Stealth vs. Supersport Stealth

[Space Cadet]

I have the K-tec/Janspeed Stealth system and de-cat on my track 172, I’ve been thinking about popping the centre section from the Supersport stealth on and loosing my centre-silencer and a few kg’s. It would be fun to have a bit more noise and I can always swap them over if it gets a bit too much. I’m just worried about whether it will foul any drive-by regs, I normally go to Brands. Anyone had any problems with the Supersport stealth (and de-cat) fitted?

 

[imprezaworks]

My old ktec supersport decatted stealth read 94ish db at oulton, so miles away from the 105db limit.

 

[Space Cadet]

Thanks, just did a bit of searching on the internet and the Club MSV site says Brands is 105 static and 92 drive-by so like you say I should be ok. I know this has been covered before, but what's your opinion on the noise of the Supersport Stealth with the decat? I'm not fussed about droning on the motorway as I do very little and can put up with it for the odd time that I do, but what's it like the rest of the time? Is it chavvy or race-car'y?

 

[imprezaworks]

You will be fine with regards to the trackday. Mmmm i found the normal one too quiet and the supersport a bit droney on journeys, but like you say you dont do motorway journeys etc. Overall id say its better

 

[Space Cadet]

Thanks, I don’t mind the sound of the Stealth & de-cat, it has a nice pop now and again but it just sounds 'normal' now, like I say it’s a track car and doesn't get used much on the road let alone the motorway so I just fancy a bit of fun and liven the noise up a little. I just don’t want it to sound like a 1.2 with a drain-pipe fitted.At the end of the day its not going to sounds like a Ferrari is it, but there's a difference between BTCC race car raspy and Chave-mobile droney.

 

[Dan519]

Supersport stealth on cup with cat at Bedford yesterday (87.5db) was fine. Mild steel sport stealth on mine barely registered

 

[imprezaworks]

You will be fine mate. Only reason i changed mine as i get bored and the one ive got was too good to miss.

 

[Space Cadet]

Thanks guys, will give it a go then, can always swap the middle-silencer back over if it gets too much.

 

[yeecup]

Had supersport Stealth on my ph1, shocking heavy droning piece of sh1t, well rid of it.

 

[Space Cadet]

Had supersport Stealth on my ph1, shocking heavy droning piece of sh1t, well rid of it.

What did you change it to?

 

[Space Cadet]

Well I’ve ordered the straight-through middle section, should arrive tomorrow so I’ll be able to fit it at the weekend. Will take it for a spin afterwards and see what difference it’s made, I can always swap it back if it’s too much.

 

[Space Cadet]

Well I fitted the straight-through middle section and yes it’s a bit louder, but not too much and its not boomy louder, more of a metallic raspy louder and it pops and bangs a lot more now which childishly sounds great. All in all am pleased with the result.

 

[imprezaworks]

Glad you like it, and yeah if it gets annoying take it off....simples

 

[domjolly]

so want to get a straight through center section on my stealth again, i bought a silenced center section off her liked it at first but then i got rid of the decat, i just cant seem to find the exhaust note i like, it sounds like a wet fart with the center silencer in. With no silencer and a decat it sounded so droney on the motorway i nearly killed myself, fingers crossed losing the center section means it will be just right.

 

[emc]

My stealth is sending me mental on the commute at the moment, spend probably 2 and a bit hours on the motorway. That drone has pushed me to earplugs and Im quite worried its dangerous, like the muppet I saw today wearing over the ear headphones in an ST.

 

[-MEAT-]

^ Is that a regular one or supersport and with or without a cat? Probably spending about the same amount of time on my commute, all motorway miles.

On one hand i want to make an obnoxious amount of noise from time to time, on the other I value me hearing.

 

[Dan519]

My stealth is sending me mental on the commute at the moment, spend probably 2 and a bit hours on the motorway. That drone has pushed me to earplugs and Im quite worried its dangerous, like the muppet I saw today wearing over the ear headphones in an ST.

which one? do you have a cat and a center silencer? if not you have the loudest possible combination

 

[Space Cadet]

I don’t have a cat or the centre silencer and its not THAT loud, I admit it might be a bit much on a daily driver but I think it sounds pretty great. I was dreading it sounding boomy or droney but actually it sounds race-car raspy. Now don’t anyone think for one minute that I’m suggesting I think my car sounds like a Ferrari but it has the same metallic sound rather than sounding like a boomy big-bore turbo Supra. I also have ITB’s so not sure if that would make any difference?

