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Old 12-09-2007, 04:26 PM   #1
davidm_sh
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Default Full race twin-scroll header question

I don't see in any of the pictures of their twin-scroll header design a provision for the front stock O2 sensor? Looking at ultimate-racings twin scroll setup I don't see one either. So where do they expect you to put the front O2 sensor?

Or a bigger question which 2 cylinders do you choose to tap for the O2 bung? Or do you simply put the O2 sensor after the turbo to get all cylinders into the equation? But isn't the front O2 sensor meant to operate under a fairly narrow range of temps that might be to low after the turbo/first common collection point of exhaust gases?
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Old 12-09-2007, 04:59 PM   #2
root
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The Full-Race kit puts the front O2 sensor in the downpipe. And the exhaust is still plenty hot immediately post-turbo. Plus my logging of my moved O2 sensor versus my wideband show no adverse effects.
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Old 12-10-2007, 09:18 PM   #3
Full-Race Geoff
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root - thanks for the reply. That is correct, the o2 sensor is relocated to the downpipe. The reason for this is that a twinscroll configuration only has 2 pulses to read from, due to the cyls being seperated.

as a result, the o2 readings are not as accurate as if they were post-turbo, reading from all 4 cylinders. if you have any other questions feel free to ask!
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Old 12-29-2010, 02:13 AM   #4
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i went on the full race site and the kit under the 02 twin scroll kit does not say that it fits the 02 just 05 and up. also is it possible to get just the header and up pipe?
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Old 12-29-2010, 11:07 AM   #5
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yes - you can order just the header and up pipe AND it will fit the 02 **ONLY with an sti oil pan**
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Old 12-30-2010, 09:30 AM   #6
KillerBMotorsport
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Hey, I call foul. It took some effort to get our pan to work with your header
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Old 12-30-2010, 10:36 AM   #7
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Full-Race is working on an oil pan for 2011 release
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Old 12-30-2010, 10:45 AM   #8
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Ah... I see what you did there
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Old 12-31-2010, 01:52 AM   #9
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Quote:
Originally Posted by KillerBMotorsport View Post
Ah... I see what you did there
Is there a "Like" button on Nasioc yet?
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Old 12-31-2010, 02:54 AM   #10
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Quote:
Originally Posted by davidm_sh View Post
Or do you simply put the O2 sensor after the turbo to get all cylinders into the equation? But isn't the front O2 sensor meant to operate under a fairly narrow range of temps that might be to low after the turbo/first common collection point of exhaust gases?
The factory sensor actually reads more accurately in the post-turbo position than in the stock position, since it no longer gets confused by the high pressure in the up-pipe. I've been running my Legacy this way for a couple years... shortly after Root (above) proved it could work.
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