Any secrets for a bumping MPG on 1998 305?

[thinger2]

My Accord is a 95 and other then a load bang and bump, and watching the muffler cartwheeling down the road behind me it's been rather uneventful.

I think I should share my exhaust related story.
Back in 1988 or so I had a 1970 f100
300 six three on the tree.
I took a 302 out of a 68 Merc Montego and put it in the truck.
Really easy swap by the way.
When it came to the exhaust, I half assed it just get running.
Stock manifolds with about 4 inches of cut off pipe and flex pipe the rest of the way back with bailing wire and hose clamps and cherry bombs.
So I go to this house party in North Seattle with some friends.
We go into the basement where the keg is and there is this girl inside of the clothes dryer with the door shut and they are trying to make it spin.
It made it about 3 times before the breaker popped and she got out.
And I start talking to dryer girl.
I found out she was from Kansas.
Just got along great, just a really cool person.
At some point, we decide we need to go to the liquor store before it closes.
So me and Kansas get in the truck and leave.
And that is the last memory I have of that night. Everything else is gone.
The next thing I know, its about 10 am the next morning, im in the passenger seat of my truck drooling out the window
And Kansas dryer chick is driving my 3 on the tree up the hills of seattle through traffic like a pro.
And it is really loud. It no longer has any exhaust system at all, just manifolds with 4 inches of pipe.
She drove the truck all the way back to my place in west seattle.
Got out, handed me the keys, didnt want me to call a cab for her.
Said she would find her own way home.
Gave me a kiss and thanked me for having so much fun that night and walked away.
To this day nobody who was at that party knows who this girl was or where she came from.
She is just the Kansas Dryer Girl

 

[PlayingWithTBI]

I thought the TBI computers had lean burn enabled too?

They do but, it was disabled in the .bin by GM to pass NOx with EGR. There's a simple "Patch" which some hackers put in the Mask file to click a box and it's all done for you. The parameters can be adjusted as far as AFR and SA.

FWIU you can't run both together, you have to delete EGR to run HLC. Aside from NOx the biggest difference, in my mind, is with HLC you're not blowing all that dirty carbonized exhaust back through your engine.

 

[cubandeathgrip]

Good info on the Highway Lean Cruise (HLC) is there a shop or member with a tuner in the St petersburg Florida area, that can help me get this done?

 

[L31MaxExpress]

I think I should share my exhaust related story.
Back in 1988 or so I had a 1970 f100
300 six three on the tree.
I took a 302 out of a 68 Merc Montego and put it in the truck.
Really easy swap by the way.
When it came to the exhaust, I half assed it just get running.
Stock manifolds with about 4 inches of cut off pipe and flex pipe the rest of the way back with bailing wire and hose clamps and cherry bombs.
So I go to this house party in North Seattle with some friends.
We go into the basement where the keg is and there is this girl inside of the clothes dryer with the door shut and they are trying to make it spin.
It made it about 3 times before the breaker popped and she got out.
And I start talking to dryer girl.
I found out she was from Kansas.
Just got along great, just a really cool person.
At some point, we decide we need to go to the liquor store before it closes.
So me and Kansas get in the truck and leave.
And that is the last memory I have of that night. Everything else is gone.
The next thing I know, its about 10 am the next morning, im in the passenger seat of my truck drooling out the window
And Kansas dryer chick is driving my 3 on the tree up the hills of seattle through traffic like a pro.
And it is really loud. It no longer has any exhaust system at all, just manifolds with 4 inches of pipe.
She drove the truck all the way back to my place in west seattle.
Got out, handed me the keys, didnt want me to call a cab for her.
Said she would find her own way home.
Gave me a kiss and thanked me for having so much fun that night and walked away.
To this day nobody who was at that party knows who this girl was or where she came from.
She is just the Kansas Dryer Girl

Sounds like the moral of that story is Kansas chicks are crazy, lol. Atleast my ex was!

 

[thinger2]

Sounds like the moral of that story is Kansas chicks are crazy, lol. Atleast my ex was!

With my friends this is known as one of the dumbest thing ive ever done.
The fallout questioning went like this..
"So you met this hot girl who could contort herself into a friggen clothes dryer, then you left the party with her and got blackout drunk.
Yep
And she not only took care of you even having never met you before, but she made sure you and your truck got all the way to the other side of the city.
And she gave you a kiss and thanked you..
Yep
And she can drive a 3 on the tree?
And you let her walk away?
You sir, are a ******* moron.
Yep.

 

[Schurkey]

A man has got to know his limitations. Sometimes our limitations turn out to be kinda cruel to us.

 

[Erik the Awful]

Not to pick on Schurkey, but there's a lot of points to concur with here, and a few where I have my own opinions.

Richer mixture than stoichiometric increases carbon monoxide and hydrocarbon emissions, but they decrease when leaner than stoich.

Leaner mixture than stoich increases NOx emissions, but they decrease as the mixture gets richer.

NOx is harder to clean up than CO and HC. They'd like to run leaner than stoich, but they get killed on NOx emissions.

The CHEAPEST balance is to RAPIDLY switch from just lean of stoich to just rich of stoich, and let the catalyst store--then use--excess O2 in the exhaust to oxidize the HC and CO, while keeping combustion temperature low enough to inhibit NOx. Combustion temp is controlled with EGR and mixture strength, among other techniques.

