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Getting better gas mileage.

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Old Aug 1, 2005 | 06:59 PM
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Default Getting better gas mileage.

I have the CC306 cam in my 383 (230/244@050). This is in a 98 silverado and im running 30# injectors. Anyways all my fuel trims are within +-10% so it would seem my VE table is pretty much where it should be. I have also added timing across the part throttle map but im getting 8-10 mpg. After talking to some people they think i should be in the 12-14mpg range which i could live with. Now my question is what can i do to get better mileage? I added 2 more degrees of timing across the low load part of the spark map on both closed and open throttle. The throttle response feels better and it seems like it might have made a little bit of difference in gas mileage, all though im not sure. Now on startup it smells like raw fuel but runs fine. After its started it still smells like its on the rich side but the l-trims indicate it should be fine. Any advice?
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Old Aug 1, 2005 | 07:04 PM
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if your trims are +-10%, your VE table isn't very close to where it should be.

Do you have your own tuing software? Do you have a WB?

FWIW, after getting my VE table dialed in, I'm getting ~20 mpg with a similar sized cam in my 383 in my bird. 12-14 sounds reasonable for a truck.
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Old Aug 1, 2005 | 07:08 PM
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This write up should get you started dailing in your VE table.
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Old Aug 1, 2005 | 07:52 PM
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Originally Posted by TAQuickness
if your trims are +-10%, your VE table isn't very close to where it should be.

Do you have your own tuing software? Do you have a WB?

FWIW, after getting my VE table dialed in, I'm getting ~20 mpg with a similar sized cam in my 383 in my bird. 12-14 sounds reasonable for a truck.
Yes i have my own tuning software. I guess i should kinda re-phrase the l-trim thing. I would think that the VE table is close enough to where i wouldn't be getting as bad of gas mileage as i am.
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Old Aug 1, 2005 | 07:58 PM
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you'd be surprised what a difference it makes. My VE table was only off by 6% at it's worst, average of 2% off. I went from 14mpg driving sane to 19mpg while tuning (driving like a mad ***).
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Old Sep 6, 2005 | 01:57 PM
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Sell your truck and buy a hybrid if you like better mileage..
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Old Sep 6, 2005 | 02:12 PM
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the biggest problem with trucks and gas mileage is the weight and aerodynamics of a brick. The best way to gas mileage is keeping the rpms low, locking the tq converter as low as your engine will allow and babying the throttle, also using cruise control where ever you can.

Ta is right on the ve thing you should be within +-4 and depending how much you want to tweak it I like to get it around +-2 in SD then re-enable the maf and tune it. I have found a slight increase in mpg by running a tuned maf over just a speed density tune.

With that cam/motor in a truck I would be happy to get 11-12 mpg especially if youve got a high stall.
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