afc and egt? - Toyota Yaris Forums

o89canucks · 09-14-2009, 10:02 AM

One of the old gatway dsm guys was running an apexi afc with an egt gauge and leaning it out as much as he could while making sure he didn't melt his turbo off...anywho, moral of the story is he was hitting around 60-70mpg highway in his 2g eclipse. Was wondering if anyone had tried this out here looking at these mods from a gas mileage perspective as opposed to a performance perspective?

I'm thinking if the same thing could be pulled off here it might be possible to hit 80-100mpg doing about 55mph on the highway...

talnlnky · 09-14-2009, 11:40 AM

hmmm... very interesting... It'd be very fun to try... anybody have a few thousand to donate to me so I can experiment with this.

Y@R15 · 09-14-2009, 12:31 PM

sounds good but what if the speed limit is 70? dont you get pulled for impeding traffic?

o89canucks · 09-14-2009, 12:48 PM

few thousand??? Wow, who are you buying parts from?

Apexi safc neo - approx 350$
autometer ultralite egt gauge with probe - approx 130$

self installed you would be talking around a 500$ investment total.

and the maximum speed limit is 70mph, minimum is usually 45mph.

talnlnky · 09-14-2009, 05:28 PM

Quote:

Originally Posted by o89canucks

few thousand??? Wow, who are you buying parts from?

Apexi safc neo - approx 350$
autometer ultralite egt gauge with probe - approx 130$

self installed you would be talking around a 500$ investment total.

and the maximum speed limit is 70mph, minimum is usually 45mph.

I don't have a turbo... I thought you were talking about doing this in conjunction with a turbo?

ern-diz · 09-14-2009, 05:38 PM

Quote:

Originally Posted by Y@R15

sounds good but what if the speed limit is 70? dont you get pulled for impeding traffic?

there has been much debate about that topic right there buddy, you don't even know LOL...

as for the topic of this thread, it'd be a nice twist to see someone get a turbo for the purpose of getting higher mpg vs. acceleration and mph lol...

AlexNet0 · 09-14-2009, 07:06 PM

how do you plan on leaning out the fuel on a stock yaris?

Tamago · 09-14-2009, 07:26 PM

don't do it

Tamago · 09-14-2009, 07:28 PM

the reason the 2G eclipse guy made those numbers was because of the turbo.. you'll never achieve it on a yaris

o89canucks · 09-15-2009, 02:17 PM

Quote:

Originally Posted by Tamago

the reason the 2G eclipse guy made those numbers was because of the turbo.. you'll never achieve it on a yaris

I don't see a difference on leaning out a turbo vs. na car, leaning is leaning wether you have a turbo or not.

o89canucks · 09-15-2009, 02:18 PM

Quote:

Originally Posted by AlexNet0

how do you plan on leaning out the fuel on a stock yaris?

did you miss the part about the air-fuel controller?

Tamago · 09-15-2009, 02:24 PM

Quote:

Originally Posted by o89canucks

I don't see a difference on leaning out a turbo vs. na car, leaning is leaning wether you have a turbo or not.

the difference is that the DSM guy is probably leaning to 14:1. turbos make engines more efficient, volumetrically and thermally (at low boost)

stoich is 14.7:1. that's what the yaris ECU is going to try to achieve in closed loop. leaning the engine out further will simply overheat the exhaust manifold, as well as your pistons, valves, everything.

so you'll get better fuel mileage at the cost of engine longevity, which does more harm to the environment than leaving well enough alone.

Penguin Garage · 09-15-2009, 02:29 PM

how much adjustment can the AFC do on the yaris?

2%, 5%, 10%, 25% adjustment?

This is an expensive test to save $40 a tank, but I'd be interested to see it perform.

Airplane pilots do this constantly while at cruise to get optimum results.

