Bolt-on plus cam auto fuel milage?

[HeadDown]

Hi All,
I just purchased a 95TA from a friend. I had previously done bolt-on's plus a small cam (lt4 hotcam'ish) on this car. It is an auto 3.73 3000 stall. The previous owner sent the pcm off by mail for a tune. The car idles well but averages ~7mpg in mixed driving. What fuel enconomy do similar setups usually get? Should I look at LT1 edit?

[BlackLT1Z28]

7 mpg does sound a bit low but at the same time makes sense.
By 'mixed driving', do you mean 'city and highway' driving or 'easy and hard' driving?

Part of it could be a combination of the loose lock-up converter and the 3.73 gears. Even the cam, though small, doesn't exactly help either.

Maybe you could try a tune-up or fuel system cleaner.

[HeadDown]

By 'mixed driving', do you mean 'city and highway' driving or 'easy and hard' driving?

Part of it could be a combination of the loose lock-up converter and the 3.73 gears. Even the cam, though small, doesn't exactly help either.



Mixed driving refers to city/highway. All driving for the purpose of fuel econ is done in at low power, mostly work and back.

The converter has been with the car for some time and didn't seem to make any difference in fuel econ. The newest tune was done after the cam and rearend. Previous fuel milage was something like 15mpg, so 7 is quite a jump for just a small cam and 3.73's...
Anyone with a similar setup have econ numbers?

[bandit95]

on my 95 ta it has the cc305 (hotcam basically), lt4 heads, msd, hooker lt's, 3 inch flowmaster, and it had 2.73's, and stock convertor with factory tune and the best i got in mixed driving was 15 mpg. it started winding down as the o2's went bad to around 9 mpg. now it's been sittin since easter with a messed up oil sending unit. i've just got so many bills that i havent had money to fix it. got the sensor i just cant reach the damn thing on the back of the block

[BlackLT1Z28]

Those gears make a bigger difference than most think, especially compared to the 2.73's. You basically giving up one whole crank revolution per tire revolution. That adds up when driving from place to place.

[Red on Red WS6]

I have the hot cam setup with 3:23 gears and I get 17 to 18 MPG with mixed driving. When I first put the cam in I got a mail order tune, and gas milage sucked around 11 to 12 so I started to do my own tuning. It runs much better now.

[bandit95]

I have the hot cam setup with 3:23 gears and I get 17 to 18 MPG with mixed driving. When I first put the cam in I got a mail order tune, and gas milage sucked around 11 to 12 so I started to do my own tuning. It runs much better now.

which mail order tune did you have?

[HeadDown]

I also need to adjust shift points, as the car will not shift from 2-3 at WOT (at least not prior to 6.5k). I am considering LT1 Edit, would something else be a better investment? What will I be able to do for fuel tuning without a wideband o2?

[5.0THIS]

LT1 edit will work fine. the tuning capability is the same with or without a wideband, just with a wideband you can more accurately monitor the changes you're making.

[Red on Red WS6]

which mail order tune did you have?

I bought it from Madz28.com It was a OK tune, it gave me a good starting point with my own tuning. I just thought I could tune it better.

[440 rwhp trans am]

dude i have a 383 stroker with a hot cam and 30lb injectors. im at about 10-13 average driving with out a tune. sorry something is really wrong with that car!!! ask sarge for help!!!!!!

[Red on Red WS6]

Hi All,
I just purchased a 95TA from a friend. I had previously done bolt-on's plus a small cam (lt4 hotcam'ish) on this car. It is an auto 3.73 3000 stall. The previous owner sent the pcm off by mail for a tune. The car idles well but averages ~7mpg in mixed driving. What fuel enconomy do similar setups usually get? Should I look at LT1 edit?

Could you do some data logging and post up the file? That would be the first place I would start. Have you dynoed the car with a wide band?

[HeadDown]

Could you do some data logging and post up the file? That would be the first place I would start. Have you dynoed the car with a wide band?

Could you suggest some software? and maybe a schematic for an interface?