Damo Donating Members 403 Member For: 21y 24d Gender: Male Location: Sydney Posted 04/09/06 12:54 PM Share Posted 04/09/06 12:54 PM Agree with ya Robin! Here is a pic of my plenum for the members who havnt seen it before.Rob...<div class='bbimg'></div>Looks noice - very tidy job. Is that the standard TB though? Link to comment Share on other sites More sharing options...
Lumpen Poison Fish. Poison Fish. TASTY FISH!!! Donating Members 5,181 Member For: 21y 8m 27d Gender: Male Location: The Bogan Shire Posted 04/09/06 12:57 PM Share Posted 04/09/06 12:57 PM Looks noice - very tidy job. Is that the standard TB though?←Even if it is, they're still using the standard throttle body on Brian's 560+rwkw monster! What I find more interesting how the full width of the TB isn't taken advantage of (piping wise) until about 4" before the T/B? Not taking anything at all away from the thing, that's just a (very) unlearned observation?Lumpy Link to comment Share on other sites More sharing options...
xlnt6 Donating Members 350 Member For: 20y 2m 10d Gender: Male Location: Melbourne, Victoria Posted 04/09/06 02:06 PM Share Posted 04/09/06 02:06 PM I beleive 3mm is fine, I will pressure test one to be sure, but like I said, my manifold is made from the same stuff, and has an area probably double the largest flat area of this plenum, it is tough, and hasnt caused any problems with 17psi... as for the big dollar plenum blowing up like a balloon, I have looked at the photos of it, and my opinion is that it is most likely made from very thin material?? considering its shape, even if it is made with a 3mm wall thickness, which I wouldnt think it would be, it is most probably made from a lower grade alloy, that is commonly used in all hammerforming techniques, it is more malleable/softand also, xlnt6 stated that mr turbos plenum is made from s.s so it is mechanically more rigid... I beg to differ, that plenum is certainly made from alloy.we have a cigweld 200A inveter tig, its an awesome piece of gear to have in your back shed.. does 6mm no worries, I weld the plenum with 100-110A.. it has full digital controls, gaslens nozzles, and a swivel/flexible head.. cost $7.5k with all our accessoriesI am certainly not questioning your construction and professionalism as the manufacturing looks excellent. When testing a plenum you need to consider three factors which directly influence structural rigidity and possible future failure. They are:(a) maximum pressure wrt atomsphere (everyone seems to understand this one).(b) dynamic loading. ie cycle between vacuum and max pressure which is repeated over a cycle time. ie. equivalent to banging thru the gears while the accelerator is nailed. ie boost, vacuum, boost, vacuum, etc.© Helmholtz resonance effect. This is a phenomena which occurs when tuned length runners are used to increase the volumetric efficiency of the engine under NA conditions to over 100%. This produces a very strong pulsing effect within the plenum.The only way you can really test (b) and © are with engine dyno tests or real world testing. Now given your design uses very short runners at normal engine RPM below 7500 RPM the impact due to Helmholtz resonance will be neglible. So what I am getting at, is that an overall pressure test isn't really going to give you the full picture. But certainly if there is wall deflection when tested under static loads of say 30 psi, then you know your in trouble.If all is well, then the best test will be the "suck it and see test", so best of luck with it all. BTW certainly the last time I looked at Rob's plenum it looked like brushed S.S, but I will check with him to confirm, I could be wrong with my previous statement wrt s.s vs Al.CheersRobin. Link to comment Share on other sites More sharing options...
ebs_4l Member 16 Member For: 18y 3m 11d Posted 04/09/06 02:37 PM Author Share Posted 04/09/06 02:37 PM I understand all that you are saying xlnt6... and, with any luck, my mates car will be cranked up soon, I am extremely eager to see its real world results..what are your thoughts on the big dollar plenum giving trouble, do you think it may be a softer material, or extremely thin walled?? it certainly appears that it would have to be relatively thin to construct that shape Link to comment Share on other sites More sharing options...
Headsex Donating Members 2,528 Member For: 19y 4m 1d Gender: Male Location: Melb Posted 13/10/06 12:37 PM Share Posted 13/10/06 12:37 PM (edited) (b) dynamic loading. ie cycle between vacuum and max pressure which is repeated over a cycle time. ie. equivalent to banging thru the gears while the accelerator is nailed. ie boost, vacuum, boost, vacuum, etc.© Helmholtz resonance effect. This is a phenomena which occurs when tuned length runners are used to increase the volumetric efficiency of the engine under NA conditions to over 100%. This produces a very strong pulsing effect within the plenum.Hi Robin... What you do for a living? You sound like the engineers where I work work..... Helmholtz resonance this hammershock that.. lol ;Pdanny. Edited 13/10/06 12:38 PM by Headsex Link to comment Share on other sites More sharing options...
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