center box and back boxes

k4lps · Post by **k4lps** » Sun Jun 05, 2005 8:53 pm

what exactly does the center box do??? is it worth removeing?

anyone experimented with the insides of a backbox??

GroovyCarrot · Post by **GroovyCarrot** » Mon Jun 06, 2005 12:27 am

The centre box just acts as a silencer. You can remove it and replace it with a straight through system if you want, and your car will sound like a 747 preparing for take off. Worth removing if you like that kind of thing

k4lps · Post by **k4lps** » Mon Jun 06, 2005 2:27 pm

747 on take off hmm maybe i'll keep it on
wait it cant be that loud can it?

JarnoVWPolo6N · Post by **JarnoVWPolo6N** » Mon Jun 06, 2005 4:18 pm

Removing your centrebox doesn't make your car sound like a jet

But is does make it sounds more aggressive and louder and in my opinion removing it makes a car sound much better. It's got that dark sound to it

And replacing your centrebox get's the best results in sounds if you also replace your back box.

GroovyCarrot · Post by **GroovyCarrot** » Mon Jun 06, 2005 5:56 pm

Yeah, it won't actually sound like a jet, unfortunately.. although the noise levels will be similar

I'm not a fan of loud exhausts on small cars, but if it's your cup of tea then go for it

ZOMBIE · Post by **ZOMBIE** » Mon Jun 06, 2005 7:25 pm

Some of the earlier polos didnt come with a centre box and ive heard one or two and to be honest they sound quite loud and farty

I dont think it sounds particularly well tuned which is what polos should sound like

Tahrey1043 · Post by **Tahrey1043** » Mon Jun 06, 2005 11:12 pm

if you just hacksaw* the backbox off (leaving the cat and centre in place), it sounds somewhere between a v8 and a revved harley, when running slow - quite nice if you can handle the volume and surprisingly non-farty. But then, it turns into a dirtbike and does your head in when you plant it and go over about 2500rpm!

removing centrebox probably goes halfway to that as it's not as large a silencer..

* not done it, but i have had the entire pipe-to-backbox weld fail catastrophically after suffering 12 years of rust then going over an evil speedbump..

carmadaaron · Post by **carmadaaron** » Tue Jun 07, 2005 10:36 am

for the loudest combination (with the cat still in) is no centre box (juss a straight thru pipe) and a back box as small as possible.

does sound a bit crackly at high revs (like ur average nova with a 5" tailpipe being revved by a chav)

basicaly for a wee polo. leave the boxes on

GroovyCarrot · Post by **GroovyCarrot** » Tue Jun 07, 2005 11:14 am

carmadaaron wrote:basicaly for a wee polo. leave the boxes on

Got to agree with that

A nice quiet burbly sound from a subtly uprated system is nice, but the moment you start going for maximum volume on a small capacity four pot it sounds awful, and just doesn't suit the car anway.

Tahrey1043 · Post by **Tahrey1043** » Tue Jun 07, 2005 8:26 pm

unless you upgrade all the engine bits, remove the limiter, and scream it round to 8500rpm

GroovyCarrot · Post by **GroovyCarrot** » Tue Jun 07, 2005 9:08 pm

Limiter? You're in the mk2 forum sunnyjim, we ain't got no new fangled rev limiters round here!

Leads me to wonder just how far my 1043 would rev before something snapped.. one of those things that will have to happen if I'm ever forced to scrap her..

ZOMBIE · Post by **ZOMBIE** » Tue Jun 07, 2005 10:31 pm

Sorry to stray from the exhaust thing- but I thought the mk 2s had a limiter in the rotor arm built in, and that most of them would have just been replaced with cheap repro rotor arms when the original was worn, I dont think theres one on my car though! i havent found it yet anyway!

GroovyCarrot · Post by **GroovyCarrot** » Tue Jun 07, 2005 10:40 pm

None of the late mk2s had limiters, the ones with electronic ignition which came in at the same time as the hydraulic tappets etc, 1986. Some of the earlier ones did, but it's a physical limiter that just stops the distributor from conducting the spark beyond a certain engine speed, and you can't fit them to late type distributors..

carmadaaron · Post by **carmadaaron** » Wed Jun 08, 2005 11:07 am

ZOMBIE wrote:Sorry to stray from the exhaust thing- but I thought the mk 2s had a limiter in the rotor arm built in, and that most of them would have just been replaced with cheap repro rotor arms when the original was worn, I dont think theres one on my car though! i havent found it yet anyway!

*cough* try it out and see how high it'll rev

polock · Post by **polock** » Wed Jun 08, 2005 11:35 am

Back on track (kinda)

My centre silencer has dveloped a hole which makes it sound like an angry bee under heavy acceleration, lol. I dont suppose the back box is far off either. And, i want to get rid of the boody awful looking corrugated pipe just after the downpipe.

Rather than having to keep shelling out for replacement standard parts i was wondering if anyone knew of a manufacturer (jetex/magnex etc etc) that do an off-the-shelf system for a '88 Polo C squareback?

Im not bothered about sound & performance, i just want a stainless system i dont have to replace every 12 months.

Cheers, Brian