Not your typical "make my 2.8 faster!" thread... my car is a daily driver. My goal is to make this car run as well as it did when it rolled off the line back in '87...and then some. So instead of making my car go faster and more powerful, I'd like to increase my fuel economy as much as possible.

This is my todo list:

Remove cat, replace with straight pipe
Fix exhaust leak
New cooling system: new hoses(bypass hose: $23,lower rad hose: $19, upper rad hose: $16, heatercore hoses: $20) rad cap($5), new radiator($120), new thermostat($5), water pump gasket($5) TOTAL: ~$220

Now I know getting a new ignition system, such as an MSD box, will help power... but is there any possibility that it can increase fuel economy? What about a catback and headers? I know some people have reported gas mileage increases after installing those two.

The reasoning for replacement of my entire cooling system is that it's so gunked up with build-up and there's leaks everywhere, and it would be simpler to just replace everything with brand new stuff. The hoses are ready to break any day due to being an Arizona car for the first 19 years of it's life. For the removal of the cat, there no emissions in my state, and mine is getting to be quite clogged up and needs to be replaced soon, so I might as well just remove it entirely.

So once things are back at OE spec, we enter in some automobile theory... what's to stop us from going even further than OE spec on fuel economy? An engine alone doesn't determine it, as far as I know, but rather the things that make up the rest of the system(sensors, computer, etc). Any insight on this?

Also, a funny story about emissions: My roommate is moving to California and wanted to test his car for emissions before leaving, so he knows it'll be be alright beforehand. He called every dealership and car shop he could find and asked about emissions testing: every single one laughed at him and asked what in the world he'd wanna do something as silly as that for. None of them had equipment to test it, of course.

 

Make what i call a "small rebuild", check and fix ignition timing, air/fuel mixture, replace all sensors (failure of electronic sensors cause almost 75% of all engine problems), and change fluids.

Then, if you have an auto tranny, swap it for a manual one, usually increases mileage greatly if driven careful. Furthermore, you might want to get headers, they do not only increase performance, but overall efficiency too due to the slipstream effect in the tubes (additionally, you can add a small turbocharger, which would convert already existing exhaust pressure into airflow to the cylinders, which would be otherwise performed by vacuum created by the pistons using engine power, but that may become a bit too expensive and complicated). Finally, you should consider head porting for an increase of compression ratio, this will increase the engines efficiency factor and greatly reduces consumption (though i have been told that it could influence emissions, but i dont know for sure). At least you should add ground effects to your ride. Ive read a sheet some time ago which stated that the drag coefficiency of a stock 3rd gen camaro without ground effects is somewhere around 0.38, while a Z28 with g/e makes for ~0.34, makes ground effects a no-brainer in my mind (although i would not mount them,, i just dont like the look, but thats your choice).

 

making the car lighter also helps with mpg, rear end gear ratio is also another big factor. if u have 3:42's and u drop down to 3:23's u can save gas but only if u do alot of highway driving. going to to low of a gear can also hurt gas milage

 

Totally forgot that, shame on me.

Get plastic hood and fenders, aluminium heads or a full aluminium engine, and maybe build yourself a grid tube front axle instead of the stock steel girder, like the guy from trans-am.de

 

https://www.thirdgen.org/forums/v6/1...ight=tomp+tune

read that and you should get a great idea of what to do. now if i may add a couple of things; a brake fluid flush and power steering fluid flush. some people disagree with doing this, but its just like an oil change. the fluids get dirty and break down. doing the p/s fluid will ease steering, reduce drag on the engine and steering components. replacing the brake fluid will make for a better pedal and shorter stopping distances. ive done these (at a dealership with machines but youll get a similar outcome) and there is a noticable difference. youll feel a decrease in drag when you turn the steering wheel and a better pedal. hope this helps you out.

 

Thanks for the tips guys; keep 'em comin folks! I'm sure this thread will help out the next guy who wants to increase fuel economy and still look stylish around town.

Edit: Will upgrading to disc brakes all around help? I would suppose that better brakes stop easier and would be a good idea. Even if not for fuel economy, for drivability's sake, right?

