N75 "J" valve install...
12-05-2005, 08:41 AM
#1
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N75 "J" valve install...
<center><img src="http://pictureposter.audiworld.com/2644/n75-j.jpg"></center><p>So, after thinking my N75 "J" was installed backward... and getting some confirmation of that from AW, I decided to flip it over opposite of what's seen in this photo.
The car boosts INSTANTLY now, but it's totally undrivable. Almost as soon as you hit boost, the wastegate opens, letting it all out.
Question is - how do I make my car boost easier, like it is now, but w/ the N75 installed correctly? WHen it's installed correctly, I really have to get on the gas for it to get into anything more than factory boost.
The car boosts INSTANTLY now, but it's totally undrivable. Almost as soon as you hit boost, the wastegate opens, letting it all out.
Question is - how do I make my car boost easier, like it is now, but w/ the N75 installed correctly? WHen it's installed correctly, I really have to get on the gas for it to get into anything more than factory boost.
12-05-2005, 08:49 AM
#2
first, the N75j is physically different from the stock N75. The orientation of the plug vs stock...
is completely different.
the only "correct" way to hook up a N75J, is the the way in which it <b>functions</b> correctly.
<img src="http://www.wseng.com/a4/stage3/16n75a-med.jpg">
check out my <a href="http://www.modifieda4.com/web/misc/3d-n75j.html">3d model</a> of a N75J:
<img src="http://www.modifieda4.com/web/misc/3d-n75j.jpg">
second,
no matter what N75 you use, you will not get more boost. by changing to a N75J you might get quicker boost onset, and a boost spike. thats it.
the only "correct" way to hook up a N75J, is the the way in which it <b>functions</b> correctly.
<img src="http://www.wseng.com/a4/stage3/16n75a-med.jpg">
check out my <a href="http://www.modifieda4.com/web/misc/3d-n75j.html">3d model</a> of a N75J:
<img src="http://www.modifieda4.com/web/misc/3d-n75j.jpg">
second,
no matter what N75 you use, you will not get more boost. by changing to a N75J you might get quicker boost onset, and a boost spike. thats it.
12-05-2005, 08:54 AM
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I'm not looking for more boost. Just looking to have the boost come on w/ less pedal...
Like now, I barely touch the gas and it boosts like crazy. But w/ the N75 J installed correctly, I really have to get on the throttle to get it to boost over 4-5 PSI.
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12-05-2005, 09:54 AM
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check your DV for problems...
if it's a plastic DV update it to a metal performance valve. If it's metal, make sure it is lubed properly. And check the vac hose from it to the intake manifold for leaks. The stock N75 F should be sufficient for you...no need for a J valve in order to get quicker response. Also, keep good spark plugs in there..I noticed quicker throttle response after I changed plugs and did a throttle body adaption. But, a failing DV can also cause some symptoms of hesitation at the pedal, particularly off the line.
J
J
12-05-2005, 10:11 AM
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I have a Forge DV. Opened it up, cleaned it out, and re lub'ed everything a few months ago.
I do have an OEM TT valve that I may throw in there to see if it makes a difference.
I updated to the N75 J after my OEM N75 went bad and was surging under load.
I updated to the N75 J after my OEM N75 went bad and was surging under load.
