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Discussion Starter #1
So my car is being tuned right now. The tuner can't get more than 420whp at 20psi.

Spec:
-6262 Precision Turbo
-850cc injectors
-FMIC (SRT)
-ECU Master
-Returned fuel system w/ Aeromotive regulator
-NA-T VVTi w/ GTE rod and pistons, ARP studs and GTE headgasket
-Stock head
-Stock intake Manifold

Tuner thinking the cams are the bottle neck. HP falls off rapidly after 5700rpm. Any input would be appreciated. I was expecting around the 500whp area on pump. To be fair it is a low reading dyno.
 

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Discussion Starter #9
You think a turbo like an S366 or a 6766 would make the difference to push to 500whp on my current setup? Just trying to get to 500whp before it comes home from the tuners without having to do the intake and cams there. I can do those this winter myself. Are the stock cams and intake that restrictive that they could be holding me back? I have seen multiple builds on stock head and intake over 500whp.
 

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You think a turbo like an S366 or a 6766 would make the difference to push to 500whp on my current setup? Just trying to get to 500whp before it comes home from the tuners without having to do the intake and cams there. I can do those this winter myself. Are the stock cams and intake that restrictive that they could be holding me back? I have seen multiple builds on stock head and intake over 500whp.
Those turbos should be fine. Stock stuff is not that bad. You would benefit from better cams and intake and throttle body. But you don't need them to meet your goal.
 

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500whp is about right for what you are have. stock throttle is a bottleneck. it's not really the throttle but the plenum. the cams are not the bottleneck. a .59 ar on 62 would un out of breath high rpm at 500whp. midrange response i am sure is awesome though. I run a t04z with a .70a/r hot side and LOVE the midrange -but even it runs out of breath on the top end. similar set-up. i got s few more horse power out of it.

not sure what you were expecting; this is not a car that you slap a turbo on and make 1,452,937 hp
 

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I see you're running a ECU Master, from what I heard their standalone is not a good unit. The ECU Master piggyback is decent, but I haven't heard positive things about their standalone.

My buddy's Aristo swapped GS300 was running 14psi on stock turbos and made about 330rwhp. When he switched over to a AEM v2 with the exact same setup he was able to hit 390rwhp. I also heard from my drifter friends at the professional level the ECU Master standalone just doesn't compare to a AEM or ProEFI. Guys would run the exact same setup on their cars except for the ECU and the ECU Master made less power every single time.
 

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Precision's site says the default outlet on the 6262 is .63ar - which as previously stated is going to start running out of steam up top. it also has a 2.5" outlet which IMHO you should be shooting for 3" for any 2JZ FI motor looking for >400whp. I do not agree that the cams are the issue at this point. Also as previously stated the stock intake manifold can be a small hindrance but it helps with down low torque.

If you have the option, I would go with the .82ar 3" V-Band outlet.
 

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Discussion Starter #14
Precision's site says the default outlet on the 6262 is .63ar - which as previously stated is going to start running out of steam up top. it also has a 2.5" outlet which IMHO you should be shooting for 3" for any 2JZ FI motor looking for >400whp. I do not agree that the cams are the issue at this point. Also as previously stated the stock intake manifold can be a small hindrance but it helps with down low torque.

If you have the option, I would go with the .82ar 3" V-Band outlet.

Awesome thanks for all the help. I ordered a S366SXE .88 a/r Do you think that can push to 500whp keeping the rest the same? If not BC 264 vvti cams and a GTE FFIM welded to my GE lower runners is in the future as well.
 

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Discussion Starter #15
I see you're running a ECU Master, from what I heard their standalone is not a good unit. The ECU Master piggyback is decent, but I haven't heard positive things about their standalone.

My buddy's Aristo swapped GS300 was running 14psi on stock turbos and made about 330rwhp. When he switched over to a AEM v2 with the exact same setup he was able to hit 390rwhp. I also heard from my drifter friends at the professional level the ECU Master standalone just doesn't compare to a AEM or ProEFI. Guys would run the exact same setup on their cars except for the ECU and the ECU Master made less power every single time.
Interesting. I have heard a lot of great things about ECUMaster EMU. Lots of cars making big power. Was the Aristo same tuner and dyno under same conditions? Seems odd as all the ECU's mentioned give the tuner the same controls over vvti, timing and fuel. ECU is not the limiting factor in this case. No knock at all just a physical bottleneck with power dropping off with lack of flow.
 

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Discussion Starter #16
500whp is about right for what you are have. stock throttle is a bottleneck. it's not really the throttle but the plenum. the cams are not the bottleneck. a .59 ar on 62 would un out of breath high rpm at 500whp. midrange response i am sure is awesome though. I run a t04z with a .70a/r hot side and LOVE the midrange -but even it runs out of breath on the top end. similar set-up. i got s few more horse power out of it.

not sure what you were expecting; this is not a car that you slap a turbo on and make 1,452,937 hp
Was expecting more than 423whp is all. But that was until we realized the exhaust side of the turbo was so small. With a larger turbo I believe it can make 500whp on stock cams and intake, but that may not be seen as I am likely going to go GTE upper intake and cams right away.
 

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What exhaust is on the car?

Almost all of the aftermarket exhaust systems for the IS are 2.5” or less. Moving from a HKS to straight 3” made a huge difference on mine.
 

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Discussion Starter #18
What exhaust is on the car?

Almost all of the aftermarket exhaust systems for the IS are 2.5” or less. Moving from a HKS to straight 3” made a huge difference on mine.
Custom 3" V-band all the way back with a small straight through muffler. New turbo has a 3.5" exit so will be 3.5" DP forsure and possibly all the way back.
 

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Custom 3" V-band all the way back with a small straight through muffler. New turbo has a 3.5" exit so will be 3.5" DP forsure and possibly all the way back.
3.5 would be better, but not necessary.

Looking at your dyno graph again, definitely drops something fierce up top. I'm assuming the lower blue line is your boost curve?

What's the target ignition timing by RPM? Wondering if you're tuner isn't feeding in enough up top.
 

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Discussion Starter #20
3.5 would be better, but not necessary.

Looking at your Dino graph again, definitely drops something fierce up top. I'm assuming the lower blue line is your boost curve?

What's the target ignition timing by RPM? Wondering if you're tuner isn't feeding in enough up top.
And there is why it didn't make as much power as I thought. I looked over the timing charts and all looks good compared to other 2J charts I have seen trying to achieve my power goals. I believe it is just a restriction on the exhaust side. 423whp on a .68 A/R seems pretty good. I will post up new numbers and sheet when the S366 gets tuned later this winter.
 

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