 

Back when I got 28mpg avg driving-33freeway driving with the 2.8 with an exhaust manifold leak and no cruise control, I had the following (still do actually, but something somewhere isn't right with the new 3.4, so I'm getting about 22avg. I managed 28mpg a few months ago driving up into the mountains and back, but that was it)

Underdrive crank pulley
synthetic oil (some cheap 'Mag-1' stuff I got at ft. lewis, so who knows.)
MSD 6A
Blaster coil
8.5mm MSD wires
.049 plug gap
K&N cone filter attached directly to MAF (I sawed off the sharp bend, but left the screen in, since it straightens the airflow) and routed through some self-sealing pvc pipe sections
2.5 high flow cat
2.5 I-pipe with dynomax 2.5 muffler
180 t-stat (I thought that's what I had in there anyway, but the old one I have sitting in my parts is a 195, so I'm not sure.)

When I built the 3.4 I installed the headers and a heated o2 (a requirement for headers apparently)

 

So spending the money on an MSD ignition system really is worth it, as far as increasing economy goes?

coolrimsatleast: Your screenname makes me laugh; my car is dirty/chipping white, has a Z28 ground effect but is sport coupe the rest of the way back, a gray hatch panel(remember, the car is white) and generally looks like crap. People will hesitate to say anything, but then say "well, cool rims at least." I reckon you've got the same treatment?

 

While you have the water pump off, pull the timing cover and install a new timing chain & gear set. It is surprising how much the chains stretch on these engines.

Instead of the MSD go with a decent set of spiral wound spark plug wires. Then a new cap, rotor and spark plugs. For plugs I usually use the Autolite #24, just a standard plug. Cheaper to replace them once a year then to get fancy plugs and then have them foul for some reason.

RBob.

 

What's your reasoning for a good set of wires over a full MSD system? Would a new/reman distributor also be a good idea? I suppose overhauling every system in the car(aside from yanking the engine itself) is just going to do nothing but help, so getting all-new OE-spec parts would be the best way to go, right? I'm sure my distributor needs a little lovin' right now.

 

Do you drive the car mostly in town, or highway? Removing the cat for intown driving will actually hurt you more then help.

Having a Full MSD6a is pointless if you have crap wires n cap. I would get a hypertech coil, then good cap n rotors.

underdrive crank pully if you dont have alot of electronics.

Then learn how to program prom chips. GM can not program for every single driver in every area of the country. Tune your car to your setup, your driving, your place of living.

 

Mostly in town. Why will it hurt?

Good coil, good wires, cap, rotor and plugs; that would put me at OE quality or slightly above. So a MSD ignition box would not help past this point?

Not a lot? What do you mean by that? Car is all stock, minus slightly-better-than-stock speakers and a new stereo(no amp/sub).

Now that'll be a doozy!

 

removing the cat decreases your torque, which is what you need in town.

The msd6a just replaces the stock unit. Usually does no good unless your under boost at high rpms. Claims of taking the car longer to start have been made too. Read up, come to your own conclusions before you buy.

If you have full power options, amp, etc. Dont get the crank pully, esp not the alt one that goes with it. Crank pully spins your other accessorys at a slower rate, reducing the drag/friction they create. I had a bare bones with radio delete and brand new alt. I noticed a fluxuation in voltage.

Hands down, the best way. I dont understand it, REALLY wish I did. I'm going to wait tell I switch intakes before I jump in. No point in me spending 100 bux on some stuff that I plan to take out.

Not trying to sound like a ****, but read up on the parts you plan to swap, learn what they do, advantages and disadvantages. All the questions you asked you would know by searching and reading. Also, dont forget the rest of the car. Proper inflated tires, alignment, fluids in trans and axle changed, and dont carry more weight then needed. But most of all, MOST OF ALL, get a vac guage and learn to drive your car with your vac guage. No two cars drive the same and me telling you how to drive your car wont do it. Going slow like grandma thinks is not the best for mpg. Its driving the fastest you can at the proper efficency of YOUR setup.

 

How about a K&N air filter and one of those tornado's.

 

tornados actually hurt mpg and performance

 

Tested by a board member, clean paper filter vs clean K&N, no difference

dirty paper vs dirty k&n, k&n wins.

Who keeps a dirty filter on there car?

 

get an aluminum driveshaft and aluminum brake drums o and aluminum rims if you dont already have them

by getting them you degrees weight and more importantly rotational weight which in turn makes your engine run smoother due to less drag

also get a recurve kit for your distributor that will also help in making your engine more efficent.

 

I read WAYYY more than I post. I'm on every single day, reading everything about a given topic I can find before asking a single question. The problem is so many topics that don't have meaningful subject names as well as a huge archive of threads; it's difficult to find something useful in the mess of useless threads that are solved by a simple 'search the forums'. The problem with the answer is that a search usually ends up giving a mass of totally worthless information with a few useful posts here and there. I've spent days researching vacuum issues on the forum and came out with only a few useful tips at all.

