Hitting that 11K HZ wall - 2005 Corvette, A&A Supercharged

[That_guy]

Howdy all. Short version of a long story...

Car: 2005 Corvette A4, bone stock engine, Longtube headers/full exhaust, A&A Blower kit w/ 3.8" pulley

Problem: I'm running this car in MAF only mode (Customer wants car tuned with a MAF), and I'm hitting some sort of invisible rev limiter between 5500-6000. The car is also spiking lean right before this happens as well. I've tried the 15K hz patch, it made no difference. I'll also note that when I hit this invisible wall, the "Service traction control" kicks on. I've tried disabling all TCS functions to no avail.

My assumption is I'm maxing out the MAF and need to switch over to a cartridge style. Is this correct?

PS - If anyone says anything about injector scaling, that is how A&A told me to do it. The injectors they provided are 60lb/3 bar and 72lb/4 bar. The OS won't allow 72lb scaling. Attached is the file. I accidentally closed out my scanner before saving the log but can make another one if needed but getting worried about constantly running this thing up in rpm when it's spiking lean.

Any help / input is greatly appreciated it.

[mowton]

Howdy all. Short version of a long story...

Car: 2005 Corvette A4, bone stock engine, Longtube headers/full exhaust, A&A Blower kit w/ 3.8" pulley

Problem: I'm running this car in MAF only mode (Customer wants car tuned with a MAF), and I'm hitting some sort of invisible rev limiter between 5500-6000. The car is also spiking lean right before this happens as well. I've tried the 15K hz patch, it made no difference. I'll also note that when I hit this invisible wall, the "Service traction control" kicks on. I've tried disabling all TCS functions to no avail.

My assumption is I'm maxing out the MAF and need to switch over to a cartridge style. Is this correct?

PS - If anyone says anything about injector scaling, that is how A&A told me to do it. The injectors they provided are 60lb/3 bar and 72lb/4 bar. The OS won't allow 72lb scaling. Attached is the file. I accidentally closed out my scanner before saving the log but can make another one if needed but getting worried about constantly running this thing up in rpm when it's spiking lean.

Any help / input is greatly appreciated it.

Without a log its tough to say. Per your tune file it shows you have not reached the MAF Airflow limit of 512 until 12,200 HZ (not 11,000 as noted in you post) and injectors are flat lined at the max (63.5). Do you have a MAP/Boost referenced Fuel pump (assume you would have a Boost-a-pump)? Based on the coded hard limits of this ECM, scaling is the only way to create the correct injector data. Normally a setup like this would be like 26% scaling factor. Stating the obvious, all air related tables including grams, g/cyl and torque need to be scaled proportionally.

Post a log and we can help more. Need to understand if you are going lean because of insufficient fueling or have reached the 511 g/sec limit which then says scaling is required. Also assume you are tuning the WOT/Boost area's with a calibrated Wide Band.

Ed M

[That_guy]

Ed, thank you for the help. I would've went and made another log before posting but yesterday was a long day and I was just ready to go home.

I'll make another run / log today and post it up. Thanks again.

[Area47]

valve float perhaps?

[ingsteve]

Service traction control can be caused by maf...try to clean it with a spray and let it dry naturally...repeat three times...and try on the street again

[That_guy]

Just wanted to give a heads up to all those who might run into this problem, an LS7 cartridge style MAF fixed the problem. It was the 05 MAF maxing out on me. I picked up a Spectra housing, couple of couplers and an LS7 MAF. Problem solved for less than $100.

[doc350]

I'm going to assume that you are using the 60 lb/hr injectors that come with the A&A kit.

Firstly, you need to scale the tune for the injectors. When you install injectors that go over the 63 lb/hr limit, the tune needs to be scaled to work properly.

Second, it looks like all you have changed as far as injector data is the IFR. You also need to input data for Offset, Short Pulse Adder, and Min Injector Pulse. Without these being properly filled with proper data your injectors are not functioning as they should, especially at low pulsewidths.

I agree that going to a card style MAF helps a lot of things with the A&A kit, since it tends to peg the MAF even on a stock car, but scaling for the injectors allows them to do what they were designed for and is well worth the effort in my opinion.

[That_guy]

I'm going to assume that you are using the 60 lb/hr injectors that come with the A&A kit.

Firstly, you need to scale the tune for the injectors. When you install injectors that go over the 63 lb/hr limit, the tune needs to be scaled to work properly.

Second, it looks like all you have changed as far as injector data is the IFR. You also need to input data for Offset, Short Pulse Adder, and Min Injector Pulse. Without these being properly filled with proper data your injectors are not functioning as they should, especially at low pulsewidths.

I agree that going to a card style MAF helps a lot of things with the A&A kit, since it tends to peg the MAF even on a stock car, but scaling for the injectors allows them to do what they were designed for and is well worth the effort in my opinion.

I appreciate the info. I was not comfortable with how the injector data was put into the tune either but that's how A&A said to do it. Would you care to elaborate on your information? Or maybe post a tune with the correct injector data?

I would assume that since these are just hogged out factory injectors, not much else would need to be changed accept flow rate?

[That_guy]

I guess that's a no?

Anyone else care to chime in with the correct injector data for a 2005 OS and the A&A supplied injectors?