How restrictive is the silencer on the T5?

[T5Tom]

Just been having a mooch under the new motor and noticed a HUGE silencer! I'm looking at decatting my car but can't help but think there would be no point unless I got rid of the big silencer aswel, or have people with experience realised its too loud when this is taken off with a decat too? Plus its got to be extremely heavy right?

Tom

[LiamT4]

First of all how many silencers do you have?

My s70r had 2, the huge "suitcase" and then a smaller one at the back.

You won't get any noticeble gains from removing the silencer, but it will sound much better.

Think my silencer weighed around 10-12kgs.

[simpT5]

My car just had the one huge "suitcase" silencer, I removed it and had a straight through pipe put in its place. So from the cat back, I had no silencers at all!

It sounded bloody lovely, but was just too loud for everyday use and it'd drone like hell at motorway speeds. I ended up getting a custom made cat back exhaust with just one small silencer fitted. It's still sounds great but doesn't deafen me on long runs!

[jayeastanglia]

oh yeah they sound so nice with the suitcase removed but beware it can be loud if you start early in the morning or roll home late at night in a quite area..and decatted it will be even louder..Got my suitcase removed and its ok for me as all my neighbours have loud pipes on there bikes or cars..only negative i have is my wife can hear me rag it going out of town or coming home as can be heard from about 1/2 mile away.. dunno if it made any power gains as mines never been on a rolling road but the exhaust box is heavy..

[Al115]

Not very.

Most vendors quote ITRO 15bhp gain from a full sports exhaust inc cat.

Not really worth cutting the silencers out on a daily driver in my view... the drone you get without them is really irritating.

[LiamT4]

I'd love to remove the small silencer on the back as well, because they do sound great with a straight through system, but i know i'd get really fed up of it when doing long journeys.

If you don't have a silencer on the back as well, then i'd have the suitcase removed but have a small one fitted at the rear.

[T5Tom]

Thanks lads, I reckon ill just chop out all the gubbins from my cat and leave the suitcase on then! Although i did that on an astra I once owned and it sounded horrible! Has anyone done this?

[jayeastanglia]

oh yeah was gonna add that but forgot they do have a drone at about 55-60mph in 5th gear or about 35-40mph in 4th gear..

[T5Tom]

At the risk of sounding stupid... Does the pipe carry on through the suitcase, or is the suitcase just one massive chamber? I'm hoping the first as the if it was a chamber it would be really restrictive wouldnt it?

So for best daily drive, strip the cat out and leave the suitcase on??

Thanks for all of your help!

[T4Rick]

Its not straight through.Ive got a 3inch cat back on mine with two small silencers and it sounds well.Im yet to build my down pipe to cat yet in 3inch

[merc85]

At the risk of sounding stupid... Does the pipe carry on through the suitcase, or is the suitcase just one massive chamber? I'm hoping the first as the if it was a chamber it would be really restrictive wouldnt it?

So for best daily drive, strip the cat out and leave the suitcase on??

Thanks for all of your help!

It's not straight through, various baffles/channels.

ask Bigrotch he had a straight threw on his and kept his cat. he Used a De-cat that i had made, ie cut and joined then re used a back half silencer system.