07-22-2014, 07:50 PM | #1 | |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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IPF Bypass Valve Spring
Decided to create a new thread for this experiment I'm going to do, put a stiffer spring the bypass valve. Our stock Evolution Motorsports bypass valve is actually real good, but will open up at -5 in/hg and be fully open at -7 in/hg. I've upgraded to a Lindsey Racing spring that starts at -15 in/hg and fully opens at -20 in/hg. I'm hoping this will fix the LTFT issues that I have, at high vacuum my LTFT's are perfect, but when I get around the -12 to -5 range my LTFT's run extreme positive, meaning more air is getting in than the MAF detects. This could be caused by the air going through the bypass.
Instead of me writing a bunch of stuff, here is a piece from this site: http://www.lindseyracing.com/hptalk/1207.htm (Go down to the area called "Shop Talk") This is based off Turbo's. Quote:
http://www.lindseyracing.com/LR/Pors...LR-BOV-RS.html |
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07-22-2014, 08:19 PM | #2 |
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Very interesting
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07-23-2014, 09:11 AM | #3 |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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Should have reset the ECU, car bucks a little and in park as soon as it goes under 15 vacuum the engine runs rich. Trims looked better though cruising, will keep playing with it since it is a cheap mod.
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07-23-2014, 11:45 AM | #4 |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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Definitely needs adjustment, in park the car wants to hover right around 15, so it starts trying stall out every time the valve starts opening, so the throttle opens up, removes some vacuum and the valve closes and no idle problem till it hits again.
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07-23-2014, 12:51 PM | #5 |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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Car stalled for the first time since December, don't know if it was because the valve was closed or open. Tonight I'm going to pull the vacuum line off the valve and see how it idles. If it stalls then the spring is too stiff and the stock spring is best.
The stiffer spring seems to make the throttle respond better, but there is probably 0 track gain from this. Nice cheap experiment though. |
07-23-2014, 06:02 PM | #6 |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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No go on this, if the bypass valve is closed at idle the engine tries to stall out. Since the bypass valve opens up at -15 in/hg and idle wants to be at -12 to -17 in/hg with the stiffer spring it won't work. The stock spring does open up at -5 in/hg, maybe getting one to open up at -10 in/hg might work but for the gains, not worth it stalling. It helped build boost a little faster because it didn't have to wait for the boost pressure to enter the intake manifold to push back on the valve to seal it up.
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07-24-2014, 11:33 AM | #7 |
Drives: 2017 1SS 6spd Join Date: Jan 2011
Location: Utah
Posts: 2,839
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Nice work and a very interesting FYI. Thanks!
And BTW- what light grease are we gonna lube with for future cleaning? |
07-24-2014, 12:00 PM | #8 |
Drives: Fastest 2010 Camaro V6 Join Date: Apr 2010
Location: Newcastle, OK
Posts: 3,571
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Probably just bearing grease, I have royal purple grease from all the suspension work.
Didn't work out, but some of this information might be FAQ worthy. |
07-24-2014, 09:20 PM | #9 |
Drives: 2014 1LS M6 Supercharged Join Date: Feb 2011
Location: New Britain, Ct
Posts: 937
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My bypass valvue Flutters when open. J&M Motorsports is replacing it with a larger Bypass valvue.
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