Downpipe done !

[ryan_GTI]

yep update us spec - but 3" dump would be more ideal.

[99gti]

I got my 3" dump and hi-flow cat going in tomorrow

[mitch_gti]

hope it all goes as well as my setup did.


But in all honestly, exhaust place said of course they are happy to charge me for a euro4 200cell cat. But that there was no real point (nice when they are honest )
He said standard cat is stainless inside and out, the only thing restrictive about the stock cat is the entry and exit to it. The inside of the cat is massive. SOo he just enlarged the enty and exit. Problem solved.

But im sure you will be happy with upgraded cat. Hope no engine lights come up. Thats what i was scared of.

best of luck dude

[Adam]

Does having a 3" pipe changes the exhaust note? making it louder, less? more throaty?

[jasn78]

Does having a 3" pipe changes the exhaust note? making it louder, less? more throaty?

ask dave and john how loud my car is to c what effect it has on the noise adam

[DaveMack]

ask dave and john how loud my car is to c what effect it has on the noise adam

Haven't you taken that cannon off yet, Jason?

Dave

[Spec83]

You got exhaust work done on an excel?

Intercooler piping and exhaust

[mitch_gti]

Intercooler pipes and exhaust ripper little excel.


The downpipe definately did make a substancial difference to noise. More throaty, more turbo spool up noises/whistles/induction etc.

Main thing is what it did to power though..

[99gti]

I agree. Got my car back and I'm very happy with it - i got a great price too considering the cat I got. It's heaps bigger than the old one, especially when you looked inside at the guts of it.

Not a massive change in noise but a noticeable change. I already had mine set up straight back to a reamus box however. I like the note of it now and it's not obnoxious.

I notice the turbo spooling alot earlier and faster. When it comes on boost now you feel it a lot more than previously.

Check out this baby that they also had in their at the same time. I have big hands so you can guage how big this thing is...



They also had a high 8 second commondore in there too which was kinda funky...

[shaneth]

Hey All...

Digging up an old thread I know, but I made a few calls this morning for all of us QLD guys looking to get a downpipe done...

Simon from Exotic Exhaust at Sumner Park has first hand experience with the 1.8T (acually had a MkIV GTI getting a turbo-back exhaust on the hoist when I called) and from the sounds of it can do a 2.5" dump pipe in mild steel for a decent price... He said he had not particuarly done a Polo GTI but expected that it would not differ too much from the MkIV.

I can't recommend these guys enough - had some piping work done by them on my old excel and the quality was top notch. I am going to check it out tomorrow morning so I'll let you all know how i go

Sounds interesting. Let us know what price they come up with as if its right im keen. And i preferably would prefer 2.5" like you said mate.

[ryan_GTI]

i thought a 3" dump-pipe has already seen decent gains from the dyno.

Just wondering whats the advantage of goin 2.5" ?

[philthy]

Hey guys. What size is the stock downpipe? I thought the exhaust was 2.5" all the way through? (admittedly haven't looked that closely myself)

[mitch_gti]

I just ran outside and looked at the standard down pipe and flex pipe. Looks to be just under 2inch. Very odd shape aswell. Instead of being circular, alot of the pipe is square

If you were upgrading the whole exhaust 2.5 would probably be the best way, smallish motor, small turbo means you should probably keep a certain amount of back pressure there.

But if you just upgrading part of the exhaust (downpipe/flexpipe) go as large as you can ie. 3inch.


Remainder of standard exhaust is about 2 or 2 1/4

[Bubu]

"Back pressure" On a turbo car??? WTF

Turbocharged cars do not need exhaust back pressure. The air is compressed in to the engine at (insert boost amount here). This pressured air is then heated through the combustion process and comes out the exhaust manifold at even more psi then it went in. Air expands when heated and contracts (if those are the right words) when cooled.

Arguably the dump pipe on a turbocharged car is the most important because the exhaust air/fumes drop in temperature by the time it travels through the pipe to the atmosphere. Therefore the exhaust system experiences higher pressure at the dump pipe as it is the hottest part of the exhaust.

I would rather have a 3' dump pipe and 2.5' exhaust, than having a 2.5' dump and 3' exhaust.

[99gti]

"Back pressure" On a turbo car??? WTF

Turbocharged cars do not need exhaust back pressure. The air is compressed in to the engine at (insert boost amount here). This pressured air is then heated through the combustion process and comes out the exhaust manifold at even more psi then it went in. Air expands when heated and contracts (if those are the right words) when cooled.

Arguably the dump pipe on a turbocharged car is the most important because the exhaust air/fumes drop in temperature by the time it travels through the pipe to the atmosphere. Therefore the exhaust system experiences higher pressure at the dump pipe as it is the hottest part of the exhaust.

I would rather have a 3' dump pipe and 2.5' exhaust, than having a 2.5' dump and 3' exhaust.

Couldn't agree with you more. The turbo provides more than sufficient back pressure to stop the car from stalling. You could (illegaly) run a dump pipe straight to atmosphere and your car would love it (neighbourse or EPA wouldn't).