Whipple Install, now Split LTFT, and Lean Split at WOT

[10_SS]

I need some help with cruise and most importantly WOT/PE and LTFT's
I just installed my Whipple kit on my bone stock 2010 Camaro LS3, and installed the stock whipple tune, then copied it out and applied everything to a 2bar OS, with ZR1 sensor.

Everything went great, it feels like it runs perfect and I dont see any knock, no codes, I have not went WOT higher than ~3500rpm since I like to take things slow and make sure they are working. at 3500rpm WOT Im at 153kpa and 1.02 g/cyl... Stock I would be lucky to pull ~0.78g/cyl at max anywhere in the RPM curve so I know the Whipple is working.

From what I see, before entering WOT/PE, Bank 1 and 2 LTFT are split a fair amount (7.8%), and going into WOT this is causing problems, or the other possibility is whatever the problem is causing the split LTFT is carrying over into WOT, causing Bank 1 to be much leaner than Bank 2 at WOT. Below is the info:

At normal driving before Frame 11984 (my WOT split LTFT example):
--------Frame------PE Mode----LTFT------o2 mv
Bank 1--<11984----NO----------~7.8%----Normal swing
Bank 2--<11984----NO----------~0.0%----Normal swing

When I enter PE around frame 11984, the LTFT switch very low, and Bank 1 goes lean but is still much higher (6.3%) than Bank 2 and is very lean:
--------Frame----- PE Mode------LTFT-----o2 mv
Bank 1--=11984-----YES---------~1.6%----100mv (eeek)
Bank 2--=11984-----YES---------~-4.7%---800mv (still lean)

So, I can see I'm still lean any way I look at it, but... why would you think my LTFT are split so bad, or is this normal with the Whipple?

Since I am lean on both banks as it is at WOT... would richening up overall at WOT help bring both O2's up closer to each other (I know 02's aren't great for other than 14.7, but I also know they are somewhat ok to use to see both banks around 800-950's.. far away from 100 and 800mv), keep in mind I would not catch this with a single Wideband and why I like to check NB02's simply to make sure things make sense.

Also what would the best way to increase the tunes overall fueling... add 5% to every MAF table entry as this attached tune is 100% MAF? It seems a bit lean everywhere based on LTFT. This morning they were all ~6-8% adding fuel, later today they are around 3% adding fuel.

Thanks for any help.. this is stumping me!

[FASSTRUK]

You need a wide band afr gauge ASAP...keep out of boost till then.

[DSteck]

I'd bet when you hit boost, it levels out side to side. PD blowers don't exactly have uniform cylinder distribution at very low airflow.

[4evervette]

You need a wide band afr gauge ASAP...keep out of boost till then.

what he said .. you will eliminate the guess work .. and it will save time ..you can hook it in the leaner side if u want ..( even i think its normall to see small variation btween banks ).. you still can add fuel but the question is how much is enough to dial your MAF curve

[10_SS]

I'd bet when you hit boost, it levels out side to side. PD blowers don't exactly have uniform cylinder distribution at very low airflow.

I would agree with that... but I've only taken it to 3500rpm WOT and I am in boost and the NB's don't agree with that... one bank is 100mv, the other is 800mv. I know I need a WB and I have one but that really doesn't help me at this point since now I need a second one (one for each bank), then I have to wonder about the accuracy of them (and the calibration into HPTuners) to rely on accurate bank to bank AFR which.. based my previous projects can be a problem. The NB's are definately accurate enough to tell me if I'm under or over 14.7, and one bank is leaner than that.. and that's just not right and I'm trying to figure out why, and that lean bank also had 7.8% added fuel under normal cruise conditions, and 1.6% at WOT while the good bank was -4% so that's what I'm trying to figure out. It almost seems like a bad or clogged injector, or even vacuum leak but everything installed perfect.

My old car was 700hp LT1 and had a Y-pipe so average WB AFR was easy... also, the NB's always agreed with the WB in the 925-950 range at WOT (both banks) so I trusted it and that setup was perfect.

[DSteck]

Haven't checked on your tune, but it could be way the hell off. 14.65 AFR could be 800mv and 14.72 could be 100mv.

[10_SS]

Haven't checked on your tune, but it could be way the hell off. 14.65 AFR could be 800mv and 14.72 could be 100mv.

Yea it definitely could be. I guess I'll have to move the WB to the lean side, and buy another one for the rich side. I actually dont like WB's! Generally speaking I've noticed if the 02's are over 925 then I'm around 11-12:1AFR so I'll work on that in the mean time.

Looking through the same log I found this where it is lean then goes rich/good for no apparent reason. I will suspect fuel pressure or NB logging error for the time being since the pulsewidths are equal.. it is using the MSD Boost a Pump so I wonder how that's configured or if there's a delay with fuel pressure.

I may also pull another 5 degree's of timing in boost and richen it up quit a bit since either way (NB or WB logging) will have to be WOT to test it.

If anybody has a whipple/supercharged log I can look through feel free to post!

Thanks everybody for the ideas so far

[DSteck]

Yea it definitely could be. I guess I'll have to move the WB to the lean side, and buy another one for the rich side. I actually dont like WB's! Generally speaking I've noticed if the 02's are over 925 then I'm around 11-12:1AFR so I'll work on that in the mean time.

