09 Z06 Blown odd behavior at wot on dyno

[HoP]

First off thanks for taking a look.

Here's the run down. Forged LS7 11.0:1 comp, AA supercharger with 3.125 pulley making @ 12psi, AA supercharger cam (do not know the specs), AA redrilled injectors ( supposed to flow 63.5 lb/min @ 43.5).

I doubled the stoich, edited .50 for the injectors. Tuned the VE and she is great all the way to 4400 rpm's.

Tuned the low maf to within 2% and the high maf up to 7,400 hz to within 2% as well.

Under wot you can see from the log the injector dc ramps up 4000 rpm's. At 4,600 It appears that I'm going back into some serious vacuum according to the g/cyl. Any ideas why this is happening? My commanded AFR (11.3:1) is spot on up to 4700 then she starts to lean out. According to the MAF I still have room to grow before it's tapped out.

I've seen this before when the VE at the given rpm range is to high causing the injectors to work to hard to maintain the commanded AFR. The car right now is laying 690 rwhp at 5500 rpm's.

I appreciate your time, thanks.

[MMGT1]

Look at your MAF Output Frequency High bud, your flatlining right where you drop off. Would explain your lean condition I would say.

[HoP]

Look at your MAF Output Frequency High bud, your flatlining right where you drop off. Would explain your lean condition I would say.

I see that it pegs lb/min. So to fix this I would need to upgrade the OS? Apparently this is a carb kit according to the customer and it does have an EO number. I would like to keep the MAF and not run in SD and still have him able to smog the car. Thanks

[IDRIVEAG8GT]

I see that it pegs lb/min. So to fix this I would need to upgrade the OS? Apparently this is a carb kit according to the customer and it does have an EO number. I would like to keep the MAF and not run in SD and still have him able to smog the car. Thanks

You have two options. Upgrade the OS, OR undo the doubling of the stoich and do a manual 50% scale of the ECM. That should give you enough room on the MAF.

[MMGT1]

Yea, that thing pegs at 2200RPM man! Holy hell.... lol

[HoP]

I can safely assume that since the enhancement tab is telling me "not available" that this vehicle needs to go back and get flashed for the most current OS from the dealer?

[HoP]

Scaled the tune by 50%, she runs great just as before. Before the maf would peg 67 lb/min and would be flat lined. Now it does the same thing but at 23.83 lb/min, what gives? When this happens you can see the injector dc starts to go down and the car begins to lean out.

To me it seems that when the maf takes over (dynamic airflow/high rpm disable set at 4,000 rpm) for measured airflow calculations is when this problem is happening. Everything gets goofy right at 4k, pulse width goes down, injector dc stays flat, maf is flat, dynamic airflow goes down. It did the same thing with the original tune as well.

Any thoughts would be greatly appreciated, thanks.

Update : Swapped maf working as intended.

[IDRIVEAG8GT]

Didn't look at the tune but are you tuning via pure MAF? We're on the right track now that you've got some room in the tune.

[HoP]

Didn't look at the tune but are you tuning via pure MAF? We're on the right track now that you've got some room in the tune.

Yeah I was tuning pure MAF. For some reason the electronics in the original MAF went sour. Swapped it out and continued.

With it scaled 50% I still peg the MAF and I still show 1.36 g/cyl in the spark table. It's making upwards of 15 psi at 6,000 rpm's. I run out of pump (the A&A pump) at 5,200 rpm's. Other than that everything is great. It made at 5,200 rpm's 701 rwhp and 674 rwtrq on a superflow.

[DSteck]

Wow, it should not be hitting airflow numbers like that with only 700rwhp. What method did you use to scale it?

[vette_c6]

post your file ,, that might help

[HoP]

post your file ,, that might help

already had it up.

[HoP]

Wow, it should not be hitting airflow numbers like that with only 700rwhp. What method did you use to scale it?

.50 to all tables that needed to be changed. Spark table just copied 1.36 to .68
and adjusted the top of the spark table as needed. The car runs and drives perfect. Just bitch slapping the MAF alot sooner than expected. I may just need to SD this car, just concerned about CA smog tests.

[vette_c6]

there is only 3 Run files

WOT
scale tune
scale WOT ,, all of them are .hpl

[HoP]

there is only 3 Run files

WOT
scale tune
scale WOT ,, all of them are .hpl

I know, I took the tune down after awhile.

[IDRIVEAG8GT]

Freaking balls man. Where is your MAF sensor located in the piping?

[Asylumwarp]

What was the outcome? im having the same problems.

[HoP]

Freaking balls man. Where is your MAF sensor located in the piping?

It's the A&A kit for the LS7. The MAF is in a 3.5 inch tube .

[HoP]

What was the outcome? im having the same problems.

Customer is going to bring the car back so I can install the stealth fuel pump. Then we can test more once I have proper fuel pressure.

[Asylumwarp]

So when you run out of MAF, are you adjusting the PE table to achieve proper a/f ratios above rpms the maf cant read?? We are also in the process of checking fuel pressure on ours now that you seem to have the same problem we do. I just got done scaling the tune, now if FP is good at rpm, hopefully we can get more out of our LS7 MAF, since were in a 4" tube. Id like to stay away from having to command a BS a/f ratio to achieve whats needed. We here in california also deal with smog, so im trying to avoid a SD tune. But its not out of the question, just SD tune it, and leave the MAF in place for visual???

I'd sure like to see a copy of the tune, so i got an idea what im looking at also.. Possible?
I got a thread going with MAF maxxed at 67.735 what next, posting my tune, and my scaled tune, possible you could look it over make sure i did everything correct?