4WD Dyno Cell Construction Blog.
(Part 3... The exhausting challenge)
Make no mistake...
Exhaust gas management is one of the most common dyno cell failures in the world.
The amount of times I visit a dyno facility and see people stood choking to death on fumes astounds me. Not only do humans not operate well on exhaust fumes, neither do engines! Even 1% of exhaust gas will have a negative effect on your engines power output, but even worse, if its mapped with it then the chances are it will detonate itself to death when used out on the open road due to the increased oxygen content the engine will see compared to its dyno tuned environment. Oh... and its bloody bad for your operators and customers health too!
Secondly, exhaust gas not being vented properly will also increase the cell temperature very quickly because, as we all know, its extremely bloody hot! So... after some in depth discussion with the three big extraction companies in the UK, I settled on one so sure he could do the job that we have agreed he doesn't get paid if we can measure any exhaust gas while a 1000bhp vehicle is on the dyno. Now that’s putting your money where your mouth is. How could I refuse?
The system is somewhat bigger than I envisaged... It incorporates 2 large exhaust collectors and a 5000cfm centrifugal fan to extract from them. I originally planned to put the 5000cfm fan up in the roof space. James is well pleased as you can see. This was about the moment I pointed to where I fancied that big heavy motor mounting.
I relented, and found a better position for it and the fan control room was born!
The exhaust extraction system runs 241mm pipework throughout.
And incorporates a huge custom built noise silencer to try and keep exhaust noise in check. Here is some ugly old fella posing next to the shiny new silencer.
We have 2x 241mm up stands in the cell, one either side of the vehicle. These go up through the ceiling and then meet in the middle, where they then branch off into one and head through the roof space and back down into the fan control room.
The silenced exhaust gas finally goes to atmosphere pointing across the industrial roofs, directly away from the closest units, so hopefully it wont create too much noise.
The business end... these are the two exhaust collectors that will sit behind the exhaust and hopefully scavenge all the exhaust gas. (What is it with Exhausts and posers?)
To give you an idea of their size behind a large car...
And there you have it. This is the fan control room that houses the exhaust extractor, engine cooling fans and associated controllers and switchgear.
The next mission is going to be wiring up the control system and networking as this dyno cell is going to be 95% wireless...