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I am trying to help a guy on another forum to get his holley to run right. He is telling me he's is running this wide band with an O2 sensor. I'm not familiar with it but the guy is all hung up on what it is telling him his A/F ratios are. Get this....he is running 72 primary jets and 66 in the back!!! He is telling me it's running rich at WOT!!! lol
 

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I am trying to help a guy on another forum to get his holley to run right. He is telling me he's is running this wide band with an O2 sensor. I'm not familiar with it but the guy is all hung up on what it is telling him his A/F ratios are. Get this....he is running 72 primary jets and 66 in the back!!! He is telling me it's running rich at WOT!!! lol
I love my wideband aem..:thumbsup:.
Whats is this guys a/f ratio at wot?
Perhaps he has a power valve in the secondary block and someone hogged out the pv channel restrictors and then attempted to lean out with a smaller jet size to compensate.
 

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Whats his version of rich at wot??
Not trying to high jack this thread but im still getting this thing dialed in and i love this tool.

Hey George out of curiosity,
I have an Innovate AFR meter and at idle it is 14-14.5 at cruise its at 13's to 14 and at WOT if i can hold it that long it goes from smashing the throttle at 10.8 and at about 6,000rpms it leans out to 13.2.....

Some times when i see a lean spike it hits 16.0 but thats at low RPM and when i get that hesitation when im releasing the clutch. I think its my accelerator pump.
 

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Not trying to high jack this thread but im still getting this thing dialed in and i love this tool.

Hey George out of curiosity,
I have an Innovate AFR meter and at idle it is 14-14.5 at cruise its at 13's to 14 and at WOT if i can hold it that long it goes from smashing the throttle at 10.8 and at about 6,000rpms it leans out to 13.2.....

Some times when i see a lean spike it hits 16.0 but thats at low RPM and when i get that hesitation when im releasing the clutch. I think its my accelerator pump.
Skip..you have a big cam in a daily driver..not really low rpm friendly.
You have enough pump shot.Your #,s look good aside from your wot a/f.
Naturally aspirated ..I would shoot for 12.5/1 af ratio at wot.
 

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Skip..you have a big cam in a daily driver..not really low rpm friendly.
You have enough pump shot.Your #,s look good aside from your wot a/f.
Naturally aspirated ..I would shoot for 12.5/1 af ratio at wot.
Thank you George, im still trying to get full throttle its about 90% fully opened... I may make a call to Patrick to pick his brain again on that WOT and my hesitation that spikes up to 16.0 when im releasing the clutch. The WOT may be closer to 12.8 but heck its kinda hard watching it when your at 120mph.... My primaries are 84 and my secondaries are 92 its flowing 972cfm on a 4150 holly 1000hp.
 

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Thank you George, im still trying to get full throttle its about 90% fully opened... I may make a call to Patrick to pick his brain again on that WOT and my hesitation that spikes up to 16.0 when im releasing the clutch. The WOT may be closer to 12.8 but heck its kinda hard watching it when your at 120mph.... My primaries are 84 and my secondaries are 92 its flowing 972cfm on a 4150 holly 1000hp.

Could the hesitations be the transition from primary accell pump shot and the power valve taking over? PV kicking in too late?
 

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At low rpm with a big cam/minimal intake vacuum and limited signal to the carb..the main ckt is not engaged until there is sufficient pressure drop in the boosters to start the syphoning effect.With no flow from the main well thru the boosters..opening the power valve sooner will increase main well head pressure perhaps..but will not enrichen until flow is initiated.
 

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At low rpm with a big cam/minimal intake vacuum and limited signal to the carb..the main ckt is not engaged until there is sufficient pressure drop in the boosters to start the syphoning effect.With no flow from the main well thru the boosters..opening the power valve sooner will increase main well head pressure perhaps..but will not enrichen until flow is initiated.
George i have about 10-12" of vacuum at 900rpm's what can i do to richen up this lean stumble at about 1300rpm's as i am releasing the clutch... At least i know now its a lean stumble/hesitation..
 

