Fox T-Bird/Cougar Forums

Technical => Engine Tech => Topic started by: SR71blackbird on February 28, 2012, 03:59:12 PM

Title: turbo Air/fuel ratio
Post by: SR71blackbird on February 28, 2012, 03:59:12 PM
What should my air fuel ratio be at at idle and at boost? at idle it goes from 14.2 to 15.0 and boost it goes into the 10.0's. is that where it should be?
Title: turbo Air/fuel ratio
Post by: Shadow on February 28, 2012, 04:15:11 PM
sounds like she's relatively close.. what is it at cruising speeds? should be in the 14's
Title: turbo Air/fuel ratio
Post by: TurboCoupe50 on February 28, 2012, 05:03:14 PM
Generally anything less than 11.5-1 is generally considered rich, max power is usually around 12-1, but risk of detonation is greater if you go overboard on the timing or get some py fuel... My Marauder has a "safe" 11.0-1 tune, which is leaving approx 25-30Hp on the table... 

If every thing is "right", idle and no load cruse should be 14.7-1, but most A/F gauges will wonder around a bit, having a fresh o2 sensor usually minimizes this...
Title: turbo Air/fuel ratio
Post by: TOM Renzo on February 28, 2012, 06:07:53 PM
11-1 sounds like a plan!!!!
Title: turbo Air/fuel ratio
Post by: turbotrav on February 29, 2012, 07:54:51 PM
My XR7 always made the best power at 11.5 as previously mentioned.  11.7 if the boost was lower...ie under 20psi.

Travis
Title: turbo Air/fuel ratio
Post by: SLEEPER T-BIRD 87 on February 29, 2012, 08:08:52 PM
.

11.50 is what i tune at for a boosted car in power  but usually 11.7- 12.1 makes better power but isnt as " safe" i like to see high14's low 15's light load cruise  and idle for max economy depending on the camshaft/motor setup

10's at wot is too fat and giving up power and could cause some issues
Title: turbo Air/fuel ratio
Post by: flylear45 on February 29, 2012, 10:08:19 PM
Quote from: TurboCoupe50;382361
Generally anything less than 11.5-1 is generally considered rich, max power is usually around 12-1, but risk of detonation is greater if you go overboard on the timing or get some py fuel... My Marauder has a "safe" 11.0-1 tune, which is leaving approx 25-30Hp on the table... 

If every thing is "right", idle and no load cruse should be 14.7-1, but most A/F gauges will wonder around a bit, having a fresh o2 sensor usually minimizes this...


+1.
Title: turbo Air/fuel ratio
Post by: SR71blackbird on March 06, 2012, 11:18:43 PM
In the morning, for the first 10-15 minutes it is running between 10.9-12.1ish. Is that normal?
Title: turbo Air/fuel ratio
Post by: SLEEPER T-BIRD 87 on March 07, 2012, 07:23:25 PM
Cold start enrichment
Title: turbo Air/fuel ratio
Post by: SR71blackbird on March 07, 2012, 07:45:11 PM
oh okay thank you! Im glad you guys know everything!!