Modded Mustang Forums banner

1 - 16 of 16 Posts

·
Registered
Joined
·
4,366 Posts
Discussion Starter #1 (Edited)
I just installed a wideband a/f gauge and it says that im at about 10.3-10.8 during boost. Is this good? Also what should it read during normal driving? Sometimes it goes up to 17?
 

·
Registered
Joined
·
468 Posts
eh stock cobras are tuned in the 10's from the factory...definately rich, but safe for flogging the hell out of it, but also down on power....cruising should be high 14's (14.7 optimal) but when letting off you will see a lean spike that will max out the guage
 

·
Registered
Joined
·
468 Posts
also, is this 10.3-10.8 during initial boost or is this at peak rpm b/c my car will read 10's at times during initial boosting but will be at high 11's at peak
 

·
Registered
Joined
·
3,719 Posts
also, is this 10.3-10.8 during initial boost or is this at peak rpm b/c my car will read 10's at times during initial boosting but will be at high 11's at peak
you have a safe tune.there is nothing to be concerned with. running 17 to 1 at cruise is highly acceptable,even 22 to 1 at cruise is alright. there might be more power available in the tune(depending on timing) but there's nothing to worry about
 

·
Registered
Joined
·
468 Posts
thats pretty normal, my guage only goes to 16 (autometer wideband) so im not sure where im at as far as that goes...i wouldnt worry about ur setup unless ur looking for more power bc u definately have room to play but like i said before, your tune is great if u want to beat the hell out of ur car
 

·
Registered
Joined
·
468 Posts
what type of induction set-up are you running @ how many pounds and what other mods, also what numbers did u put down? im just curious to see what u put down with those afr numbers
 

·
Registered
Joined
·
4,366 Posts
Discussion Starter #10 (Edited)
It's like 10 psi or so I've been told but my boost gauge isnt working for some reason. It made 393hp/356tq on a vortech with fmic. I also have mac lt/prochamber and magnapacks and t/b and plenum.
 

·
Registered
Joined
·
1,388 Posts
Do you have a dyno sheet of your a/f ratio? Not a fan of the fmic, its just another band aid fix. 10.3 is a very safe tune...but your jumping up to 17 thats past the 14.1 stoich level. Jgorm would be a good person to talk about with your levels. 17+ is going to burn up your motor quick...17 represents the amount of air your getting versus the amount of fuel....you will be running very lean during that time (engine getting very hot)

Without the forged bottom end, you should keep a nice flat range of 11-12
 

·
Registered
Joined
·
4,366 Posts
Discussion Starter #12
The intercooler is a band aid for what? I don't have a dyno sheet for the a/f. It goes past lean and the gauge actually says Lean on the digital display. Only when I'm driving normally though.
 

·
Registered
Joined
·
1,388 Posts
err sorry i was thinking of something else...no the front mount is not a band aid. I was thinking of the thing that was like the MAFia but on the older mustangs.

But yeah you should never be reading that lean.
 

·
mm's nitrous mod
Joined
·
12,988 Posts
17:1 is acceptable for a normal driving or coming down th rpm range. the computer is always changing fuel delivery when not in WOT, there is no way to ever change that. the tune is little to the rich side, but each tune is a little different.
 

·
Registered
Joined
·
468 Posts
wow i cant believe u made that much power with such a rich tune....thats incredible
 

·
Premium Member
Joined
·
4,464 Posts
Its too rich for me. You should see 14.7 at part throttle (steady input). During transitions it may shift lean or rich depending on how accurate your tune is. My guess is that you have a little of the hesitation issue, especially if you are seeing 17 after a shift. (hopefully not more than a second max). It can be tuned out. You should see 20+ on decel when it goes into coasting fuel shutoff. I shoot for 11.5:1 at WOT on blown tunes. Plenty safe but decent power. Getting into the 10s will loose hp, especially in the low 10s.
 
1 - 16 of 16 Posts
Top