adjustable exhaust cam sprocket

Discuss topics related to the QR series engine.
08specv
Posts: 39
Joined: Sun Aug 02, 2009 3:19 pm
Car: 08 Sapphire Blue Spec V

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does anyone know if using this to remove overlap would work on the new qr25?

-matt


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RED_DET
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Car: 2004 6 speed G35 Sedan, 2011 G37x, 1992 Nissan Sentra SE-R SR20DET, C7Z06
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on the stock cams?

08specv
Posts: 39
Joined: Sun Aug 02, 2009 3:19 pm
Car: 08 Sapphire Blue Spec V

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yeah dont the 02-06 qr's use exhaust valve overlap instead of an egr system to help clean up the exaust a bit, i heard people using cam gears to take this away and gain a few ponies. I was wondering if this system is used in the new qr's.

-matt

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nametakennow
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Joined: Sat Aug 24, 2002 4:14 pm
Car: '06 MINI Cooper S

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Yes, Nissan skipped EGR and used a bit of overlap to provide the same emissions benefit. This sounds like a fairly reasonable way to gain a few hp, but probably not really worth the cost without upgraded cams.

08specv
Posts: 39
Joined: Sun Aug 02, 2009 3:19 pm
Car: 08 Sapphire Blue Spec V

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ok, i wanna do cams but i'll have to wait until we get some support.

-matt

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nametakennow
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Joined: Sat Aug 24, 2002 4:14 pm
Car: '06 MINI Cooper S

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One foreseeable concern is that this may alter the exhaust air composition and, via the reading at the O2 sensor, cause the ECU to throw a code and/or alter other parameters to get the mixture it's looking for.

Q45tech
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Car: 1990 Q45 342,400 miles 22 years ownership with original engine
1995 G20t 5 speed 334,000 miles 16" 2002 wheels - 205/50/16 Sr20ve vvl

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EGR [whether cams or piping ] is only active at steady speed cruise [2,000-3,300 rpm] and light load. It is shut off at idle and during acceleration.

Careful you don't try to solve a nonexistent problem and create a bigger one.

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djtorello
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T
08specv wrote:ok, i wanna do cams but i'll have to wait until we get some support.

-matt
here are quite a few companies that you can get custom cams from. I have a custom set, im quite happy with. BTW, if you can make friends with a tech at a dealership, see if someone can bump your timing 2 degrees with the Consult tool. those 2 degree's is a nice bump in performance, though your mileage will decrease a bit.


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