Think im going to start with 4 in down pipe exiting somewhere shortly after firewall with a 4 in bullet style muffler and measure back pressure and go from there. Also going to measure back pressure pre turbine to see where the baby wheel is limited. Been reading a little about using map sensors to data log back pressure. This sounds like a fun experiment as well instead of just having a check ball for max.

Heads are box stock 317 and motor is just a little 05 lq4.

Thank you Atomic for the Clarification on the loss from A/C

 

usually no one will mess with just swapping an AR around, unless you just happen to have to laying around. You are correct at XXX power that baby wheel will cause a bunch of back pressure and will hurt top end power. BUT will be a blast to drive off the line. The larger wheels + large AR will allow much higher top end power at the cost of bottom end fun off the line grunt. Dont bother with the 87wheel. get the 92 or the 96 or the 100 t6 . 100 for max effort stuff. Several customers have the 92wheel and are having a blast with balance of response and top end power.
4" down pipe will flow a huge amount and being as short as it seems your rolling with will not show much in the BP world. And you do not want it to.
The only down fall to NO bp in the final exhaust in some cases requires a larger gate or a 2nd gate, since that BP also backs up in to the pre -urbo exhaust helping to open the gate.
The system is more efficient and requires more BYPASS to keep boost in check.

Had customers go from a full exhaust to a fender bump and ran into boost control issues.

 

Just to throw the wrench in the whole idea......
Run a large turbo and one of these!

 

 

 

 

I need some Black Friday Love from Trick! It would give me a good excuse to visit my wifes family in Seymour. Need that hotside!