Honda Car Forum

Elmo P. Shagnasty wrote:
> In article <d8oIl.35465$gC1.24884@newsfe19.iad>, Leftie <No@Thanks.net>
> wrote:
>
>> The thing about knock
>> sensors is they only stop knocking - they don't increase performance. In
>> fact, they are there so the engine can run a more advanced timing curve
>> when you use higher octane gas.
>
> No, that's not why they're there.
>
> Knock sensors are there so that when you use a gasoline that does NOT
> have the anti-knock properties that are called for in the
> gasoline--let's say you used a lower octane gas--then the engine doesn't
> detonate.
>
> But when the engine is already designed for 87 octane fuel, and if
> you're using a proper 87 octane fuel (not piss water), then the knock
> sensors don't come into play at all. (I am ignoring the effects of age
> and bad maintenance causing carbon buildup inside the combustion
> chamber, which would lead to knocking with 87 octane fuel, which means
> that a higher octane fuel will help. Rather, I am discussing a properly
> maintained and clean engine.)
>
> Again, the knock sensors don't come into play at all. You can put all
> the higher octane gas you want in, and the knock sensors don't move the
> timing around to keep the engine just at the point of knock. No, the
> knock sensing system is designed to work with fuels lower than what the
> engine was designed for. The system was NOT designed to advance timing
> in the presence of higher octane fuels that are beyond the octane rating
> specified by the engineers.


There is a contradiction being promoted here: that my car is
designed for 87 octane gas only, and that it has knock sensors in case I
use gas below 87 octane - below Regular grade. Perhaps Honda doesn't
respect American gasoline? BTW, my Civic Si also did better power-wise
on midgrade (but with worse fuel economy), and IIRC it noted that higher
octane gas was preferred in the manual.

Leftie <No@Thanks.net> wrote in
news:q6yIl.113971$qO1.59271@newsfe13.iad:

> Elmo P. Shagnasty wrote:

>>
>> Again, the knock sensors don't come into play at all. You can put
>> all the higher octane gas you want in, and the knock sensors don't
>> move the timing around to keep the engine just at the point of knock.
>> No, the knock sensing system is designed to work with fuels lower
>> than what the engine was designed for. The system was NOT designed
>> to advance timing in the presence of higher octane fuels that are
>> beyond the octane rating specified by the engineers.
>
>
> There is a contradiction being promoted here: that my car is
> designed for 87 octane gas only, and that it has knock sensors in case
> I use gas below 87 octane - below Regular grade.



Not quite. It is possible to have gas that's nominally 87, but is
contaminated, of substandard quality or has degraded with age.

In any case, the primary purpose of the knock sensor is EMISSIONS, not
engine damage. Protection against engine damage does allow the computer to
advance the timing as far as it can without risking detonation, but it can
only go up to its designed-in limits, which are configured for 87 octane.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Tegger wrote:
> Leftie <No@Thanks.net> wrote in
> news:q6yIl.113971$qO1.59271@newsfe13.iad:
>
>> Elmo P. Shagnasty wrote:
>
>>> Again, the knock sensors don't come into play at all. You can put
>>> all the higher octane gas you want in, and the knock sensors don't
>>> move the timing around to keep the engine just at the point of knock.
>>> No, the knock sensing system is designed to work with fuels lower
>>> than what the engine was designed for. The system was NOT designed
>>> to advance timing in the presence of higher octane fuels that are
>>> beyond the octane rating specified by the engineers.
>>
>> There is a contradiction being promoted here: that my car is
>> designed for 87 octane gas only, and that it has knock sensors in case
>> I use gas below 87 octane - below Regular grade.
>
>
>
> Not quite. It is possible to have gas that's nominally 87, but is
> contaminated, of substandard quality or has degraded with age.
>
> In any case, the primary purpose of the knock sensor is EMISSIONS, not
> engine damage.

not necessarily true. the more advanced, the more NOx because
combustion temp is higher. but the trade is better fuel economy and/or
power. thus, in an ideal world, you want the ignition as advanced as
possible for any given day, and the only way to determine the max limit
is to use knock detection.


> Protection against engine damage does allow the computer to
> advance the timing as far as it can without risking detonation, but it can
> only go up to its designed-in limits, which are configured for 87 octane.

modern ignition timing algorithms, for want of a better word, are highly
advanced.

http://www.google.com/patents?id=Dto...J&dq=5,038,736

In article <tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net>,
jim beam <retard-finger@bad.example.net> wrote:

> modern ignition timing algorithms, for want of a better word, are highly
> advanced.

