Hi altitude performance changes

[dgoetz]

Is there anything I can do to improve the engine performance in a 04 ZO6 running in SS class between 5000 - 6000 ft elevation? I have already installed an K&N stock rpl filter. Will an engine programer be a worth while investment and what would I change if I did have one?

[RocketSled]

Probably not. A good tune is always worth a shot, but your fundamental problem is lower air pressure/density. Less air is less air, and power is proportional to air and fuel. The Z's PCM measures air pressure/density with it's MAP sensor, and it adjusts fuel trims accordingly. If the Long Term trims are way out of whack, you might be able to gain some WOT performance by making adjustments to the fuel injector timing. But I think that the lower air pressure at altitude means your trims will already be negative, which means you're already leaner at WOT and there may not be anything to gain (assuming your not getting Knock Retard).

Supercharging (either mechanical or turbo) is your best bet for high-altitude performance. It works for airplanes just as well as it does for automobile engines, for all the same reasons.

[Jim Lembo]

A street tune and dyno tune by someone with HPTuners or LS1 edit will definitely give you some more power, even on a stock motor, but don't expect alot. (maybe 10-15whp) Living here in the thin air at 7500+ elevation I feel your pain. I have modded my car extensively, but stayed NA because I just didn't want to do forced induction on a stock bottom end motor. It does run alot better than it did stock, (about 1 second faster in the 1/4 mile and maybe 10mph better trap speeds), but I now that FI would give me better results here in the thin air. It just depends on what you want to do with the car and how deep your pockets are. If you intend on road racing, HPDE's etc, then IMO, NA is the best way to go. HTH

Jimbo

mods are in my sig below.