Help optimizing my setup
03-01-2016, 01:20 PM
#1
Help optimizing my setup Hi all,
Ive made a couple of posts on here now about my setup. Cliff notes is:
SBE 5.3 (ARP 2000 Bolts)
BTR Stage 4 NA Cam
243 heads cut .030" right about 10:1 cr
Edelbrock Victor JR intake
Demon 850 carb with annulars Carb is jetted 83/96.
MSD 6012 box
NOS Cheater plate system jetted .063N .057F
Engine is in a Jet Boat
I have an AEM Wideband gauge/sensor, and currently running BR6EF plugs gapped at .030.
Engine runs very well, revs good clean and strong. Im currently running 30 degrees of timing and mixed fuel (113/91)
The nitrous hits hard and runs cleanly as long as i stay on the button.
Plugs look great, no speckling and they dont look rich either.
My question has to do with AFR ratios.
With my Carb jetting where it is, my air fuels read on the "rich side". But leaning it out and the thing starts to lose RPM/power.
My cruise rpm AFR is around the 11.5 or so range now, and on the bottle its right about the same.
If i lean the carb out to where the air fuels "read" in the 12.5-13.0 range i loose wide open RPM and it becomes somewhat sluggish.
Is it possible, the gauge is misreading because of the Leaded fuel? Or is this thing really that thirsty? Should i just live off of the plug reading, and use the AFR gauge as a guide line?
Lastly, Timing. Im currently running 30 degrees total. No signs of detonation on the plugs, and from what i can tell no detonation when on the bottle.
I do have a retard switch that drops 6 degrees of timing when activated, mainly on the bottle. Last trip out i forgot to retard the timing before a nitrous run. I gained about 4 mph and the nitrous seemed to pull harder than previously. Once i got off the bottle i remembered i never retarded the timing.
Pulled multiple plugs, and again no speckling or signs of detonation. Is this possibly to much timing? Or since my coolant temps are so much cooler (maybe 150 on a hot day) its allowing me to burn the extra timing?
I hope this makes sense.
Ive made a couple of posts on here now about my setup. Cliff notes is:
SBE 5.3 (ARP 2000 Bolts)
BTR Stage 4 NA Cam
243 heads cut .030" right about 10:1 cr
Edelbrock Victor JR intake
Demon 850 carb with annulars Carb is jetted 83/96.
MSD 6012 box
NOS Cheater plate system jetted .063N .057F
Engine is in a Jet Boat
I have an AEM Wideband gauge/sensor, and currently running BR6EF plugs gapped at .030.
Engine runs very well, revs good clean and strong. Im currently running 30 degrees of timing and mixed fuel (113/91)
The nitrous hits hard and runs cleanly as long as i stay on the button.
Plugs look great, no speckling and they dont look rich either.
My question has to do with AFR ratios.
With my Carb jetting where it is, my air fuels read on the "rich side". But leaning it out and the thing starts to lose RPM/power.
My cruise rpm AFR is around the 11.5 or so range now, and on the bottle its right about the same.
If i lean the carb out to where the air fuels "read" in the 12.5-13.0 range i loose wide open RPM and it becomes somewhat sluggish.
Is it possible, the gauge is misreading because of the Leaded fuel? Or is this thing really that thirsty? Should i just live off of the plug reading, and use the AFR gauge as a guide line?
Lastly, Timing. Im currently running 30 degrees total. No signs of detonation on the plugs, and from what i can tell no detonation when on the bottle.
I do have a retard switch that drops 6 degrees of timing when activated, mainly on the bottle. Last trip out i forgot to retard the timing before a nitrous run. I gained about 4 mph and the nitrous seemed to pull harder than previously. Once i got off the bottle i remembered i never retarded the timing.
Pulled multiple plugs, and again no speckling or signs of detonation. Is this possibly to much timing? Or since my coolant temps are so much cooler (maybe 150 on a hot day) its allowing me to burn the extra timing?
I hope this makes sense.
03-01-2016, 01:55 PM
#2
TECH Enthusiast
Engines vary on what they like with afr and timing. Go where its safe and makes hp, for me usually richer and least amount of timing.
Did you reduce timung when you leaned it out?
Did you reduce timung when you leaned it out?