Dyno Results
I took my Holley 390 280Z to the Dyno last week. I rebuilt the engine about 4 years ago but never had the time to get to the dyno - life got in the way. A quick summary of my Z:
1977 280Z
274/274 Cam, performance springs
Flat top pistons, ~10:1 compression
Arizona Z cars 4bbl intake and 6-1 headers
2.5 inch exhaust, straight through muffler
Holley 390, 47 main jets, 7.5" power valve, metering plate secondaries, short white spring on the secondaries
Running 100LL
Summary of the dyno run: way too rich at WOT. I'm running about 10.5:1 A/F. Even with that I'm pushing 155HP/162ft-lbs at the wheels. I'm happy. I've got a metering block on order for the secondaries. The plate is equivalent to 53 jets, we believe that putting in 47 or 49 jets in the secondary will bring up the A/F ratio and give me even more power. Once I get the carb reconfigured I'll be going back to the dyno.
The 4bbl setup works VERY well!
Here's the run: