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Performance Exhaust?
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Etienne
Hoodrider


Joined: 25 May 2007
Posts: 2829

PostPosted: Thu Jan 31, 2008 1:01 pm    Post subject: Reply with quote

Olli wrote:

I also dont understand why car what is after all slow, should keep
many noise. Silent cruise or moving fast is much more cool! Cool

-Olli


Now than my car is really really loud, I can say it's cool when you drive slow... But when you drive like top speed it's making so much noise than everybody can see you drive crazy... but it's still very slow compare to regular cars!!
With silent exhaust, you can drive crazy and just look like if you drive really cool! haha! Laughing
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sivipas
Snailer


Joined: 17 Oct 2007
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PostPosted: Thu Jan 31, 2008 1:03 pm    Post subject: Reply with quote

ok but if you make sidepipes from the point where original crossbox bolts to manifold, you still have connection below carburettor, right? or is that not enough? also, I've seen many two cylinder motorcycles with separate exhaust system without connection pipe. how come?

I agree that loud system does not go well with 2cv. it looks silly when the car is slow and makes a lot of noise. what I would like to have, is deep bass sound, but not loud on high revs.
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Etienne
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Joined: 25 May 2007
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PostPosted: Thu Jan 31, 2008 1:11 pm    Post subject: Reply with quote

sivipas wrote:
ok but if you make sidepipes from the point where original crossbox bolts to manifold, you still have connection below carburettor, right? or is that not enough? also, I've seen many two cylinder motorcycles with separate exhaust system without connection pipe. how come?


I dunno if it's enough or not, but for sure better than no connection.

If motorbikes don't have usually this connection, it's more about space and better looking.
2cv cross don't use cross box neither, but it's in order to make the simpliest way (lighter and nothing to damage during the race).
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Bart
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PostPosted: Thu Jan 31, 2008 7:17 pm    Post subject: Reply with quote

Quote:
2cv cross don't use cross box neither, but it's in order to make the simpliest way (lighter and nothing to damage during the race).

For dutch 2cv cross they actually have to use the crossbox to keep te sound within the restrictions.
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Etienne
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PostPosted: Thu Jan 31, 2008 7:28 pm    Post subject: Reply with quote

Oh ok! Like on the 24hours of Spa, cars are really quiet now!

The exhaust of NES :

Better only with heavily modified engine, in other case it makes loose power (Geoff explained me that). There is a silencer under the floor.
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Etienne
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PostPosted: Thu Jan 31, 2008 7:33 pm    Post subject: Reply with quote

Johannes had that:



It sounded good, only bass sound even at high revs. I don't remember if he keeped original crossbox or not.
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Bart
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PostPosted: Thu Jan 31, 2008 9:53 pm    Post subject: Reply with quote

If I remember it right Johannes had a normal as well as a empty crossbox on his car. If I'm correct in his case the empty one was faster but the normal one sounded better.

Cheers, Bart
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max
Dropped


Joined: 01 Jul 2007
Posts: 332
Location: England

PostPosted: Thu Jan 31, 2008 10:37 pm    Post subject: Reply with quote

[quote="Etienne"]Johannes had that:


thats nice, Cool
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backfire
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Joined: 14 Nov 2007
Posts: 346
Location: NL, 's-Hertogenbosch

PostPosted: Thu Jan 31, 2008 11:04 pm    Post subject: Reply with quote

Etienne wrote:
Pimslet wrote:

My thinking is that best exhaust is one per cylinders and it is more beautiful to have two exhaust on a 2cv.


You definetly loose power with two single exaust!
You need to keep a connection between the cylinders to get the max power!


Sorry Etienne but this is not true, you don´t loose power, you shift the rpm in where it will get the torque and horsepower. What is important is the diameter of the piping if you maken 2 exhausts and also the lenght of the piping.

The reason why exhausts are connected is to get good torque at a wide as much rpm range.

A twin exhaust will have the torque and power in the top rpm range, so for driving not good. Also with crossbox the diameter of the connection pipe is also important, depending on the pulse of the engine.

MotoGP bikes don´t have silincers needed anymore, and have configuration of 5 into 2 into 3, with all different diameters of pipes, unfortunatelly we don´t have milllions of euro´s to experiment with it :)

In the old days, they used 6 cilinder 250cc four stroke engine with 6 open exhausts, but driving them was very difficult.

But as we all know, exhausts are a difficult sience, so I guess we make system the way we think works or is good looking or good sounding, as long as we have fun doing it. Laughing

Wink

ps I still like Johannes system great, reminds me of what I am going to use.
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Shedspeed
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Joined: 13 Jul 2007
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PostPosted: Fri Feb 01, 2008 12:09 am    Post subject: Reply with quote

http://www.youtube.com/watch?v=mHyNqmWEusQ

Neils exhaust (sounds ace at 0:45)

http://www.youtube.com/watch?v=qgkaVsd_P5o

My exhaust, (camera sound recordings not very good) same as Neils but they do sound slightly different.

I doubt you will notice a difference in power when driving on the road even if you can tell on a dyno, its gonna be such a small gain.
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Neil
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Joined: 03 Jul 2007
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Location: Cornwall UK

PostPosted: Fri Feb 01, 2008 12:37 am    Post subject: Reply with quote

Shedspeed wrote:
http://www.youtube.com/watch?v=mHyNqmWEusQ

Neils exhaust (sounds ace at 0:45)

http://www.youtube.com/watch?v=qgkaVsd_P5o


that's true, shame i sound like a screeching lil bitch! Laughing Rolling Eyes
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Shedspeed
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Location: kent, England

PostPosted: Fri Feb 01, 2008 12:46 am    Post subject: Reply with quote

Neil, you make that video hilarious! i love the 'game on!' bit!

I wish I could find a video of one of our cars sounding exactly like it does in reality.
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robin2cv
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Joined: 18 Jun 2007
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PostPosted: Fri Feb 01, 2008 9:43 am    Post subject: Reply with quote

for the sound try this.
If you have a original airfilter. You kan screw the top of. Just to this. did is the place whre the filter is in. and then drive. You will hear a beutiful soun. I drive whit this on my visaengine for about 50 000km. No prob most of the time alle the plastic of the filter is removed and I have nothing that functions like a filter.

greets robin
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max
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Joined: 01 Jul 2007
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Location: England

PostPosted: Fri Feb 01, 2008 12:30 pm    Post subject: Reply with quote

Shedspeed wrote:


I wish I could find a video of one of our cars sounding exactly like it does in reality.


these any good my boy? neil is still screaming. fool Laughing

http://www.youtube.com/watch?v=TDGGT_0cmOc
http://www.youtube.com/watch?v=CDk_boSTdmY
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Kustombart
Tiki burner


Joined: 25 Jun 2007
Posts: 901
Location: Arnhem, Netherlands

PostPosted: Sun Feb 03, 2008 2:10 pm    Post subject: Reply with quote

I do remember one Burton which had the best sound. Not too loud but really bassy. It had a Visa engine and first damper, but the trick was that the pipe from the first to second damper was a bigger diameter. It gave a really deep sound when accelerating. Second damper was original 2CV.
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