1 minute ago, cat handler said:

 

Did you tune the ECU for the change of fuel, if you had your times would have been quicker.

What's an ECU...?    

 

 

 

23 minutes ago, cat handler said:

 

Did you tune the ECU for the change of fuel, if you had your times would have been quicker.

Back in the Knight Rider days they released a clamp screw and dialled it in. If that failed to increase power more shiny parts were added to the engine bay.

1 hour ago, cat handler said:

 

What the? Really, I wonder why motorsports use a higher octane fuel then and not just 91, I higher rated fuel actually does increase your horsepower or kilowatt output.

Geez...we are not talking about motorsports where many other engine parameters are changed also!  On a road car, with no other modifications, using higher than recommended octane fuel will not increase power output!  It can't.

13 hours ago, Just Weird said:

Not sure what point you are trying to make but if it is that 95 RON petrol makes your bike faster than 91 gasohol you've got it the wrong way around, the gasohol is less efficient then petrol so it reduces the performance and economy

which is exactly as i said ? not 95 ron but 95 ron  benzine makes my bike faster and has more mileage than 91/95 gasohol. I have re-read my post a few times and i  cannot see why you think i said gasohol is better ?

1 hour ago, cat handler said:

 

What the? Really, I wonder why motorsports use a higher octane fuel then and not just 91, I higher rated fuel actually does increase your horsepower or kilowatt output.

It's about the compression ratio of the engine: https://en.wikipedia.org/wiki/Compression_ratio

So in a car with an engine with high power, like one used in motorsports, there is a high compression and fuel with 91 octane would ignite before the cylinder is fully compressed and the "knocking" as described before would occur. But the engine of a standard road car does not have such a high compression and 91 octane fuel is sufficient

1 hour ago, cat handler said:

 

Did you tune the ECU for the change of fuel, if you had your times would have been quicker.

How do you tune an ECU that isn't there?

1 hour ago, dragonballz said:

which is exactly as i said ? not 95 ron but 95 ron  benzine makes my bike faster and has more mileage than 91/95 gasohol. I have re-read my post a few times and i  cannot see why you think i said gasohol is better ?

OK what bike is it and how do you know it's faster by how much ?

A higher compression engine will generate more power and give better efficiency but requires a higher octane fuel.

The other point to note is that the power/efficiency is related to mass not volume (although we nearly always quote miles per litre rather than per kilogram).  Higher octane fuels typically contain more aromatics which are a higher density than lower octane parafins. (The definition of 100 octane is pure iso-octane, cf. 0 octane which is pure n-heptane).

So more mass per unit volume gives a slightly higher energy content and a better range... but will always be more expensive since it requires additional refining/treatment.

 

The ethanol blended fuels have a much lower specific energy content (even though they may be slightly a higher density), so they will not give the same power or range.

So using ethanol blended petrol only makes it cheaper, helps the finite supply of petroleum last longer, gets farmers involved in wide-spread maize/sugarcane production but offers no particular benefit to the car engine?

1 hour ago, chingmai331 said:

offers no particular benefit to the car engine?

Ethanol is supposed to be good (more power)  for turbocharged engines ?

I suppose for supercharged (compressor) too ?

A NZ engineer gets lots of power from ethanol fuel in performance cars.

Snippet :-

If you’re looking for more performance out of your car, tuning to suit E85 can provide impressive results for a modest investment. But it does demand some respect to ensure good performance and reliability. 

It does improve performance over other fuels, yet that power wont increase the mpg for some reason.

On 5/15/2018 at 3:00 PM, cat handler said:

 

Did you tune the ECU for the change of fuel, if you had your times would have been quicker.

I suspect the 'ride' would have been a distributor with fly bobs. I have to add an anti knock supplement on my 73 sportster,,,,wasn't made for unleaded petrol.

Two different things here Ethanol content and Octane Rating. The Ethanol content of Gasahol is low , but will still give slightly less mpg ( miles/km per gallon/litre ) than say Benzine. Octane certainly can make a difference to power. Some engines can advance the timing to take advantage  of the fuels better 'anti knock ' qualities, either automatically or by manual adjustment ..A lot of engines will retard the timing ( and lose potential power ) to prevent pinking /knocking on low octane fuels . Or some engines that dont adjust (or  dont adjust enough)  they just pink all the time losing power un be-known to the driver, or worse still  severe pinking  leading to detonation not only losing power, but potenially big engine damage to. I would only ever use the highest octane fuel available , and yes I happen to find Shell one of the best brands . In UK their 99 Ron V Power is essential for me on any modified car/bike, and most Std spec cars to. As much for engine protection as power! 

Knock is the biggest engine killer btw. Not suggesting you try it, but a long haul flat in top gear is very different to a quick overtaking move in 2nd/3rd gear. Whats more worrying is 99% people cant even hear it . In Thailand in my Honda click ? ..Shell 95 Gasohol is my choice. 

Regarding std engines, many may be right on the knock point already using 'min recommended octane' fuels.  Is it pinking occassionally but not being heard ? Or backing the timing a little under high load conditions ?..Either way its losing power when it does. (In comparison to having used a higher octane fuel in the first place .)

On 5/15/2018 at 2:48 PM, Kwasaki said:

OK what bike is it and how do you know it's faster by how much ?

Can you not read ? its faster by the amount i put in my post which you are quoting from . the bike is a 125cc honda wave 

15 minutes ago, dragonballz said:

Can you not read ? its faster by the amount i put in my post which you are quoting from . the bike is a 125cc honda wave 

Does it also go faster after you wash it.?.

Does it also go faster after you wash it.?.

For best result put 80-100 psi in the tyres,

a much harder option is to sculpture golf ball like dimples all over to lower drag

and of course wash and wax + duck down so your chin is on the speedo...remove the exhaust "mufler" 300kph guaranteed.

 

38 minutes ago, johng said:

For best result put 80-100 psi in the tyres,

a much harder option is to sculpture golf ball like dimples all over to lower drag

and of course wash and wax + duck down so your chin is on the speedo...remove the exhaust "mufler" 300kph guaranteed.

 

Dont foreget the Black Visor n rims n tyres thinner than a CD. Youths wasted on the Young.?