3.4L supercharger

No photos. Sorry. Is it an exhaust leak possibly?

 

http://blog.innovatemotorsports.com/how-an-exhaust-leak-affects-wideband-o2-sensor-readings/

are your numbers similar to any of these scenarios?

 

Somewhat

I think you might be right

I’ll take a wrench to ALL the connection points on my headers and see if it changes

Thanks!

 

Are you going wide open throttle when you see it at 14.7?

Reason I ask is because these trucks are well known to have issues with part-throttle enrichment, where you give it 1/2 - 1/3 throttle and get into boost yet you don't see your AFR get richer until about 3 - 5 seconds after you hold the throttle down. If I only give it 1/2 throttle and get a few psi of boost, I have to hold it there for a few seconds before the AFR adapts to the condition. If I go WOT though it's pretty much immediate enrichment.

URD makes an AFR calibrator piggyback or something like that, which is designed to address the very issue - part throttle enrichment. Other ways of dealing with it would be tuning the 7th injector kit to spray earlier, methanol, etc

Also you installed the AFR O2 sensor right before the 1st cat, yes?

 

He and I have the same gauge but different superchargers. Mine the grey unit, his the Magnuson.

Mine supercharger on full throttle is 11.5 with NO lag.

 

Thats what I mean, with full throttle there is no lag. But half throttle there usually is

It's not the supercharger that creates the lag it's the truck's ECU. Part throttle enrichment (not wide open throttle) has always been an issue with these trucks and boost. Go wide open throttle, no problem...go half throttle and it usually takes a few seconds for the AFRs to adjust. Unless you have measures in place to prevent it like most of us do to some extent

 

Just saying that if he's seeing 14.7 on his AFR gauge and only doing 1/2 throttle or 2/3 throttle pulls, then that could be why. But if he's doing a full wide open throttle pull and only seeing 14.7 then something's definitely not right

 

Yes, part throttle is still closed loop, right?

WOT goes into open loop and actually uses the sensors and adjusts things.

 

Yea, with part throttle the ECU is still in closed loop and fights to keep the AFRs at 14.7 until it finally goes into open loop, WOT will put you into open loop right away

 

AFR right before first cat

I do see a change in AFR after a time (not sure how long) in WOT, AFR drops and you can feel the acceleration jump.

 

Maybe it’s my Automatic Transmission causing the problem

Y’all have manuals

 

I'm leaning towards this being normal, what you're experiencing...though without being in the truck with you it's hard to say for sure. But the ECU will always fight to keep AFRs at or as close to 14.7 as possible unless you go into open loop, which usually happens quickly with WOT

 

Interesting

I don’t understand why these others guy don’t have this problem though

 

A lot of them are running fuel mods (methanol, 7th injector, AFR calibrators, etc.) to richen up AFRs in boost

 

I’m running methanol

Just turned in on

It started spraying and nothing...no drop in AFR

I’m going to take the nozzle back off and double check that is still spraying, but past that, it make no sense that it’s not dropping the AFR unless the ECU is cutting back fuel as methanol is spraying

 

Hmm interesting, didn't know you were running meth. Ya something's up then, either with the meth not spraying when it should be or something else. I would start there with checking the meth system

 

Anyone aware of any thanks giving sales for an SC kit?
Not from last year, for this year.

 

Haven't heard of anything yet but Magnuson usually does the Black Friday deals on the 3.4l supercharger package, I would keep an eye out for that coming up soon

 

Yup. You’re right about that. I’ve skipped that jazz and just full throttle when I want to go.