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"optimal" A/f ratio for supercharged 4.6

  • Thread starter Thread starter 98stangv8
  • Start date Start date Dec 18, 2008

98stangv8

Active Member
Oct 3, 2003
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36
fayetteville, nc
Dec 18, 2008
#1
  • Dec 18, 2008
  • #1
Hey guys,

I have a 98 block with a v2SQ...what is the optimal a/f ratio I should be shooting for when my car gets dyno tuned tomorrow morning?

Thanks!
 

squeak93

15 Year Member
Jun 2, 2005
2,277
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164
Joplin, Missouri
Dec 18, 2008
#2
  • Dec 18, 2008
  • #2
14.7 is ur static a/f...

12.5-13 depending on how safe want to go.

Lean is fast, fat is safe.....
 
2

2002BLGT

Well-Known Member
Dec 18, 2003
2,945
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59
Bedford VA
Dec 18, 2008
#3
  • Dec 18, 2008
  • #3
for wide open throttle with stock engine 11.8-11.5 and with built engine 11.7-12.0
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Dec 18, 2008
#4
  • Dec 18, 2008
  • #4
I tuned my 351 n/a fox to 11.5-12... was telling him a bit safer #'s for the blowers sake...
 

CobraRed_96_GT

Active Member
May 20, 2006
1,421
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39
UCSD/La Jolla
Dec 18, 2008
#5
  • Dec 18, 2008
  • #5
squeak93 said:
14.7 is ur static a/f...

12.5-13 depending on how safe want to go.

Lean is fast, fat is safe.....
Click to expand...
12.5-12.6 is where my car is safe - 13 would be too lean even for me
 
2

2002BLGT

Well-Known Member
Dec 18, 2003
2,945
4
59
Bedford VA
Dec 18, 2008
#6
  • Dec 18, 2008
  • #6
CobraRed_96_GT said:
12.5-12.6 is where my car is safe - 13 would be too lean even for me
Click to expand...


anything higher than 12 is not considered safe with a blower
 
P

PAzYearazzUP

Banned
Dec 12, 2008
33
0
0
Dec 18, 2008
#7
  • Dec 18, 2008
  • #7
2002BLGT said:
anything higher than 12 is not considered safe with a blower
Click to expand...

Bingo! 11.9 Pea Yes Eye dare little blow machine is 10 is overkill is you shoot for the 11'somwhere is BLGT is not blowing lean up yer waste gate.
 

CobraRed_96_GT

Active Member
May 20, 2006
1,421
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39
UCSD/La Jolla
Dec 18, 2008
#8
  • Dec 18, 2008
  • #8
2002BLGT said:
anything higher than 12 is not considered safe with a blower
Click to expand...
I don't have a blower. High compression with heads/cams. I'm saying his blower a/f recommendation is closer to my N/A range - and even still too lean
 

the98stang

Active Member
Aug 12, 2005
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47
Clovis, CA
Dec 18, 2008
#9
  • Dec 18, 2008
  • #9
On a forged motor and boost you can safely tune for 12 flat. On a stock engine I would say no more than 11.8 AFR . Be sure the timing is 16 or below if you are running pump gas...
 

98stangv8

Active Member
Oct 3, 2003
1,036
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36
fayetteville, nc
Dec 18, 2008
#10
  • Dec 18, 2008
  • #10
Cool...around 12 then...I am at 13 now without the blower, just the engine...does that mean I am running lean or rich? Lower the number, the higher or lower the fuel content?
 

CobraRed_96_GT

Active Member
May 20, 2006
1,421
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39
UCSD/La Jolla
Dec 18, 2008
#11
  • Dec 18, 2008
  • #11
98stangv8 said:
Cool...around 12 then...I am at 13 now without the blower, just the engine...does that mean I am running lean or rich? Lower the number, the higher or lower the fuel content?
Click to expand...
Low means rich. 13 is fine stock n/a. Most shoot for 12.9-13.1
 
B

blubullett

Member
Jun 22, 2006
535
6
18
Modesto, CA
Dec 18, 2008
#12
  • Dec 18, 2008
  • #12
Mine is 11.6 to 11.8 and I passed emissions with flying colors (in california too) and my car runs great.
 

squeak93

15 Year Member
Jun 2, 2005
2,277
368
164
Joplin, Missouri
Dec 19, 2008
#13
  • Dec 19, 2008
  • #13
Ignore me.... Posting at work causes dislexia(sp)....



11.5 for a blower..12.0 on a n/a. My counting was backwards for some reason... my bad.
 
2

2002BLGT

Well-Known Member
Dec 18, 2003
2,945
4
59
Bedford VA
Dec 19, 2008
#14
  • Dec 19, 2008
  • #14
98stangv8 said:
Cool...around 12 then...I am at 13 now without the blower, just the engine...does that mean I am running lean or rich? Lower the number, the higher or lower the fuel content?
Click to expand...

whos tuning it ? hopefully not Haywood ?
 

CobraRed_96_GT

Active Member
May 20, 2006
1,421
4
39
UCSD/La Jolla
Dec 19, 2008
#15
  • Dec 19, 2008
  • #15
squeak93 said:
Ignore me.... Posting at work causes dislexia(sp)....



11.5 for a blower..12.0 on a n/a. My counting was backwards for some reason... my bad.
Click to expand...
12.0 is too rich for a N/A 4.6
 

billfisher

Active Member
Jul 17, 2005
1,296
4
38
huntsville, AL
Dec 20, 2008
#16
  • Dec 20, 2008
  • #16
you know, my opinion is"it depends". i noted the factory WOT a/f for the gt500 (11.8).

for my setup, it has the same c/r as the gt500(8.5:1) but i think i am going to risk a bit leaner. but my combustion chambers will have no sharps. and my temps will be cooler than a stock car(160).
 

BK_CAULEY

it's built for speed not longevity, woman
Dec 26, 2006
0
10
49
Thomasville, ga
Dec 20, 2008
#17
  • Dec 20, 2008
  • #17
PAzYearazzUP said:
Bingo! 11.9 Pea Yes Eye dare little blow machine is 10 is overkill is you shoot for the 11'somwhere is BLGT is not blowing lean up yer waste gate.
Click to expand...

what the **** are you babbling about?
 
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