Fuel Economy w/ 450's

Turbo and Supercharger discussion
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Fuel Economy w/ 450's

By BLaCkSiLo
- Thu Aug 20, 2009 2:21 pm #138944 hey guys, just wanted to see what you boosted guys get for fuel mileage and what do your AFR's run at?

i just got tuned on monday for the first time @ 9psi and i love it so far but she is running rich and with my narrowband i can't really tell what the afr's are, input would be great! 8) i have the blacktop dsm 450's
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By teal_dx
- Thu Aug 20, 2009 4:08 pm #138979 still running rich after having it tuned :? :eh:
I'd go back...

MPG is going to depend on your entire setup, type of driving, and your driving habits.

Say you drive on the highway @ 3200k rpm with a larger turbo that has not even started to spool vs a tiny turbo that is already spooling up. Your ecu is going to be putting in extra fuel for the small turbo then to compensate for the extra air.

Now at 6500 rpm, the ecu would be dumping in a lot more fuel for the larger turbo than it would the tiny one.

Gear ratios also come into play.

What is your whole setup?
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By BLaCkSiLo
- Thu Aug 20, 2009 4:23 pm #138987 in short: z6 bottom end with FJ rods/vitara pistons 75.5mm, cast mani, t3/t4 .50 trim that spools around 4-4.5k or so, 3 in downpipe to full 3" exhaust, 450 blacktop injectors, walbro 255 fuel pump, b&m A-FPR, NGK 7's and an exedy stage 1 clutch...

stock z6 trans (gear ratios), i only have a narrowband AFR gauge right now, but it's always pegged in the green indication richer than 14.7 which is a good thing for boost, but during vacuum and normal driving, is it supposed to be close to stoich or are the afr's always rich is a boosted setup?

i would much rather run rich than not, but i don't wanna foul a plug, i should go check those...... how rich is too rich?
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By teal_dx
- Thu Aug 20, 2009 5:15 pm #139016 you should have tuned with a wideband. narrowband AF gauges are more like an idiot light because they are not very accurate. They are good for a light show and for letting you know when something has gone terribly wrong.
You can't really monitor your AF ratio with a narrowband because they are either all over the place and/or inaccurate.
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By BLaCkSiLo
- Thu Aug 20, 2009 5:50 pm #139019
teal_dx wrote:you should have tuned with a wideband. narrowband AF gauges are more like an idiot light because they are not very accurate. They are good for a light show and for letting you know when something has gone terribly wrong.
You can't really monitor your AF ratio with a narrowband because they are either all over the place and/or inaccurate.


no no, the tuner tuned with a wideband...i just have a POS narrowband on my pillar, he literally raised it up, took my o2 out and put his in the DP...

do you have a wideband and are you tuned yet? i just wanted to know about decel / boost / cruising
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