Can an EGT gauge be used to tune a boosted vehicle, instead of a wideband? I'm not a big fan of widebands, i don't like the flashy lights, lol.
2002 Cavalier "LS Sport"
Uh, no. An EGT gauge is nice to have
in conjunction with a wideband, but you want to know what the actual AFR is at any given MAP/RPM in order to properly tune...
2001 Olds Alero (LD9)
650 whp / 543 ft-lb
@turboalero
not a chance in hell. egt cant measure air fuel. get the db series gauge from innovate, simple digital numbers.
Well yes it can, but you need to know what AFR= what temp on the EGT gauge. Wideband is better, and they should be used together. It has been said already bit you can get widebands that do not have flashy lights. Get one that has the handheld box with number readings.
FU Tuning
Just get the cheaper gauge that comes with the innovate that just shows the numbers.
" To study and not think is a waste. To think and not study is dangerous. "
EGTs cannot be used the same way as a Wideband to tune.
AF is only changed by changing the amount of fuel.
EGTs can be changed by many other things, most notably timing.
Also any specific EGT reading can be caused by BOTH being too rich or too lean if they travel far enough out from optimal.
Finally no one really knows what EGT reading they should be targeting to get a good tune anyway. And if power is the target, hotter usually always = more power until everything melts.
sig not found
GM did find a good number for the ecotec, they said full power at 1230*F and not to exceed 1350*F. I figure those are pretty good numbers to shoot for.
Both is a very good idea, as mentioned before. Although, before widebands they used egt to tune cars, but that was before efi.
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4 Cams...32 Valves...5 Liters...This Could Get Fun!
You *can tune with just an EGT gauge....its scary to say the least....wouldn't do it on anything but low comp NA motors but it is possible. As said earlier, it wont tell you anything about what is causing the increase in temp. The best way is set a decent timing table you know will work and then adjust fuel to get the temps desired as that's the typical method of EGT tuning. It's really a lost art. You gotta know one and fine tune the other.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
Joshua Dearman wrote: ...The best way is set a decent timing table you know will work and then adjust fuel to get the temps desired as that's the typical method of EGT tuning...
How do you know you have a "decent timing table"?
What temperature is desired? and Why?
sig not found
Joshua, unless you're pulling the #'s out of thin air there is no way to just randomly come up with a "decent" timing table and go from there - everything would be assumptions.
As Todd said, there are a LOT of factors that change EGT's and the fact that you could swing on each side of each factor and have the EGT's go up also plays into the difficulty of tuning with just EGT's in mind.
Beyond that, we do not know what EGT's are optimal. Some motors like higher EGT's, other's don't.
The only true way to nail them down is lots of time on the dyno, with a proper AFR gauge to assist. If you can at least get your AFR's perfect you've taken one thing out of the EGT equation. Then you tune and see what the motor tells you it likes, torque-wise.
The only true lost-art in this day and age is the willingness of people to spend the $$ on dyno time. We blow thousands of dollars on turbos and engines and splurge on fancy things like ball bearings and ceramic coatings and big intercoolers, and somewhere along the way it's been forgotten that all that money is a waste if you don't have a small pile saved up for dyno tuning. PROPER dyno tuning.
Street tuning truly is barely sufficient to nail down an afr, and that's assuming you have a base "known to be good" timing map... which as I said is very hard to come up with since timing affects afr's too.
To the OP - get a wideband and book some dyno time.
-Chris-
-Sweetness-
-Turbocharged-
Slowly but surely may some day win this race...
Skunk wrote:GM did find a good number for the ecotec, they said full power at 1230*F and not to exceed 1350*F. I figure those are pretty good numbers to shoot for.
Both is a very good idea, as mentioned before. Although, before widebands they used egt to tune cars, but that was before efi.
That was on that set-up. I know a Ecotec turbo set-up that had a good AFR and made good power at 1400, so it is not always the same.
I agree with Protomec and Chris. IF you have your car tuned with a wideband for a certain timing, fuel etc... and it is at 1300 on the EGT gaug you can then remove the wideband and always watch for that EGT. Save the wideband instead of running it everyday.
FU Tuning
You guys are right, dont get me wrong. I'm not saying I can do it or it should be done. I've SEEN it done. I've even seen a "spit" tune done and dammit it was actually good. All this guy did was spit on the header and adjust the fuel to trims based on the time it took for his spit to evaporate....LOL....seriously....I couldn't make this @!#$ up. Once we got the engine to the dyno later in the week it was a very good tune. Again, this guy was very familiar with the engines as he has tuned several with the same setup. He picked the spark table out of thin air based on experience and went from there. So.......yeah, not possible on a boosted setup at all nor would I do it.
"Never argue with an idiot. They'll drag you down to their level, then beat you with experience!" -Anonymous
plus if you're going to log with EGT you need something to convert to a 0-5v reference voltage, since the output from the probe is in the millivolt range.
you can use a wideband without a gauge.. and skip the lights, or use a needle based gauge like the innovate g2/3
14.82 @ 97 mph
EGT is a great way to see knock. Knock will shatter the boundry layer of gases that protect your internals and cuase everything to start heating up rapidly. the wideband cant always see the results of knock. You cant always hear the knock. EGT can. it can let you know before its too late that you should let off the gas and make some changes. I say wideband is a must, EGT is icing on the cake.
M90'd Built LGO-15 PSI
http://webstarts.com/quadper4mance
