Downpipe question..

[MR2crazybyong]

Hello guys!!!
i have been testing my car just recently before it gets painted. i've noticed even if i fully close my MBC my boost doesnt reach 15 psi anymore!! it kept on boosting 15 psi before!!now its just around 9 to 10psi.. so i figured to take the whole turbo out and clean it since it was so drity and replace all the hose clamp to prevent any leaks.. while in the process of taking the intercooler pipe out i've noticed a cut on the hose coming from the intake manifold to the blow-off valve. so i guess my boost problem is solved!! i think this was the cause of low boost. anyway,(sorry for the long story) i took the whole turbo out with the downpipe and catalytic converter and saw what a restriction the cat-converter was!! so i plan, instead of taking it out of the pipe i am going to build myself a straight-thru downpipe with a 3" iron pipe. making it one-piece. im thinking this would help my turbo spool earlier and maybe faster.. am i right? i need your confirmation and other suggestions.. Thanks in advance!!
here is an inlustration of my plan..

[MR2crazybyong]

by the way this is where the catalytic converter is inside right? i just want to make sure that its the cat-converter..


and this is my turbo with my homemade MBC.. how will i know that its a ct26? it doest say it anywhere..

Tahnks for your help guys!!

[CompanyFlow]

Well, it says toyota, so check if its dual entry and you have yourself an MR2 charger.

[Piddy]

Show us the exhaust side of the turbo. Could be a CT20b.

[MR2crazybyong]

damn! i've been searching on ebay and ive noticed the ct26 have the name ct26 on while the ct20b hae only toyota!! so mine could be a ct20b!! all this time i thought i had a ct26 because i have a 2nd gen 3sgte engine!! wow!!
ishcoleobo, heres a pic of the exhaust side of the turbo, pls confirm it for me.. thnks..

[Piddy]

Ct26... notice how a 20b has 7 studs on the exhaust side...




PS: I have a DP for sale..

[MR2crazybyong]

really? but how come my compressor housing does not say ct26 like all the other ct26s? it only says toyota like the ct20bs?

[MR2crazybyong]

this is what im confussed about:


your right about the stud bolts though..

[Drifting Dane]

it COULD be a ct26-a... the ct26 from the mk.III supra. but im not all that knowledgable on the subject, just pointing out a possibility.

[Piddy]

Originally Posted by Drifting Dane

it COULD be a ct26-a... the ct26 from the mk.III supra. but im not all that knowledgable on the subject, just pointing out a possibility.

Nope.... it is clearly twin entry.... definately not a CT26a.

[MR2crazybyong]

i just got back from my test drive with my new downpipe, and my 2 is boostn the hell out of my 3sgte!! it hits fuel cut faster than before.. i got a question though, WHY does my CHECK ENGINE light light up(before the fuel cut happens)? is it because i dont have a catalytic converter anymore? thanks

[Piddy]

^ You tell us. Pull the codes and post them up. I'll look them up and tell you what they are.

[MR2crazybyong]

i cant! i live in the philippines! hehe.. code readers are hard to get here.. is it possible that its because the cat is gone?

[Piddy]

^ NO HONKEY!!! You dont need a code reader. Hehe. I know they have paperclips out there.

Open your engine lid.
Open the diagnostics box.
Short out E1 and TE1 with a paperclip.
Turn the car to ON.

Watch the CEL blink. Count the blinks.

They are two digit codes.... 1 second pause between each one.

If there are multiple codes.... there will be a 3 second pause between the first and second. You will figure it out.

[MR2crazybyong]

thanks man! i got 52! i heard that its the Knock Sensor Signal, is this true? What should i do? this happened after i changed my downpipe, having a short in the alternator and hitting fuel cut at around 16 psi..