Dump /front pipe combinations options

[gimmelovetattoo]

Hi all, I am now running atr45sat with stock dump, hks front pipe, stock cat(empty inside ) , trust pe2 catback on my gtt. Only manage to get round 350 whp@1.2bar.Tuner told me to the main issue is the dump pipe. I have a few options in my mind now, wishing to seek advise from experts here. 
1: possible to get a 3inch elbow dump (tomei/hpi) to pair up with my hks front pipe and  a xforce  hi flow cat? 
2: hks elbow dump ,hks front pipe ,xforce hi flow cat.

3:tomei/hpi elbow , with Japspeed full 3inch front pipe, xforce hi flow cat

my concern is the fact that the inlet of my hks front is 2.5 Inch, only the outlet is 3inch, if I use a 3inch elbow, will it affect the flow? (That’s why I am contemplating to get the japspeed front pipe, looks like it’s 3inch both inlet and outlet ) 

Ps:due to local authority restriction , I need to have my cat intact , and I cannot do ewg. 

any advise will be greatly appreciated 

Edited September 20, 2020 by gimmelovetattoo

[hardsteppa]

One piece jjr bellmouth dump perhaps? Nice n easy

[gimmelovetattoo]

1 hour ago, hardsteppa said:

One piece jjr bellmouth dump perhaps? Nice n easy

Unfortunately , that’s not an option for the authority here:(

[Murray_Calavera]

3 hours ago, gimmelovetattoo said:

Unfortunately , that’s not an option for the authority here:(

What's the issue with it though? The JJR dump doesn't stop you from running a cat.

[gimmelovetattoo]

Well, it’s really a pain in the ass for car modification here. Yes I can run a cat with single piece bell mouth, but since the oem part come with elbow and a connecting front pipe, I am not allowed to change to a single piece . Therefore my options are limited , and I wish to make the best out of the limited options, so any more advise will be greatly appreciated !

[Murray_Calavera]

So there is no issue fitting a bigger turbo and being road legal, but it's not ok to remove a flange from your dump/front pipe? 

Where abouts are you located anyway?

[gimmelovetattoo]

Fitting a bigger turbo is somewhat in the grey zone, usually if it’s still on factory’s mounting position, you can get away with it. As for the exhaust system, they are super strict with it, we are only allowed SOME jasma approved catback . And as for front pipe, I am using hks, but I wrap it with the stock shield . I am located in Singapore .

[GTSBoy]

I would buy the JJR one piece, then cut it and add a flange in the middle. Presto.

[UWISSH!]

This^^^^^^^^

[gimmelovetattoo]

9 hours ago, GTSBoy said:

I would buy the JJR one piece, then cut it and add a flange in the middle. Presto.

super great idea!!
 

[hardsteppa]

That's our GTSBoy, doesn't just think outside the box; he cuts the box in half and puts a flange on it. Ideal way to go. 

For a real oem look, you could even weld on some brackets to the dump and bolt the stock heatshield to it....possibly.