Exhaust Advice

[Viper_r32]

hey Guys I'm just looking for some advice in exhaust systems

for quite a while i have been running just a stock exhaust from the turbo to the cat, and an aftermarket Apexi N1 muffler with 3" pipe to the cat.

I am looking at putting on an after market dump pipe and cat

firstly I want to ask about response, I visited an exhaust shop today and got offered a set up containing a Dump pipe, cat, and hot-dog to keep the noise level down. I was told by the guys at the exhaust shop that this would cause the turbo to spool 1500rpm earlier. is this a true claim or am i being told porkies.

second i got quoted $750 installed. is this price reasonable.

and third is there advantages and disadvantages to how the pipes on the dump join, because the one they sowed me didn't even have a split section on the inlet of the dump pipe.

any advice would be greatly appreciated

[Bullet32]

Don't bother getting an exhaust shop to supply and fit a dump pipe and cat for you... If you're reasonably handy with a spanner you can easily do it yourself.

I was using a Just Jap mild steel dump pipe from the turbo and a high flow 3" cat (also from Just Jap) with my standard turbo and I can tell you from experience that turbo response does improve because put simply - with a larger diameter dump pipe and free flowing system you allow more gas to pass through the turbo quicker meaning more boost response and faster pressure build up (less lag).

With a large diameter dump pipe you also allow the wastegate to exhaust gas more efficiently as well, allowing you to control boost levels better.

Oh and you wont need a hot-dog muffler to keep the noise down, there wont be a noticeable increase in db just from fitting a bigger dump and cat... You'll probably only notice that the exhaust note will be deeper and more rumbly (which is a good thing)

"I was told by the guys at the exhaust shop that this would cause the turbo to spool 1500rpm earlier" - Not true, the most you will notice will be around 400 - 500rpm (depending on the condition and type of turbo you have).

Check out the dump pipes and cats available from Just Jap, find a 'how to guide' on these forums and install it yourself - you'll save heaps of cash!

http://justjap.com/store/product.php?produ...=276&page=1

[Viper_r32]

WOW thanks heaps dude,

very greatly appreciated.

[Viper_r32]

looking at the justjap web site the sell 4 different types suitable for the r32

what are the differences aside from the just the look and the fact that one type is bolt on and the other need to be welded.

http://justjap.com/store/product.php?produ...at=0&page=1

http://justjap.com/store/product.php?produ...at=0&page=1

http://justjap.com/store/product.php?produ...at=0&page=1

http://justjap.com/store/product.php?produ...at=0&page=1

[ZCR]

the only problem you might have doing it yourself is snapping exhaust bolts cos they get too hot, then you have to be able to get them out

i'm running an xforce 3 inch dump front and high flow cat on mine (got esp to install it)

[Bullet32]

WOW thanks heaps dude,

very greatly appreciated.

No problem, just trying to help out

looking at the justjap web site the sell 4 different types suitable for the r32

what are the differences aside from the just the look and the fact that one type is bolt on and the other need to be welded.

Apart from the differing brands, they all have different internal diameters and filter types which means that they would have different flow characteristics.

You want one with bolt on flanges - don't get a weld in one, they're a pain in the ass!

This one would be my choice -

the only problem you might have doing it yourself is snapping exhaust bolts cos they get too hot, then you have to be able to get them out

i'm running an xforce 3 inch dump front and high flow cat on mine (got esp to install it)

Zane is right, if youre to rough with the studs on the back of the turbo they can snap or strip the thread. Every time I have removed and installed a dump pipe I have had very 'sticky' exhaust studs.

Soak them in WD40 for half an hour or so (respray them every 5 minutes) and they will be A LOT easier to work with.

OR - You could get the boys at ESP to install it all for you (although you will have to pay for it obviously) - tell them that Mick from Federal sent you

[Viper_r32]

Apart from the differing brands, they all have different internal diameters and filter types which means that they would have different flow characteristics.

dose that mean if they had different flow characteristics that there would be advantages and disadvantages to different cats with different flow ratings?

e.g. sacrificing response vs top end power

Edited July 24, 2010 by Viper_r32

[natett]

Considering the size of the turbo, exhaust and amount of boost your running you would barely notice any difference with the flow charateristics of each cat.

Cats are a plug so you will loose a few hp but it's nothing like what you would see in a large 4" system that has significantly more exhaust flow from the larger aftermarket turbo. Eg. My 42 with 4" all the way lost 20+kws with a cat and reduced spool but my stock twins with 3" and high flow cat increased power everywhere from stock but the cat made no real world changes over a catless system