OP's cam has 6 degree's which isn't all that crazy. 
Bye Bye O2
On The Tree
Joined: Aug 2004
Posts: 104
Likes: 2
From: Central, IL
What would be the best way to setup a hybrid OLMAF? Are you making it so PE is active during idle? Or are you turning off / limiting the STFT's / LTFT's during idle?
Tighten the STFT max correction to what you want. Typically let it pull more fuel if needed and cut down the max add.
Set PE to 14.63 or leaner depending on what you need based on exhaust and cam overlap.
Set PE mode enable to 0% from 0-1200/1600 rpms.
I typically cut the afterstart coolant temp enrichment as well since its really rich from the factory for a cammed car.
OL idle, CL cruise.
Only "issue" I had was IDLE being too lean, since it was commanding a 14.68:1 AFR.
By running Open Loop, and fattening it up to mid 13:1 at idle, I gained almost 2" of vacuum and a smoother, more steady (consistently) idle RPM.
Now, I am running E-85 (using a flex fuel OS and ethanol content sensor) and, for a few months now, an OL-MAF ONLY tune.
Originally, went OL-MAF to tweak the existing tune after converting to flex fuel...
Car is super responsive now and I've actually not even considered re-enabling the VE table, or any ST or LT fuel trims.
The "hybrid" OL IDLE/CL STFT CRUISE fueling question that turbo_bu asked (and ddnspider answered) while I was typing, was something I was also wondering about (and going to ask), so may give it a try.
I've read some people had issues with tuning those. Some don't obviously as well. FWIW, the guy who I am having tune my car asked about what injectors I was going with and recommended against Racetronix and was happy when I said I was using the gm 3800 42# ones. He is the go-to LS tuner for the Twin Cities.
If Pat G tuned the car, then just roll with it. That is one guy who I would never second guess his tuning ability or recommendation. Ignoring the o2's isn't a big deal if that's what it takes to make a particular setup run correctly. I agree with what is being said that you shouldn't have to go that far on a setup like this, but all cars are different. I ran a hybrid tune like DD suggested on my Fbody and it worked well. However on my brothers Fbody I had to disable fuel trims all together and run open loop maf... that setup has a cam motion solid roller with 31 degrees overlap. It absolutely hates fuel correction and likes the AFR in the 13's at idle. #bigcamlyfe
I'm sure somebody will chime in how they made their 50 degree overlap setup run with o2's and drive like stock.
I'm sure somebody will chime in how they made their 50 degree overlap setup run with o2's and drive like stock.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
To me, with the injection and ignition systems LS engines come with, there is no such thing as too much incoming info. That is what sensors provide, ESPECIALLY MAF, MAP, and O2 sensors. Your setup might not be able to use all the info all the time, but it is there for when it can/does. Running without them all the time is just shorting yourself on available and usable info the engine can use at different times. This is especially true for any street driven engine.
BTW, just because some yutz drives his bucking, coughing, wildly loping engine on the street does NOT make it a street engine.
BTW, just because some yutz drives his bucking, coughing, wildly loping engine on the street does NOT make it a street engine.
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Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
All I know is that my O2's kept jacking my tune up, and Patrick deleted them and my car runs like a boss.... 6th gear going 45mph cruising no issues at all. this thing is smooth, engine revs smooth and car pulls really hard and throttle response is way better. I'm working a Shut Down right now so car is mainly getting me to a from work for the next month. I'll throw my wide band AFR in it in a few weeks and I'll be watching AFR. Then hopefully I'll hit the track in early December. All I can say is night and day difference and I don't think Patrick would steer me wrong. I do not doubt the other ways to fix the tune either. I could post the tune file if somebody wants to dissect it, but I feel like I should ask Patrick first before I do that.
I do think this is a good thread though, I found lots of info on tech forums in regard to O2 problems but no one really posted up solutions.... Maybe the 13111 sensors do suck and I should of got NGK..... maybe should of left my stockers in with an extension harness I dunno. But car loves what he did.
I do think this is a good thread though, I found lots of info on tech forums in regard to O2 problems but no one really posted up solutions.... Maybe the 13111 sensors do suck and I should of got NGK..... maybe should of left my stockers in with an extension harness I dunno. But car loves what he did.
I think some people forget this is a almost 20 year car that has been modded. If the car couldnt be tuned with the O2 senors working then most likely it has a wiring issue vs a tuning issue IMO. We have seen ground issues and all kinds of harness issues from years of mods being done and just getting older and alot of miles.
Personally..and this is just my opinion. I think the only reason you would need to run OL with this combo is either bad injector data, shitty injectors to begin with or wiring issue.
Guys like Pat G have enough experience that they know how to "tune around" those issues and still have the car perform like it should. Nothing beats experience.
Guys like Pat G have enough experience that they know how to "tune around" those issues and still have the car perform like it should. Nothing beats experience.
TECH Senior Member
Joined: Jun 2016
Posts: 22,291
Likes: 3,616
From: Central Cal.
Anytime you disable MAF &/or O2's you are forfeiting the flexibility that makes LS engines as good as they can be.
It narrows the scope of performance available when all sensors are on board.
An exception to this is Holley's use of a full-time wide band O2 sensor, which greatly reduces the need for the broad spectrum capabilities of the MAF..
It narrows the scope of performance available when all sensors are on board.
An exception to this is Holley's use of a full-time wide band O2 sensor, which greatly reduces the need for the broad spectrum capabilities of the MAF..
I picked up a gen 4 4.8 pickup this summer and immediately ripped into it. (Cam/Intake/exhaust/stall/gears/posi/nitrous)
I can not for the life of me get this e38 ecm to run CL. Not a big fan of the coefficient system and the virtual VE table thing. Just doesn’t tune like the ls1 pcm.
Anyways it runs far better and fueling far more on using OL. And further more I like the way it runs/drives in OLSD. If I wanted to get particular I could “work around” the OL and use iat for temp correction... but summer is short here and lucky to drive it four times a month during the summer. Weather not to particular different when it’s driven. So OL isn’t really a problem... for me anyway.
I can not for the life of me get this e38 ecm to run CL. Not a big fan of the coefficient system and the virtual VE table thing. Just doesn’t tune like the ls1 pcm.
Anyways it runs far better and fueling far more on using OL. And further more I like the way it runs/drives in OLSD. If I wanted to get particular I could “work around” the OL and use iat for temp correction... but summer is short here and lucky to drive it four times a month during the summer. Weather not to particular different when it’s driven. So OL isn’t really a problem... for me anyway.
Thread Starter
12 Second Club
Joined: Aug 2014
Posts: 205
Likes: 26
From: Houston, Texas
My car runs better in OLMaf, I don't think I have a wiring problem had the engine out in April and went through everything, doubt I have a bad ground either I think that would effect other things besides the O2's. Maybe its just the 13111 Bosch sensors and I should of run NGK or Denso. The car did run fine with my stock AC delco sensors but they were old which is why I changed them when I did the heads/cam swap. Its funny when I originally posted my build thread a lot of people including trick flow recommended running OLSD. BTR also recommended it. But there is a massive amount of data that supports running O2 sensors perhaps there is a gremlin that I missed in the wiring harness. Any how Hopefully this thread will help people down the road and if I fall into an issue with the tune I have now OLmaf I will update this post. As of now car runs great!! Patrick is a great tuner!!
The suggestion about running OL was likely because of the cam overlap and LT's skewing any trims at idle. The hybrid info I posted is simply a way to have your cake and eat it too. Long as its running good and you're enjoying it that's what matters.