Engine/Power - EJ20T (pre-2006 WRX and JDM) There is replacement for displacement, it is forced induction - OEM 2.0 liter turbo engines in the USDM WRX. 90-94 Legacy Turbo EJ22 turbo engines can also be discussed here.

VF34 max boost

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Old 11-26-2006, 04:54 PM
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VF34 max boost

i know this has been beaten to death

but what is the max boost and HP wit the vf34, with this set up helix 660cc injectors, walbro fuel pump helix up and cattless down and cat back exhaust, wit stock IC

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Old 11-27-2006, 01:04 PM
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i was running 1.5 bar

but that was with a spring
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Old 11-28-2006, 07:28 AM
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I ran 18-19psi on my VF30 (basically the same turbo) with a nice, safe ECUtek tune. This was in my 02 WRX which saw several track days on this turbo before I traded it in for my STi.

YMMV
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Old 11-28-2006, 11:33 AM
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1.1 bar with out the spring
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Old 11-28-2006, 12:25 PM
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For those of you that are not conversion savvy:

Originally Posted by sigma pi
i was running 1.5 bar

but that was with a spring
21.7 PSI



Originally Posted by sigma pi
1.1 bar with out the spring
16 PSI
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Old 11-28-2006, 12:49 PM
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im not conversion savy hehe
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Old 11-28-2006, 04:39 PM
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how much power were/are you guys puttin down?
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Old 11-28-2006, 06:40 PM
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Originally Posted by cbf246
how much power were/are you guys puttin down?
My old WRX w/ VF30 and all of the supporting mods was putting down 249whp on Vishnu's Dyno Dynamics dyno.
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Old 11-30-2006, 04:20 PM
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teh butt dyno said fast with 1.5 bar

and 1.1 meh not like the 1.5
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Old 12-14-2006, 12:33 PM
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if i want to get a turbo that is one step above the vf 34 what would that b
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Old 12-14-2006, 02:46 PM
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Originally Posted by hayakunai
if i want to get a turbo that is one step above the vf 34 what would that b
"one step above" is kind of subjective. What do you want to accomplish with the car? Drag race? Road race? Auto X? Street performance?

In addition to higher boost, you need to take into account turbo flow rates and spool characteristics. Simply going to the next bigger turbo may not get you what you really want. Give us some more info and we'll give you a better suggestion.
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Old 12-17-2006, 11:54 AM
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i want it for the street. i was first thinkin of gettin the FP green turbo but i think thats way too much for what i want. im lookin for a good turbo for the street and tryin to seek about 325-350 whp, also sumthing that doesnt have alot of lag
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Old 12-17-2006, 04:21 PM
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Origami posted by hayakunai
im lookin for a good turbo for the street and tryin to seek about 325-350 whp, also sumthing that doesnt have alot of lag
For a street-driven car, that's always the problem - how can I get the most power without suffering too much lag?

Part of the problem is that going too much bigger beyond the VF30/VF34 with the EJ20 moves the torque curve higher. Good custom tuning can alleviate only some of the lack of low end and mid-range torque but the combination of small displacement and a turbo that isn't doesn't have much velocity at lower engine RPM makes for lackluster street performance until the revs get 'up there'. I do know someone that is happy with his 18g turbo but is tuned for race gas, only. He doesn't let his revs fall too low at the track (road course).

The boost lag effects aren't as noticeable with the EJ25 turbo or with the use of race gas, where tuning can yield additional mid-range torque with a more aggressive ignition advance and more boost.

That's the reason that the VF30/VF34 and similar bolt-on turbos like the 16g work out well for street-driven cars with 2.0 liters and limited to running pump gas - they are more efficient at lower engine speeds compared with the bigger turbos.

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