of curiousity.

TK

 

Stillen twin screw superchargers need alot of backpressure to maintain high boost.Hence I have to run stock headers/cats/ and preferably a restrictive Y pipe

 

Just weld a plate across the exhaust tips. That will get you all the backpressure you need. Really though, the Tanabe Y-pipe has 'smallish' dimensions, 2.36/2.75". Not sure it's what you want, or that you will notice the difference over the Nismo.

 

I am not a supercharger guru or anything, so I am hoping you could shed some light on this subject for me.

Doesn't a roots type charger always move the same amount of air for a given shaft speed?

Also, isn't it more efficient at lower boost levels?

Don't lower boost pressures produce less heat so the intercooler is more efficient making the lower boost charge denser?

And if it is making higher boost because of backpressure, doesn't that also mean that you are contaminating the fresh charge with burn gases because they cant leave the cylinder fast enough?

Just curious?