I have a 90 miata 1.6 liter with a garret gt2560r running ten lbs of boost.

the charge pipe on this thing is seriously about 1.75 inches wide.

it seems to me that this setup doesnt need huge intercooler piping but what it has seems a bit small. i would imagine that with a little bit bigger piping, maybe 2.5 inches, that the turbo would spool faster.

what do you guys reccomend?

 

i am no expert but the bigger pipe you put on the the more the turbo has to fill up before building boost. thus turbo lag. the smaller it is it may choke the turbo and higher rpm creating HP loss.i have a t 28 with a 48 trim and im puting 2.25 pipe on it if the helps .

 

larger piping = more lag
10lbs is a pretty decent amount tho, so you could go 2 or 2.25" to get a bit more power, but it'll also increase the lag

 

ahh. i see.

so whats the verdict? should i go bigger or keep it the same?

 

if it was my car i would run 2in pipe to the IC and 2.25 Pip to the TB. but it may in crease lag. you will get more out of your turbo at Higher rpms though.

 

i guess ill wait until i have it tuned and see whats going on then. if my top end hp isnt what it should be then ill go with some bigger piping. if the top end looks pretty good, then ill probably just leave it alone since this thing is a 1.6 and extra lag would make it even slower. lol.

 

smart man.