How to know quality of a tune?
 

I recently bought a 2013 evo X which has modifications. The vehicle was bought in a city with an altitude of around 1k feet and I live at 5.5k feet. This is my first evo so I wouldn't really know the difference between a stock tune and it's current tune, or the performance of the current tune. What are some observable signs of a high quality tune vs an evo that badly needs a tune? Does changing 4.5k feet in altitude require a tune? Thanks!

If you have a way of doing a few logs of the ECU, you could share the results w/us on the boards / your tuner

Seems like a significant change in elevation where a tune check-up might be in order

WB? What is this?

IMO, if you are unsure of the tune, I would definitely have it looked at. WB = Wideband. This shows your a/f *air/fuel* ratios and gives you an indication if your tune is good or not. If this car was tuned at sea level and you are at 5,500ft, you will definitely want to have the car calibrated for the difference in altitude. It is peace of mind. You can spend $500 getting a retune or you could spend 10x that amount if you blow your motor up. Just my .02 worth.

A good tune is one that generates 0 knock and has your AFR's spot on. A great tune is one that makes power, generates as little knock as possible, and has your AFR's spot on. An excellent tune is one that does what a great tune does, but makes the car behave as it did before your mods were added in terms of a smoothly operating car. This includes no issues starting, (cold or hot) idling, and no problems with roughness or stuttering during your drive. Keep in mind that not all problems are related to the tune.

Once you have a wideband to look at, your cruising AFR should be around 14.7. Your full throttle AFR on 91 should be between 10.9 to 11.3. This will provide enough fuel to keep your engine happy when you are using boost.

Best way is to get it inspected by a tuner. If tune has no knock CEL built in, you wouldn't even know if it's knocking when you in boost.