"Droney" exhaust - any experts out there?

[kilmo_172cup]

I've just had a custom-made full stainless steel exhaust system fitted to my 172 Cup - 6” Rosi sports cat, 4” round centre box, 8.5” x 6.5” back box and 2.25” piping. I specifically asked for it to be “as quiet as possible” and as close to the standard OEM exhaust sound as could be done. I didn’t want it to have a drone sound during idle or at motorway speeds.

Unfortunately, it does drone somewhat during idle and at motorway speeds, especially on throttle.

Does anyone know if this drone can be eliminated and if so, what specifically needs to be done / changed? A different back box or piping maybe? I want to have my facts straight before I go back to the garage.

Thanks.

 

[botfch]

Tbh your always going to get some drone with these cars especially the stripped out cup editions
Best option is to tell them and see what they say, it may be that they where worried about impacting on the performance so have tried to hit a middle ground.

Personally I would just get some sound deadening and stick a barrier in the boot there's a thread on it somewhere.
http://www.cliosport.net/threads/sound-proofing.561994/

 

[kilmo_172cup]

Thanks Archtronics. I just don't recall my original OEM exhaust having a done sound - so don't know why they can't just make it like the original?!

 

[StevenMc29]

I found the KTec/Janspeed system with middle silencer and standard cat to sound pretty much like standard on my 182! Maybe have a look into that system and see if there are any major differences!

 

[kilmo_172cup]

Thanks Steven. Is this the one you are referring to for a 172?

http://www.k-tecracing.com/show_product.asp?id=3937&appid=2

 

[...]

Thats the one we have on our cup , quiet ,no drone and pleasant little sporty note pretty much quieter than standard.
They do get a little noisier with mileage and ours has done about 50k in the last couple of years

 

[kilmo_172cup]

Thanks for the info Harvsurrey. I will look into this exhaust further.