Changing exhaust back box

[Mastodon2]

Hey guys, I'm considering changing the back box of the exhaust on my car and I've got a few questions I hope someone will be able to help me with. I'm thinking of going with a cherry bomb straight pipe, because they are cheap, have potential to be really loud (although I won't be making mine obscenely loud) and apparently an easy fit. Having googled "cherry bomb pistonheads" I see they are popular with TVR owners. I don't have a TVR though, just a 1.3L Fiesta.

I am aware I will have to inform my insurance company and in all likelihood, pay a small amount extra for the modification. However, I will not be modififying the cat (no decats, cat-backs, high-flows etc) and the centrebox will be staying, which keeps the pipe from being ridiculously loud. If the cat and centre box are intact and standard, will fitting a cherry bomb affect the MOT passability for emissions or noise? I am not aware of the back box doing anything for emissions, but there is a chance it could be too loud for an MOT pass, with noise level tests being quite stringent these days if I am correctly informed.

So heres what I want to know; can the current back box be removed (saw off between the box and the centre pipe) and saved for MOT time? Apparently the bomb pipes are "slip on", does this mean the exhaust can be sawn off by a mechanic, and the new pipe put on with ease, and the OE back box saved and put back on for MOT time? Is this a difficult job and is it likely to cost much in labour?

I should point out, I'm not doing this for any Asda car park or bombing-run through council estate type antics, I just want a bit of glassy rumble from my exhaust, which currently is loudish (all standard parts too) but quite raspy and harsh sounding.

Thanks

Dave

[hombrepaulo]

Grabs Popcorn

[ADEuk]

Save yourself some time/money/face by fitting a proper backbox.
A cherrybomb will not make it faster, or more economical it will just sound silly

[V88Dicky]

I run a MK 4 Fiesta as a daily snotter, and it's needed an exhaust for MOT before. I ordered a back box and centre section, complete with all the clamps and rubbers for the princely sum of £45 iirc.

The back box is removed by loosening the rear clamp and, with the help of a rubber mallet, seperating it from the centre section. Mine was siezed, so needed to be cut off. It really is a simple job.

No idea why you want to make that old pushrod lump sound any louder, but hey ho, each to their own I guess.

[Cost Captain]

don't. just don't. the reason you don't like the noise that comes out your exhaust is because the engine supplying the sound is never going to make a lovely noise.

all you'll do is make a bad noise louder.

[V88Dicky]

doogz said:

V88Dicky said:

I run a MK 4 Fiesta as a daily snotter, and it's needed an exhaust for MOT before. I ordered a back box and centre section, complete with all the clamps and rubbers for the princely sum of £45 iirc.

The back box is removed by loosening the rear clamp and, with the help of a rubber mallet, seperating it from the centre section. Mine was siezed, so needed to be cut off. It really is a simple job.

No idea why you want to make that old pushrod lump sound any louder, but hey ho, each to their own I guess.

Is the 1300 still the kent?!

I'd assume the OP has the 60BHP chain cam OHV engine thats been around forever, and was last seen in the MK1 Ka up until about 2003?
Don't know if thats called a Kent though.

[thinfourth2]

You car is a quiet crap sounding car

Change the back box and it will be a louder, more annoying crap sounding car with the added bonus of increasing the chance of a tug from plod


Go ahead change the back box

[Cost Captain]

doogz said:

V88Dicky said:

doogz said:

V88Dicky said:

I run a MK 4 Fiesta as a daily snotter, and it's needed an exhaust for MOT before. I ordered a back box and centre section, complete with all the clamps and rubbers for the princely sum of £45 iirc.

The back box is removed by loosening the rear clamp and, with the help of a rubber mallet, seperating it from the centre section. Mine was siezed, so needed to be cut off. It really is a simple job.

No idea why you want to make that old pushrod lump sound any louder, but hey ho, each to their own I guess.

Is the 1300 still the kent?!

I'd assume the OP has the 60BHP chain cam OHV engine thats been around forever, and was last seen in the MK1 Ka up until about 2003?
Don't know if thats called a Kent though.

That's the one. Well, it's been called a lot of things, Crossflow, Valencia, Kent, etc.

Man, that's been around a long time.

A cherry bomb on that is going to really accentuate that lovely tappety noise they all make.

It's called the Endura E when fitted to mk4 fiesta and mk1 kas.

[OllieWinchester]

I think it is called the Endura-E now.

OP, ignore all the naysayers and do it, they have just forgotten all their own forays into faffing about with their own sheds at the same age.

