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Originally Posted by rangieman
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Originally Posted by rangieman
Was the "well put" comment a favourable comment about the technical explanation or a sarcastic comment about the spelling, grammar and syntax?Quote:
Originally Posted by mcrover
A Ron wanna be me thinks :rulez:Quote:
Originally Posted by vnx205
A Ron wannabe methinks :pQuote:
Originally Posted by rangieman
O lny srmat poelpe can raed tihs.
I cdnuolt blveiee taht I cluod aulaclty uesdnatnrd waht I was rdanieg. The phaonmneal pweor of the hmuan mnid, aoccdrnig to a rscheearch at Cmabrigde Uinervtisy, it deosn't mttaer in waht oredr the ltteers in a wrod are, the olny iprmoatnt tihng is taht the frist and lsat ltteer be in the rghit pclae. The rset can be a taotl mses and you can sitll raed it wouthit a porbelm. Tihs is bcuseae the huamn mnid deos not raed ervey lteter by istlef, but the wrod as a wlohe. Amzanig huh? yaeh and I awlyas tghuhot slpeling was ipmorantt! if you can raed tihs psas it on !!
:p:p
Good one mate:Rolling:Quote:
Originally Posted by rovercare
I'll accept that, if it's repeatable ;) :pQuote:
Originally Posted by mcrover
actually there is naff all back pressure with a straight through perforated tube. The turbulence would be minor, as the boundary layer of gas is almost at a standstill anyway, and so velocity reduction would be minor.Quote:
It's all about air speed with turbos and the perforated straight through pipe is desighned to disrupt the flow there for increasing back presure by slowing down the airflow and in turn it also cuts down the noise via reflection off the turbulance within the muffler.
Quoting from "Scientific Design of Intake and Exhaust Systems" (Smith and Morrison)
Quote:
"The operating principle is that sound waves passing down the main tube penetrate into the close-packed absorbent material via perforations and are frictionally damped; the damping is usually very effective on the highest frequency waves."
As I said, I'm surprised it does anything worthwhile, but you have the acceleration figures to back it up, so I'll accept it, but it does really surprise me.Quote:
Take out the muffler and lower back pressure, increases airspeed passed the inpeller in the turbo thus spooling on boost faster, it doesnt increase the noise factor that much as the turbo it self acts as a muffler by reflection off the inpeller blades.
The sound is a bit weird but can be made a bit nicer by removing the ressy as well so you get a little bark back in the note.
It isnt a huge increase but it is an increase and for the price is well worth while.
'cause I don't trust 'seat of the pants' results. I've seen far too many people led up the garden path by things they 'thought' were happening but weren't.Quote:
Originally Posted by rangieman
Placebo effect.
How do all those Hiclones get sold ? There are a lot of people out there that want to believe it works, and so it does. ;)
<edit>FWIW, when I built the 3" system it had no muffler/resonator at at all. (I don't believe in back pressure on a turbo either :p)
The noise was horrific. Don't let anyone tell you a 300Tdi doesn't need some sort of silencing, at least with a big bore pipe. The resonance at 100km/h was frightful (the cab became the muffler) and the sheer noise was just too much, so a resonator went on at the rear. Much better, but still tiresome on a trip.
I've also since lagged the down pipe to the back of the t/case with exhaust lagging after a post by Inc (where I questioned the long term effects, he's had it for over 80,000km, so far, so good, so I threw some old stock on mine too). Don't know if it's done anything, but it is quieter. One of the Qld exhaust places are HPC coating the dump pipe on Patrol and L/Cruiser 3" pipes after back to back dyno testing found an increase in HP/torque. It appears that by keeping the heat in the dump, gas velocity is kept up and back pressure reduced.
Hmmm, I wonder if the sheer size of the 300Tdi muffler is acting as a huge heat sink and cooling the gas too much, reducing velocity and that's where the benefit is derived....naa, but maybe, naa....</edit>
getting my muffler removed today, and will be wrapping the pipes to the back of the transfercase on this truck with header tape very shortly, now i have found where i stowed the last lot i bought :P
i do it to cut down on the mechanical noise transferred down the exhaust pipe on a diesel. well worth the fifty dollars or so the header tape sets you back IMHO.
just got mine back.
definitely a difference, spools up significantly quicker IMHO.
not a bad way of spending $40 bucks it has to be said, tho it makes the truck a marginally noisier inside but the header tape will fix that i believe...
I don't think it does produce more power but it does rev quicker and thats without doubt.In my truck it has smooth out the driveline slap in on-off throttle area's which is a big difference. Pat