How loud are they

gas guzzler · #1 4th August 2016, 17:19

I find my 2.8 Z300s a little on the quiet side, standard exhaust system still on, so I was wondering how loud are they with the rear box removed. Thinking of just having a straight exhaust out the back. I've seen WCA's and Ian's but not actually heard them. Just wondering if you go on a long drive by the end of it are you thinking 'could do with being a bit quieter'.
So opinions from anybody who's removed the rear box would be gratefully received.

Cheers Andy

fatbloke · #2 4th August 2016, 18:14

On my MX I had an exhaust built which took out the mid box and I have a decat pipe which helps makes it sound pretty good. Not sure if you can do the same with a Z3.

IanA · #3 4th August 2016, 19:02

My Z300S has a large bore stainless steel pipe from the rear of the centre silencer to the wheel arch. I've found it a little wearing in traffic but great on a long run.

For commuting I fit a baffle (4 perforated plates) which does affect performance but makes it more liveable with. Flooring the throttle produces a hiss like a leaking exhaust. There is still a lovely crackle on the overrun however. I usually remove the baffle for shows... I've not used the stereo since I fitted that pipe.

hurnleft · #4 4th August 2016, 20:35

Have a look on the Kebab thread if you like. It runs a rear silencer suitable to give it a bit more bark than standard but fine for distance travelling. There's a remote cut out for when I want to play…sounds lovely. A big grin every time I rev it and on the overrun.

Bob.

casamolino · #5 5th August 2016, 08:49

Morning Andy just before i had my current exhaust system fitted , the company that built and fitted it tried the car with the large rear box removed , it is very loud i would be surprised if livable with over a long distance . I opted for a pair of silencers with twin pipes out of each , sound good on acceleration and on overrun , but usable day to day , so far longest drive in one day was 360M , thanks Geoff .

WorldClassAccident · #6 5th August 2016, 09:40

When not under load the engine is relatively quiet so quite easy to live with having said that...

...on the drive to the Le Mans Classic I was in fast convoy with a Ferrari 612, Aston Martin Vantage, Maserati Granturismo and Jaguar XKS, I didn't know the guys and just tagged along. We were making good progress with lots of sillyness like driving alongside the car in front and then full throttle acceleration away and every tunnel sounded glorious.

We stopped for petrol and they were very curious about my car as they couldn't work our what it was or what engine was in it. For quality of sound in the drive-bys and the tunnels they put it ahead of the Jaguar and on a par with the Aston which I founds flattering.

When I told them it was just a 2.8 BMW through an autobox they were genuinely surprised as two had decided it was a 4.0 V8 from a TVR and the other two weren't sure because it wasn't bass enough for a V8 but they couldn't think of any large capacity sixes that were right.

I regularly drive Southampton to Stevenage and back in a day. No stereo in the car and very rare to have the roof up. Motorway speed cruising the noise is just a background hum mostly drowned out by the tyre noise from other cars.

I will try to find a photo of it. A very neat installation with a 1:2 box squeezed behind the cat and in front of the diff allowing to pipes to flow unrestricted out to the back of the car. Similar to above but without the need for the two silencers.

WorldClassAccident · #7 5th August 2016, 09:44

This shows the two (rusty) pipes from the engine going to the Cat. There is a single pipe about 6 inches long between the Cat and the new shiny silencer. Coming out of the customer made short silencer are two 2" pipes that are nice and symmetrical and unobstructed to the back of the car where there are some 3" upturned tips

gas guzzler · #8 5th August 2016, 18:10

Thanks for the replies, looks as if some type of rear box is needed

Cheers Andy

WorldClassAccident · #9 6th August 2016, 06:56

Probably best, but just a small one.

My middle photo shows the size for mine and that is fine

275NART · #10 6th August 2016, 16:08

I'm not sure if it's legal in your country but there are mufflers which have built in electronic diverter valve which passes the exhaust gas through an un-baffled section in the muffler, effectively making it a straight pipe with the flip of a switch. This is a much cleaner install than having two separate pipes.

http://www.xforce.com.au/products/varex-mufflers

Paul L · #11 6th August 2016, 20:13

Quote:

Originally Posted by 275NART

... there are mufflers which have built in electronic diverter valve which passes the exhaust gas through an un-baffled section...

This is exactly what Bob/Hurnleft did on his SWB 250.

WorldClassAccident · #12 6th August 2016, 20:17

You can do the same but route the 'special pipe' inside the silencer. Same effect but neater

gas guzzler · #13 20th August 2016, 18:00

Well I cut the rear box off and had bought a silencer (cherry bomb) to fit but thought I'd see what it sounded like first. Sounds nice, not to loud at all, at 40mph hardly noticeable, however open it up sounds just like an old Jag or Healey 3000, very nice. Only drove a short distance to try out will take it for a long drive tomorrow to see what it's like in a variety of conditions.

Andy