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| Forum name | Turbo/Nitrous Tech |
| Topic subject | Running Lean after my headgasket is done |
| Topic URL | https://forums.2gnt.com/dcboard.php?az=show_topic&forum=i8&topic_id=56478 |
56478, Running Lean after my headgasket is done Posted by MmmDeion, Sep-17-03 05:37 AM
Ok so after a grulin battle with my engine I replaced my own headgasket and timing belt, WOO HOO!! But now when I boost and have it at WOT my turbo timer reads that my air/fuel is only 10psi (or whatever the hell the measurment is)... I remeber before I did all this it would stay around 12.5 at WOT and now it has no problem just droppin right below 10 at WOT... Any suggestions or am I gonna have to guy and buy a SAFC now, cause I dont have one... :thumbsup
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56490, RE: Running Lean after my headgasket is done Posted by turbo8u, Sep-17-03 07:05 AM
ok im thoroughly confused as to what you mean....
try to explain what you mean better
_________ 96 talon esi-t san clemente, ca
Uberingram> I bow down to the Geo
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56500, RE: Running Lean after my headgasket is done Posted by lickscissors, Sep-17-03 08:17 AM
are you sure you had your timming correct?... does it idle properly?
screw flanders
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56517, RE: Running Lean after my headgasket is done Posted by MmmDeion, Sep-17-03 11:35 AM
ok here we go... i boosted my car 2 months ago and installed an Apexi TT at the time... The TT read my air/fuel ratio and at WOT it read my air/fuel as 12.4... Now after i put my new t-belt and headgasket on my air/fuel ratio on my TT reads 10 at WOT... I was wonderin if i messed somethin up along the way, or if I need like an SAFC to adjust my air/fuel curves... understand now? :thumbsup
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56519, RE: Running Lean after my headgasket is done Posted by siueclipse, Sep-17-03 11:49 AM
if it reads like a wideband then the lower number would be better..
i run 10.7 at wot on the wideband.
James
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56526, RE: Running Lean after my headgasket is done Posted by XtremeRS, Sep-17-03 12:23 PM
>if it reads like a wideband then the lower number would be >better.. > >i run 10.7 at wot on the wideband. > >James
Holy fuk that rich! Did you get best HP and TQ with that tuning?? Just curious...Most shoot for 11.5:1
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56529, RE: Running Lean after my headgasket is done Posted by siueclipse, Sep-17-03 12:29 PM
i hi 329 on the dyno with that. oh but im sorry.. i screwed that up.. im at 10.7 at idle and 11.2 at wot.. my bad
James
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56595, RE: Running Lean after my headgasket is done Posted by MmmDeion, Sep-18-03 05:29 AM
>im at 10.7 at idle and 11.2 at wot.. my bad
Jesus... At idle im at 14.6 I think I have some really messed up fuel curves, and sure as hell dont have the money for a SAFC
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56597, RE: Running Lean after my headgasket is done Posted by ner947, Sep-18-03 06:33 AM
if i were you, i wouldn't trust your piston ring landings to the apexi turbo timer for accurate readings of your a/f ratio. remember, it just runs off of the stock 4 wire lambda sensor. stock type oxygen sensors aren't THAT accurate, but they'll give you a very decent ballpark of what your mixture really is.
here's a hint: i dyno'ed my car in june. (from memory) my a/f curve looked kind of like this (man, i wish i had the dyno printout):
 i remember running lean down low. dangeriousally lean. also, there were some weird ups and downs in the midband which affected my torque curve. as i got closer to redline the mixture got closer to where i wanted it to be but it was still lean. (the big thick red line would have been ideal) the whole time, my air/fuel gauge was reading in the green, and corbin's air/fuel gauge said .94. cheers, for the stock oxygen sensor.
personaly, i'm gathering parts for the DIY-WB setup. much more accurate IMO.
as for now, i "tune" for .96-.98 for my oxygen sensor voltage. that way it can be off by 4 to 6 hundredths of a volt from what it should really be and in theory i'd still be running "safely".
so, it boils down to this: unless you've used a wideband oxygen sensor of some sort to tune your car, tune it to what you would think is almost too rich. that's just my opinion though, i don't trust my OEM oxygen sensor very much.
EDIT: BTW, i made 235 WHP and 245 WT at about 12-14 psi of boost.
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