[Cost Captain]

doogz said:

Cost Captain said:

doogz said:

V88Dicky said:

doogz said:

V88Dicky said:

I run a MK 4 Fiesta as a daily snotter, and it's needed an exhaust for MOT before. I ordered a back box and centre section, complete with all the clamps and rubbers for the princely sum of £45 iirc.

The back box is removed by loosening the rear clamp and, with the help of a rubber mallet, seperating it from the centre section. Mine was siezed, so needed to be cut off. It really is a simple job.

No idea why you want to make that old pushrod lump sound any louder, but hey ho, each to their own I guess.

Is the 1300 still the kent?!

I'd assume the OP has the 60BHP chain cam OHV engine thats been around forever, and was last seen in the MK1 Ka up until about 2003?
Don't know if thats called a Kent though.

That's the one. Well, it's been called a lot of things, Crossflow, Valencia, Kent, etc.

Man, that's been around a long time.

A cherry bomb on that is going to really accentuate that lovely tappety noise they all make.

It's called the Endura E when fitted to mk4 fiesta and mk1 kas.

Same engine though yeah?

Virtually identical, i think there are a few differences in terms of packaging the thermostat and obviously the endura is injection, but mechanically, i think they are the same.

[Cost Captain]

OllieWinchester said:

I think it is called the Endura-E now.

OP, ignore all the naysayers and do it, they have just forgotten all their own forays into faffing about with their own sheds at the same age.

the fact i remember what happened when i modified my endura-e equipted car is what leads me to tell him to avoid it like the plague.

[B'stard Child]

hombrepaulo said:

Grabs Popcorn

Steals some of hombrepaulo's popcorn & pulls up a comfy chair

[mrmr96]

Mastodon2 said:

Hey guys, I'm considering changing the back box of the exhaust on my car and I've got a few questions I hope someone will be able to help me with. I'm thinking of going with a cherry bomb straight pipe, because they are cheap, have potential to be really loud (although I won't be making mine obscenely loud) and apparently an easy fit. Having googled "cherry bomb pistonheads" I see they are popular with TVR owners. I don't have a TVR though, just a 1.3L Fiesta.

I am aware I will have to inform my insurance company and in all likelihood, pay a small amount extra for the modification. However, I will not be modififying the cat (no decats, cat-backs, high-flows etc) and the centrebox will be staying, which keeps the pipe from being ridiculously loud. If the cat and centre box are intact and standard, will fitting a cherry bomb affect the MOT passability for emissions or noise? I am not aware of the back box doing anything for emissions, but there is a chance it could be too loud for an MOT pass, with noise level tests being quite stringent these days if I am correctly informed.

So heres what I want to know; can the current back box be removed (saw off between the box and the centre pipe) and saved for MOT time? Apparently the bomb pipes are "slip on", does this mean the exhaust can be sawn off by a mechanic, and the new pipe put on with ease, and the OE back box saved and put back on for MOT time? Is this a difficult job and is it likely to cost much in labour?

I should point out, I'm not doing this for any Asda car park or bombing-run through council estate type antics, I just want a bit of glassy rumble from my exhaust, which currently is loudish (all standard parts too) but quite raspy and harsh sounding.

Thanks

Dave

Dave, the backbox has nothing to do with emissions. The MOT does not contain a noise limit for cars. (It does for motorbikes). You will not need to refit the original backbox to pass the MOT. I think a lot of people on this forum have forgotten what it was like to be young and poor but still want an 'interesting' exhaust note. It will never sound like a TVR, or Ferrari etc. It will sound like a 1.3 with a bean can. But if that's what you want then do it.

[superman84]

mrmr96 said:

Mastodon2 said:

Hey guys, I'm considering changing the back box of the exhaust on my car and I've got a few questions I hope someone will be able to help me with. I'm thinking of going with a cherry bomb straight pipe, because they are cheap, have potential to be really loud (although I won't be making mine obscenely loud) and apparently an easy fit. Having googled "cherry bomb pistonheads" I see they are popular with TVR owners. I don't have a TVR though, just a 1.3L Fiesta.

I am aware I will have to inform my insurance company and in all likelihood, pay a small amount extra for the modification. However, I will not be modififying the cat (no decats, cat-backs, high-flows etc) and the centrebox will be staying, which keeps the pipe from being ridiculously loud. If the cat and centre box are intact and standard, will fitting a cherry bomb affect the MOT passability for emissions or noise? I am not aware of the back box doing anything for emissions, but there is a chance it could be too loud for an MOT pass, with noise level tests being quite stringent these days if I am correctly informed.

