I went to the Vette Fun Fest at Effingham yesterday - first time for everything. It was impressive. Was invited to caravan down w/ a local Vette club - mostly C5s, but a few C6s and a C6 Z06 as well...Oh...and one gorgeous(!) ZR-1!!
It rained on the way down, and on the way back. But, at least for the daylight hours on Saturday, it was perfect. But, I digress...
I have wanted to baseline my Z before beginning my winter projects. Far as I know, it has new injectors and a Borla catback and stock chip. So, I was a little surprised at the better than expected runs.
Not surprising, the pulls got stronger with each successive run, ending at 339.0 hp/336.8tq - the ECM was "learning". Extrapolating by 15% for a manual transmission, etc, the fwhp would be in the "hood" of 399 for the top pull - not a bad starting place.
What is a concern is the air/fuel trace confirmed what I saw on the plugs a few months ago: Lean. I'll want to check my fuel pressure and perhaps inspect/change the sock and FF too. That said, I see the air/fuel ratio graph flattens out above 5k, which would not be the case if leaning out was purely due to pressure drop across a dirty filter. It appears (to me) the catback was probably installed w/o subsequent (necessary) retuning. What say U?
(Note: The "throttle man" did not know my tac reads high, as so he shut it down when it read 7k. It appears he captured the peak hp, but I would like to have seen the rest of the graph too. And, b/c I pulled the plugs some time ago, after a few 7k runs and the plugs looked "lean", I had them run the air/fuel track as well. (See below))
Although it was was human error to cut it off just above 6k, I was very pleased with the torque curve's flateness. Gotta love these LT5s!
Penny for your thoughts!
P.