N12 Turbo Forums

Hey there, i had simular trouble recently with mine. I changed from the original turbo to a T28. Not knowing that T28 really means nothing without knowing the A/R ratio i had bad lag up to nearly 5000 rpm. I looked into the A/R radio ( air speed radio) from the turbo housing. The original has a .48 housing and the replacment one i was sold for the car had a .86 housing. After lots of investigating i found that i needed a T28 with a .48 housing. I sent it back to the supplier and asked for the exhaust housing to be changed so i had a T28 with a .48 exhaust housing. I got it back and what a difference. It now boosts at 3200 which is good for what i want. Its all to do with the amount off puff you get out of the engine to spool up the turbo and the volume in the exhaust housing.
Im not a turbo expert and to be honest didnt know anything about them until i started playing with this one but i have lernt a lot in a short time. Hope this helps your situation.

+1

i got a t25g with a a/r .86 at 10psi n i dont have a problem with boosting issues. I got a front mount,cam, forgies, afm in the piping, and its pretty quick compared to my other et with a t25 with the a/r of .48 does not have much guts for 10psi. nothing compares to driving a ca18det powered n13 exa with a t25g running a wold3d ecu.. fukin quick as for 10psi.

ET87 wrote:i got a t25g with a a/r .86 at 10psi n i dont have a problem with boosting issues. I got a front mount,cam, forgies, afm in the piping, and its pretty quick compared to my other et with a t25 with the a/r of .48 does not have much guts for 10psi. nothing compares to driving a ca18det powered n13 exa with a t25g running a wold3d ecu.. fukin quick as for 10psi.

are you running stock ECU? has there been any head work done?

i had a T25G with .64 ex housing with a near stock setup, and with redline at 6000rpm i couldnt get it to boost pass 3psi.

the moment i got the .48 ex housing on, the boosting issue was gone.

running a .86 housing has huge potential for out right power as it has more flow.

yer mate stock ecu and stock head just some cam work. i think u had a boosting issue for sure.. only 3psi somethin is wrong there.. it picks up awesome after 3grand n goes thru to 7grand rpm well thats as far as i have taken it..

[quote="bristol"................. I looked into the A/R radio ( air speed radio).[/quote]

Umm, It might help you that A/R Ratio actually stands for Area to Raduis Ratio.
L8r
E

i know this threads old, but, can i use my stock t2 .48 ar rear housing on a t28bb? car will only have minor mods, but, if im gonna change the turbo i only wanna do it once.

Ahhh no M8. if you want to have it run like stock then stay with stock.
E

tassuperkart wrote:Ahhh no M8. if you want to have it run like stock then stay with stock.
E

+1