Tunning risks?
 

It's fairly clear that tunes will void your warranty in some regard, but how risky is it to run a tune in terms of vehicle reliability.


Part of me is under the impression that the factory tunes these cars a certain way for a specific reason. The torque dip obviously isn't the result of the exhaust manifold expressly as replacing it doesn't completely fix the dip. the largest portion of the dip is removed with a tune.

If you're tunning the engine to take advantage of a higher octane fuel, aren't you pushing the envelope of grace (bad fuel, overheating, etc etc). Isn't the car more prone to failure and damage in these situations now?

That being said, with a tune and headers, you've changed the operation of the engine. I recognize the tuners generally have a really good idea what they're doing, but that little part of me worries that Toyota / Subaru left the car that way for a good reason.

are that any negative effects by running a tune with headers (or just a tune)? Why the hell didn't the factory do anything about that torque dip if it was so easy to tune out?

You forget these extra things cost more money to do. Their goal is to stick to a price point and get the most out of what they can at that point. I don't remember a stock manifold on any car I've owned that wasn't restrictive. Also, this car is one of the most economical sports cars I've ever owned. 0w20 from the factory is an eco oil. The dip has been consistently eliminated with the header along with the tune. The tune by itself to an extent affects it, but not fully.

There should not be any negative effects of a tune with headers. Infact, the engine probably is healthier because it can breathe better. As long as your AFR's are balanced and safe, you're getting nothing but gains that were left restrictive from the factory.

I'm not a fan of jumping to using e85 and the very high octane race fuels. I'm sticking with the 93 octane I have in my area and not diving into a fuel type that wasn't designed for the car. Not to mention, do you really want jugs of e85 in your trunk whenever you drive somewhere far with no e85?

A good tune by someone who knows what they're doing will be more efficient and no less reliable than stock. A shitty tune can blow your car up. It has a lot more to do with who performs the work than anything else. Any of the reputable tuners from this board can hook you up with some safe gains.