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Discussion Starter #1
just like the title says, how much vacuum does your stock engine + turbo makes at idle? i know all engines are different, but im just trying to search if -12-13 is ok, that's what my engine made at idle with the egr vacuum line capped, but afr was low 11 high 10s, now that i connected my egr vacuum line, it is reading -4, -6 and the idle is erratic, but afr reads near 14.7...
 

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12-13 with a stock motor is very low

my f cam motor makes 10 and im pretty sure my stock cam was 15-17
10 actually sounds pretty low for an f-cam....mine hangs right around 12.

The stock cam should pull 18+.
 

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now that i connected my egr vacuum line, it is reading -4, -6 and the idle is erratic, but afr reads near 14.7...
Vac leak in the EGR system somewhere. ..... would throw off A/F's too
cause un-metered air is getting into system.
 

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Discussion Starter #8
ok, found what i was doing wrong, while searching the forum I found that vacuum shouldn't be present at the egr when the engine is idling, since i remade all the vacuum lines, then that's why it idled bad with the egr vacuum line connected...


anyways, my first problem still exists.. 10.5-11.5 afr at idle @ 60psi fp, if i lower it to about 40-45psi, still gets low 11 afr at idle, but leans out at WOT, that's why i put the fpr at 60psi, still sees 12-12.5 afr...

don't know why i have this problem, i have 42lb/hr injectors, pmas maf calibrated for those 42, and a 255 walbro fuel pump....
 

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don't know why i have this problem, i have 42lb/hr injectors, pmas maf calibrated for those 42, and a 255 walbro fuel pump....

Thats exactly what I have with NO issues. PMAS pro tube??do you have any bends before/after the MAF?? what size are your cold side pipes?

I dont have a wideband just a cheap/junk narrowband but can still see it idles lean.
 

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can you switch the maf with that small pipe? (3rd pic) so you have the 90* elbow then that short piece of pipe and then the MAF. I HERD bends closer then 6in from the MAF can cause a "issue". or maybe "clock" the maf.

PMAS called me and asked exactly how my cold side was set up before they would calibrate/send mine out. I ordered it from JD's

not sure if any of that will help lol

I myself would be happy as long as WOT was good lol
 

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Discussion Starter #13
im really happy at wot... lol.. made 410whp and 470lb/ft yeah!!!...

i also bought my pmas from jd's performance, im going to change that short piece with the maf..


how's your afr at part throttle??
 

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im really happy at wot... lol.. made 410whp and 470lb/ft yeah!!!...

i also bought my pmas from jd's performance, im going to change that short piece with the maf..


how's your afr at part throttle??


well the narrow band basicly only tells me if Im richer, leaner, or at 14.7 lol it idles around 14.7 at part throttle it goes bounces from full rich to mid lean back and forth pretty regularly lol and at WOT its about mid rich lol. its a ghetto setup I know but just cant afford a wideband or tune yet.

I did have the car on a dyno with a wideband before the turbo and got a general idea of where on my gauge was what.

the only time its peged full lean was a Fuel pump issue with a dry nitrous kit and the gauge saved my a$$ lol only time it hits full rich is on the 2step.
 
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