Reduced Engine Power - C5 Corvette LS3 (416) with LS2 TB

[Track Addict]

Hi all,
Newbie here. I have an Corvette C5 that recently was upgraded as follows:
- LS3 stroked to 416
- LS2 TB
- FAST 102 mm intake manifold
- MSD coils
- LS2 injectors

At the track, the car intermittently goes into reduced engine power with no consistency of when. Two times low rpm rolling into the throttle in 3rd, once under breaking maybe during the 4-3 blip, three times under hard acceleration, high rpm in 3rd. Five of the six times - no codes. The most recent time (high rpm in 3rd) it threw P1516. It may be my imagination, but I believe this is temperature related. I did three days at the track without issue (mid 70s to low 80s, short track sessions), then in 91F it happened twice once on lap 8, then lap 7. Did another whole weekend without issues (mid-70s). All other times have been mid to upper 80s after 12 laps, 11 laps, 14 laps and 6 laps (91F).

I've checked all the grounds, wire resistance, TPS and reference voltages, etc.

My tune attached. This tune is targeted at about 410 rwhp average. I have zero experience tuning and the shop that did my tune is not local. I did note the ETC scalar is still stock as is the cylinder volume and the Desired Throttle Position table has been changed from stock. No idea if any of those may cause intermittent REP. Unfortunately, I didn't have HP Tuners for any of the track sessions and have no on track scans.

Thanks for any suggestions anyone has!

[Lakegoat]

Yes, you need to change the cylinder volume and etc scalar. You will have to retune the maf and ve table. Also, look in DTC's and make P0103 --MIL on second error, instead of first error. Make sure you injector data is correct.

[Track Addict]

Thanks for the reply Lakegoat. Do you believe any of those issues could cause the reducted engine power I am intermittently getting?

[Pekka_Perkeles]

Thanks for the reply Lakegoat. Do you believe any of those issues could cause the reducted engine power I am intermittently getting?

Limit your Airflow/Electronic Throttle/Max Rotation/vs Pedal to around 97% or so.

[Track Addict]

Thanks for the tip. I had read that tip on other related threads and will make that change, thanks.