FCS black flags, what did you do?

[MuZiZZle]

FCS was my first outing in the VTS, like many, I was black flagged for noise.

First static was 87db, then after a few laps I was pulled in for a driveby of 99.2

A retest on the static and it was up a few db, I blocked off my morette feed and doubled the CDA pipe back on itself to please the scrutineer, then basically drove like an old lady as if we were flagged again we were off!

The static was done at 4500rpm, I'm guessing the extra 12db was when I was within the powerband of the cams.

what modifications did/do you guys use to bring your volume down?

I'm running a 4-2-1, decat, silenced magnex

Cheers

[greyjasper51]

we had that at cadwell the other week and literally in the back of the exhaust after the silencer we put like a restricter in, made 0 difference to power and quietened it by 3dB.. other people will prob say different but thats how we cured it and after the race put a new silencer in it and worked a dream :)

[MuZiZZle]

that 3db would probably save my bacon!

Croft is my local track but no way am I going to get down to 85db for there

could you show/tell me about the restrictor?

[barwell1992]

Stick exhaust baffle in eBay they should show up

[harry289]

Just use a quieter exhaust system? Pop a standard system on for Croft?

[AndySAXO]

Are you using a middle box? Mine was 88 db there, no problem with drive bus.

[sexy_gt]

I have throttle bodies and never got flagged. Strange. Was it you who asked me for advise?

[MuZiZZle]

I have throttle bodies and never got flagged. Strange. Was it you who asked me for advise?

Yeah it was mate

[MuZiZZle]

Just use a quieter exhaust system? Pop a standard system on for Croft?

I thought the magnex was!!!!

[blackie_2k5]

magnex are quiet :p

it must be your induction mate?

[harry289]

Yeah with your car under load on track it could just be your induction? :P

[MuZiZZle]

12db from a CDA feeding from a morette

Bah!

[MiniGibbo]

Bmc cda's are known for being quiet too.... :detective:

[MuZiZZle]

So it's just got to be that the static wasn't in the cam "zone"?

[MiniGibbo]

That would be my guess, do you have a cat..? That makes a huge difference on mid range noise.

[MuZiZZle]

Negative my huge gay friend

I'm catless

[MiniGibbo]

In that case put it back in and it'll solve your problem.

Weird though as I have no cat, silencer or baffles in the back box... Must be all the extra noise your 8v's make :homme:

[Olly]

It wont be the insuction noise.

Silencer (s) in the exhaust... decent ones?go big if possible, it wont effect power really.

[Mochachino]

Drive like a fanny on the straight at Donnington :y:

[MuZiZZle]

Drive like a fanny on the straight at Donnington :y:

He wouldn't tell me where the mics were

:(

[Alanapone]

I was thinking about this the other week.

Here's my theory...

We all know that just changing a back box on a standard car makes near as damn it, No difference to the power but you get the extra noise..... Conversely then, could we say that fitting a standard backbox would have the inverse effect i.e. not affect power but reduce the noise?

Would be interesting to try it on some rollers to see if a tuned engine and breathing mads is affected much by the choice of backbox.

Just throwing that out there, feel free to shoot me down now :y:

[MiniGibbo]

To add more to that, some 205 gti's run the oem exhaust on gti6 engines and make good power.

[Alanapone]

I might book 2 sessions at the Rolling Road day I'm organising to do a comparison. :y:

Piper backbox Vs. Standard backbox.

[MiniGibbo]

Unless you can flash your Ecu it won't make a difference fast enough as iirc it takes a few hundred miles for the Ecu to adjust..

[Alanapone]

hmmmm..... scuppered that one then. :( lol.

[benkelsall]

106 GTi standard back boxes are good, but hard to come by.
I'm sure changing the back box to a standard one on a saxo/106 isn't going to effect the power much, would hardly notice I bet. (Unless running high power)
Be worth it, save the hassle at track days.

[AlexB]

To add more to that, some 205 gti's run the oem exhaust on gti6 engines and make good power.

quite a lot of people say the 205 gti exhaust is a damn good design be peugeot but its from the days before emmissions noise ect made restrictions in the system

[titchster]

He wouldn't tell me where the mics were

:(

Just past the pit entrance. :beard: When you go into the pits, it's near the pit wall, up on a big black pole.

The reason it'll have been louder on track will have been because it was under load. Drive by usually is louder than static because of that.

[Harv]

Cut a big square hole in your silencer and I can almost guarantee you'll have no packing left within the silencer with db readings like that. You can buy some more packing for dirt cheap, get it welded back up and jobs a good'un. I did it on my old exhaust system and it came down from 98db to 84. It's a common thing to do with track cars as the extreme temperatures and fast passing exhaust gasses on track make the packing slowly disintegrate.

The above procedure takes about an hour max :)

[Ryan]

Regarding a standard silencer and non standard center pipe.

I've run a car like this, it was quieter but did sound shit. The car did seem to suffer a touch but then it was a crappy 8v anyway.

[gazza808]

Regarding not making any extra power when just fitting a back box to a standard system, it's because the rest of the exhaust is still the restriction,
So the theory doesn't work the same way with fitting a standard back box to different system.