1jz + twin dumps boost control needed?

[rshuwy]

im just wondering if i will need a to buy some kind off boost controller to run 18psi.

what sort of psi do 1jz normally run with twin dumps + decent exhaust and no boost management?

just wondering if i should buy it before i get it dynoed.

cheers

huw

[BEVANI]

im running a y pipe 3in exh. with cat and muffler on a turbosmart boost tee which is wound down to its lowest setting and im seeing 15psi... i wanna upgrade/rebuild the turbos before i start winding up the boost.. and i think the stock twins put down between 9-13psi?

[naten]

i have stock 1jz with 3" dump (off stock y pipe) 3" zorst with 3" cat and 2.5" muff bringing up the rear + fmic
sees 11psi with no help of a boost controller so Y pipes would be above that, probably depends on the zorst parts aswell

[Slim]

I had my cressida on the dyno a while back... No boost controller. It has twin 2.5" pipes from the turbos to the cat, then a mandrel bent 3" exhaust from the cat back. The boost meter on the dyno read 10.5psi.

My autometer boost gauge read 12psi. They're the biggest rip-off. Wouldn't buy another one. a) it never read boost accurately from day one, b) the rubber fitting has perished after 3yrs and pops off occasionally, c) the backlight has stopped working.

[HAVABEER]

i thought 1j's stock computer had boost/fuel cut at 14psi anyways

so anything over that your going to need a new computer or a boost cut defender thing.

this is based off a stock 1jz soarer, so might not be the same for other cars with a 1jz

[midnight_purple_GA70]

i thought 1j's stock computer had boost/fuel cut at 14psi anyways

so anything over that your going to need a new computer or a boost cut defender thing.

this is based off a stock 1jz soarer, so might not be the same for other cars with a 1jz

all turbo jz motors have this...

1bar boost cut
so 14.7psi...

to the OP just get yourself a bleed valve and if it doesnt boost as much as you want it to then wind it up maybe borrow one if you intend on getting an electronic one later so you can tune the car for 18psi then swap it later

[mznut]

I have a 1jzgte in a z10 soarer and with stock y-piece and down pipe and 3 inch exhaust from there, i get 10 psi when i hook up my turbosmart manual boost controller at its lowest setting i see 13 psi.

I have heard that running above 15 psi isnt really good for the turbos and they run out of puff above this. correct me if im wrong anyone!

[BEVANI]

i thought the 2jz ran a 3bar map?

[chaserbuddy]

just to clear up rshuwys inquiry, He has steel wheel turbos and 2.5" seperate turbo dumps that merge to 3 inch and an safc II which I've heard deletes boost cut. Huw will need a boost controller of some sort either a tee or an electronic, depending if he wants to run a few different boost settings. Unless his actuator springs are upgraded to 18psi springs then you wont need a boost controller and then lower boost levels are unable to be achieved. Boost controller is probably easier and will have more tune-ability then just upgrading springs.

[midnight_purple_GA70]

safc II which I've heard deletes boost cut.

it doesnt delete it... it just raises it which is a good thing as if boost spikes you will hit the cut how much it raises it is based on how much fuel is put in or pulled out...

also is good as if someone winds the boost up it will hit boost cut rather than destroying motors

[midnight_purple_GA70]

I have a 1jzgte in a z10 soarer and with stock y-piece and down pipe and 3 inch exhaust from there, i get 10 psi when i hook up my turbosmart manual boost controller at its lowest setting i see 13 psi.

I have heard that running above 15 psi isnt really good for the turbos and they run out of puff above this. correct me if im wrong anyone!

i ran 17psi through mine... now they are on another car running 14psi... still seem to be going ok... did notice an increase from 13psi to 17psi however they do produce alot of heat at that boost level

[JZA70 R]

im just wondering if i will need a to buy some kind off boost controller to run 18psi.

Boost with those mods vary, if your lucky it might hit 18 pound like mine did. One thing for sure is it wont hit peak boost straight away due to the nature of boost creep. So a simple answer to your question would be to use some sort of boost controller if you want to hit 18 pound and hold it there.

all turbo jz motors have this...

1bar boost cut
so 14.7psi...

As I said in another thread, im pretty sure boost cut comes in below 1 bar. IIRC is ~13.5 psi

I have heard that running above 15 psi isnt really good for the turbos and they run out of puff above this. correct me if im wrong anyone!

It all depends on your mods AND the condition of your turbos... I ran between 18 and 20 psi on stock turbos for years.

i thought the 2jz ran a 3bar map?

Nope, it has the EXACT same capacity as all 1JZ map sensors... 2 bar

[rshuwy]

turns out it ran 15 pound with no adjustment, and it hits boost cut if you go over that even with the safc,

im happy with the power it made at 15 psi.

[mznut]

what power did it make??

[rshuwy]

242.6 kw atw