RE: Chris Harris video: Noble M600 and Atom V8
Discussion
jetpilot said:
I know it will cause a commotion on here, the technology that gives us "driver aids", also gives us decent brakes, suspension and tyres that make the Noble possible! So dismissing technology isnt perhaps a good thing, unless of course you want crossply tyres, shocking suspension that is either compliant for the road or track, not both and brakes that wouldnt stop a shopping trolley!
All be it that it would take an exceptionally talented driver to get take this car anywhere near its abilities just keeps making me ask, why, when you can buy more for less?
I'm not sure anyone in this thread has said anything negative at all about modern tech. Personally, I think it's great. I just don't want to drive a fruit machine. Brilliant tech doesn't need lights, bells, knobs and buttons to be brilliant.All be it that it would take an exceptionally talented driver to get take this car anywhere near its abilities just keeps making me ask, why, when you can buy more for less?
red uk said:
This is all I have at the moment. Factory visit about 2 weeks ago. Nice production line!
There is something very nice about that pale blue colour, it just seems to look perfect.Even if those of us of a certain age associate that colour with one of two things:
The underside of an Airfix B109:
or the Invacar:
What is quite interesting is that the car appears to be able to carry any colour and look good unlike many cars.
Hollowpockets said:
Wrong, it is, the M400 makes the same noise.
The noise is commonly referred to as wastegate chatter, but it is in fact a myth. The sound is caused by the compressed air flowing backwards through the compressor wheel of the turbo as the throttle is closed. Partial or full closures produce differently pitched noises and it is impressive how loud it can get. The M600's air intake system is probably relatively shielded from the cabin and the sound is more in the background than it would be for a car with less sound deadening between the engine bay and the cabin. I don't know how much sound deadening separates the engine bay and the cabin, nor can I quantify the volume of the sound the Noble makes.It is not unheard of for external wastegates (commonly seen on competition cars with large turbos, but also used in road applications also) to be audible, but it is not this sound.
For a turbo with the wastegate housed internally, any noise emitted by it clapping shut repeatedly would be muffled by the exhaust system. This clapping is apparently also possible as the turbo reaches the boost threshold, but thinking about the operation of this I cannot understand what would cause the actuator to act in this way.
The term "wastegate chatter" does sound cool though (even though it is not correct) which is perhaps why the term has stuck amongst motoring discussions.
Etided for speeling
Edited by LandingSpot on Friday 20th April 13:53
The fact that wastegate chatter gets mentioned during reviews to large audiences also helps perpetuate the myth...
http://www.youtube.com/watch?v=ONVZ8QFTnb4
Edited by LandingSpot on Friday 20th April 20:15
WOW. Stunning!
what a video. Amazing work Chris. Congrats. EPIC. Was worried when you left Evo that we would see less of your awesome stuff like this. Glad to be proved very wrong!
I was there that day by the way, Met you in bar afterwards, still be up for driving my Westy? I'd love you too!
what a video. Amazing work Chris. Congrats. EPIC. Was worried when you left Evo that we would see less of your awesome stuff like this. Glad to be proved very wrong!
I was there that day by the way, Met you in bar afterwards, still be up for driving my Westy? I'd love you too!
LandingSpot said:
Hollowpockets said:
Wrong, it is, the M400 makes the same noise.
The noise is commonly referred to as wastegate chatter, but it is in fact a myth. The sound is caused by the compressed air flowing backwards through the compressor wheel of the turbo as the throttle is closed. Partial or full closures produce differently pitched noises and it is impressive how loud it can get. The M600's air intake system is probably relatively shielded from the cabin and the sound is more in the background than it would be for a car with less sound deadening between the engine bay and the cabin. I don't know how much sound deadening separates the engine bay and the cabin, nor can I quantify the volume of the sound the Noble makes.It is not unheard of for external wastegates (commonly seen on competition cars with large turbos, but also used in road applications also) to be audible, but it is not this sound.
For a turbo with the wastegate housed internally, any noise emitted by it clapping shut repeatedly would be muffled by the exhaust system. This clapping is apparently also possible as the turbo reaches the boost threshold, but thinking about the operation of this I cannot understand what would cause the actuator to act in this way.
The term "wastegate chatter" does sound cool though (even though it is not correct) which is perhaps why the term has stuck amongst motoring discussions.
Etided for speeling
Edited by LandingSpot on Friday 20th April 13:53
The fact that wastegate chatter gets mentioned during reviews to large audiences also helps perpetuate the myth...
http://www.youtube.com/watch?v=ONVZ8QFTnb4
Edited by LandingSpot on Friday 20th April 20:15
GTiFrank said:
what is the difference between this and a dump valve releasing the pressure from the turbo when the throttle is closed?
A wastegate allows exhaust gas to bypass the turbine to control boost, a blow-off valve allows compressed intake air to escape from the inlet tract when the throttle is closed (either to atmosphere or back into the inle, pre-turbo).Trommel said:
GTiFrank said:
what is the difference between this and a dump valve releasing the pressure from the turbo when the throttle is closed?
A wastegate allows exhaust gas to bypass the turbine to control boost, a blow-off valve allows compressed intake air to escape from the inlet tract when the throttle is closed (either to atmosphere or back into the inle, pre-turbo).When you consider where in the system the wastegate is, one realises that it is impossible to modify to produce an audible affect like this one.
Consider the fact that you can have dump valves for different applications and that these will have differently rated springs for each application (Cosworth: 2 bar +, Jap stuff: 1-2bar, and OEM boost levels of around 0.5-0.7 bar etc) each spring rate means that the dump valve will only be forced open at a preset pressure. Therefore, when you are at full boost and you close the throttle completely for a fast gear shift, you will get a full dump, because the compressor wheel is pushing flat out to force air in to the engine. Closing the throttle means this air has nowhere to go and there for pushes open the dump valve. No imagine that you have a super hard spring in the valve (or no valve at all), it would take much more pressure to push it open, right? Therefore the compressed air would go backwards through the only place available; where it came in. That's where the sound comes from.
My understanding of the operation of the wastegate at full pressure and load could be better, but I'm now thinking about the wastegate "bouncing" off the housing. This apparently only happens at the threshold of maximum boost, where the waste gate is having to open extremely quickly to control the boost. Why would it happen (and cause this noise) if it only occurs when the driver comes off the throttle (and boost drops)?
Another great video.
neilski said:
I met Chris in the Pistenklaus after the first day of filming and the following day he took me round in the Noble and it was every bit as good as he says it is and then some! Definitely a motoring highlight for me.
If you're reading this, thanks again Chris.
Lucky bugger!If you're reading this, thanks again Chris.
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