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Discussion Starter · #1 ·
Hey guys, my 1JZ idles at steady 700rpm, runs nice and strong.

El-cheapo OBX-R boost gauge shows -15 in/HG vacuum at steady warmed-up idle.
Highest boost in 3rd, 4th and 5th is 8PSI, holds it rock solid.

Does the above sound right? I thought stock boost was 11PSI, like on the Supra?

PS Engine is running stock boost, only mods are FMIC, Blitz BOV, intake, Walbro pump and ACT 6-puck. Running straight exhaust too, no cats.
 

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GT40 1.5JZ
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1,211 Posts
could be the gauge.

I really think you've got a leak. I went to the dyno with 8 psi max because of leaks. All I had was intake, dp and exhaust.

-joseph
 

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1JZ BLING!
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2,747 Posts
get a diff gauge

I'm at -19 or -20

only 8?? that is way off.. with a hole in my IC piping I could still manage 10 psi.

since the leak was fixed I boost @ 12 psi with just a high flow cant and exhaust..
 

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67mm of pleasure
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852 Posts
I go from -18 idle to +12 full boost, 3'' dp, 3'' hi flo cat, hks dragger, and cone filter
 

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Republican
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8,421 Posts
500 -hg at idle.. stock boost, i have no idea
 

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Madd Tyte JDM yo ®
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7,014 Posts
with chris on this one -500 mm/hg at idle warmed up.

stock boost is like 10psi or something... i think. itll hit 12psi w/ stock dp and no exhaust and 1.0bar w/ 3" DP and exhaust.
 

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Banned
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3,588 Posts
-18, -19 here...hitting 10psi till 4,000rpm...then anywhere from 12-14.7 depending on the weather...stock dp, 3" exh w/3 crush bends and hks ti muffler, no cats, intake.
 
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Discussion Starter · #10 ·
My OBX gauge is CRAP (like we didn't know that already)!!!! I've used MittyVac specialty vacuum gauge and vaccum off the manifold at fully warmed up idle is -19 in/Hg. Installing new Autometer 20PSI gauge in there to get more accuracy in my boost range and see whats up with top boost.
 
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Discussion Starter · #11 ·
Installed 4" GT Spec exhaust on the 1JZ, sounds amazing. Boost is now 9 PSI during the day (hot/humid) and 10 PSI at night with fuel cut around 4500rpm from time to time when boosting at night. I have Blitz Access ECU on the way, so that will take care of the fuel cut, and I'll get the boost up to 15-16 PSI and see what stock twins can do in the 1/4 mile on ET Drags. Auto TT LSD diff going in next week too.
 
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