The one thing I did not research first, and I'm man enough to apologize for it, is the MSD. I've seen people talk a lot about helping ignition and start-up times, but have not done a whole lot of research into myself. I'll go do that now.

 

Agree on the plethoura (sp?) of information, and threads going off on other subjects. As well the slow and limited search time.

MSD coil is good, hypertech claims a higher voltage. IMO though, the 6a is useless on a DD. You could spend that amount of money on something more useful (automotive, or not). It would take ALOT of driving to make up for the, if any, higher mpg you would get.
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Not all aluminum shafts are lighter then the v6 n 305 one. My v6 shaft weighted in at 12.5 lbs. The lightest rating I have seen on an aluminum is the LS1 at 11lbs. Now there are some very hard to find aluminum rear drums that one could find and drop some there.

 

a cheap alternative to the msd 6a is a msd 5 box, or a mallory box,

they do have benifits,but they are minimal on a stock engine

 

Well, back in 01 when I registered on here, I couldn't think of much for a name. Since I just got the rims, and my car is a base model V6 automatic, I figured, "well, it's got cool rims at least". Granted, there are other rims that are wayyyyy cooler, but they also cost way more. I'd like to maybe get some different ones now. Not sure what though.

As for the MSD ignition system, I didn't notice much of a difference. The intake I built seemed to make the biggest difference over the others, and was about the cheapest.

I'm going to look into the vac gauge setup. I'm desperate right now for any improvements after losing mileage with the new engine.

I've also been reading into mega-squirt.

 

a good tune up will be more beneficial then trying to upgrade parts when you engine isn't tuned for it.

 

You can get an underdrive pulley for the crank and be fine with a sub. Just don't get the one for the altenator.

 

I have had my Camaro for seven years and have increased gas mileage using the following.

1. Use AC-Delco tune-up parts.
2. Change out the canister for the dual snorkle filter arrangement.
3. Make sure all the fluids are clean.
4. Put on significant lighter 16 inch wheels (Enkei 92s) (rotational mass).
5. Put on tires with lower roll resistance. Requires research. Toyos are the best but expensive. I chose Kumho.
6. Installed rear aluminum brakes ($40.00 on ebay) (unsprung weight)
7. 34mm hollow front sway bar (sprung weight).
8. Changed out rear LCA and panhard rod to tubular (better traction and lower sprung weight).
9. Removed every bracket that was unnecessary (sprung weight).
10. Removed the rear seats and seat beats (sprung weight plus more room for golf clubs).
11. Make sure that the tires are aligned and wheel bearings are good.
12. Make sure that there are no vacuum leaks!!!!!

Possible mods for the future.
1. Roller rockers.
2. ASP crank pulley (but I am concerned about my AC performance).
3. Composite hood from 82/83 Camaro if I can find one locally.
4. Install tubular front control arms.
5. Install lighter seats.
6. Complete change of engine gaskets.
7. Get my Fiero Valve covers bead blasted and installed.

Current gas mileage 18-19 city and 30 highway. Acceptable by even current day standards.

 

Make sure your EGR system is working 100%, so you can reburn exhaust

And what every you buy [really don't need a fancy ign] but if you go fancy make sure you get a "true dual spark" system that is all your gonna need.

cept for normal tune up stuff, good tires at proper inflation, good alignment n junk

the true dual spark will be the ticket, but make sure. Some say it is dual but it ain't true. should be as percise as regular spark

some that just say they do dual spark only do it sometimes, then others it can't caculate right n it don't 2nd fire.


true dual spark system also spark off on the down exhaust stroke, just like the power stroke. re-pops off the gasses before they leave. even though exhaust valve is opening it makes a big difference.

 

actually the main reason EGR is on cars is for lowering NOx emissions. there may be some hydrocarbons that are reburned, but they were put on the car to pump exhaust back into the combustion chamber to lower combustion temps. at about 2500 degrees, NOx starts to form, so keeping it below that temp reduces NOx.

 

This stuff has been getting quite a bit of media coverage. Might be worth looking into.....

http://www.ca40g.com

 

I would have to try that stuff for myself in someone else's car to believe that any additive that gives me twice my fuel mileage. (I get ~20)

 

is it average to get around 20mpg on a 3.1 1990 firebird?

 

id say its a lil on the low side unless you do a lot of stop and go driving. but if you are usually cruising around, its probably a lil low.