Downpipe Q
 

Posting it on behalf of my mate.

Hey Pple, if i change my current down pipe which is a straight thru( with no splits) to one with splits, do i need a retune?

Appreciate your input :)

To make the most of the changes, yes.

if you expect gains, yes get a tune.

if you dont expect gains, no dont bother getting a tune, whats the point of changing the dump?

What i would like to know is, by changing the dump pipe to having a splitter in it, does this compress hot air further and allow for faster gases? Or is there another reason behind it?

And whatever is the case, is the gains worth a retune for a street light warrior?

hmmm... just verso my car..... feel like putin in a split to have an earlier spool( as not it only hits full boost at 4000)..... do i have to retune my car again?

exhale, repeat!

if you expect gains or the car to run differently, yes get a tune.

if you dont expect gains or the car doesnt run differently, no- dont bother getting a tune

[QUOTE=Sphoolin]What i would like to know is, by changing the dump pipe to having a splitter in it, does this compress hot air further and allow for faster gases? Or is there another reason behind it?

And whatever is the case, is the gains worth a retune for a street light warrior?[/QUOTE]
I believe it reduces turbulence by splitting the gas that comes out of the exhaust housing with the gas that comes out of the wastegate. This leads to less back pressure that spools the turbo quicker. When I had a splitter and bellmouth put in, after running a flat plate over the wastegate, I noticed a reasonable increase in low down torque (without a tune... :)). Maybe there is even more potential in it with a good tune to match.

[QUOTE=Lorry]I believe it reduces turbulence by splitting the gas that comes out of the exhaust housing with the gas that comes out of the wastegate. This leads to less back pressure that spools the turbo quicker. When I had a splitter and bellmouth put in, after running a flat plate over the wastegate, I noticed a reasonable increase in low down torque (without a tune... :)). Maybe there is even more potential in it with a good tune to match.[/QUOTE]

where did u get ur split done??? and how much issit?

[QUOTE=kenneth2koh]where did u get ur split done??? and how much issit?[/QUOTE]

Ummm from an exhaust shop or a workshop.

I would talk to a workshop before running off to get your bits.

1. New dump pipe might not merge up to existing system
2. Might need some rewelding or modification to the exhaust system

There are most likely better mods to be done then just a splitter.

A splitter alone wont nett 1 zillion hp and 2 billion nm of torque. Once again, it comes down to application and your goals for your vehicle. In the 2.5in thread there's a graph of what a china bellmouth can do.. food for thought...

if you have an x-force bell mouth dump pipe i may have a solution for you, my mate is currently developing a splitter gasget that sits between the turbo and the dump pipe, when its finished it will be around $50 but cheaper if we get more on board, here is the link :[url]http://forum.gtrydaz.com/showthread.php?t=20215&page=5[/url]

check the 1st page for different applications and turbo type