LS6 supercharged speed density - reduced power issues despite maxing C6101 table

[ChurchAutoTest]

Hi all, long time user, first time poster.

I working on a 2005 LS6 car punched out to 7 liters and running a Harrop blower setup. We had previously tuned the car up to about 12 psi on the MAF but we were nearing the limits and the customer wanted more power so we converted to speed density using operating system 05120003. I have done speed density conversions before, but this is the first one on a high powered supercharged engine like this (previously torque was in excess of 700 lbs-ft).

After some issues with a faulty cam sensor, we got the car up and running properly on the SD map, but past about 3000 rpm at full throttle we get a hard cut and throttle disable. I've maxxed out the 6101 table, and no codes are being thrown other than some miscellaneous body and traction control items (car is a race car with many items removed), but these were all present on the MAF tune anyways. Car revs cleanly to limiter provided load doesn't get too high.

I suspect that I'm hitting some hard coded limit beyond the 6101 table. During my search here I found a post that mentioned rescaling some VE tables to fix the issue but couldn't find any more details. Can anyone shed some light on this (link or otherwise)? I'm assuming that reduction in VE in boost needs to be done to avoid freaking out the ECU and then recal the injectors to keep fueling appropriate.

I've attached a brief log (frames 485-495 are the relevant points where we went full throttle).

Again, to summarize - reduced power mode, no codes on EFILive Scan but OBD2 reset clears problem, using EFILive 7.5.6.

Thanks in advance.

9940

[louis]

I had similar problems and running a c5 corvette with 1750 hp on my daily driver. I am sure you had to install large injectors and rescaled the injector flow rate. If you did I had to go back to the stock settings, and start over which cured the reduced power mode immediately. I am not sure if you are also using an ls1 style ecu but I also pretty sure there is a limit to (I think it was dyncylair_dma) of 2.4g/s.

When I hit the 2.4 g/s it would auto go lean and nothing I could do about it. Reducing the injector flow rate got me out of that 2.4 g/s wall and it worked fine since then. I did have to redo my fuel and timing maps also.

I hope this helps

[ChurchAutoTest]

Thanks Louis,

We are using 82 lbs/hr injectors, so I did have to recal. I'll try reducing the injector size and reducing the VE simultaneously and see if that helps.

[O1Z06]

Is it a 1 to 1 ratio? If you reduce injector size 20% do you have to rescale VE by 20%?

[louis]

I would use stock injector flow rates to start with. Change B4349 to make up for the difference in throttle body sizes. C6301 map scaler needs to be changed also.

I am not sure injector flow is 1 to 1 reduction in ve due to the fact every car is different but your on the right track assuming the ve has to be changed also.

Let me know how it goes. Its tough finding someone close to the same setup we have