QUIET performance mods?
 

I would love to get more power out of my AP1 doing it the NA way. Looking for an extra 20ish HP or so. Nothing crazy. But here is the catch. I am wanting to keep it close to stock sound as possible. Is that even an option or as soon as you start the modifications you sacrifice sound? Wonder if anyone has done a NA build with the emphasize on keeping the sound as close to stock as possible. I am thinking of going air intake, header, exhaust, and EMS. Thanks for the input!

Add lightness :shrug:

Evan

Best you can do is stroke it if you want to keep the stock sound. Intake is going to make it sound different. For reference take or airbox lid off and drive it. It will sound similar. Header and exhaust will make it louder if you want power.

I don't mind going a little louder. But I still want a reasonably quiet car for longer trips. I understand you have to give to get but would prefer not give up too much!

Most important na mods will cause an increase in noise. Period. The only logical mod would be stroking your motor, but leaving everything else stock. Some my say its a waste but its what you're looking for

I know that you can get some pretty quiet exhaust systems. Does adding the header and test pipe up the noise lever that much? What about a high flow cat? Not sure if I am into rebuilding my engine though.

Replace the Cat with a TP, get a KN drop in filter/stock intake box and tune it, you will gain 20hp in the mid range for sure, but probably not peak. But you will retain similar sound DB. A larger aftermarket TB is worth a few ponies as well, as improved throttle response. Not many proven headers out there that can beat the factory, and a headerback is only going to free up 5whp or so but at the expense of quite a bit of DB.

Tanabe Touring Medallion is insanely quiet, barely louder than stock if you keep the stock cat, slightly louder with a high flow cat or test pipe. Proven to make a few HP, and it's good quality stuff - should last forever. And it's lighter than stock, but what exhaust isn't? lol.

http://www.tanabe-usa.com/touringmedalion.asp?id=7

http://www.tanabe-usa.com/exhausts/files/204_img2.jpg

^^^ But think about it for a moment, a Cat delete with factory exhaust will free up just as much (if not more) then a OEM cat and new cat back, and at 1/10th the cost. A TP with stock exhaust if I remember (its been years) is still quieter. I run a Tanabe 93db Concept G with TP BTW, the sound is excellent! But bang for buck, "quiet per hp" I stand by my original suggestion.

Totally agreed, but if you can afford it - a high flow cat + Tanabe cat back will give you power gains, while staying quiet and providing an amazing sound.

I have been told by a very reputable source that Tanabe doesn't sell exhausts in the US if they don't actually show gains on US cars and stay under 93db - and that's why certain exhausts are not sold here.