Operation Lipstick on a Pig

[fleming442]

I'm guessing the F body donor had a 3.08 or 3.42? The 6 is working too hard with that tall highway gear (2.41). Put a little more gear in it and a quieter muffler. Consider the Dynomax Ultraflow. Very mellow but high flow. Is there any chance the harshness is the compressor up against the control arm?

Yep, 3.42s. I'm thinking 3.08 would be a good compromise. There isn't any paint off the compressor pulley, yet.
Right now, I'm just sick of working on it. I need to turn my attention to my very jealous Silverado (halfshaft, oil change, BCM, exhaust).

 

[olds307 and 403]

Hmmm, not liking this so far. Initial mileage rating is 17 with 93 octane, injector cleaner, and various WOT stints. I had a coolant leak at the water pump inlet on the engine; replaced the hose clamp and crossed my fingers. The damn thing is loud inside the car and vibrates like it has solid motor mounts sitting at a red light. That may be from stiffening up the body mounts and new motor and trans mounts? It downshifts constantly on the highway trying to hold that 80mph cruise altitude. I may have to put some lower gears out back just to maintain my sanity. Not recommended.

Ouch, that is poor. I got that 19 mpg imperial in my 70S with my 9 to 1 Olds 350, 2004R and 2.78 gears running at 65 to 70 mph. That rpm should be no issue at 80 mph, a 3.42 should be perfect, don't go any lower or higher. Any check engine lights?

 

[Texas82GP]

Yep, 3.42s. I'm thinking 3.08 would be a good compromise. There isn't any paint off the compressor pulley, yet.
Right now, I'm just sick of working on it. I need to turn my attention to my very jealous Silverado (halfshaft, oil change, BCM, exhaust).

You've pushed hard for awhile. Take a break.

 

[fleming442]

No SES lights. There is a Service Vehicle light, but I was reading that could be anything (light bulb out). I'm pretty sure it's the Uxxxx codes that I need to make No Reports.
That's also a rough estimate as I haven't adjusted the speedo/odo reading in HP Tuners yet. Hope to get that done Sunday. I just divided 3.42/2.41 and multiplied that by the current odo reading, then divided the fuel burned.

 

[fleming442]

I just ordered one of these to see if it takes some of the drone out:

 

[DRIVEN]

I used that style baffle on my motorcycle. Took some of the rasp out but didn't seem to be any quieter.

 

[fleming442]

I'm being cheap (also have a habit of trying many things before success). All the 3" mufflers I could find are $40-200. I'm trying to put some sort of resonator where the cat was.....

 

[Wageslave]

I'm being cheap (also have a habit of trying many things before success). All the 3" mufflers I could find are $40-200. I'm trying to put some sort of resonator where the cat was.....

I have had luck with a set of Quietmasters. Factory quiet and about parts store replacement price.

 

[olds307 and 403]

What do you have for exhaust right now? I used GPS to figure out distance with my odometer off on my 88 Cutlass and it being straight highway. Make sure it hasn't gone into limp home mode. That mileage with any amount of highway driving seems 10 mpg low.

 

[fleming442]

What do you have for exhaust right now? I used GPS to figure out distance with my odometer off on my 88 Cutlass and it being straight highway. Make sure it hasn't gone into limp home mode. That mileage with any amount of highway driving seems 10 mpg low.

The Firebird Y-pipe is 3", so that's where I'm putting the collector baffle. It also seems that the source of the drone is there (plus a small leak). Right at the y, it drops to 2.5, then to 2.25, then to a 3.8 mid-pipe, and a generic muffler. The first 3.8 wasn't anywhere near this loud; it must be the bump in compression.
The tank of 87 seems to be getting much better mileage as I've eclipsed the previous odometer reading, and still at 5/8 of a tank as opposed to 1/4. I guess the new build, happy foot, WOT pulls really sucked some fuel!