my 7afte drops its boost when it reaches 5000 rpm. i already got a free flowing exhaust. my downpipe is 2.5 inches. but my flexi pipe is only 2 inches. what could be the cost of this boost drop. need your help guys. because Im about to race it against a honda b16 type r engine tnx!

What turbo are you using?

more info on your set up would help. checked for boost leak?

well boost drop is completely normal to experience if the motor can't move enough CFM at those levels to produce that amount of power.

par example
a 1.8L jetta will boost ~17psi but up near 5500-redline u will see a drop to nearly 10psi or so...just because in the higher RPM you can't move enough...
not necissarily anything wrong with your setup, just a fact of turbo charged cars..

but yet there could be an issue causing it...

what turbo are you using? how much boost drop are you seeing?, how much boost are u running?

asking questions without providing information is like giving a hungry person a plate w/o food

This post has been edited by playr158: Dec 19, 2006 - 1:55 PM

Doesnt he got a Toms 7afe corrolla turbokit....?

yes im the one with the toms turbo kit. i thought it was just an exhaust issue but now i have a 3 inch free flowing exhaust and tanabe smh muffler but still the boost is dropping at 5000 rpm. i think the turbo is a ct9 the kit was originaly designed for the 4afe engine but mine has a 7afe when i bought the car. im boosting it at 13 psi. when it reaches 5000 rpm it slowly drops to 5 psi.

how are you controlling the system ?

the kit has toms tecs computer box which i believe is programable. also im using a turboxs high performance boost control, hks filter, hks fcd, and a tanabe smh muffler.

i'd probably drop it back to a 2.5" exhaust since you won't outflow it on a 7afte.
and if you can, find a compressor map for that turbo, i'm not familiar with a CT9? but find out what turbo you exactly have and i can do some math on the compressor map to see what u should be getting up into that range with that turbo..

i think the ct9 is the turbo used in the 4efte starlet glanza v engine

my best guess is your just working outside the turbo's efficiency range...and damn thats an old out dated turbo

that's what im thinking also im planning to upgrade my turbo. what turbo could you guys suggest. im planning on retaining my set-up just changing the turbo and manifold. my car has a TMIC. I'll show some pics later. im thinking of using ct20 from celica anybody has a pic of a celica with ct20 so that i can compare the turbo. i know that the celica has a TMIC also. can you guys give me some info

FMIC will most always be better thena TMIC unless you have an ST205 TMIC W2A intercooler. GT4 celicas used a CT26 turbo which i wouldn't even bother to think about for a 7afte
i'd suggest something along the lines of the T3s60 turbo...T3 turbos are going to probably be your best range to pick from IMO and ease of compatability
and don't forget, if you change the turbo you'll need the downpipe changed along with the turbo + manifold

This post has been edited by playr158: Dec 21, 2006 - 10:23 AM