So heres what I want to know; can the current back box be removed (saw off between the box and the centre pipe) and saved for MOT time? Apparently the bomb pipes are "slip on", does this mean the exhaust can be sawn off by a mechanic, and the new pipe put on with ease, and the OE back box saved and put back on for MOT time? Is this a difficult job and is it likely to cost much in labour?

I should point out, I'm not doing this for any Asda car park or bombing-run through council estate type antics, I just want a bit of glassy rumble from my exhaust, which currently is loudish (all standard parts too) but quite raspy and harsh sounding.

Thanks

Dave

Dave, the backbox has nothing to do with emissions. The MOT does not contain a noise limit for cars. (It does for motorbikes). You will not need to refit the original backbox to pass the MOT. I think a lot of people on this forum have forgotten what it was like to be young and poor but still want an 'interesting' exhaust note. It will never sound like a TVR, or Ferrari etc. It will sound like a 1.3 with a bean can. But if that's what you want then do it.

Funnily enough when I got pulled by a copper a few weeks ago I was told that my exhaust shouldn't have passed the MOT based upon the noise and that any exhaust 'louder than the factory standard is illegal'. Obviously I ignored the copper but it's not entirely clear to me what the legal position on loud aftermarket exhaust systems is. With a de-resonated centre-section, decat down pipe and a large backbox, my car isn't quiet and I have no intention of changing it, only the cat come MOT time, but still can the police force you?

To the OP - don't put a fart can on a 1.3. It will pass the MOT but sound awful.

Edited by superman84 on Wednesday 27th October 12:37

[mrmr96]

superman84 said:

Funnily enough when I got pulled by a copper a few weeks ago I was told that my exhaust shouldn't have passed the MOT based upon the noise level its making and that any exhaust 'louder than the factory standard is illegal'. Obviously I ignored the copper but it's not entirely clear to me what the legal position on loud aftermarket exhaust systems is.

Did you ask the copper what the official noise level for your car is? He won't be able to tell you because it's not recorded. There is therefore no noise limit as part of the MOT for cars.

[ADEuk]

You can potentialy fail on exhaust noise if it is significantly louder than the same car with a similar system.
The key words are 'significantly' and 'similar'.
A car with a standard sytem IS NOT similar to a sytem with a 'cherry bomb' on it and cannot be used as a comparison, so it should be pass and advise

Edited by ADEuk on Wednesday 27th October 12:42

[GPT]

I'd say don't do it.

There's nothing worse than a car with a crap sounding engine and a loud exhaust...

..except a slow car with a crap sounding engine and a loud exhaust.

You hear one of these things coming down the road and you can still see it half an hour later when it's wheezing off into the distance. At least crap sounding loud motorbikes are normally into and out of range pretty quickly.

Still, if a louder exhaust is what you want, do it.

[Mastodon2]

mrmr96 said:

Dave, the backbox has nothing to do with emissions. The MOT does not contain a noise limit for cars. (It does for motorbikes). You will not need to refit the original backbox to pass the MOT. I think a lot of people on this forum have forgotten what it was like to be young and poor but still want an 'interesting' exhaust note. It will never sound like a TVR, or Ferrari etc. It will sound like a 1.3 with a bean can. But if that's what you want then do it.

Thanks for a good response. I'm aware it's not going to sound fantastic, but I can't get insured on an Impreza / Lancer Evolution or anything with a V6 or a V8. I just think it sounds a bit strangled and st at the moment, and I have seen, in person, examples of simple cherry bomb exhausts making harsh sounding engines sound quite good in the case of Suzuki Swifts and and older Honda Civics, giving them a nice throaty rumble. I just want to do it for a bit of a laugh and for the sake of tinkering a bit, and to give it a little bit of a talking point. I know it's an old car, with an ancient engine design, and it's not at all fast and I have no pretentions of making anyone believe it is. Cheers mate!

[ShadownINja]

Just drill a hole in the backbox. Mine's got a rust spot that's now a hole and it has transformed the car.









By transform, I mean it sounds st and I will have to get it resealed.

[grimfandango]

When the exhaust on my Ginetta snapped in the middle, I just welded a bit of exhaust pipe sticking out the side of the car. It passed 3 MOT's like that and it was pretty loud obviously having no silencer I never got stopped or anything, So I'd say if you want to put a Cherrybomb on it then get on and do it! dont worry about the cops, MOT ect, Still might sound crap though!