TBI gas mileage, am I doing it wrong?

[350chevy719]

OK so assuming they haven't been changed I have rpo gt4 so 3.73 with 5x1. And g80 posi

 

[vic_v8]

Have you factor in that your speedo is now probably off? So you are probably going farther than its reporting. Also, whats your driving style? Drive like there is an egg under the pedal and you'll be better.

 

[Big Jon 95]

I got 13 before and after i put my 285s on no matter how I drove, truck was a 94 with a 5 speed and a 3.73 rear end


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[350chevy719]

Have you factor in that your speedo is now probably off? So you are probably going farther than its reporting. Also, whats your driving style? Drive like there is an egg under the pedal and you'll be better.

How would you recalibrate for the odometer?

 

[df2x4]

How would you recalibrate for the odometer?

Only way to properly re-calibrate TBI clusters is DRAC modification/adjustment. You'll need to do this any time you're running non-factory tire sizes or gears if you want accurate readings.

http://tbichips.com/?page_id=504

 

[350chevy719]

Only way to properly re-calibrate TBI clusters is DRAC modification/adjustment. You'll need to do this any time you're running non-factory tire sizes or gears if you want accurate readings.

http://tbichips.com/?page_id=504

So how exactly do you do it? I input everything with my tire size and stock tire size and the difference is my new code reads 1011110 stock reads 1011011

 

[df2x4]

So how exactly do you do it? I input everything with my tire size and stock tire size and the difference is my new code reads 1011110 stock reads 1011011

It's right there on the page. On the DRAC/VSSB, they've numbered the jumper bars in the pictures. One through seven. Then when you input your information it marks each of those jumper bars as a one or a zero. One is for on/connected, zero is for disconnected. Kind of labeled like the Binary system for computers if you're familiar with that at all. So for example... The new code it gave you would read like this.

Bar one, on.
Bar two, off.
Bar three, on.
Bar four, on.
Bar five, on.
Bar six, on.
Bar seven, off.

Most people recommend replacing the jumper bars with dip switches, that way you can adjust them easily without having to re-solder things every time.

 

[350chevy719]

It's right there on the page. On the DRAC/VSSB, they've numbered the jumper bars in the pictures. One through seven. Then when you input your information it marks each of those jumper bars as a one or a zero. One is for on/connected, zero is for disconnected. Kind of labeled like the Binary system for computers if you're familiar with that at all. So for example... The new code it gave you would read like this.

Bar one, on.
Bar two, off.
Bar three, on.
Bar four, on.
Bar five, on.
Bar six, on.
Bar seven, off.

Most people recommend replacing the jumper bars with dip switches, that way you can adjust them easily without having to re-solder things every time.

This actually makes sense to me haha so how would I go about ordering a dip switch. Just match the prong number? Or is there a certain one for these computers? Would I need a standard 7 pin or 14 pin to do the inverse speedo too?

 

[df2x4]

This actually makes sense to me haha so how would I go about ordering a dip switch. Just match the prong number? Or is there a certain one for these computers? Would I need a standard 7 pin or 14 pin to do the inverse speedo too?

That I'm not really sure about. I've never done this personally, never owned a TBI truck. I'm sure someone else can answer that though.

@someotherguy, @magimerlin, you guys have any idea? Seems like I've seen you all talk about this before.

EDIT - You'll definitely need to do all 14 if you have the later style VSSB though.

 

[350chevy719]

The switches themselves are pretty cheap so as soon as I can figure out how to I'll do it. I like the idea of the switch better because once I regear and lift I'll need to do it again