CT26 t3/t4 question

[nuk1ear]

I have a CT26 from a supra with t3/t4 wheels in it and was wondering if anyone knows much about their max safe boost pressure? Its on my MR2 and I was told 18psi, but im not really sure about that. The rest of the system is setup for it, but i would like to get it tuned at a boost that wont completely destroy the turbos life.

[Cuts]

as a highflowed unit (assuming its in good nick) 18 psi should be fine.

[nuk1ear]

man i keep getting told all sorts of stuff. someone told me that supra ct26s cant have any different wheels cept the for T4 wheel only. I dunno if thats true, i was told that its a ct26 with T03 and T04 wheels in it....such a drainer haha

[Cuts]

if you get it tuned on the dyno it should be become obvious where its at peak efficiency.

[nuk1ear]

Yeah ill get that done soon and we shall see i guess. I hear these units are pretty laggy too

[jonathan yee]

well it depends on what trim the comp wheel is and to what extent they modified the ct26.

generally they retain the toyota exhuast steel wheel (sometimes they trim the exhaust turbine for greater flow at higher rpm which makes it laggier) and just fit a larger comp wheel. the comp wheels can come in vaious sizes, which will influence the amount the turbo can flow etc.

if they've gone to the extent of machining/fitting a different exhaust wheel then it's prob gonna be more laggy.

my hiflow i had was stock metal exhaust turbine with a to4e 50mm trim from memory. didnt shove me into the back of my seat until 4000rpm tho it spooled earlier than that and was quite driveable still i thought.

[nuk1ear]

how much boost were you running then?

[jonathan yee]

well i only had stock gen2 eng and ecu/AFM and general consensus is to only run 14psi, 16 if your brave. basically the ecu doesnt have maps for over 12psi and you hit fuel/boost cut if you go over, so you put an FCD in. ecu will read less boost than your running but the AFM will still sense the huge amounts of air being drawn in but it'll be out of it's range as well so the stock ecu dump's fuel in (more than it does anyway over 4000rpm) but as your running more boost it'll lean out the richness abit........ follow my ranting.

thats why you put it on a dyno to make sure it's not leaning out too much as obviously how much my turbo flowed at 14psi will be different to how much air your's flows at the same psi.

so put it on the dyno, make sure the AFR's are right, it's not pinging and hope your HG doesnt blow apart.....heh.

but i think you said the head's been of at some stage so hopefully they put a metal HG in there but i doubt it.

[nuk1ear]

im running a microtech. Ill check up about the headgasket, i guess when tuning it they can see where the turbo is getting its best efficiency and tune accordingly. Im not a harsh driver either not that it mnakes much difference.