exhaust temp help

[Ed Wright]

Originally Posted by buzzinhalfdozen

No arguing that Tom with properly working wide band o2's fuel management is greatly simplified. If for nothing less than the increased response time they are a worth while addition to any tuning arsenal. The biggest issue I've seen is racers searching for that "magic AFR" basically there isn't one. Joe

Ain't that the truth? Kids come in for tuning read on internet message boards that 13-1 is the magic number, and that is what they want. Heck, 13.5-1 will often make big dyno numbers, seldom goes down the track as quick. Depends on the engine and fuel of course, but there is no magic number. Mine likes mid-twelves. (Air/Fuel ratio, not EGTs)

[Mike Taylor 3601]

I think EGT's can be alot like dyno's numbers vary I'd say you would have to find your spot on jetting for fastest,quickest,then use that # your EGT shows to be your reference.
I've not had any in car EGT's but on engine dyno on gas around 1375 was close to best temp alky was around 1200.
I had engines where EGT would be 900-1000 move jetting,timing never get to change,so would have to jet by power&torque to find best jetting,those engines were always better than average of comparable engine I had dynoed and had wider and flatter power&torque curves. On those engines when you pull headers they would be black about 2-3'' down tube then go to nice toasty tan.
EGT thermocouples are'nt the most consistent thing,they go bad they change,you can buy thermocouple tester that checks accuracy of thermocouple.
Where you put in header tube makes a difference I think Superflow told us to go about 3'' out from head.
I think most people put probe in #5 in BBC it seems to be hot cyl on BBC.
Usaully on dyno adv.timing would drop EGT,ret. would raiseEGT.
Mike Taylor 3601