I wanted to start a list of boltons that should be complimented with a tune to avoid being overly lean whether it be a reflash or a custom tune. I will update the list as people reply.

 

Nothing requires a tune (just to clarify). Anything that modifies air in or out of the engine can be enhanced by tuning. Intake, 02 housing back exhaust, cams, boost levels, octane change, turbo, etc.

 

I think you should of worded it "Recommended" Rather than "Required"

 

That would work.

 

We aren't driving Subarus here... We don't require a tune for minor bolt-on parts!

 

I would consider a tune with turbo back exhaust.. but that's just my opinion..

 

But it isn't required and won't do any damage.

 

In my opinion, a tune should be done with everything. This to make sure you are getting the most of your parts/boltons as well as to keep the car in optimal condition (target af, timing, knockless).

Whether or not it will do damage is another question.

Now with that said, most people can't afford to pay or have the time to re-tune after every small bolt on. You should do many bolt ons together to minimize the number of tunes required.

 

Hmm, I've personally seen just an intake lean out an otherwise stock X gsr to 12:1 under WOT. If you don't think that is too lean for safety then I guess your correct. However, IMHO, that would REQUIRE a retune.

Anything that either modifies the ve of the engine or affects the metering of air and fuel should, at a minimum, warrant a check on the dyno to make sure everything is within acceptable ranges.

 

Here's what i did, I brought my bolt-on's piece by piece and installed them, I waited until I was satisfied with all the parts I installed and then got it tune. I was running my car untune for 2 months and nothing happened.

 

You couldn't be more wrong.
Subaru ecu's adjust timing to avoid knock.

ours don't.

what made you say that though?

 

I was just wondering b/c back in the day when I had my evo 8 2003, I put on all the buschur boltons and I was running 12.7-1 afr. Really lean.

 

I was under the impression that almost every car since the 90's has had some sort of knock compensation VIA the ECU. Am I mislead?

 

What about the 02 downpipe? Would I need a tune with that?

 

The key word here is optimize...You don't have to have a tune, but will get the most out of the parts with it