Uhhhhhh... Good luck.

/facepalm

[Ben Charles]

Don't trust your 02's, get a WB on either bank and tune your WOT Hz ranges with it, let your 02's (fuel trims) fix everything outside of PE.

[10_SS]

Yes ok.. I know all about the widebands, I use them. My problem is why is WOT so lean when the commanded AFR is in the low 11's? Lets forget about NB and WB discussion for a bit. :/

My PE table and injector settings are per Whipple, I do have a 2bar OS so I also have a "boost PE vs MAP" table which is all 1.000, but if I increase fuel there won't my commanded AFR just go lower? I don't think 11.0 commanded and 14.7afr actual is right.

[DSteck]

Just becase you're using what they suggest doesn't mean it's right. You can command 11.8 all day, but if your MAF/VE calibration isn't right, it doesn't mean it'll hit it.

[HRD]

If I were you, I would swap all injectors from left to right to see if the lean bank swaps sides. Then swap the O2's left to right to see if that changes anything. Also check closely for exhaust leaks, even at the collector after the O2's. They can make the LTFT's go crazy.

[10_SS]

I may have good news. Since that last pic I posted where the low NB reading went high (to normal), the problem hasnt returned. On the way home today I did a bunch of low rpm WOT runs and not one time did the one bank go lean.

The lean bank was also Bank 1, which is opposite the fuel feed side. I'm willing to bet the large Whipple fuel rails had air trapped in them and were bleeding that air though the injectors on Bank 1 on high flow (WOT). The first few logs I posted that had this problem were the very first WOT I did since the Whipple install is just completed.

It makes sense... and now the problem is gone.. which makes even more sense, and being a returnless (Dead-head) system the air only has one place to go?

Now.. fingers crossed that the problem stays away and I guess I can focus on real tuning with a wideband!

[Ben Charles]

It shows its getting fuel on that WOT, just make sure my friend.

If PE is set to the commanded AFR of your choice, just adjust the MAF so it matches it at a given HZ flow

[10_SS]

Yea, I know I need to WB AFR, I was just really concerned with why the one bank was dropping lean, I am not WOT'ing often I just did at lower RPM a few times right after I got it running and saw this which from my past WB and NB history I know was messed up.

But yea 830mv on a NB is still lean but I will touch up the MAF table as ya'll say to do once I get my WB connected (now will only install on one bank) so I can actually know what my AFR is but they are now consistent and follow each other so I consider it solved... unless it comes back.

I'm thinking the air was trapped at the top of the rails or on the end connector hoses since it has two, one front and one back that connect each rail, then gets pushed down in at higher flow, and since everything's new, it was probably full of air. The first time I started it, it misfired a bit then came to idle ok, then the first time I gassed it I heard a backfire.. then it was fine but then my first few short low RPM WOT run leaned out on the non-fuel supply side only, and air would explain it.

Thanks for all the help I do appreciate it!

[ingsteve]

I think that if you put the wb in you can compare some afr of the wb with the O2 mv readings. Then after you have a comparison table so at least an idea of the mv range to target even without 2 WBs...

[10_SS]

Yea this is what I did on my old car. My WB is in, just need to connect the power wires.

[10_SS]

BTW this is solved. Air in the rails. Now I hate dead end rails for another reason. The WB showed 12.3-11.01 in the same RPM band as tested above consistently on bank 1. So some MAF cal and we should be good to go.

Now I have to move on to relying on the WB for 100% of my WOT fueling cal. And with the NGK AFX single point cal... yes I have trust issues, how do you know 11.2 isnt 13.3? I have an Ave of 14.5AFR WB in my normal cruise histogram where the NB 02's are in control and are assuming 14.67, so pretty close, but it will never be a perfect so is this close enough?

The WB is connected direct to battery with a relay controlling power from the cig lighter, with the NGK ground signal and the HPtuners signal ground both go to batt -. Using DStecks "0.7096 and 9.102" recommendation (thanks DSTeck, once again).

[Throttle]

I had crazy fueling issues when i had dead end rails too!! I switche to the rails being fed from the back by dual lines then two lines feeding the regulator then to a return line.That seriously evened out the fueling.

[DSteck]

BTW this is solved. Air in the rails. Now I hate dead end rails for another reason. The WB showed 12.3-11.01 in the same RPM band as tested above consistently on bank 1. So some MAF cal and we should be good to go.

Now I have to move on to relying on the WB for 100% of my WOT fueling cal. And with the NGK AFX single point cal... yes I have trust issues, how do you know 11.2 isnt 13.3? I have an Ave of 14.5AFR WB in my normal cruise histogram where the NB 02's are in control and are assuming 14.67, so pretty close, but it will never be a perfect so is this close enough?

The WB is connected direct to battery with a relay controlling power from the cig lighter, with the NGK ground signal and the HPtuners signal ground both go to batt -. Using DStecks "0.7096 and 9.102" recommendation (thanks DSTeck, once again).

The NGK goes through a startup sequence where it will spit out 1 lambda for a short period of time. How do you know a piece of crap LC-1 is actually showing 11.2 instead of 13.3? Their products are junk. The AFX is made by ECM... An industry leader. Trust it.