I have a 3" exhaust with a testpipe and muffler by the tip of the exhaust. If I remove that muffler, will that affect my tune somehow? Or will it just effect the noise?

 

Just the noise really. Its not going to affect airflow very much if at all. Definitely not enough to throw off a tune.

 

I did something similar using an exhaust cutout. I know there was an increase of 30 HP/TQ. I'm sure that put it in a different load range on the Fuel and Timing Maps. I don't have the data in front of me, but I can look for it if you want.

 

Did you have a catalytic converter on your exhaust?
I took the muffler off and like the sound, but would that throw off the tune? I thought only the catalytic converter changes things.

 

Good point. No cat on either systems.

Your set up isn't an apples to apples comparison with the exhaust cutout. Easiest thing to do is to log a few runs with both the muffler on and off. Post those up and it will be easy to tell what's going on.

Which state do you live in? Do you have any noise laws? If so I'd get a cut out.

 

I don't have any equipment to do that. I did not tune the car myself.

The car isn't really a daily driver and it's not as bad unless I'm on it.
I have the Greddy comp tic exhaust and I disconnected the exhaust like right before the muffler starts.

So my main questions is, would it do any harm to the car if I disconnected the muffler? do you think it will effect my fuel ratio or things like that?

 

You're talking to a guy who likes to take a theory and test it. From my testing, IIRC, it bumped the boost up a couple of pounds and changed the load, which can change the AFR and timing.

I know this doesn't answer your question, because IDK, but I'll take a guess. Then you'll need to verify and see if I was right. Regardless, IMHO, you need a laptop, wideband, tactrix cable, evoscan and a 4 bar map sensor at the minimum. PM me if you need any product and I can get you a price.

My guess: You will increase boost by 1-2 psi and increase HP by 10-15 HP if tuned for it. That will put your load up by 10+. That's not significant. However, to take advantage of this new found HP you'll need to tune it. I guess you'll gain 5 HP if you leave it as is.

 

If I leave it without re-tuning, the disconnected muffler shouldn't realty cause any harm in any way.. Right?
I just don't really see how something could go wrong

 

Nothing will go "wrong". But you will be able to squeeze out some more power if you retune it.