doblo 2007 petrol - custom exhaust for disabled access van

Honest John Back Room » Technical matters
What is life like with your car? Let us know and win £500 in John Lewis vouchers | No thanks
View Threaded
Sat 26 Aug 2023 09:32
doblo 2007 petrol - custom exhaust for disabled access van - mark bbb

hi,

custom exhaust for disabled access van

anyone got any ideas for getting an exhaust for disabled access van, the one on there is a stock item but no way to tell what car its off [no label] . its not a fiat exhaust as the floor was lowered for wheel chairs and exhaust re-routed

i dont want a s/steel one at £350 PLUS VAT. its so annoying to know theres one out there but i need a name/part number

the conversion firm dont know either

thanks

Reply | Report as offensive | Link
Sat 26 Aug 2023 09:45
doblo 2007 petrol - custom exhaust for disabled access van - RT

It's ridiculous that the conversion firm don't know!

Find a big exhaust fast-fit in your area - they may recognise the shape or be able to suggest fitment of one of their stocked items.

Reply | Report as offensive | Link
Sat 26 Aug 2023 10:23
doblo 2007 petrol - custom exhaust for disabled access van - Adampr

It's ridiculous that the conversion firm don't know!

Find a big exhaust fast-fit in your area - they may recognise the shape or be able to suggest fitment of one of their stocked items.

I agree. Most will be able to stick on a lift and find another exhaust that will fit even it's not an exact replacement.

Otherwise, someone like Jetex can supply the components to make a custom one. Personally, I would just go stainless.

Reply | Report as offensive | Link
Sat 26 Aug 2023 09:52
doblo 2007 petrol - custom exhaust for disabled access van - Big John

I'd normally suggest getting a custom made stainless steel exhaust in these circumstances - is £350 really that bad for a fit for life exhaust? The important thing is asking for one that has the same noise levels of the original - many get SS exhausts that are made up to have a noisy (er some would say sporty) sound.

I did have a mild steel exhaust made up for my kit car years ago but regretted it long term wishing I'd gone for Stainless as it quickly rusted through.

Edited by Big John on 26/08/2023 at 10:08

Reply | Report as offensive | Link
Sat 26 Aug 2023 13:30
doblo 2007 petrol - custom exhaust for disabled access van - edlithgow

Agree stainless probably makes more sense, though I;ve had pretty good service from the mild steel one on the Skywing.

Cant be sure (or prcve it), but I think that flame spraying of the inside with aluminium might be a factor, achieved by shoving some beer can into the downpipe,every now and then, plus a teaspoon of portland cement, for acid buffering.

Maybe wouldn't be a great idea if I had been unfortunate enough to have an exhaust catalyst, but I've avoided that so far'

Reply | Report as offensive | Link
Sat 26 Aug 2023 18:41
doblo 2007 petrol - custom exhaust for disabled access van - gordonbennet

If you are within travelling distance www.mijexhaust.com/ at Walsall are probably the best value custom maker/fitter of stainless exhausts in the country.

Last one we had made and fitted was to the current Forester XT, £300 all inc, that was probably 3 years ago so prices will probably have gone up a bit, incidentally that was some £50 cheaper than the mild steel pattern part would have been which would have been wrong anyway because there are no aftermarket exhausts sold for the turbo Foresters which are 2.5" bore, the aftermarket are wrongly sold as suitable which they arn't because they are 2" bore which is correct for the NA engines....you'df need to be sitting down before asking for a price of an OE system.

Reply | Report as offensive | Link
Sat 26 Aug 2023 22:42
doblo 2007 petrol - custom exhaust for disabled access van - bathtub tom
the mild steel pattern part would have been which would have been wrong anyway because there are no aftermarket exhausts sold for the turbo Foresters which are 2.5" bore, the aftermarket are wrongly sold as suitable which they arn't because they are 2" bore

I did quite a bit of research into exhaust systems many years ago. Never quite got my head round 2-strokes - expansion chambers - tail pipe diameter and length.

There was a lot of information about 'pumping losses'. The longer and larger the diameter of the exhaust, the more the gasses can slow and cool, thus become denser, resulting in greater resistance to flow. Look at aircraft engines, venting exhaust almost directly from the head. Also, I understand, the reason for insulating and ceramic coating the exhaust on competition cars (not just to prevent the occupants getting burned). I presume they knew all about this stuff pre-war. Ever seen the diameter of an Austin 7 exhaust?

Reply | Report as offensive | Link
Sun 27 Aug 2023 08:16
doblo 2007 petrol - custom exhaust for disabled access van - skidpan

I did have a mild steel exhaust made up for my kit car years ago but regretted it long term wishing I'd gone for Stainless as it quickly rusted through.

The stainless exhaust on the Caterham was made by a local one man specialist in 1996 and the headers were modified in 2002 when I fitted the Zetec engine. the repackable silencer has needed new wadding once in those 27 years (but in truth if I was still using it on the track it would need doing again now).

It replaced the factory Caterham exhaust which was too restrictive as the engine was modified and also too noisy as the MSA lowered the limits. The Caterham one sold for not much less than the one off cost me.

Reply | Report as offensive | Link
Mon 28 Aug 2023 13:09
doblo 2007 petrol - custom exhaust for disabled access van - edlithgow

The longer and larger the diameter of the exhaust, the more the gasses can slow and cool, thus become denser, resulting in greater resistance to flow.

Wouldnt the reduction in volume as the gases cool reduce the back pressure? I'd think the boundary layer shear and turbulence friction on a long pipe is likely to be a more important factor

Having said that, I hope you are right, since I have aluminium cladding (salvaged ifom air conditioning piping) on the first half of my exhaust.

I put it on to hopefully reduce surface corrosion, but I wouldn't object to some fluid thermodynamic bonus

Edited by edlithgow on 28/08/2023 at 13:22

Reply | Report as offensive | Link
Mon 28 Aug 2023 16:40
doblo 2007 petrol - custom exhaust for disabled access van - bathtub tom
Wouldnt the reduction in volume as the gases cool reduce the back pressure? I'd think the boundary layer shear and turbulence friction on a long pipe is likely to be a more important factor

I'm trying to recall what I learned decades ago. You have to realise, it's not a smooth laminar flow, but pulsed. IIRC that makes a difference.

Reply | Report as offensive | Link
Tue 29 Aug 2023 03:10
doblo 2007 petrol - custom exhaust for disabled access van - edlithgow
Wouldnt the reduction in volume as the gases cool reduce the back pressure? I'd think the boundary layer shear and turbulence friction on a long pipe is likely to be a more important factor

I'm trying to recall what I learned decades ago. You have to realise, it's not a smooth laminar flow, but pulsed. IIRC that makes a difference.

Very big difference on 2-strokes, which exploit reflected exhaust pulses from the exhaust system to modify flow in the cylinder. Perhaps less of a factor in 4-strokes with cam driven valves

Reply | Report as offensive | Link

We give you the low down on how to save on insurance, little-known tricks and tips, what insurance groups mean and how to use insurance aggregators to beat insurers.

Insurance group finder and how to save on insurance