Hey there. I read a lot about how bad an 3" exhaust piping is for an NA car like the 420A. Nonetheless I want to buy one for the following reasons:

1) It's cheaper than a so called 2.5" catback (that is actually just 2.3") when shipped to Germany, even when it's only 20 bucks.

2) There is some kind of second resonator on the 3" catbacks that will help me pass the street-legal-test over here by dampening the noise.

3) I want to chop off the fart can and weld on an SS dual tip muffler that's street-legal. The I.D. of the piping is about 2.25".

4) When I want to boost my car I won't need to order a new exhaust.

Will the smaller piping of the muffler create enough back pressure that I won't lose any low end torque? Or should I just buy the 2.5" catback and call it a day? I'm afraid that the missing second resonator will make the car too loud.

The issue with 3 inch is not back pressure that is a myth, its gaseous velocity. And there are plenty of real 2.5 inch exhausts. Where in Germany is it being shipped to? and just remember you get what you pay for with material! Have you checked a local shop to see if they could bend an exhaust for you?

Learning never stops. I live in eastern Germany. A custom made catback costs about 1500$. That's the cheapest I could find without driving more than 200 miles.

There are pre-made midpipes that cost about 900$, but fitment is an issue. The ebay catbacks are sold for about 600$ (!) over here. Used catbacks are as good as non existing and overpriced, I'm looking for one in the lower price range (under 400$) for about 1 year! So getting an ebay cat-back from the USA is cheaper than any alternativ. I read the quality and fitment is not that bad. And I really need a new exhaust since mine is rusted and has holes everywhere. I guess even a temporary use of an ebay cat-back would be better in any way:)

So sticking to a 2.5" catback is the choice? I hope it's not louder than the 3".

Almost all of the ebay catbacks come with a silencer you can insert into the muffler outlet that severly dampens the sound.

If you think its your best option, i've personally had pretty good luck with the ebay 3" catbacks.

As I stated above I want to mount a dual tip muffler instead of using the single tip muffler that's usually delivered with these catbacks. The muffler looks like this:



This one is street-legal without any registration in Germany and much less attention-whoring than the fat muffler. There is no silencer that I can put into it, but it's not that loud.

The main question was if the car will be drivable with the 3 inch catback. As I read out from previous posts it's not the best. I plan to turbocharge my car in the next 2 years and until then it's my daily driver. The only thing that really bothers me is: will the 2.5 inch catback without the second resonator be as quiet as the 3 inch catback? The system has to be as quiet as possible.

I've had no experience with that muffler but my header back 2.5" straight pipe 420a with and silencer was a nice low rumble not a loud ricey exhaust.

As long as you plan on keeping the cat on the car you should be fine with 3" exhaust.

Check out the Apexi Noir series, they don't make one for the 2gnt/GST but you can buy the muffler and get your own piping for it. I LOVE the way they look, its the same as a Apexi WS but in all flat black! Exhaust tone is mellow and has an attractive muffler that is not flashy!

I wanted one of those for a while but I have no need for one now :( but I have a nice 3" gibson on my jeep.