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I am trying to help a guy on another forum to get his holley to run right. He is telling me he's is running this wide band with an O2 sensor. I'm not familiar with it but the guy is all hung up on what it is telling him his A/F ratios are. Get this....he is running 72 primary jets and 66 in the back!!! He is telling me it's running rich at WOT!!! lol
Have you heared anything from your buddy.
 

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George i have about 10-12" of vacuum at 900rpm's what can i do to richen up this lean stumble at about 1300rpm's as i am releasing the clutch... At least i know now its a lean stumble/hesitation..
Skip..its vehicle specific and no one can tell you with any accuracy.You are not on the main ckt at 1300 rpm with your application.Rule that out.
You idle on the curb port and rely on the ifr,s/low speed air bleeds and a pump shot to transistion smoothly to the main ckt.Which one is giving you the fits??You may not like me for this..but I bet it is all in your left leg.That roller big block is just not happy at low rpm and will require you to slide the clutch out off the traffic light and keep the revs up.
 

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Skip..its vehicle specific and no one can tell you with any accuracy.You are not on the main ckt at 1300 rpm with your application.Rule that out.
You idle on the curb port and rely on the ifr,s/low speed air bleeds and a pump shot to transistion smoothly to the main ckt.Which one is giving you the fits??You may not like me for this..but I bet it is all in your left leg.That roller big block is just not happy at low rpm and will require you to slide the clutch out off the traffic light and keep the revs up.
Yeah you are correct about the clutch, i even rolled the clutch in and back out with the rpm's rising and it helps (because i could watch my Innovate AFR meter and when i see it starting to lean out i can give it more fuel or double clutch it so it smooths out.. But i know it can be better because at one time i almost got reed of the stumble. I guess i need to keep playing with it and maybe the air bleeds going from 76 to 84 might be to much.
 

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Discussion Starter #15
Have you heared anything from your buddy.
I've been trying to type for an hour but you hijacked the thread ya cyber terrorist!!! lol :p

It's late enough that the East Coast is in bed I think. Maybe he doesn't like the fact that I said when all else fails....read those plugs!!!

Just how accurate are those A/F sensors? Is there a % margin of error? Do you put the sensor in the collector?
 

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Just how accurate are those A/F sensors? Is there a % margin of error? Do you put the sensor in the collector?

They are extremely accurate and are used by dyno tuners as one of their main tools. I would friggin' love to have one in my console pod but the AutoMeter one that matches the rest of the gauges cost more than every other gauge in the car put together. So, I had to settle for the narrowband one that just has a lean/stoich/rich indicator.

Yup, you put it as close as you can get it to the head while still getting a feed from multiple cylinders.
 

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I've been trying to type for an hour but you hijacked the thread ya cyber terrorist!!! lol :p

It's late enough that the East Coast is in bed I think. Maybe he doesn't like the fact that I said when all else fails....read those plugs!!!

Just how accurate are those A/F sensors? Is there a % margin of error? Do you put the sensor in the collector?
Heres my Innovate AFR meter and yes i have bong welded in 1" past the collector for the O-2 sensor and at 1-O'Clock position on the driver side .Sorry about the high jack...lol

 

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I got lucky Stewart Warner makes a nice A/F gauge to suppliment my Fast A/F meter (which I'll probably stick in the glove box). Going to put that gauge on my console along with the rest of the tuning type gauges (ignore the volts had to stick that someplace :) ):



so I can eyeball the A/F ration from a normal gauge and if I need more data can look at the Fast display in the glovebox.
 

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I've been trying to type for an hour but you hijacked the thread ya cyber terrorist!!! lol :p

It's late enough that the East Coast is in bed I think. Maybe he doesn't like the fact that I said when all else fails....read those plugs!!!

Just how accurate are those A/F sensors? Is there a % margin of error? Do you put the sensor in the collector?
The heated widebands are so close to real time..even the engine could care less.We are talking maybe a variance of 1/10th of one point.Example.14.7/1 and as read 14.6/14.8/1.
The sensor should not be closer than 18 inches to an exhaust port or it will overheat and fail.
its best to have the 02 sample the entire bank..not just one primary pipe.
I have mine located just behind the reducer fwiw.Oem applications do fine with narrow bands..the controller is always striving for stoich for emissions.They do not have a big window like a wideband.
 
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