Nick_Scooby

I have a purchased an HKS Hi Power Silent back box with centre section for my 1994 WRX, How loud is this system likely to be? I also have 3" decat downpipe.

I know it's named Silent but with the downpipe as well will it be that quiet?

myblackwrx

iTrader: (1)

My mate has an HKS system on his 94wrx (with decat) and last week he nearly got a section 59 as the police officer didn't like the noise.

https://www.scoobynet.com/non-scooby...affic-act.html

Nick_Scooby

So just because it's called silent, doesn't mean anything?
Or does it mean its quiter than other straight through back boxes?

RRH

The silent is quite quiet; hks make other systems, some of which are rather loud- as per post #2 above.

exvaux

iTrader: (1)

yeah post 2 could be an hks super dragger like my mate has on his gts skyline which is way too loud

Nick_Scooby

When you say quiet, surely it can't be that quiet! I hope not, I don't want it to really loud, but I don't want it to be really quiet!

I want loudish - With decat downpipe maybe it will be quiet loud?

RRH

Probably not- its just about the quietest after-market system you can buy hence its name.

philc

The spec c I purchased had a 3 inch Rage turbo back exhaust fitted - and this clocked in at 94.5 dbs when tested (the legal limit here is 80dbs), so I fitted a 3 inch HKS turbo back hi-power silent instead.
It's much, much quieter, but still provides a nice engine note when the accelerator is depressed.

btw - the Rage exhaust saw a gain of 18kw ATW; there was a loss of 2kw after fitting the HKS (which may be explained by being on a different dyno on a different day .... so negligible difference)

RRH

If the HKS silent for the Impreza is the same as the Evo, although the majority of the system is 3" it does drop to 2.5 just behind the cat (or cat replacement pipe), and narrows even more as it exits the backbox- just look up the tail pipe and you'll see the restriction.

Unfortunately this is the trade off for a very quiet exhaust. I did like the fact that it was a lot quieter on the Evo, but it felt approx 100bhp down on the A'Pexi (true) 3" system that I sold. I ended up buying the A'Pexi back again- while its real noisy I couldn't live with the loss of power and was concerned that it wasn't carrying heat away from the engine as quickly.

All in all, on a reasonably standard car, if you want a quiet exhaust then the HKS silent is about the best money can buy- but it sounds like you may have bought the wrong one for what you want it to do.

On the plus side, they do seem real easy to sell and doubt you'd lose anything if that's what you decide to do.

Personally, if you want noise, I'd look at the scoobysport, h&s or TSL offerings.

Hope this helps- sorry if its not what you wanted to hear.

Nick_Scooby

I just found this:- HKS silent HiPower Muffler

And it doesn't sound to quiet to me, I know it's not a great indicator of sound but it's something!

A few months back I got a straight through 3" system from Cobra Exhausts UK Custom Stainless Steel Exhausts, but it was MEGA LOUD!!! Crazy crazy, driving a long gave me a headache, and I felt it was more sluggish?!? but in theory it shouldn't had been should it?.

Also, my midpipe at the moment has loads of small holes in it -rusty, would this car my car to do small coughs at low revs on odd occasions or would that be something else?

Nick_Scooby

BTTT

gizgrey

i just took one of these off my scoob with full decat,sounded great not too loud for cruising around sounded nice outside car,great exhaust unless your after attention.

Nick_Scooby

was it quite loud though?

gizgrey

was louder than standard exhaust its about the same as a magnex oval system if that helps not as loud as most aftermarket systems

20withascooby

i have a stainless steel down pipe de cat and a hks super drager exhaust de baffled and everyone asks me wats it is coz the noise ppl say it sounds like a jet when im goin slow its got that nice flat four noise but when i put my foot dwn every1 looks il try post a link to a video of me in it.soo nto be de silenced stainless steel centre section aswell

20withascooby

also if you wanted a exhaust with noise why wud you go for one with silent in the name dnt make sense