perfect air:fuel ratio - Zilvia.net Forums | Nissan 240SX (Silvia) and Z (Fairlady) Car Forum

madwilly240 · 03-25-2003, 07:46 AM

I read that 14.7:1 is the perfect air:fuel ratio for gasoline to combust. Do most cars have that ratio? or is that why people get air-fuel controllers.

Foxcolt · 03-25-2003, 08:30 AM

That's good for stock.

BUT once you get into high hp land the correct a/f ratio at full throttle is usually around 12 to 1.

A very talented tuner once told me that if your car isn't pouring out black smoke at full throttle then it's running too lean

d240t2 · 03-25-2003, 10:27 AM

14.7:1 is good for emissions, not for power. Peak power is usually around 12:1 (rich). This is true stock or not.

**Phlip** · 03-25-2003, 04:54 PM

14.7 will also cause a very high temperature with such a lean ratio, I agree with dennis, aim more towards 12, you'll be less prone to detonate with that too.

03-25-2003, 07:46 AM	#1
madwilly240 Zilvia Junkie Join Date: Dec 2002 Location: na Age: 39 Posts: 331 Trader Rating: (0) Feedback Score: 0 reviews	perfect air:fuel ratio I read that 14.7:1 is the perfect air:fuel ratio for gasoline to combust. Do most cars have that ratio? or is that why people get air-fuel controllers.

03-25-2003, 08:30 AM	#2
Foxcolt Zilvia FREAK! Join Date: Apr 2002 Location: Northern VA Posts: 1,264 Trader Rating: (0) Feedback Score: 0 reviews	That's good for stock. BUT once you get into high hp land the correct a/f ratio at full throttle is usually around 12 to 1. A very talented tuner once told me that if your car isn't pouring out black smoke at full throttle then it's running too lean __________________ Driftec www.midatlantic240sx.com

03-25-2003, 04:54 PM	#4
Phlip Yes, I look like that Join Date: Mar 2002 Location: In my supervillain's lair Posts: 27,980 Trader Rating: (19) Rides Gallery: Phlip Feedback Score: 19 reviews	14.7 will also cause a very high temperature with such a lean ratio, I agree with dennis, aim more towards 12, you'll be less prone to detonate with that too. __________________ Weirdo And I write too!

03-25-2003, 10:27 AM	#3
d240t2 Zilvia Member Join Date: Mar 2002 Location: Atlanta, GA Age: 44 Posts: 205 Trader Rating: (0) Feedback Score: 0 reviews	14.7:1 is good for emissions, not for power. Peak power is usually around 12:1 (rich). This is true stock or not.