actually it is based on both wheels. Read the Third post here: http://www.rx7club.com/printthread.php?t=345518

A larger turbo is in no way gonna save gas. they have nothing to do with each other. it all depends on your driving style, injector size and tuning.

 

i think im going to go for the .48, i'd like a bit less lag and im not really going for all out power seeing as its a daily driver.

 

63/60

 

63/60 and if you don't like it pick up a 48 ex housing and you can just swap it if they both are for a stage 1 exhaust wheels(I believe that is true)

 

as a daily driver i guess i should have said it COULD save gas, if you stay out of boost, use the lag as an advantage.

matt

 

Sorry that i bring this thread up again... but i'am also confused a bit...

the basics are clear... small turbine ar -> quick spool up but not so high top end
big ar -> late spool up, high top end

isn't there any way to determine which powerband a turbine will give you on a given specifications?
something like a compressor map for the turbine...

i've seen them for the new garrett GT series turbos but i'am not sure how to read them.
for the older T3 and T3/T4 turbos i haven't seen them anyway...

i don't want to relay on guessing and experience because everyone tells you a bit different stuff. by the way thats ok because everything is also personal favorite.

 

Yeah, if your not driving like a douchebag around town you wont hit boost, 3000 rpms at WOT is diffrent than 3000rpms driving normal at low duty.

 

i wouldnt use either of them, there both 2 small

 

False! The slower you spool you will save gas because you won't be boosting much at lower rpms. Ask anyone who has went for a small fast spooling turbo to a larger laggier turbo. Even just at crusining speeds with you hit the gas(Without downshifting) it doest build as much boost therfore saving you gas. My cousins Srt-4 went for 19mpg with a the stock mitsu turbo to 28mpg with .60/63ar T3/t04e almost a 10mpg increase