eifacHasan

Hi guys

I want to modify my stock exhaust / muffler to get a nice louder but NICE sound from it.
I heard alot of the UK mod which i cant/dont want todo, because i do like the exhaust look as stock as possible.

reason is I want to avoid problems with the cops in our country since they are going crazy the last few years catching tuners and their ilegal mods. lol.
I am looking for modifying my muffler like this, cut and weld these two parts together wich basically looks like the UK mod just inside the Muffler.

did anyone do this and can give me some feedback or suggestions for improvement or any different idea to improve the sound but make it look stock?

thanks alot

engifineer

I think it would be LOUD the way you are describing, as it would literally be a straight pipe if you just connected those. As I understand it, the UK mod puts in a parallel path with a smaller tube so that some of the exhaust is diverted but some still flows through the muffler . So you would want a smaller diameter pipe to connect between those two pipes closer to the point of where they exit the main enclosure to better simulate the UK mod.

Closer to my poorly marked up image below (The green part). Have not seen it done that way so cannot tell you how it comes out, but based upon what I have seen of the UK mod this seems as close as you can get and keep it on the inside

Car Analogy

... And it's going to cost a LOT more to do it internally. Not to mention how ugly the muffler is likely to look after that open heart surgery. Muffler shops aren't known for making clean welds.

You'd instead want to take the exhaust to someone with a tig welding setup, not the mig welder most exhaust shops would use. Not sure how much of that applies to whatever country you're in.

The shop is going to have to strip the whole muffler skin so they can reach the underside of pipe they would weld.

So which will look worse, a small uk mod pipe you can't really see even when you're under the car working on it (unless you get in the exact right spot, and look straight up behind the muffler), or a pair of mufflers with ugly weld seems running around the entire front and rear circumference, a large part of which will be visible just bending down behind tbe car?

The uk mod is virtually invisible. If you do a 1" (25mm) bypass pipe uk mod, it won't raise any unwanted eyebrows or make any inspectors question what mufflers are on the car. It'll just sound like a factory high performance exhaust.

engifineer

I think his concern is not aesthetic, but rather the inspection folks noticing the exhaust has been modded. Would have to get under the car to look though either way. And you could do the mod he wants on the top side of the muffler and no one would ever see it. But would probably charge you a chunk. Now if you can do it yourself then that is not an issue.

Chuck S

Those pesky Swiss gendarmes won't be fooled for a second your proposed annoyingly loud exhaust is stock. For noise loosen the bolts holding the exhaust to the catalytic converter and put one or several stainless steel washers between the parts and tighten the bolts. The exhaust leak will add noise depending on how many you use. Completely ghetto but won't be nearly as bad as your proposal. A favorite of high school guys everywhere. Especially those with no money.

It's after the cat so the exhaust is "clean."



-- Chuck

eifacHasan

Thank you guys for your responses.
first of all, it is really as bad here in switzerland as it sounds with the cops. I had the invidia q300 wich was one of the best sounds ive ever heard on the s2k and I had street legal papers for switzerland BUT after a DB noise measurement it showd that my car is louder than it may be. (for understanding, every Car haves a different registret max. DB Noise that it may have.) so the legal papers where for SH.T ! so i got fined with converted 2000$... no joke.

so thats why the muffler shops are like doctors here in switzerland. see the pictures below... you cant see sh.t.

anyways

thanks for the advices so far guys!

I am really looking for anyone that did this type of modification on his exhaust / muffler who can tell how it sounds.

the finish product (the under one), after a few weeks it will look like a normal old, and used muffler

open heart surgery

more open heart surgery

flanders

So you need to pass both dB and visual inspection?
Q300 is pretty loud but I bet it would be even louder with a stock exhaust modified like that^.

eifacHasan

exactly. well... if your exhaust is/look stock and its too loud its because it is an old car and normaly exhausts do get louder after years so... yeah at the end you just have to replace the exhaust with a quiet one. lol.
trust me i figured it out. its the best way to get an nice loud exhaust. unless you have a supercar

engifineer

I think then going with my pictured approach may be your best bet. It "should" be like the UK mod which from what I hear is not much louder. Your straight through approach will be louder than that Hard to say what it will blow for sound. I run mine sometimes for big autox events with the muffler section pulled (turndown just behind the drivers compartment and it is pretty loud. Not as bad as you would think (94dBm passing the sound meters at WOT at events) but very obvious there is no muffler . Your straight through mod may be quieter since it uses more pipe and splits through two mufflers, but would still be pretty close to that I think.

The spacers after the Cat from the posts above you would HATE. That sounds like a terrible exhause leak, which it is and nothing like a louder exhaust. One of the crappiest sounds I have ever heard to be honest short of some of the super blarey ricey exhausts. Plus if it is a the Cat, you would smell it a lot from the passengers compartment.

Chuck S

The cat spacers will sound loud -- which I thought was the goal. Won't sound good.

In the two weeks I had the obnoxiously and painfully loud Invidia Q300 on my car I measured the noise level in excess of 106 dBA, a level that if your employer subjected you to would require double hearing protection. No surprise the Q300 wouldn't pass. The Tanabe Medalion Touring dual exhaust current on my car measures no louder than 95 dBA. My wife says it's too loud (of course!).

-- Chuck