Tuning with EGT

Grant Crockett idratherbedriving at yahoo.com
Tue Mar 13 22:55:24 GMT 2001


How close is your probe to the exhaust port?

--- Steve.Flanagan at VerizonWireless.com wrote:
> I use 8 EGTs to aid in tuning a 1600 HP Turbo setup.
> We see temps from 1700
> F to
> 1900 F.  Lets say we do not like to see anything
> over 1900 but we have seen
> it.
> 
> Typical range I would say for blown applications is
> 1600 - 1800 F.
> 
> As far as tuning, its aids in individual cylinder
> tuning, but there is no
> absolute
> value that you can tune for.  Its more or less used
> as a reference from the
> last 
> pass.  Its also great to see if you have a problem
> with any one cylinder.
> We use
> 116 octane.  Combined with wide band 02 provides a
> great basis to tune from.
> 
> steve
> 
> -----Original Message-----
> From: Larry Heath [mailto:lgheath at earthlink.net]
> Sent: Monday, March 05, 2001 3:24 PM
> To: diy_efi at diy-efi.org
> Subject: Re: Tuning with EGT
> 
> 
> Most guys that drag race use EGT to tune. Most of us
> look for a max of about
> 1200 to 1250 degrees F as the car crosses the finish
> line, i.e. max load max
> rpm. This is of course using fuels with very high
> octane ratings, generally
> no less than 105 octane and as much as 118, that are
> generally not prone to
> detonation even under extreme conditions. I lot of
> guys use the EGT's in
> tuning alcohol fueled engines, as the typical signs
> use to tune gas fired
> engines are generally not present, the alcohol fuel
> being very clean burning
> and has such a wide range of flammability. Most guys
> seem to use the same
> basic temp range as a max, although I have seen
> references to EGT's much
> lower than the 1200 to 1250 range as being ideal for
> max power.
> 
> Thermocouples (K type) are generally fairly slow as
> far as response time
> goes, at least for the typical thermocouples used in
> this application. The
> faster the response rate of the couple the shorter
> the average life of the
> unit is.  I have seen bare wire thermocouples with
> standard response times
> of as little as .004 sec, but these would not last
> any significant amount of
> time, in an exhaust gas environment. About the
> minimum wire size that would
> be usable as a EGT is .015" and this has about a .8
> sec response time going
> from 100 to 800 degrees in 60 ft/sec gas.
> 
> Along these same lines I have a question; does any
> have any info about
> tuning alcohol fueled engines using an O2 sensor or
> other similar sensor to
> allow A/F ratios to be determined on a much faster
> basis than the typical
> EGT thermocouple sensors.
> 
> Later Larry
> 
> ----- Original Message -----
> From: "Grant Crockett" <idratherbedriving at yahoo.com>
> To: <diy_efi at diy-efi.org>
> Sent: Monday, March 05, 2001 11:41 AM
> Subject: Tuning with EGT
> 
> 
> > Has anybody done air-fuel mixture tuning with
> exhaust
> > gas temp rather than O2 sensor?  I have read that
> the
> > thermocouple has a much quicker reaction time to
> high
> > heat/lean fuel conditions than an O2 sensor.
> >
> > If so, what are you getting for temperature
> readings?
> > I am wondering what temps (deg F) would equate to
> > optimum performance, without detonation.
> >
> > end
> >
>
--------------------------------------------------------------------------
> --
> > To unsubscribe from diy_efi, send "unsubscribe
> diy_efi" (without the
> quotes)
> > in the body of a message (not the subject) to
> majordomo at lists.diy-efi.org
> >
> 
>
----------------------------------------------------------------------------
> To unsubscribe from diy_efi, send "unsubscribe
> diy_efi" (without the quotes)
> in the body of a message (not the subject) to
> majordomo at lists.diy-efi.org
>
----------------------------------------------------------------------------
> To unsubscribe from diy_efi, send "unsubscribe
> diy_efi" (without the quotes)
> in the body of a message (not the subject) to
> majordomo at lists.diy-efi.org
> 

----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org
----------------------------------------------------------------------------
To unsubscribe from diy_efi, send "unsubscribe diy_efi" (without the quotes)
in the body of a message (not the subject) to majordomo at lists.diy-efi.org




More information about the Diy_efi mailing list