Split dump pipes

[drewecrome]

hey guys i have got the CES Double dumps, HPC coated on my car. They are awesome i picked up heaps of power. My car gained extra mid range power, and spool up time was greatly reduced. Trust me they are worth it, they shit over any of those HKS, Trust stuff.

[gtir_94]

Trust me they are worth it, they shit over any of those HKS, Trust stuff.

I assume with that comment, you have tried all other dumps, including dyno readings etc, and also compared the Jap stuff to CES for quality?

[Ronin 09]

I have not 'tried' any other pipes except for my Trust pipes.

I too will claim that, not so much 'I', but my car, "picked up heaps of power. My car gained extra mid range power, and spool up time was greatly reduced"

"Trust me they are worth it, they shit over any of those INSERT ANY OTHER MAKE HERE stuff"

A pipe is a pipe is a pipe. As long as construction is good (no weld dags etc) the performance gain will be very similar between brands. Ditto flow.

[Sydneykid]

Hi guys, we use a Performance Metalcraft fabricated split dump, engine pipe and cat replacement all in one. I had it made that way because it only has 2 flanged joints instead of 4, this saves weight as flanges, nuts and bolts are heavy. Plus I only have 2 gaskets (not 4) to worry about leaking. There is 450 mm separation until the wastegate pipe joins the turbine exhaust pipe.

All of that is good reason, but the main one was, I didn't like the short separation on the Japanese replacement dump pipes. I believe the turbulence, created when the wastegate rejoins the turbine outlet, is a big cause of reduced throttle response and delayed boost build. There is most likely a max power benefit as well as the substantial average power gain. I couldn't find an off the shelf solution at the time, so I had PM make one to my spec's.

Now a 3" piece of mandrel bent pipe is pretty much the same, no matter who you buy it from, so this is what I looked for;

* Nice dag free welds

* No welding intrusion into the inside of the pipes

* A smooth blending of the wastegate pipe, it comes in at a low angle and has no distortion or reduction of the main pipe diameter

* A separation plate that fits into the turbine housing to ensure that the exhausts (wastegate and turbine) stay separated into their individual pipes

* Flat smooth flanges, they can distort if not welded properly and I hate gasket leaks

* The flanges and pipes have easy to get at nuts and bolts, some of them are so badly designed that it is almost impossible to get a spanner (or socket) on them

* The mountings are strong and in exactly the same location as the standard mounts, I don’t like hanging the weight of the exhaust system off the turbine housing

* The main pipe has a fitting for the standard lambda sensor in pretty much the standard location, I don’t like having to rerun the wiring harness just to fit the sensor.

* The combined pipe has a fitting for another lambda sensor, the one used when the car is on the dyno. This gives much more accurate and speedier response to A/F ratio changes than sticking a broom stick up the exhaust pipe.

* I wrapped ours, but ceramic coating inside and out would be good. Note that HPC is not necessarily ceramic, it may be just fancy protective paint with no thermal barrier properties

Hope that is some help in choosing a pipe

[locosam]

ok, so im confused.

CES seems to have a good reputation, and thier dumps do wonders for s15's. Plus the wastegate pipe seems to join later down in the pipe, which sorta makes more sense.

On the other hand, you have the HKS Split Dumps which joins much shorter down the pipe, but with the possiblity of more lag? But what about all the testing and supposedly R&D HKS has done?

The CES dump/front pipe is $530 in the group buy (without delivery)

HKS Split Dump is around $400 (delivered new to my door)

With the HKS, you would have to the front pipe from somewhere...

So in the end, the CES probably costs a bit more than the HKS + custom front pipe, but not by much. Both would be around $550-600 installed right? But which one is the best?

Is there any exhaust shops in sydney that can do copies for cheaper?

[Sydneykid]

ok, so im confused.

CES seems to have a good reputation, and thier dumps do wonders for s15's. Plus the wastegate pipe seems to join later down in the pipe, which sorta makes more sense.

On the other hand, you have the HKS Split Dumps which joins much shorter down the pipe, but with the possiblity of more lag? But what about all the testing and supposedly R&D HKS has done?

The CES dump/front pipe is $530 in the group buy (without delivery)

HKS Split Dump is around $400 (delivered new to my door)

The HKS slit dump pipes, as with most Japanese parts, are very well made. But they suffer. like a lot of Japanese parts, from the "bolt on" culture. They must bolt on exactly the same as the original parts and that's the problem. HKS have designed a split dump that perfectly replaces the standard dump, that means it has to have a short separation to mate up to the flange on the standard engine pipe. Then they make an engine pipe that bolts up perfectly to the standard dump and the standard cat. Therefore you can use the engine pipe with the standard dump or the HKS split dump. etc etc

Why do they do this, surely it would make more sense if they made a combined split dump and engine pipe (with longer separation)? My opinion, good Japanese mechanics charge like brain surgeons. So the "bolt on" culture means any "not so good" mechanic can replace the standard part with the aftermarket part. Plus HKS would have to make 3 parts, as they would have the short split dump, the engine pipe and the combined dump and engine pipe. Much simpler to have 2, cuts down the stock carried by distributors by 1/3.

Hope that makes sense

[sweetr33]

and these performance metalcraft dumps made your style cost how much sk??

[rs73]

I've already have this bolt-on Trust front pipe, would it be better just getting the bolt-on HKS split dump only, or sell the Trust front pipe and get CES split dump+front pipe in one piece?

[Ronin 09]

The HKS slit dump pipes, as with most Japanese parts, are very well made.  But they suffer. like a lot of Japanese parts, from the "bolt on" culture.  They must bolt on exactly the same as the original parts and that's the problem.  HKS have designed a split dump that perfectly replaces the standard dump, that means it has to have a short separation to mate up to the flange on the standard engine pipe.  Then they make an engine pipe that bolts up perfectly to the standard dump and the standard cat.  Therefore you can use the engine pipe with the standard dump or the HKS split dump. etc etc

Why do they do this, surely it would make more sense if they made a combined split dump and engine pipe (with longer separation)?  My opinion, good Japanese mechanics charge like brain surgeons.  So the "bolt on" culture means any "not so good" mechanic can replace the standard part with the aftermarket part.  Plus HKS would have to make 3 parts, as they would have the short split dump, the engine pipe and the combined dump and engine pipe.  Much simpler to have 2, cuts down the stock carried by distributors by 1/3.  

Hope that makes sense

Kinda like these Trust dumps for GTR?

http://www.skylinesaustralia.com/forums/at...achmentid=17294

[Sydneykid]

and these performance metalcraft dumps made your style cost how much sk??

Performance Metalcraft have their own style and it's pretty damn good. Let's face it, there isn't a lot not known about how and why to make split dumps. The value is in the quality of the workmanship not the basic design. PM's workmanship is right up there so I use their stuff when I need to (as in when our race team fabricator is too busy). As for price, you really need to ask PM directly.

Kinda like these Trust dumps for GTR?

Yep exactly, personally I think Trust went the right way. Pitty the others didn't follow.