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What is the optimum EGT? #1318444
10/10/12 11:56 AM
10/10/12 11:56 AM
Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
M
MRMOPAR622 Offline OP
top fuel
MRMOPAR622  Offline OP
top fuel
M

Joined: Sep 2003
Posts: 2,008
Sweet Home Alabama
I finally found someone with the latest state-of-the-art dyno, it is capable of reading the EGT in each pipe and I have welded the bungs in my headers, what would be the optimum EGT running alcohol? I hope to get the engine to the dyno the first to the middle of next week. Thanks,

Last edited by MRMOPAR622; 10/10/12 11:57 AM.

"To Be The Man'You Have Got To Beat The Man" "T/D and Pro-Bracket Racer"
Re: What is the optimum EGT? [Re: MRMOPAR622] #1318445
10/10/12 01:29 PM
10/10/12 01:29 PM
Joined: Jul 2010
Posts: 1,491
Oologah, Oklahoma
Big Squeeze Offline
pro stock
Big Squeeze  Offline
pro stock

Joined: Jul 2010
Posts: 1,491
Oologah, Oklahoma
Quote:

I finally found someone with the latest state-of-the-art dyno, it is capable of reading the EGT in each pipe and I have welded the bungs in my headers, what would be the optimum EGT running alcohol? I hope to get the engine to the dyno the first to the middle of next week. Thanks,




Whatever makes the most power....


If you can't handle the truth, you're living a lie.......
Re: What is the optimum EGT? [Re: MRMOPAR622] #1318446
10/10/12 02:15 PM
10/10/12 02:15 PM
Joined: Feb 2008
Posts: 714
Central TEXAS!!!!
sr4440 Offline
super stock
sr4440  Offline
super stock

Joined: Feb 2008
Posts: 714
Central TEXAS!!!!
On my dyno, I never use EGT’s to tune with, I use them to check fuel distribution. I get the A/F one of 2 ways. 1. O2 sensor (this takes the average of all 4 cylinders, someday I buy the upgrade for 8 O2 sensors. ) 2. Measure the lbs. of air and fuel flowing into the engine.

The EGT’s can be all over the place based on timing and A/f ratio.

Get the A/f right then adjust the timing for the most power.

Joe


Without Data, you’re just another guy with an opinion.
Re: What is the optimum EGT? [Re: MRMOPAR622] #1318447
10/10/12 02:21 PM
10/10/12 02:21 PM
Joined: Aug 2003
Posts: 43,198
Bend,OR USA
C
Cab_Burge Offline
I Win
Cab_Burge  Offline
I Win
C

Joined: Aug 2003
Posts: 43,198
Bend,OR USA
EGT temps depend on many things, fuel type, ignition timing, cam overlap, as well as probally several other things I can't think of right now. On my airplane I would lean it out until it reach max EGT and then started miss and to go colder, I then would fatten it up enough to make it run from 25 to 75 F colder than peak EGT The big thing to look at is how much spread there is, I like to see no more than 50F difference on all 8 cylinders, that is relly hard to get on a single four carb. set up I would start out fat and then slwoly, a little bit at a time, lean it out to get max power, go past that maybe one jet size to make sure you got the most power from jetting. Be ready to change that tune up once you get the motor in the car and run it at the track be open minded and test, test, and test somemore One of the dyno operator I used in SO CA was really big about wanting to advancing the ignition timing to cool the EGT down when breaking in the cam at 1500 to 2000 RPM I usually wouldn't, that irritated him, I would tell him this ain't no Cheverolet, George Last thing, I have heard of motors burning up the pistons at 900 to 1200F degrees EGT and the same motor not hurting a thing with EGT at 1700F One of the airplane guru like to see EGT in the 1400 F range at peak power on the N/A motors, the higher altitudes run cooler EGT than you do down low, under 8000 Ft above sea level Use the spark plugs and time slips to tune the car for best 1/4 MPH

Last edited by Cab_Burge; 10/10/12 02:47 PM.

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)






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