Flexi Exhaust Section - Why, What For, and is it needed?

[ian_kennett]

I need to replace the centre section of my exhaust, and was considering replacing the lot with stainless.

What's the deal with the flexi section and what does it do? Would the replacement stainless exhaust need to have a flexi section too?

Cheers,

Ian K.

[francophile1947]

Welcome to the madhouse - please read http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=29471 - it really does help to know where you are
My stainless system has a flexi section - I assume it probably cuts down on vibration, but I'm not really sure

[scanner]

Yes, unless you want a lot of extra noise and vibration.

It isolates the exhaust manifold (and thus the engine) from the rest of the exhaust system which is mounted on the vehicle body (albeit by rubber mounts) if it isn't there those mounts have a lot more work to do.

[ian_kennett]

Thanks for the welcome and thanks for your rapid replies.

Since posting, I've had a chat with the guys at the garage I use for all my servicing and they explained that it is indeed to do with the extra vibration generated with diesel engines (especially those mounted transversely). They also strongly recommended having a flexi section if I replaced the system with stainless - especially when considering that stainless can be prone to cracking (but I guess that depends on the quality of the system).

Cheers,

Ian K.

[jaylee]

While were on the subject..
I had the back box down as an advice on the MOT a month ago..
So, i'm thinking stainless replacement! (lighter weight & all that?)

Anyhow.. Can a stainless rear section be fitted to the front, or is there some kind of incompatibility with the two different compositions when hot & all that??

Or do you think "false economy" & get the lot done?

[scanner]

While were on the subject..
I had the back box down as an advice on the MOT a month ago..
So, i'm thinking stainless replacement! (lighter weight & all that?)

Anyhow.. Can a stainless rear section be fitted to the front, or is there some kind of incompatibility with the two different compositions when hot & all that??

Or do you think "false economy" & get the lot done?

If it's only an advice all I'd do is wire it together so that if it breaks in half it doesn't hit the road and possibly take your rear valance with it. Then see how long it lasts and at that time check the condition of the rest of the system and make a decision then.

[ian_kennett]

Well I've had the whole lot replaced now with stainless (excluding the down-pipes).

Longlife in Plymouth did a great job - and made a system with a single back box nice twin pipes. I also wanted it de-catted (although having had a quick peek underneath it look as though this has already been done - which turned out to be the case).

I went for a fairly quiet sound (as the Bongo is pretty noisy as is) and am happy with the purrr! Performance seems ever so slighlty better too, although that may be psychological

[kelv]

[quote="francophile1947"]Welcome to the madhouse - please read http://www.igmaynard.co.uk/bongo/forum/ ... =3&t=29471 - it really does help to know where you are

But don't be too specific because the information could be used by a gang of Bongo thieves in order to identify vehicles for winching on to low loaders, never to be seen again.

[scanner]

I also wanted it de-catted (although having had a quick peek underneath it look as though this has already been done - which turned out to be the case).

I didn't even know Bongos were fitted with cats?

Mine (and all the others I've seen) must have been de-catted as well then.


PS

Suits me - I hate cats and just wish I could find a (legal) way of de-catting my garden as well.

[dave_aber]

(lighter weight & all that?)

Lighter than what?

Stainless is heavier than mild steel. A full stainless system is going to be a lot heavier than a standard one.

[scanner]

Only if it's the same size as the gigantically oversized standard one, which is the size of a small depth charge and weighs nearly as much as a submarine.

[mikeonb4c]

Only if it's the same size as the gigantically oversized standard one, which is the size of a small depth charge and weighs nearly as much as a submarine.

Yup - may not use the same mass of material either if reqd strength can be obtained from thinner steel.

Sounds like a lovely job you got there ian_kennett. Is it rude to ask what it cost?

[Simon Jones]

Just to back-track a bit: the downpipe is clamped to the gearbox & then there is a hanger mounting point further back on the transfer box, so the front of the exhaust is firmly attached to the engine. Without the flexi-section, when the engine moves from side to side it would put a lot of stress on the exhaust. I've actually got two flexi-sections in my stainless exhaust, but that's as a result of having to modify it to fit.

I'm not aware of any diesel Bongos being fitted with cat's, although I can't comment on the later petrol models. I don't think the Japanese are quite so strict on the emissions for their own markets, as opposed European models.

[ian_kennett]

I'm not aware of any diesel Bongos being fitted with cat's, although I can't comment on the later petrol models. I don't think the Japanese are quite so strict on the emissions for their own markets, as opposed European models.

Maybe mine never had a CAT in the first place - I know not of such things. I just wanted it removed if it did happen to have one.

Sounds like a lovely job you got there ian_kennett. Is it rude to ask what it cost?

Longlife charged £299 - it made no difference if I wanted one box or two. This price only includes a basic rounded pipe end, I paid an extra £40 for the twin pipe - so £339 in total.

[mikeonb4c]

I'm not aware of any diesel Bongos being fitted with cat's, although I can't comment on the later petrol models. I don't think the Japanese are quite so strict on the emissions for their own markets, as opposed European models.

Maybe mine never had a CAT in the first place - I know not of such things. I just wanted it removed if it did happen to have one.

Sounds like a lovely job you got there ian_kennett. Is it rude to ask what it cost?

Longlife charged £299 - it made no difference if I wanted one box or two. This price only includes a basic rounded pipe end, I paid an extra £40 for the twin pipe - so £339 in total.

Not bad at all - very tempted to think about it one day if I can save the pennies (dream on!)