The Science of Dump Pipes

[GTBR46]

Hi guys,

A search of the forum reveals a number of different dump pipes being used by memebers. Certainly, the Phat GT DP is very popular. One of the major differences is Avo using A CAST collector, as opposed to the welded steel being used by Phat GT. Im not casting any judgement on either, but obviously, there is some science involved in the decision between the two, and Im wondering what that is? Is it that the part can be mass produced? Does the thermal mass offer any advantage? Is it just that it will last longer? Anyone?

[GTSPECB STI]

Well the can of worms has been opened and let the debate begin.

Both designs are vast improvements over the oem design. Both allow you to make significant hp and torque increases. MSR (Michael South Racing) will give you a good explanation and case for using a splitter I believe.

The phat dump as well refer to it here is also an excellent design and I am sure the designer himself might give you his own reasons behind it.

Subscribed

[GTSPECB STI]

Well the can of worms has been opened and let the debate begin.

Both designs are vast improvements over the oem design. Both allow you to make significant hp and torque increases.

The phat dump as well refer to it here is also an excellent design and I am sure the designer himself might give you his own reasons behind it. I suggest price to produce comes in to play in most cases.

Subscribed

[GTBR46]

Yep, seen the splitter threads, read the MSR site, some good "science" there....

[smythie]

can of worms indeed. The debate occurred, ad nauseum, towards the end of last year. See this 7 page long thread.

[cpitts]

A loooong time ago in a Galaxy faaaar faaaaaar away........

I demand science as my preferred option. As such, I prefer the dump pipe with a splitter in it (~25mm long) to preserve airflow split and turbulence reduction.

The VF46 has some special requirements to ensure full safety of the setup, but it's still a better solution (from a scientific perspective).

An open bell mouth design will still be far better than stock though, so either is a better choice than stock.

* sneaks back off to the sidelines and waits *

[Spec B Wgn]

Yep, seen the splitter threads, read the MSR site, some good "science" there....

have to agree with this statement.

having read a stack of info on dumps i learnt a lot from Michael South and the reasons for having a splitter
for example at the right length etc and the perfect dump pipe.

http://www.msengineering.com.au/

have a read for your own info

http://www.msengineering.com.au/exhaustsystems.html

[GTBR46]

Actually, we are OFF TOPIC. I have read the MSR site, and a lot of other stuff. Very happy with that part of the argument. Both the AVO and Phat GT pipes for the 2.5 have a similar (though different ) collector design, including the splitter.

What I asked about was what is the science behind a cast collector, vs welded steel,

[GTSPECB STI]

I would suggest welded steel is cheaper to build in small numbers where as casts of anything require minimum numbers to recoup initial cost of tooling.

[coyote]

You can get almost anything cast really cheaply in Chinese foundries.

The thermal properties of a ceramic coated welded setup are far superior to that of a cast lump, but that cast lump costs just a fraction to make.

[GTBR46]

That was hilarious....just read that 7 page rant. Now i know why i cant get "Phat" to respond to me messages re his downpipe.
No, Im not picking sides, I like both designs. I like "phats" because, well I own an engineering workshop, and thats some pretty work Mike...and I like the AVO one because....well, I can buy it, or just the collector tomorrow!

I suspect, as has just been pointed out, the real reason is price / scale of manufacturing, but, I did want to determine if there was another performance based reason, such as having more thermal mass in the collector might somehow aid in the performance/longevity of the turbo.

[GTSPECB STI]

LOL that was some funny shit that thread....I bought mine from Phat in what was his first production run back in Sept 08...at the time there were no real options and he filled the void perfectly. The ceramic coating on mine still looks like brand new and the fitment was perfect. For my $800 it was a great buy at the time and still is.

[Arith]

LOL! Phat being Phat, I don't see him engaging in this pissing contest to prove the worthiness of his dump pipe. Phat's done his research and his dump pipes are proven, especially to the many buyers of them thus far. I can see him yelling if you don't like the product or found something better, don't buy his dump pipes!

In any case, I am also open to new ideas and theories, and look forward to an actual product for the Liberty with the tongue splitter that proves its superiority .... whenever that might be.

[WhiteGTB]

Another interesting thread to keep an eye on

[Sentinel]

Another interesting thread to keep an eye on

+1