Tuning
 

lets say i live at sea level and i get all my tuning at x amount of altitude, when i come home will the tuning suffer because of the altitude change?

Depending on the type of air/fuel sensor your using a I don't think it should. A good tune shouldn't change varying density of the air

From what I remember the mk3 had an altitude adjuster which compensated for altitude but unless your in malaise it shouldn't make that big of a difference. I could be wrong and also are you running a factory ecu or aftermarket.

Also if you can include any mods and what ur car specifics it would help out in giving you a better answer

i will be running the innovative motorsports LC-1 along with either NEO, or MAFT not sure which route i should take

The ECU doesn't monitor the AFR all the time. There's a good deal of time that it doesn't. The HAC sensor is in place because when the ECU isn't reading the O2 sensor it determines proper mixture based on AFM readings and other fixed data. BUT, the oxygen content of our atmosphere isn't directly proportionate to the pressure... So the HAC is used to determine bigger shifts in atmospheric pressure so that the calculations can account for the difference in oxygen content as well.

Any after market fuel control should be re-tuned if you're going to be spending any significant time at an elevation that is greatly different from that where it was originally tuned.

Neo or MAFT? Two totally different systems; The MAFT isn't something I'd use to tune fueling, It's really just intended to adapt from the KVAFM to a MAF. If you meant a MAFT Pro or MAFT Gen II they can be set to monitor AFR much more aggressively than the stock ECU and to do so at times when the stock ECU doesn't monitor the O2 sensor (the same goes for the Neo).... BUT I still wouldn't rely on it and advise that the base tune be properly adjusted with this feature turned off. If the wideband were to fail you would be running on a crap tune.

Depending on how your system is setup in the end it may be advisable to delete the HAC sensor.

Well in my case, where i live we are 12gonna feet above sea level, the nearest place i can get a dynotune at is los angeles and they are 233 feet above sea level. Will there be a big difference? Is it critical to swith from KVAM to MAF?
These are my specs and plans
rebuilt motor. 20 over
Hks stopper hg. Arp studs. Ct57. Bic ddp. 550cc injectors and i plan on getting the lc-1 and neo, walbro( and i need a AFPR too right?) Very soon. Any body suggest different route? I want to land any where from 350-450rwhp

Altitude change..... 200' difference......

Let me put this gently....

Bwaaahahahahahahahahaha.... <cough>... hahahahaha.... <wheeze>.... hahaha.....

Um, I think you'll be just fine. ;) You're being overly cautions, which isn't a bad thing. No, I'm talking about altitude changes of 4,000ft.

time to stop smoking m8
:p