Subaru exhaust

Post by **klatuu** » 27 Apr 2006, 13:33

Good point, but we don't know what jiggery pokery is going on inside the collector.

Saying that we don't really know if the length of pipe makes a difference at all.

Post by **Diamond Hell** » 27 Apr 2006, 15:53

After extensive research into the collector here's what our leading scientists found:

Post by **Louey** » 27 Apr 2006, 16:06

you got one fussy cat and one who eats like a pig too

Post by **HarryMann** » 27 Apr 2006, 16:36

Now I may be incorrect but I would be conerned about the difference of lengths of pipe from the manifolds, having a long pipe from one manifold and a short pipe from the other would create an imbalance in back pressure and make the engine uneven, the only way I would see it working if correctly, would be for the short pipe having a large I/D.

Now I may be incorrect

Sorry, but you are!

And if there was bit more more 'technical wittering' in this country, perhaps it wouldn't slowing be turning into a paradise marketplace for those who do know how to engineer and market things properly... rather than just one that uses, abuses, modifies or simply re-labels other's more thoughtful efforts

Post by **Diamond Hell** » 27 Apr 2006, 19:10

No we need more directness, shorter sentances and clear technical writing.

Technical wittering is the last thing we need more of.

Post by **klatuu** » 27 Apr 2006, 19:39

Would you care to elaborate or is that automatic gainsay of anything I type

HarryMann wrote:
Now I may be incorrect but I would be conerned about the difference of lengths of pipe from the manifolds, having a long pipe from one manifold and a short pipe from the other would create an imbalance in back pressure and make the engine uneven, the only way I would see it working if correctly, would be for the short pipe having a large I/D.

Now I may be incorrect

Sorry, but you are!

And if there was bit more more 'technical wittering' in this country, perhaps it wouldn't slowing be turning into a paradise marketplace for those who do know how to engineer and market things properly... rather than just one that uses, abuses, modifies or simply re-labels other's more thoughtful efforts

Post by **Diamond Hell** » 27 Apr 2006, 19:43

DON'T encourage him!

(long post coming from Harrymann)

Post by **HarryMann** » 27 Apr 2006, 19:48

Shorter sentences

... usually disguising a complete lack of rigour in the argument, ignoring ramifications, fear of exposing your arguments to genuine critical examination, and so common today, superficiality.

Post by **klatuu** » 27 Apr 2006, 19:51

No actually I would be interested to hear about the subtlelties of exhaust tuning, y'know rarefaction wave and compression waves 'n stuff.

Post by **scoobyvan** » 27 Apr 2006, 20:21

i could be wrong but point em out the back bung a supertrapp on each pipe,and it goes like f*ck.(not sure of the technical words)

Post by **klatuu** » 27 Apr 2006, 20:47

Still waiting

Post by **klatuu** » 27 Apr 2006, 20:49

scoobyvan wrote:bung

scoobyvan wrote:pipe

scoobyvan wrote:f*ck

Yep I think youve got all the techinical words there.

Post by **Diamond Hell** » 27 Apr 2006, 21:50

Hey, all I said was that the pipes looked nice and there's a lot of happy SmallCar customers out there.

It either works, or it don't. If it don't work THEN we'll get into the whys and wherefors.

Post by **HarryMann** » 27 Apr 2006, 22:35

Sure is a lot of marketing hype out there, and its really amazing when your silencer blows a hole in it, how much faster you car goes...

until you actually time it

So its not all about this mythical 'back-pressure' - fits nicely into a Sun reader's 6.5 word sentence, but is as good as meaningless... as its not what te pressure actually is - as much as 'when' it is what it is, and a high (back?)-pressure at the exhaust port can be a very good thing - at exactly the right moment

... but I detect you probably know something about that Klatuu, and there's plenty of treatises out there explaining it - and there's also not a lot new out there either - as with most engineering sciences, the basic fundamentals were all in place many, many years ago. All that's been happening in the last 50 or 60 years or so, and many more in other disciplines, are incrementally small improvements as materials and production technology makes them realistic, or affordable. A few new ideas (enginuity), as well as better instrumentation and analysis techniques allowing poor implementation and old compromises to be improved upon.

The 2-stroke is the more complex to get right, or was, until the 50's when I think it was the East Germans (DKW maybe), or Hungarians who worked out the proper theory of 'designing' expansion boxes rather than second-guessing through years of cut and shutting - and still missing the real trick.

Post by **RJES** » 27 Apr 2006, 22:38

Thought I'd have my say on this exhaysts thread....
For ultimate power (light cars like Beetles, expecially racers), equal length headers are the way to go. If I remember fight they can add about 7bhp at a specific rpm to a Beetle engine (Hot VW's did a test a few years ago). However, becuase you are tuning the exhaust for a particular rpm by optimising the header lengths, you make the torque curve more peaky. Foe a heavy bus with the areodynamic properties of a brick, a well designed non equal length header system will make the bus more driveable. Yes maybe not as much peak bhp, but the wider spred of torque gained should make it much more driveable instead.

Richard