|The Exhaust : Getting it right|
|Written by Lars H|
|Sunday, 14 October 2012 19:28|
After some weeks of inactivity ( with the Espada project that's it ) I finally find the inner strength to "attack" again the issue of bending the D50mm tubes from headers to silencer.... I've have tried to make the samples from PVC tubing...no good, it colapses and looks awfull. Then I hit the idea of using flexible steeltubing...and fixing the form by "locking" it with a layer of poliester...now that looks much better.
The next days find me visiting several profesionel "tube-benders"...but on seing the artwork they kindly refuses to undertake the work : they claim it is impossible to bend such a tube...only by welding it up from many parts can it be made....and it is of course ver costly.
So, back to origins : do it yourself ! I reason that if I could make 12 off 1" exhaust headers......then I should be able to make 2 off 2" tubes.
I modify my bending tool with an additional fixed burner, create a press-tool with the correct section of the tube to avoid point-pressure, fill each tube with highly compacted sand, hammer steel-plugs to the ends and fix them with spotwelds.
With cardboard I make samples of the "tube" en the horizontal plane ( the needed downward slope will be made "by eyesight" )...and set to bend the tube.....with lot of patience and adding the "final touch of heat" with an Oxi/Butan torch....and slowly the tube starts to take form......without collapsing !!
When the first tube has cooled down I losely fit the sleeve that adapts to the larger diameter exhaust header....... install it in the car....PERFECT FIT !!!
I carry on making the 2nd tube....again perfect fit !!
With both tubes installed and the silencer correctly lined up....I spotweld the sleeves to the tubes to have them positively fixed ( they are intentionally offset and sligthly angled )
So much worries and asking experts.....in one afternoon both tubes are ready and now need the sleeves to be fully welded to the tubes.
When fully welded I will polish them...and then hide all this work behind heat-protecting wrap........( also to hide the slights dents !!)
Next I meassure up the remainder of the tube routing after the silencer...but now that's childs work : it's straight tubing and pre-fabricated 45º and 90º bends.....no harrasing bending needed !!
|Last Updated on Monday, 15 October 2012 10:27|