please dont laugh at my question....

**SoVeReIgN** · 19-01-2008, 03:36 PM

Weird for them to split it up like that - But yes that will fit and be fine.

FYI though - A GTI's exhaust is 2.25" - If you got your hands on one and removed the middle muffler you'd have a decent sound and the same performance increase (read - very little) as your Borla exhaust.

Someone on here would surely sell their old exhaust cheap as - I know i'll have mine available shortly.

**Bubu** · 20-01-2008, 03:33 AM

If you do decide to still go ahead with the exhaust, then I hope the following is simple enough to understand and help you make an informed decision.

Just be aware that going too big in your exhaust can actually reduce power of your car. Maximum for a non-turbo car would be 2.5' inch. Having said that I wouldnt recommend that size for your application.

I guess you are not getting extractors (also known as exhaust manifold or headers), these can also give you a bit of power. A 4-2-1 system (where 4 pipes join into 2 then into 1, which then joins to your exhaust) would be best for you as it increases torque in the lower rpm range. Rther than a 4-1 system (where all 4 pipes join into one).

The other thing to think about is if you want 'mandrel' or 'press' bend. Mandrel bends maintains the diameter of the exhaust when there is a bend in the exhaust. A press bend is pressed in to bend the pipe therefore its smaller in diameter where the pipe bends. Press bend is a lot cheaper but its also not as good as the bends restrict flow and the reduced diamater in the bends makes it even worse. But then your not really after huge power increase.

Stainless steel is more expensive but it looks nicer (for those people that like to look under cars

) and it lasts longer than mild steel. But I doubt you will have the car long enough for a mild steel exaust to deteriorate to the point where you will need to change it (im talking around 10 years ++)

**dubbed** · 05-05-2008, 11:42 PM

Pipe = 2"
Catalytic Converter = 2" (both inlet and outlet)
Muffler = 2" (both inlet and outlet)
Resonator = 2" (both inlet and outlet)
Exhaust Tip = 2" (both inlet and outlet)

It just doesn't make sense to me because if everything above was 2", how would they fit/connect with each other when putting it together?

The pipes are either welded together seamlessly, or in the case of connecting to cats/mufflers etc there might be a few mm difference so the pipe can slide over the join snug.

I'm new to VWs but I would think replacing the existing two litre system with a 2" or 2.25" mandrel bent system would be your best bet, using one less muffler and possibly changing an existing muffler with something 'straight through' or more free-flowing.

If the diametre of the exhaust is too big there will be a loss in back-pressure; meaning exhaust gases will exit the system slower, which will result in a loss of power. Here's a really bad example but I'll try my best anyway... Just imagine when you drink through a straw - if it is small like those found in small tetra juice/prima boxes, you get a decent rate of liquid sucked up (like your stock exhaust which does the job efficiently enough). If you use a thicker straw like one from McDonalds (a slightly bigger diametre exhaust system) you suck in more liquid with comparable/less effort. But going bigger again like the diametre of a toilet roll (2.5"-3" on a standard two litre) you would struggle to suck up anything because you can't suck in as much (unless you had turbocharged lungs!).

It's all about comprimising for efficiency. Too small and it's hard for anything to pass through, too big and the rate that air moves slows down. The gains you get will be negligible, but if it's what you want to do and your bro is paying for it then go for it!!

**mk3pete** · 06-05-2008, 03:47 PM

well said dubbed

**mk3pete** · 06-05-2008, 03:50 PM

welcome aboard luv how did ya find out about this site

**Been DUBBED** · 08-05-2008, 08:50 PM

For your car you should look at gettin a 2 and a half inch locally made system with a sport muffler with say a 3 inch tip this will give you both a good sound and a performance increase without going overboard and will not cost you to much.