2JZ overboost problem.....fixed :D

[PlacentaJuan]

so its running ttc then...

dont listen to the nay sayers, but we should aknowledge that they did help people like us know which path would lead to failure and without guys like 2jzr31 i probably wou8ld have quit long ago.

look foward to the sequential,

[ProjectSleeper]

Good write up.. I was lazy and just fitted a 2.5" restrictor

[brett_celicacoupe]

this was my restrictor i was previously using

horrible!

[ProjectSleeper]

My restrictor is actually a replacement section of the exhaust.
It's flanged both ends and easily swapped..

Basically a section about 60cm long between the Cat and 1st Muffler. Standard piece is 3" straight through, but the 'restrictor' is a 2.5" section of pipe that is flared up to match the 3" flanges at both ends.. works a treat..

[PlacentaJuan]

i got mine laser cut...

[PlacentaJuan]

http://www.turbofast.com.au/lexusturbo.html

he copied your idea!

[brett_celicacoupe]

hahaha.... why they bothered 'seperating' the manifolds makes no sense.

[brett_celicacoupe]

sequential works...


put your foot down from low rpm..... 13psi by 2400rpm then at 4000rpm it dips very briefly to 8-9psi and then bang, straight back up to 14-15psi

[PlacentaJuan]

fucking awesome!

so did you need to make up a controller circuit or can the ecu control it by himself?

[brett_celicacoupe]

thats with no other mods.

essentially the 2nd turbo has no prespool and comes online once the EGCV opens.

you could experience the sequential operation yourself (as i have it now) if you want to disconnect the prespool actuator and go for a drive.

[PlacentaJuan]

oh no prespool.....

how long will you run it like that?

[cambelt]

Well time will tell i guess , is there any info regarding spinning turbos up to quickly .
Maybe you could pre open the EGCV then have it fully open .
My guess is the surge from 1 to both coming online is much greater now?
Dave

[PlacentaJuan]

^ yea thats what i am planning to do.

now brett has tested NO prespool for me (i was too scared and was going to do it right before i pulled the turbos) and seems to be ok.

[brett_celicacoupe]

maybe the rear turbo life will be halved from 15yrs to 7 years now.

[brett_celicacoupe]

bit of an update.

this is how i am running it now with the boost controller.


i get about 14psi on the 1st stage and 17-19psi on the second stage.

transistion drops very briefly to 8psi. its pretty unnoticable IMHO.

bear in mind this is without the a prespool valve

here is a schematic of how it is setup. note that the boost controller reference line doesnt actually come from the manifold, it comes from the front compressor housing. essentially the same thing though.