Choosing Afr

For discussing B&G MS-I/MS-II set-up and tuning of fuel parameters (including idle valves, etc.).
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bmcewen
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Location: northern colorado

Choosing Afr

Post by bmcewen »

How do I know if I have entered the correct AFR. I am trying to get my tables dialed in with no ego corrections or accelerator enrichments. I dont really see any lean surges but there is a very light flutter to the exhaust note and seems a little light on power with only slight acceleration (less than 10% throttle). When I maintain any givin rpm/map bin it seems to run smooth but giving it a little gas it flutters until the mph is maintained again,is this a symptom of being a little rich? It stays right around 14.5 to 15.5 afr. I have driven the car several times with VE Analyzer live on and it doesn't seem to change the way it feels so Im assuming that its just tuning to the afr i have specified but I dont know which direction to go from here... I can't upload the log file cause it was too large I'll get another tomorrow after work.
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1978 Camaro Lt 383 L98 HSR Th350(for now) 3:42s
MSII v3 main board rev2.891 8-pin HEI MSD BlasterII
COMP CAMS XR276HR
TRICKFLOW 23° 2.02/1.6
Full roller valvetrain, 11.1:1 compression
WASyL
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Location: Warszawa - Poland

Re: Choosing Afr

Post by WASyL »

around 14,7 idle, leaner on cruise and WOT around 12's, i run similar setup to yours

best regards
Pontiac Firebird 305 LT1 intake, L82 cam
MegaSquirt II with mod's + TPI adaptor board, MSExtra 3.3
bmcewen
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Posts: 70
Joined: Tue Feb 22, 2011 3:17 pm
Location: northern colorado

Re: Choosing Afr

Post by bmcewen »

To Wasyl, Your also at 106(346 ft) meters right? My elevation is 5000 ft which i believe is 1.52 kilometers. So I believe that would make a bit of difference in tuning. I have read in the manual so i know where abouts to start and it does drive around ok.I was just looking for some advise on how to dial it in a little better before turnning on the ego corrections, AMC and AE.
1978 Camaro Lt 383 L98 HSR Th350(for now) 3:42s
MSII v3 main board rev2.891 8-pin HEI MSD BlasterII
COMP CAMS XR276HR
TRICKFLOW 23° 2.02/1.6
Full roller valvetrain, 11.1:1 compression
trakkies
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Location: SW London, UK

Re: Choosing Afr

Post by trakkies »

WASyL wrote:around 14,7 idle, leaner on cruise and WOT around 12's, i run similar setup to yours

best regards
That idle sounds a bit lean to me - I'd go for 14.1:1
Dave P, London UK.
Rover V-8
MSII V3
EDIS
Tech Edge Wideband
bmcewen
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Posts: 70
Joined: Tue Feb 22, 2011 3:17 pm
Location: northern colorado

Re: Choosing Afr

Post by bmcewen »

I'm not really worried about Idle here.
1978 Camaro Lt 383 L98 HSR Th350(for now) 3:42s
MSII v3 main board rev2.891 8-pin HEI MSD BlasterII
COMP CAMS XR276HR
TRICKFLOW 23° 2.02/1.6
Full roller valvetrain, 11.1:1 compression
WASyL
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Posts: 102
Joined: Tue Dec 16, 2008 7:46 am
Location: Warszawa - Poland

Re: Choosing Afr

Post by WASyL »

i meant engine not the elevation which You did not mentioned. Well if your VE map is almost ready it's time to start playing with AMC, EGO and AE as you will newer get rid of these spots with base map. And as onece told to me here about tuning, don't only rely on numbers and listen to engine what it wants.

best regards
Pontiac Firebird 305 LT1 intake, L82 cam
MegaSquirt II with mod's + TPI adaptor board, MSExtra 3.3
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