[Formulajones]

All good suggestions from Scott.

I don't remember if you mentioned what this combo is but I find anything with a decent camshaft doesn't generally like idling that lean (14.9)

Exhaust leaks anywhere before the 02 can skew those numbers and make tuning a bit more difficult. And Scott is correct, on both of our Snipers I had to go in and manually tune the idle areas to get it where I consider acceptable. The self tuning will get you close if you command a reasonable AFR for the combo, but I found it could be better manually tuning in more precise increments and smoothing the fuel table.

You'll have to experiment with the idle AFR your engine likes by watching MAP (vacuum) Lower Map is higher vacuum and that's generally what you'll be trying to accomplish. Assuming the timing is dialed in, you'll have to move the idle AFR around to find what works best.

On ours, My 454 for instance with a 242/248 camshaft on a 110 LSA, and an RPM air gap intake and using a spacer, it tends to like about 14.2 on the Sniper AFR, which actually reads about 13.7 on my other AFR gauge. This gives me a MAP reading around 62-65. If I lean it out more it gets worse (number goes higher) and the engine isn't quite as happy.

Dad's 571 with a 261/265 cam on a 112 LSA seems to like about the same oddly enough, and idles with a 14.2 AFR at it's best MAP readings of about 65-67.


This is assuming you can get the car warmed up and set the TPS correctly.