The rapid switching strategy is why you look for switching when you test your O2 sensor. NOx is the bane of modern engines, otherwise we'd just tune everything to run as lean as possible without melting pistons. It'd be great for fuel economy, but I'm old enough to remember acid rain in the northeast. If you went out in a rainstorm, the next time you washed your shirt it would be pockmarked with little holes.

Highway Lean Cruise (HLC) mimics what carburetors were tuned to do for decades--allow the engine to run lean at light load without actual misfire. Stoich mixture is great for emissions, but not optimal for fuel economy. It's too much to hope for that the EPA and CARB would come to their senses to allow better fuel economy. They've already made Diesel engines nearly illegal with excessively-stringent emissions regulations. They clearly want to do the same with gasoline engines, in order to force us into hateful shitebox electric cars that will destroy our electrical grid.

Highway Lean Cruise sounds amazing for fuel economy, and people who've used it attest so. It will increase your NOx output, but by how much? How much fuel are you saving? Turning on HLC is technically illegal, so it's a moral decision for you.

I'm not an opponent of electric cars. Hot rodders gonna hot rod. Electric cars can have immense torque. I'm looking forward to them becoming cheaper and easier to own.

Ehhh. Not something I recommend on any vehicle that's got a MAF. I have K&N filters on several of my vehicles; with mixed feelings about them. (None of them are on vehicles with MAF sensors.)

As said, the big "normal paper" air filter is as good as it gets for the MAF-equipped Vortecs.

I'm fine with K&Ns. Don't overuse the oil, and after you've applied it, use an air nozzle to blow off the excess and your MAF should be fine.

BAD idea. Leave the EGR alone. Fix it if it's broken. Makes a big difference in NOx emissions, can improve fuel economy in certain circumstances.

ALSO illegal at the Federal level to disable EGR. Also not likely to get caught unless there's emissions testing in your area.

Yup. See my comments on acid rain above.

Deleting the cat is a bad idea. Illegal. A high-flow (monolithic) catalyst IN GOOD CONDITION doesn't reduce power very much, and you don't get complaints about the horrible exhaust smell from SWMBO.

Getting rid of the OEM muffler will likely make a big difference on the highway. Not so much at low throttle/low rpm like in-town driving. I'm told that the OEM muffler on the 7.4L 2500s and 3500s was a horrible, restrictive design--the inlet and outlet stubs were big enough, but the muffler piping inside the case (hidden) was tiny.

"Chambered" mufflers as typified by the Flowmaster brand, are more advertising bullshite than actual flow improvement.

Be a good neighbor, keep your cats. Mine were missing when I bought my truck, so when I built my exhaust I bought new ones. They're garbage and the honeycomb is falling out, but I need to get the truck tuned before I replace them.

There are really good mufflers out there that aren't expensive. Ditch that heavy factory muffler.

Wisdom. These trucks are never going to get the fuel economy of a shitebox car. There's plenty of trips I could take in a shitebox car, that are kinda wasteful to drive a truck instead.

Yup. If you have a long commute, a econobox daily driver is worth it.

 

[cubandeathgrip]

Not to pick on Schurkey, but there's a lot of points to concur with here, and a few where I have my own opinions.


The rapid switching strategy is why you look for switching when you test your O2 sensor. NOx is the bane of modern engines, otherwise we'd just tune everything to run as lean as possible without melting pistons. It'd be great for fuel economy, but I'm old enough to remember acid rain in the northeast. If you went out in a rainstorm, the next time you washed your shirt it would be pockmarked with little holes.


Highway Lean Cruise sounds amazing for fuel economy, and people who've used it attest so. It will increase your NOx output, but by how much? How much fuel are you saving? Turning on HLC is technically illegal, so it's a moral decision for you.

I'm not an opponent of electric cars. Hot rodders gonna hot rod. Electric cars can have immense torque. I'm looking forward to them becoming cheaper and easier to own.


I'm fine with K&Ns. Don't overuse the oil, and after you've applied it, use an air nozzle to blow off the excess and your MAF should be fine.


Yup. See my comments on acid rain above.


Be a good neighbor, keep your cats. Mine were missing when I bought my truck, so when I built my exhaust I bought new ones. They're garbage and the honeycomb is falling out, but I need to get the truck tuned before I replace them.

There are really good mufflers out there that aren't expensive. Ditch that heavy factory muffler.


Yup. If you have a long commute, a econobox daily driver is worth it.

Thanks.

I like to do the HLC, and a replacement muffler, I ordered the over size AC delco air filter.
I have a crv for my main car, still sometimes I have to take my truck on long runs to the property.
Wanting a bit better fuel economy. I think these 3 upgrades will help.

How do I go about get the ECU updated using the HLC?
Local shop? what would I expect to pay for this tune?
Can you recommend a good quality quiet (<if that is possible) straight through muffler?

thanks

 

[PlayingWithTBI]

Highway Lean Cruise sounds amazing for fuel economy, and people who've used it attest so. It will increase your NOx output, but by how much?

Back when my 88 was made, all they had was 2-way pellet style Cats which didn't help with NOx. Now I have a 3-way high flow honeycomb Cat which does help with NOx. Without a 4 gas sniffer, I couldn't say by how much but, I'm comfortable with it. My truck is exempt anyway but, I'll keep the Cat.

 

[cubandeathgrip]

I was thinking a walker school bus muffler, does flow better than stock?