[Shotimes] Gas

[Zach Leahy]

and to comment on my comments.......

If fill the tank with 93, blank the computer, and "re-train" it in a
systematic flogging of the engine.  I think you will notice that the
engine will run much more aggressively becasue it knows where the
threshold is based on the driving style exhibited to it.

try it sometime, if nothing else it's a lot of fun...

Zach 
...maybe my car is just "special"....

On Apr 8, 2005 10:50 AM, Zach Leahy <leahyz@gmail.com> wrote:
> I'm in Dave's boat.
> 
> Once the car senses knock and pulls timing, it doesn't just add it
> back in later.  It usually adds in advance in small incremaents as it
> goes, so it's more like 20 littel steps forward, and when it senses
> knock, one big step back.  20 little steps foreward... so on.  I
> believe (and ya'll can correct me later) that the computer will
> eventually learn the knock threshold of the engine, and will maintain
> somewhere near, but under it.  If it has adavanced the ingition based
> on a "sensable" driving pattern, but then is subject to a fast accel,
> it attempts to use the threshold it knows, which applies to cruising
> and hence it detonates, and abcks out the timing.
> 
> So in a long way, yeah it does add the timing back in, but probably
> not on your 1/4 mile run.  the knock sensor is there as a fail safe
> and while aggressive in the way it works, does work.
> 
> Z
> 
> On Apr 8, 2005 10:39 AM, Dave Kegel <d.kegel@comcast.net> wrote:
> > A lot depends on the weather (I believe it was pretty damn cold when
> > Porter was setting records).  He was also driving a Gen3.  I'm not sure
> > how those handle the different grades of gas.
> >
> > Not sure about dyno numbers.  Are you saying someone has done back to
> > back dyno runs with 87 vs 93 and saw no difference?
> >
> > Just last week I saw a show on Speed (I think it was Sports Car
> > Revolution) where they dynoed a newer 911 with both grades of gas.  It
> > made several more HP with the better gas (can't remember the exact
> > amount, 3-5 I believe).
> >
> > The bottom line (IMO) is if you can hear it ping, you need better gas.
> > Again, this depends on what you're doing.  Daily back and forth to work,
> > sure, I guess don't spend the money.  But track days, dynos, drags, I
> > believe you'll do better with the better gas, regardless of what Mr.
> > Porter's about to say.  :)
> >
> > Dave
> >
> > -----Original Message-----
> > From: Paul L Fisher [mailto:sho@paul-fisher.com]
> > Sent: Friday, April 08, 2005 10:28 AM
> > To: 'Dave Kegel'; shotimes@autox.team.net
> > Subject: RE: [Shotimes] Gas
> >
> > I understand what you are saying but how would that explain Ron P being
> > the fastest at the drags running 87 and other doing dyno runs with 87?
> >
> > While it might pull timing for when you punch it, I would assume it
> > would let the timing back in later.
> >
> > Paul L Fisher
> >
> > Visit my website: http://www.paul-fisher.com
> > SHOClub Member: http://www.shoclub.com
> > Amsoil dealer: http://www.paul-fisher.com/oil
> >
> > -----Original Message-----
> > From: shotimes-admin@autox.team.net
> > [mailto:shotimes-admin@autox.team.net]
> > On Behalf Of Dave Kegel
> > Sent: Friday, April 08, 2005 10:15 AM
> > To: shotimes@autox.team.net
> > Subject: RE: [Shotimes] Gas
> >
> > This is where I tend to disagree with you guys.  Timing is being pulled
> > out and you're not getting all the power that you could.
> >
> > Dave
> >
> > -----Original Message-----
> > From: shotimes-admin@autox.team.net
> > [mailto:shotimes-admin@autox.team.net] On Behalf Of Dave Garber
> > Sent: Friday, April 08, 2005 10:09 AM
> > To: shotimes@autox.team.net
> > Subject: RE: [Shotimes] Gas
> >
> > When it's hot out, if I stab the throttle on either of my remaining
> > SHO's (91 and 99), I get a quick ping out of it. But it's nothing even
> > remotely severe enough to warrant running over 87 octane.
> >
> > Dave Garber
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