Chalky

iTrader: (2)

A friend with a stock C6 LS3 M6 dyno'd in November. It put down 366 RWHP on a DynoJet. the WB showed a AFR of mid 10's. Car was warm from the drive and air temp was in 40's.

He was expecting better HP and a leaner AFR. Fuel was 93 octane non-RFG and a a quart of Torco in for good measure.

LS1curious

First culprit I would suspect is Cat ovetemp protection.

Chalky

iTrader: (2)

That was my, first thought as well. I can't rule it out. we did two runs back to back with minimal cool down but COT has a max enrichment of 12.14:1

Ragtop 99

iTrader: (7)

I've seen a lot of people post up very rich LS3 stock dynos. Most have had good results from leaning them out a bit.