409 exhausts, Australia

[MYTA21]

I wondered if anyone in the Australian group had experience of getting a new exhaust system for a 409 made. Apart from getting the factory items from BCL with the inevitable shipping costs, the currenet solution seems to be to get a "local" firm to make something to fit.
That is what appears to be fitted at present, resulting in smaller silencers being fitted, plus " burble' boxes in the front pipe section.
Am I correct in thinking that the original boxes were probably made by Burgess or Servais? "Straight through" construction with concentric inlet and outlet? Box length about 24'' each?
Thanks for any help
Mike 0

[Kevin H]

Mike, realistically I think a custom job is the only economically viable solution in Australia. Those "burble boxes" in the front sections were also on my 411, I think they were originally fitted to the cars.

[Rubbond]

I couldn't sleep tonight, hence this e-mail.
Isn't it amazing that car manufacturers don't fit proper (type 304)
stainless steel exhaust systems themselves?
It would maybe cost them about USD 15 more initially, but they would last
well beyond any of our lifetimes.
Not to mention the hose clips, etc..
Am I mad?
Andrew Knox.

[Claude]

Originally Posted by MYTA21

I wondered if anyone in the Australian group had experience of getting a new exhaust system for a 409 made. Apart from getting the factory items from BCL with the inevitable shipping costs, the currenet solution seems to be to get a "local" firm to make something to fit.
That is what appears to be fitted at present, resulting in smaller silencers being fitted, plus " burble' boxes in the front pipe section.
Am I correct in thinking that the original boxes were probably made by Burgess or Servais? "Straight through" construction with concentric inlet and outlet? Box length about 24'' each?
Thanks for any help
Mike 0

My 411 has original exhaust (stainless) purchased from BCL. Not sure if I can get under it, but if necessary I could try to take some digital pics. Alternatively remember this is a standard Chrysler V8, and any decent muffler shop should be able to fabricate a setup that will work.

Claude

[Nick Challacombe]

Hi Mike,
My 407 has a stailess steel system made locally in England at reasonable
cost
and this seems to be the way many owners have gone.
The actual manifolds are still original. ( they are difficult to come by)

Nick

[Kevin H]

Originally Posted by rubbond

I couldn't sleep tonight, hence this e-mail.

Well writing emails won't help!

The only negative I have experienced with a SS exhaust is a rather tinny sound (on an Aston DB4), but maybe that was a design issue.

I suppose car manufacturers could improve every part of their cars by throwing a few more dollars at them, but their goal is usually to reduce the cost of manufacture rather than increase it, and they probably don't really care, providing the parts last longer than the warranty period.

In fact the way some parts are made nowadays you could be forgiven for thinking they were designed to fail!

[MYTA21]

Yes Kevin, I think that will be the way to go, but I'll leave the small
front boxes in as those and the down pipes are in good condition. I would
the car be quieter than noisy!
Mike O

[Rubbond]

You're absolutely right Kevin, but thereafter I slept like a log.
The tinny sound on your Aston was probably caused by the supplier using the
wrong type of Stainless Steel.
Thin gauge in the wrong type can even be brittle on impact.
P.D.Gough's in Watnell, near Nottingham in the UK, make very good
reproductions in thicker, ductile types of SS. By ductile I mean you can hit
it with a hammer and it will just dent.
Car manufacturers of course don't care initially about how long parts will
last, but would you choose to buy a 10 year old second hand Fiat, rather
than a Saab?
I do believe that manufacturers of anything that contains a "chip" design
them to fail on a pre-determined date, after the power has been turned
on.That includes washing machines etc..
I now own my fourth AIO printer, having only paid for the first one. Believe
it or not, the failure appears to be programmed into the ink cartridges.
Can anyone confirm this?
Maybe I am going mad!
With best regards,
Andrew.

[RGSchmitt]

I have no idea if muffler (silencer) shops outside the US use this
feature, but many shops here use pipe benders that can be programmed
with standard templates which claim to be able to reproduce original
factory exhaust systems. However, I'd be surprised if you could
drive in with a Bristol and find a template for it.

Bob

[lansdownplace]

I am curious, what is a burble box?

[MYTA21]

Just what I would have called a resonator box, generally rounded ends.
Often a standard box is taken out and these put in, making a different
not. Either that or fitted in addition to other standard silencers to
reduce noise or change the note.
Mike O

[lansdownplace]

Thanks Mike. So the resonator is the first box that tunes the sound
and the second box controls the volume?

I have 2.5 inch pipes from the engine to the first box and a two inch
system after that. would that affect performance?

Regards

Paul

[MYTA21]

Hello Paul,
I am not an expert in the muffler field, so I may not be right in what I
say!
A resonator may go either before or after the main silencer, stopping some
noise or resonance in a particular pipe length.
As regards the dimensions, I am not sure as to what size the car was
originally fitted with, but for standard applications, I cannot think of a
pipe leaving the silencer being larger than the inlet, apart from the cases
where users want more noise!
Matters such as required back pressure are also a factor- but as I said I'm
not an expert.
I can think of lots of older cars where the outlet was a lot smaller than
inlets.
I'll try to go for little difference when I see the firm down this way.
Mike O

[Kevin H]

Originally Posted by MYTA21

Matters such as required back pressure are also a factor- but as I said I'm not an expert.

What required backpressure ?

I'm no expert either, but I know this notion that backpressure is required in exhaust system is a complete myth. The truth is in fact the opposite - backpressure is bad!

Paul, a reduction in exhaust diameter after the resonator from 2.5" to 2" isn't ideal, but on your car it shouldn't make too much difference. It also depends on what type of resonator it is and how much restriction it introduces.

Exhaust theory, which is inextricably linked to intake system theory, is a complex science because there are so many factors involved. But at the end of the day the exhaust system needs to get the exhaust gases away from the engine as fast as possible while reducing noise to an acceptable level.

[David Olivant]

>>I went the 'local company' route [in Scotland].
However I took in the spare parts book to give them an idea.
I specified 314 austenitic stainless for all parts, including the
internals, all 14 gauge, including stainless welding rods.
They were very good and the total price was £400.00 fitted.
I had previously had a local engineering workshop manufacture stainless
manifolds as mine had already been welded [poorly]
I would go with word of mouth, look at some of their work, talk to them,
but mainly write down what
you want done in as much detail as possible.

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[Kevin H]

Looking at the parts list for the 409, the exhaust didn't have any resonators fitted in the front pipes.

I have attached a photo below of a resonator from my 411. It's a straight through design but the inside wall is perforated. It's very heavy for it's size and I suspect it is a "glasspack" resonator.

I'm not sure whether these were fitted to the 411 originally. The resonator body itself is handmade and there is no sign of rust so it is probably stainless steel.