Air/Fuel Sweet Spot?

TDS · 04-11-2018, 11:38 PM

Was wondering where the Air/Fuel ratios should be on the LT4. I am sure this has been covered but didn't show up on a search. Mine is slightly modified with headers, ported TB, intake and 9.10 lower. Seems to be running a little rich and want to know where I should be so I bought a wideband and gauge. Want to make sure the tuner did not go to rich before I and some meth to the mix. Any info is greatly appreciated. Defiantly still in the learning stage.

Stephen12ZL1 · 04-12-2018, 06:09 PM

No one can answer this as it can vary. My previous ZL1 liked 10.8-11.0.

TDS · 04-12-2018, 09:50 PM

Quote:

Originally Posted by Stephen12ZL1

No one can answer this as it can vary. My previous ZL1 liked 10.8-11.0.

Thanks for the response. I figured it would very car to car mod to mod. I was just hoping to get a safe range target for WOT

JamesNoBrakes · 04-12-2018, 11:33 PM

Quote:

Originally Posted by TDS

Thanks for the response. I figured it would very car to car mod to mod. I was just hoping to get a safe range target for WOT

I've modded turbo cars and many of those use some pretty amazingly rich ratios, to ram fuel down there and cool everything off under boost and acceleration. This was designed into the cars I modded and screwing with it can have real bad consequences.

rjacobs · 04-13-2018, 09:08 AM

11:1 is typical for forced induction cars... MAYBE slightly richer, but not by much.

Ryephile · 04-13-2018, 09:20 AM

Quote:

Originally Posted by rjacobs

11:1 is typical for forced induction cars... MAYBE slightly richer, but not by much.

For port injection, sure 0.75 to 0.8 lambda is rational for typical chemical quench. GDI changes the game for target lambda as the inherent chemical quench is significantly higher. As such over-rich that was common with port injection is often not relevant.

Look at what a stock LT4 runs for WOT lambda, and emulate that.

TDS · 04-13-2018, 09:29 AM

Quote:

Originally Posted by rjacobs

11:1 is typical for forced induction cars... MAYBE slightly richer, but not by much.

Quote:

Originally Posted by Ryephile

For port injection, sure 0.75 to 0.8 lambda is rational for typical chemical quench. GDI changes the game for target lambda as the inherent chemical quench is significantly higher. As such over-rich that was common with port injection is often not relevant.

Look at what a stock LT4 runs for WOT lambda, and emulate that.

Thank you for your responses.

Boost or bust · 04-13-2018, 09:45 AM

Quote:

Originally Posted by Ryephile

For port injection, sure 0.75 to 0.8 lambda is rational for typical chemical quench. GDI changes the game for target lambda as the inherent chemical quench is significantly higher. As such over-rich that was common with port injection is often not relevant.

Look at what a stock LT4 runs for WOT lambda, and emulate that.

Anybody know what the stock a/f Target is?

Buzzmanb12 · 04-13-2018, 10:37 AM

I watched a Weapon X dyno day video of a stock ZL1...
AFR was 10.4 at very beginning of the pull and slowly went to 11.0 at redline.

Buzz

NicD · 04-13-2018, 10:50 AM

Stock a/f doesn't mean anything since cat overtemp jumps in to ruin the fun pretty quickly. On the LT4 I personally would be shooting for a low 12 a/f ratio for stock/bolt on applications.

04-11-2018, 11:38 PM	#1
TDS Drives: 2019 Jeep Rubicon Sold:2017 ZL1 A10 Join Date: Feb 2017 Location: Scappoose, OR Posts: 560	Air/Fuel Sweet Spot? Was wondering where the Air/Fuel ratios should be on the LT4. I am sure this has been covered but didn't show up on a search. Mine is slightly modified with headers, ported TB, intake and 9.10 lower. Seems to be running a little rich and want to know where I should be so I bought a wideband and gauge. Want to make sure the tuner did not go to rich before I and some meth to the mix. Any info is greatly appreciated. Defiantly still in the learning stage. __________________ Travis SOLD ZL1 Summit White, A10, Black Strip, PDR, ZL1 floor mats Ordered 2/11, 2000 2/14, 3000 2/20, 3100 2/24, 3300 3/7, 3400 3/8, 4300 3/16, 4B00 3/21 Bayed at train yard in Ohio, 4200 3/26 All Abroad for the West Coast, 4800 4/4 Deliverd to portland train yard, 5000 4/7 3:00AM Deliverd to Dealer, 6000 4/7 6:45PM Delivered to Customer

04-12-2018, 06:09 PM	#2
Stephen12ZL1 Drives: '21 ZLE A10 Join Date: May 2012 Location: Mechanicsville, VA Posts: 6,808	No one can answer this as it can vary. My previous ZL1 liked 10.8-11.0. __________________ '21 ZLE A10 Wild Cherry PDR 2:00.78 VIR Full 10.68@131.69 1.68 60' '17 ZL1 A10 Mosaic Black PDR/Nav 2:03.08 VIR Full 11.003@129.2 1.75 (sold) '15 Z/28 #325 Black a/c & stereo. 2:10.1 VIR Full (sold) '12 ZL1 A6 Black 10.52@131 1.55 60' 2:13 VIR Full (sold)

04-13-2018, 10:50 AM	#10
NicD Drives: Camaro Join Date: Mar 2017 Location: Phoenix, AZ Posts: 157	Stock a/f doesn't mean anything since cat overtemp jumps in to ruin the fun pretty quickly. On the LT4 I personally would be shooting for a low 12 a/f ratio for stock/bolt on applications. __________________ 19 ZR1 \| 16 Viper GT \| 09 Z06 \| 94 LS1 GT \| 16 Denali \| 19 CTS http://www.gonicd.com

04-13-2018, 09:08 AM	#5
rjacobs Drives: none Join Date: Nov 2012 Location: Dallas, tX Posts: 248	11:1 is typical for forced induction cars... MAYBE slightly richer, but not by much.

04-13-2018, 10:37 AM	#9
Buzzmanb12 Drives: '17 ZL1 Join Date: Jan 2018 Location: Bama Posts: 99	I watched a Weapon X dyno day video of a stock ZL1... AFR was 10.4 at very beginning of the pull and slowly went to 11.0 at redline. Buzz

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