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Custom exhaust modification for HKS system??

LuPix_S15

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Hola :wave:

Quick question - now that I have turbo elbow, front pipe and decat installed, wanted to make my exhaust system even more free-flowing (and louder + more aggressive sounding hehe). I currently have the HKS Silent Hi-Power but wondering whether I can get Powerflow to custom replace the pipe + silencer on the section outlined in red and replace with just straight-through pipe??



Has anyone done this type of mod and will it deffo be more beneficial for flow hence more power etc??

The reason I don't want to buy a new system is cos I've got the rear diffuser custom fitted so it goes around the back box just nice... a new system with new back box might shag the whole setup and I CBA to mess with the rear diffuser again :wack:

Cheers peeps :thumbs:

James
 

craig8585

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Hi James,

Powerflow will do it for you but I dont know how much benefit you'll get. I have the HKS Hi-Power on my current S15, but had the Silent Hi-Power on my old 15. Both midboxes look the same, but the Hi-Power back box has a lot smaller with less 'insulation' than the Silent Hi-Power. The Hi-power is generally a fair bit louder than the Silent version too. I found with the Silent one, you dont get much in the way of engine tone, but just a lot of 'thrust' noise on boost. With the Hi-power you get a lot more engine tone aswel as the on-boost thrust.

As for the midbox, I dont think there is any real restriction in there as AFAIK it is a straight thru perferated pipe indide the box. Removing it would make it louder, but how much..?
If you want more noise I'd change the system, but understand where your coming from with the diffuser.

:)
 

LuPix_S15

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Cheers craig - I was wondering that if I was really bothered, should I just change the whole cat back system from Silent Hi-Power to Hi-Power??

In your opinion, will there be a significant or even noticeable difference in volume and tone - I know you've said the above but is it worth another £350 or thereabouts minus the ££ I'll get back from selling the current system which is in excellent condition??


If there's not much the midbox is doing then why did HKS put it there lol?? (not aimed at you but HKS!!) *puzzled*


Cheers mate :)
 

craig8585

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The difference in noise between the 2 systems is definatly quite noticable, mostly from outside the car. The Hi-power is also a mild steel pipes with stainless boxes. I'm not sure how much you would get for your silent Hi-Power, but I know their expensive to buy new. Having had both systems I would choose the Hi-power for sure. If you go on track a fair bit you might want to check the noise level it emits though.

I'm not sure how much noise the mid box takes out, but cant imagine it being a massive amount due to the size of the box. It may be worth trying though as it would be a lot cheaper than a new system.


If you want to decide if its worth the change I'd be more than happy to kane it past you :)
 

LuPix_S15

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lol yes mate - can we arrange you drive past me in your car at 70 mph with me standing on the side of the road and then do it again in MY car lmao :D really... I'm serious!!!


Cheers dude :)
 
C

cougar power motorsport

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lol yes mate - can we arrange you drive past me in your car at 70 mph with me standing on the side of the road and then do it again in MY car lmao :D really... I'm serious!!!


Cheers dude :)
Someone has crazy ideas here:D
Mate the silencer there should only make the exhaust system more loud and when you take it off then i am not even sure if it will meet the track regulations. Since the Silent Hipower is a lot more expensive than the Hipower you should check if there is someone else willing to buy a silent one so that way you will save lots of money. But you still have the diffuser matter:p
 

DeanS15

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mate once you tune the car more and you take it for a few good blasts it will get louder :nod: im pretty sure mine has burnt a lot of wadding out as it really does boom now, and its definitely not a restriction worth worrying about, if a restriction at all;)
 
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cougar power motorsport

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mate once you tune the car more and you take it for a few good blasts it will get louder :nod: im pretty sure mine has burnt a lot of wadding out as it really does boom now, and its definitely not a restriction worth worrying about, if a restriction at all;)
+1
 

LuPix_S15

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Cheers guys...


Yeah it is tuned more - got a decat plus turbo elbow and downpipe but only very small amount of noise difference although I'm sure the flow is better :)

TBH I think I'm gonna source the 409 system from somewhere or someone soon and replace the Hi-Power I currently have.
 
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cougar power motorsport

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Cheers guys...


Yeah it is tuned more - got a decat plus turbo elbow and downpipe but only very small amount of noise difference although I'm sure the flow is better :)

TBH I think I'm gonna source the 409 system from somewhere or someone soon and replace the Hi-Power I currently have.
You ve got a pm man;)
 
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