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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

what is a good afr for an HCI car?

  • Thread starter Thread starter grey5.0beast
  • Start date Start date Apr 21, 2008

grey5.0beast

Cookies should never be DUNKED!!!
Aug 3, 2004
0
1
0
atl ga
Apr 21, 2008
#1
  • Apr 21, 2008
  • #1
I tried searching but I didn't get much. What is a good AFR for an HCI car. It was flat at 12.9 all the way across but the tuner said it could make more power running around 12.1. Yall agree? If so I'll bump the FP and timing tomorrow to see how the car reacts.
 

mrmustangman357

Member
Feb 11, 2007
763
3
18
Apr 22, 2008
#2
  • Apr 22, 2008
  • #2
at cruise 13.4-14:2:1
WOT 12.5:1
getting on it in spirited acceleration 13:1

your fuel mileage is really suffering if you want to run around town at cruise on 12:1 WAY RICH
 

mustangfan1990

New Member
Jul 17, 2005
505
1
0
Lenoir, North Carolina
Apr 22, 2008
#3
  • Apr 22, 2008
  • #3
yeah 12.1 is way to ich on a NA car. I bought afr 185cc for my car when it was a HCI engine and to be honest the heads are to big for a 302. A 302 doesnt really flow enough air to reach the HP levels those heads are capable of producing. If you plan turbo/ supercharger then 185cc work great. If you just want to stay NA I would go 165cc heads
 
8

86bluecobra

Advanced Member
Dec 20, 2004
4,265
12
69
B.C. Canada
Apr 22, 2008
#4
  • Apr 22, 2008
  • #4
I would have thought you were right where you wanted to be.
 

strtrcr50

New Member
Jun 21, 2006
0
4
0
Previously from Dirty Jerzey exit 7a
Apr 22, 2008
#5
  • Apr 22, 2008
  • #5
86bluecobra said:
I would have thought you were right where you wanted to be.
Click to expand...
+1 I think you are right where you want to be for a full throttle pull.
 

mrmustangman357

Member
Feb 11, 2007
763
3
18
Apr 22, 2008
#6
  • Apr 22, 2008
  • #6
yea at wide open. at cruise with no load on the brake applied, you were still running 12:9:1?
 
3

347HO

Member
Jan 13, 2008
462
2
16
Seattle
Apr 22, 2008
#7
  • Apr 22, 2008
  • #7
12.9 across the rpm band is an accomplishment!
In my experience I've never seen a single pull on an engine dyno nor a chassis dyno where it was that "controlled".

+3 IMO you are good to go right where you are. I also would expect you to gain a few more at 12.0 and some more advance IF you're not already there.

When do you have all the advance "in" at? and how much is it?

Post up your run sheet, it would make it easier than asking/answering back and forth.
 

grey5.0beast

Cookies should never be DUNKED!!!
Aug 3, 2004
0
1
0
atl ga
Apr 22, 2008
#8
  • Apr 22, 2008
  • #8


 
3

347HO

Member
Jan 13, 2008
462
2
16
Seattle
Apr 22, 2008
#9
  • Apr 22, 2008
  • #9
I'm used to seeing the basic tune setup on the run sheet. My bad for assuming there would be the timing, fuel pressure, egt, cht and what not on it.

I do see one serious issue you have.
See how your power and torque band get erratic from 5200 to 6000? That IMO and I'm pretty sure I'm correct is... valve train instability. If I were in your position, that's what I'd be concerned with because it definitely isn't your A/F ratio.

Good luck
 

BlooDReigN

Member
Feb 22, 2004
283
1
16
Calgary, Alberta
Apr 22, 2008
#10
  • Apr 22, 2008
  • #10
Most of you guys are crazy! 13:1 is a great AFR for an N/A motor going WOT. Unless you are getting detonation, going richer will just cause you to lose power.
 

The O.G.

Member
May 28, 2007
145
0
16
witch city,mass
Apr 23, 2008
#11
  • Apr 23, 2008
  • #11
i have a sct switch flip

it has a few ratios

it pulls well at 12.8, i have one at 12.5 it doesnt pull as hard ,or clean
 
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