I live at 5280 feet elevation, since there is less air up here, will I want a lower setting on my AFPR (like 47psi) so it doesn't run too rich.

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1987 Chevy Camaro IROC-Z
L98 TPI 350 (5.7L)
TH 700R-4 Transmission with 2.77:1 Rear End

Current Mods: Edelbrock TES 1 5/8" Headers, Hooker Aerochamber Cat-Back System, Performance Resource Chip with 160* Thermostat, Accel Ignition Components, K&N Filters, All Free Mods, Falken ZIEX Z-Rated Tires.

Best ET : 14.3 @ 97mph
(corrected for elevation)

 

definatly. 305 or 350? my 305 responds best at 46-48 psi at standard elevation. stock setting with mild mods should be all you need. try one setting that feels good, then monitor performance over about a week. if falls off then lower it until you get it back, then burn up a set of new eagles. stock is anywhere between 42-46psi.

 

350. try 46 as a baseline.

 

I say drop down to 19lb/hr injectors with higher fuel pressure. i bet that would give you a killer combo at a higher elevation. better atomization since less air density.

 

I agree with Scotty on using a 46/47 starting point for AFPR....most people get excited and set it too high. The AFPR mod on a stock engine is mainly to correct a weak factory setting. Otherwise it would take some pretty serious intake/exhaust mods to "need" an AFPR. You seem to be somewhere in between...with your mods.

What I can't see is how altitude or air density has any relation to AFPR. The AFPR will affect the atomization of the fuel from the tips of the injectors and your ideal setting would be to produce a vapor or cloud as opposed to a "squirt".

Your air to fuel ratio, which on a carburated car would be greatly affected and require possibly a jet swap due to altitude is not the case on a fuel injected car which is automatically adjusted by the MAF as well as other components.

BUT....as always....you can correct me if I'm wrong.