Exhaust???

[DaddyA]

Hi,

while we are all waiting for a certain somebodies test results, just thought I'd throw a question out there.

Does the exhaust have to be made from round tube???

I was thinking (probably shouldn't), to keep the side of the roadster clean looking and with a close proximity to the ground - could you not make the exhaust (main system) from rectangular tube?

Obviously the silencer would be an issue, but rear engine cars seem to manage. Repositioning of the fuel tank might have to done to get the silencer where the fuel tank would normally be.

Twin exhausts out the back - whats your thoughts??

[gingea1pom]

I have often thought about having the exhaust exiting out the rear but there just isn’t enough room.

But now you mention rectangular tube under the car.

My initial thought, without thinking to hard about it (trying to play the wii) have a 30mm by 300mm box section.

But like you say a silencer could be problematic.

I might need to sleep on it. I have my best ideas when I am a sleep.

Cheers Ginge

[spud69]

I might need to sleep on it. I have my best ideas when I am a sleep.

Cheers Ginge

Sorry Ginge, but we don't want to know about your thoughts when you're asleep......:(

[davidimurray]

No reason why you couldn't ..... but firstly I expect the flow characterstics would not be that good. It could also be quite difficult to manufacture, bends etc. If your looking to save space, then the critical parameter will be the cross sectional area. As the flowrate of the gas will be the same up both exhausts, the cross sectional area will dictate the gas velocity which is the key performance parameter. If you take a 35mm diameter pipe has a CSA of 962mm2, then you need a 31mmx31mm square to match that CSA.

[HandyAndy]

I do like the idea of twin pipes at the rear but with the car only 5 inches from the bottom chassis rail to the tarmac i,m not sure how it could be done,

sleeping policemen would be a pain to get over i imagine.

cheers
andy

[gingea1pom]

Excellent,

Working on that theory if my exhaust is 1mm x 962mm, I maintain the correct CSA, Hardly any decreas in ground clearance.

Does anyone know where I can get some 1mm x 962mm box section and a silencer to mach.

Cheers Ginge

[twinturbo]

I had the same thought of twin rectangular section.. As I have a V6..

TT

[alga]

Working on that theory if my exhaust is 1mm x 962mm, I maintain the correct CSA, Hardly any decreas in ground clearance.

I'm guessing the 17.5x increase in exhaust system surface area will have some effect on gas flow. :)

[gingea1pom]

On a plus side would the increase in surface are not reduce temperature?:)

[twinturbo]

How big a silencer is needed on a normal 2.0 4 pot car?

I will need 2 smaller ones, one on either side.

TT

[DaddyA]

When I said twin exhausts - i was thinking along the lines of a MR2 type silencer sitting where the fuel tank would be sited originally with the outlets through the rear panel.

And finding some way of running the rectangular tube as straight as possible to the said silencer.

Getting from round to rectangular at either end would probably be a pain.

But just wondering if it could be done (challenge and all)?

I'll ponder more once this build is out of the way - got you thinking though!:D

[twinturbo]

I think round to rectangular would be not to difficult with an engineers fettle.

TT

[flyerncle]

Double floor on the passenger side and put it through there and that way you dont get fried with the heat

[gingea1pom]

And the Mrs keeps warm

[gingea1pom]

I have just been out to the garage and been looking at the Roadster and this idea is growing on me.

Problems are the front of the passenger foot well is to narrow and we still need a silencer.

[flyerncle]

Leave the underside of passenger floor open and raise the inside to meet your requirements. Making a silencer is not hard and given the space created under that side it could be fairly large and its one less thing on the outside of the car.

Thought's Ginge ? ( not your nightly one's thanks):rolleyes:

[tkpm]

We need Chris to design a rear engined roadster next so there would not be a problem with twin exhausts :cool:

[les g]

We need Chris to design a rear engined roadster next so there would not be a problem with twin exhausts :cool:

Chris
has already sketched a rear engined roadster...........................
and it looks really good too.............
but i think its still a long way off unfortunately....................
if you meet him get him to show you his sketches.............
and tell him to pull his finger out and start writing
cheers les g

[twinturbo]

I am thinking now...

As I have a V6.

Run two silences one either side, then under the rear wing to a pair of small rear boxes to exit at the rear..


That should pass the IVA noise...

TT