 

[Laine_16v]

My stealth with cat is quite boomy on the motorway to be fair, and that is the quietest combo.

Will be changing soon

 

[Space Cadet]

I had a 350Z a few years ago with a Nismo exhaust and it sounded fantastic, I popped a set of sports-cats on and it ruined it, it totally changed the ‘type’ of sound – so I took them off. Just goes to show that just changing the OEM cats to aftermarket sports-cats can make such a difference. Perhaps it’s the Renault cat that is contributing to the droney noise?

 

[Dan519]

I don’t have a cat or the centre silencer and its not THAT loud, I admit it might be a bit much on a daily driver but I think it sounds pretty great. I was dreading it sounding boomy or droney but actually it sounds race-car raspy. Now don’t anyone think for one minute that I’m suggesting I think my car sounds like a Ferrari but it has the same metallic sound rather than sounding like a boomy big-bore turbo Supra. I also have ITB’s so not sure if that would make any difference?

Well I have the mild steel stealth and I can't hear it over throttle bodies. I put a cat in for MOT and it made a big difference to noise, and none on power (it's a very small, non renault cat) so I left it in.

Cat makes the biggest difference to noise, center silencer is next on the list

 

[Space Cadet]

So could keeping the cat on actually contribute towards the boom? Whereas I’ve taken mine off and it’s not boomy, just raspy.

 

[emc]

Hi Dan, I've got a cat but to be honest I'm not sure if the exhaust has been right since the car got a knock in back. Using a sound meter I get around 95db when at 70 on the motorway, which isn't that bad but I could tell it was causing damage to my hearing as they were starting to ache pretty bad after getting home. Not sure if the lack of sound proofing helps. I've got a de cat lying around which I haven't fitted yet, but if Space Cadet is right it might be worth trying. Love the sound of the exhaust at hi revs driving around normally, just the boom I can't stand. Got the car booked in with you on Friday Dan for a service, so you'll be able to tell if all is ok I'm sure.

 

[Dan519]

So could keeping the cat on actually contribute towards the boom? Whereas I’ve taken mine off and it’s not boomy, just raspy.

fitting a cat makes it a LOT quieter

Ah, didn't realise it was you in on Friday

 

[Space Cadet]

fitting a cat makes it a LOT quieterAh, didn't realise it was you in on Friday

Not me Dan, don’t know you or your garage. I'm no mechanic therefore am just thinking of all the different permeations of cat/middle-silencer/rear-silencer. I know its subjective, but as mentioned before my car just isn't boomey and all I have is the rear-silencer. It actually sounds less boomey but more raspy having removed the middle-silencer. Because of my experience on my old 350Z I wondered if the Cats were making things boomey. In addition to the ITB's my car is completely stripped out, so may be the lack of interior and sound-deadening is changing the resonance of the exhaust??

 

[Space Cadet]

Well I’ve had the straight-through middle section on now for a couple of weeks and IMO it sounds great, its not boomy on the motorway but admittedly is a bit OTT for pootling around town, but since its on a track-car it doesn’t matter. It pops and bangs and sounds really raspy. It recorded 94DB at Brands yesterday so all in all am very happy with it.

 

[Poopensharten]

SuperSport for me! Gets louder with miles! I loved mine!

 

[w33 brl]

ive just put a decat into my stealth system and it is raspy...doesnt seem loud yet

 

[Space Cadet]

I’m not sure what all the fuss is about with it being too loud or boomy. In fact it’s not boomy at all; it’s just metallic-raspy. My car is completely stripped, has ITB’s, is de-cat’ed and has the straight-through middle-section and its fine. Like I say it’s a bit OTT for a daily driver but for a weekend toy/track-car its fine and passed the noise regs at Brands with ease.