<rimshot>

Thank you, thank you. He's here all week, folks.

jim beam <retard-finger@bad.example.net> wrote in
news:tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net:

> Tegger wrote:
>> Leftie <No@Thanks.net> wrote in
>> news:q6yIl.113971$qO1.59271@newsfe13.iad:
>>
>>> Elmo P. Shagnasty wrote:
>>
>>>> Again, the knock sensors don't come into play at all. You can put
>>>> all the higher octane gas you want in, and the knock sensors don't
>>>> move the timing around to keep the engine just at the point of
>>>> knock.
>>>> No, the knock sensing system is designed to work with fuels lower
>>>> than what the engine was designed for. The system was NOT designed
>>>> to advance timing in the presence of higher octane fuels that are
>>>> beyond the octane rating specified by the engineers.
>>>
>>> There is a contradiction being promoted here: that my car is
>>> designed for 87 octane gas only, and that it has knock sensors in
>>> case I use gas below 87 octane - below Regular grade.
>>
>>
>>
>> Not quite. It is possible to have gas that's nominally 87, but is
>> contaminated, of substandard quality or has degraded with age.
>>
>> In any case, the primary purpose of the knock sensor is EMISSIONS,
>> not engine damage.
>
> not necessarily true. the more advanced, the more NOx because
> combustion temp is higher. but the trade is better fuel economy
> and/or power. thus, in an ideal world, you want the ignition as
> advanced as possible for any given day, and the only way to determine
> the max limit is to use knock detection.



You're absolutely correct.

But even very slight knocking that would cause no damage to the engine
will dramatically increase NO emissions. Knock sensors, once rare,
became ubiquitous as part of the OBD-II emissions management system.




>
>
>> Protection against engine damage does allow the computer to
>> advance the timing as far as it can without risking detonation, but
>> it can only go up to its designed-in limits, which are configured for
>> 87 octane.
>
> modern ignition timing algorithms, for want of a better word, are
> highly advanced.
>
> http://www.google.com/patents?id=Dto...J&dq=5,038,736
>
>


Bedtime reading, anyone? I was fine until I got to the flowcharts. :^(



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

"Elmo P. Shagnasty" <elmop@nastydesigns.com> wrote in
news:elmop-38F92B.12370925042009@mara100-84.onlink.net:

> In article <tYOdnXM1-5d0lm7UnZ2dnUVZ_i2dnZ2d@speakeasy.net>,
> jim beam <retard-finger@bad.example.net> wrote:
>
>> modern ignition timing algorithms, for want of a better word, are
>> highly advanced.
>
> <rimshot>
>
> Thank you, thank you. He's here all week, folks.
>



Is there an intermission? I'm out of popcorn.



--
Tegger

The Unofficial Honda/Acura FAQ
www.tegger.com/hondafaq/

Anyone driving a coupe or sedan that gets less than 35 mpg is a leach
on society.

<honda.lioness@gmail.com> wrote in message
news:e30b4f2b-c43f-4f86-9da5-9efb77fbc04a@l16g2000pra.googlegroups.com...
> Anyone driving a coupe or sedan that gets less than 35 mpg
> is a leach on society.

You are so ridiculous...

Why 35mpg and not 55mpg?
Because your junky honda happens to be just over 35 line?

I drive 2004 honda accord coupe...
In what way am I a leach on society more than you are?

At least I am not cheating Carfax to get my fee back...

"Pszemol" <Psze...@PolBox.com> wrote:
> <honda.lion...@gmail.com> wrote in message

> > Anyone driving a coupe or sedan that gets less than 35 mpg
> > is a leach on society.
>
> You are so ridiculous...
>
> Why 35mpg and not 55mpg?

Because 35 is easily obtained today.

> Because your junky honda happens to be just over 35 line?

You have not seen my Honda.

> I drive 2004 honda accord coupe...
> In what way am I a leach on society more than you are?

It was written partly tongue in cheek, as a partial response to by
someone else that this is about what God intended. ;-)

> At least I am not cheating Carfax to get my fee back...

? You have the wrong person.

In article
<33f30032-a6bf-418b-b223-3eb36ce41db5@n7g2000prc.googlegroups.com>,
honda.lioness@gmail.com wrote:

> > Why 35mpg and not 55mpg?
>
> Because 35 is easily obtained today.

Then why aren't you on a scooter that gets 65mpg?

Oh, I see--YOU get to set the qualifications for what KIND of car people
should be driving, and--interestingly enough--that would be YOUR car.

Nothing more, nothing less.

Go ahead, put your money where your mouth is--buy a scooter and quit
being a "leach" (sweetheart, you meant "leech") on society.