I was getting a bit tired of constantly repacking my exhaust and the noiselevel when driving.
So I build myself a simple exhaust (just a test one using old bits and pieces). Aim is to see how that works (and to learn myself to tig-weld :-))
It is MUCH quieter and I don't notice a powerdrop. Does anybody here know if and how much power is taken away by such an exhaust?
The design:
A 130mm diameter tube, 650mm long and entry and exit both 60mm in diameter. The tube is split into three chambers:
1: 150mm long. In this chamber the entry flows in and the fumes can go through a perforated 60mm diameter pipe of 110mm to the next chamber.
2: 450mm long. The fumes enter this chamber through the end of the perforated pipe as mentioned above. The fumes exit to the next chamber through 6
25mm diameter tubes, all between 250 and 350mm long. These tubes are attached to the barrier between chamber 2 and 3 and are hanging freely in chamber
2
3: 50mm chamber. Fumes enter via the 6 tubes and exit through the 60mm exit.
Total weight is 300grams heavier than the Laser open one I have.
Total opening everywhere is 60mm. So how will this affect power and how much?
It sure is quiet!
Mies.
I'd be interested to know, as my exhaust is still intrusively loud even though I've recently repacked it. I wouldn't mind losing a few
BHP if I could reduce the dB a lot more!
And before anyone suggests it - I don't want to fit a stock car silencer as they usually look 'orrible on the side of a 7.
David
Vizzard made an interesting discovery / published known knowledge (don't know which).
If you have your exhaust enter a chamber that is big enough to hold the volume of gass escaping from all your cylinders it will allow the exhaust to
breath freely & reflect the pulse. You then send the gass via the 'what ever' to quieten it. Sounds like you've done something
similar by accident
Thnks for that knowledge. I plan to make another one (with more pleasing looks..). Will use that info.
I know of one place in the Netherlands where I can buy part for the exhaust (main pipe, end caps en internal barriers, etc.). Anybody know of a cheap
UK supplier? Want to compare prices.
Rgrds,
Mies.
quote:
Originally posted by miegruSo how will this affect power and how much?
There was a great article about exhaust in last months PPC. Definately worth a read.
quote:
Originally posted by greggors84
There was a great article about exhaust in last months PPC. Definately worth a read.
these guys do something very similar with a bypass to make it straight through on demand. most of any benefit for scavenging etc is done at the collectors after the header so i cant see there being much of a power loss either. unless you are running a cam with overlap in which case back pressure pulses would be quite important.
quote:
Originally posted by 02GF74
quote:
Originally posted by greggors84
There was a great article about exhaust in last months PPC. Definately worth a read.
errm, cough any chance of a scan cough
The loss of an odd horse or two is not an issue for me.
I've made a few cans in my time but they have mostly been the straight through re-packable type,
but only because that's what people want.
Personally I wouldn't fit one to my own car, preferring a through design that doesn't require repacking.
IMHO you can lose more power from the drag of wide tyres than you will from using a moderately baffled can.
Just my 2p
Paul G
In my case, the exhaust note is starting to irritate ME, let alone the neighbours...
...I'm seriously considering a quieter exhaust.
David
I belive milner offroad can supply the parts you need: http://www.milneroffroad.com/PIPE.HTM
I've used them for tube and they seemed good.
HTH