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Predator help with running rich on headers?

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Old Jul 9, 2003 | 08:58 PM
  #1  
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Default Predator help with running rich on headers?

I've got long tubes with off road y-pipe. My O2s are pretty high, 950 or so millivolts at WOT, and a little off 0 in the LTFTs. Will the predator enable me to lean out satisfactoriy? In addition, it looks like I can use a little more timing when analyzing my ATAP readings - the predator will help with this too, right?

Anyone with similar mods had success with the predator? If so, how much HP might I expect?
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Old Jul 9, 2003 | 09:58 PM
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Default Re: Predator help with running rich on headers?

+5% put me at 940mV, 0% to 890mV or so on the
Predator power enrichment settings. So I think
you might have enough range. Thing is, 950mV is
a reading you can get from 12:1, 11:1 or 10:1 -
it just isn't changing much, way out there on the
curve. So it's hard for anyone to say that it
will or won't be enough, as-delivered.

Buy it from the right vendor and they will do
special tunes for your combination. That is, the
right vendor to buy from, is one who has been
doing it. And the more they've been doing it, the
smarter they'll be about getting it right for
your combo. Some outfits will just give you some
mumbly "promise" or not even; check around and
see who's really standing behind the product after
the sale, for a serious-mods car it matters.
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Old Jul 9, 2003 | 10:11 PM
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Default Re: Predator help with running rich on headers?

I thought a reading of 950 mV would = a static air/fuel ratio, i.e. 12:1; and 900 would equal maybe 12.5:1? How can you get 12:1, 11:1 or 10:1 from 950 mV? Call me a newbie...
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Old Jul 9, 2003 | 10:40 PM
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Default Re: Predator help with running rich on headers?

By the time you get to 950mV you're pretty well
pegged out. Maybe see 10-20mV change for a movement
from 12:1 to 11:1. Check these charts out:

http://community.webshots.com/album/74289894mbMeMp

OK, maybe not dead flat, but pretty close to it.
And without knowing the EGT value, 950mV could be
anywhere from 13:1 to 10:1 (looking at the chart
that's in color).
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Old Jul 10, 2003 | 04:18 AM
  #5  
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Default Re: Predator help with running rich on headers?

The stock O2's are scaled to be decently accurate at the factory location in the exhaust and at 14.7:1. So, first you add headers which change the location and then you have not a 14.7 so you are shooting in the dark. You need a wideband to figure that one out. A good vendor is James, email him at sales@runninwiththedevil.com and explain your LTFTs idle, pt, and WOT, and your O2's at WOT. He willa sk for all your mods up fornt and much other stuff. Good-luck.
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