Tamago · 09-15-2009, 02:38 PM

Quote:

Originally Posted by Penguin Garage

h
Airplane pilots do this constantly while at cruise to get optimum results.

airplane pilots have sub-zero air to induce and cool their intercoolers ;)

Penguin Garage · 09-15-2009, 02:43 PM

Quote:

Originally Posted by Tamago

airplane pilots have sub-zero air to induce and cool their intercoolers ;)

and not alot of traffic, oh and auto pilot.

kind of a bad example really. haha.

Tamago · 09-15-2009, 02:45 PM

stop and go air traffic FTL

o89canucks · 09-15-2009, 02:53 PM

Quote:

Originally Posted by Tamago

the difference is that the DSM guy is probably leaning to 14:1. turbos make engines more efficient, volumetrically and thermally (at low boost)

stoich is 14.7:1. that's what the yaris ECU is going to try to achieve in closed loop. leaning the engine out further will simply overheat the exhaust manifold, as well as your pistons, valves, everything.

so you'll get better fuel mileage at the cost of engine longevity, which does more harm to the environment than leaving well enough alone.

Longetivity, yes, if you exceed safe temp ranges...which is what the egt gauge is for. Cast iron exhaust manifolds are made to withstand temperatures up to 1600F before doing major damage, I still wouldn't recommend running that hot for any extended period of time though. You still may get a decent gain by running egt temps 2-300 degrees over stock levels.

Tamago · 09-15-2009, 02:58 PM

and what car has a cast iron exhaust manifold?

aluminum pistons?

09-14-2009, 10:02 AM	#1
o89canucks Mechanic from hell Drives: 2007 Toyota Yaris Sedan Join Date: Sep 2009 Location: St. Louis, MO Posts: 20	afc and egt? One of the old gatway dsm guys was running an apexi afc with an egt gauge and leaning it out as much as he could while making sure he didn't melt his turbo off...anywho, moral of the story is he was hitting around 60-70mpg highway in his 2g eclipse. Was wondering if anyone had tried this out here looking at these mods from a gas mileage perspective as opposed to a performance perspective? I'm thinking if the same thing could be pulled off here it might be possible to hit 80-100mpg doing about 55mph on the highway... __________________ 2007 Black Sand Toyota Yaris Sedan AT 2006 Sonic Blue Volvo S60R AWD 6MT

09-14-2009, 11:40 AM	#2
talnlnky Audio Junky Drives: 08 liftback Join Date: Oct 2008 Location: Spokane, Wa Posts: 1,412	hmmm... very interesting... It'd be very fun to try... anybody have a few thousand to donate to me so I can experiment with this. __________________

09-14-2009, 12:48 PM	#4
o89canucks Mechanic from hell Drives: 2007 Toyota Yaris Sedan Join Date: Sep 2009 Location: St. Louis, MO Posts: 20	few thousand??? Wow, who are you buying parts from? Apexi safc neo - approx 350$ autometer ultralite egt gauge with probe - approx 130$ self installed you would be talking around a 500$ investment total. and the maximum speed limit is 70mph, minimum is usually 45mph. __________________ 2007 Black Sand Toyota Yaris Sedan AT 2006 Sonic Blue Volvo S60R AWD 6MT

09-14-2009, 07:06 PM	#7
AlexNet0 View User's Garage Drives: '07 Yaris 3dr Join Date: Nov 2008 Location: Rockland, ME Posts: 1,638	how do you plan on leaning out the fuel on a stock yaris? __________________ ---------- MI-YW ----------

09-14-2009, 12:31 PM	#3
Y@R15 Dude wheres my car? Drives: 98 honda VTi Join Date: Sep 2009 Location: Okinawa Japan Posts: 86	sounds good but what if the speed limit is 70? dont you get pulled for impeding traffic?

09-15-2009, 02:29 PM	#13
Penguin Garage Drives: Yaris Join Date: May 2009 Location: FL Posts: 197	how much adjustment can the AFC do on the yaris? 2%, 5%, 10%, 25% adjustment? This is an expensive test to save $40 a tank, but I'd be interested to see it perform. Airplane pilots do this constantly while at cruise to get optimum results.