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High Dyno Figures on low (93) octane points, in the US

Started by INFLYTmelb · 28 May 2012 · 4 replies

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INFLYTmelbArchived member
Hi All, just recently its been racking my brain, how many of the high powered cars in the USA, are making mega figures, on low octane 93 fuel.......where their regular octane is a measly 87 point, unlike our 91 and 95. I cant figure it out? i know that Barometeric Pressures, Ambient Temps and various weather factors play a part, but i cant see what else would make it happen, in a different part of the world. Forgive me if you find this thread silly, but i think its very intertesting, if there is an explaination for it.
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Duke57TTArchived member
There 93 is out 98 and so forth and so forth. Also their Dyno figures are inflated due to the style of dyno(inertia vs retarder I think).. they just don't run the mph for the same power like we do.(In a fair comparison, plenty of shops give dyno sheets and cars here don't run the mph, like all dynos, nothing is the same)
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xAsh-Archived member
Is there a specific HP to MPH conversion? Say 1000hp to ___ mph?? obviously changes for manual cars i'd think
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RB30DEVLArchived member
Quote: Forgive me if you find this thread silly, but i think its very intertesting, if there is an explaination for it I don't think what you're saying is silly at all, I got temporarily banned for talking "nonsense", that was about the coal industry but I am hoping Caterpillar start endorsing bio-diesel for the machinery they make, they are also into forestry so they are more open minded (Westrac) , I mean, the petrol companies start pushing to convert oil places like McDonalds use cook their french fries, etc to diesel biofuel a bit harder. I'll get back to what you were talking about, someone was saying on the internet that if there is no detonation present there is no point in going to higher octane fuel than what the ECU is programmed for, E10 here in Australia has an octane rating of around 94 even though Caltex advertise it as 91 octane fuel. There is a site which explains the advantages of bio-ethanol fuel over traditional fuels which I have listed here :- http://www.doe.gov.ph/AF/Bioethanol.htm They estimate that a vehicle will use 3% more fuel when using E10 over non ethanol based fuels, I'm doing a bit of a feasibility study on E10 at the moment and so far the car appears to be using a bit more fuel around town on the display ,which I always take with a grain of salt because the calculated economy figures are always better with my car. I've only used 1/4 of a tank of fuel so it is too early to say what fuel economy I am getting, but I have noticed for some strange reason the car has started to perform better on it than on 98 octane premium unleaded fuel, they were saying on that website that ethanol burns cooler and also contains oxygen, which makes the engine put out less emissions but should also result in more power as well, it is somehow also supposed to increase the volumetric efficiency of the engine. I've got a clip of an RB30 turbo engine running on E98 (98% ethanol fuel) , you can watch that for yourself :- www.youtube.com/watch?v=ieVDfnUKN9s (http://www.youtube.com/watch?v=ieVDfnUKN9s) The only difference here it's not 98 octane, rather 120. When Shell had the Optimax 98 octane fuel out, there was something with its density in the way it was more expensive than the standard fuel but I ended up spending the same amount of money on that as with standard unleaded fuel to fill the tank up. Ethanol obviously doesn't have the density of even standard unleaded so you use more of it, about 3% more with E10 or up to 34 % more with E85 flex fuel, they are going to have to come up with a way to produce that fuel cheaper so it costs the same to run the car as with conventional fuel.
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xAsh-Archived member
You always find a way to squeeze in something about westrac into your posts...
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