How to build a muscle car for better fuel economy?

[Phoenix'97]

Originally Posted by triangles

I'm also not reading thru the 20+ previous pages so I apologize if anything below has already been suggested.

I had recommended the engine swap as a cheaper easier alternative than monkeying too much with your thirsty V8. From what I know about late 90's engine technology, it's fuel injected and has a computer managing the ignition timing and fuel injection. This is probably both a blessing and a curse. I'm not sure what is available in the aftermarket that allows tweaking of the base engine map. I'm going to assume there isn't much (probably wrong) but the first thing I would do is get some cams that are optimized for fuel economy. Sure you'll take a hit in max HP but like you said you're not racing it. Further you could also see what pistons are available to change the compression ratio to work best with the new cams. Beyond that there' isn't much you can do and even monkeying with the cams and pistons probably won't get you more than 1-2mpgs since the factory ECU will try and compensate for the changes you make.

Taking things to the next step you can "delete" your cars ECU and put in something like a Megasquirt or microsquirt controller. This will give you complete control of the engine map (ignition timing and fuel) and you can really tune it for efficiency. I would guess this might yield +5mpg maybe as much as +10mpg if your factory engine is really inefficiently setup and you drive very efficiently. I'll repeat that is just a guess but it's about the only way I see of making the engine more efficient.

I am doing this with a 2 cyl motorcycle that is optimized for HP and is also carbureted. Since the ignition control is so crude and you can't lean out a carburetor for low load cruising conditions as well as you can with EFI I should see some significant improvements. That's kind of the beauty of having computer engine management. Tweak for max fuel economy at light load and then switch to max power when floored. It's kind of like cheating having the best of both.

I'm sure this one has probably already been thrown out there but you could find a way to "deactivate" 4 cylinders under cruising conditions.

Originally Posted by BLSTIC

It's a blessing because the stuff is technically there to get the best economy. It's a curse because you can only get incremental improvements over what's there (without altering factory goals). It's not like cars were ever programmed to use more fuel for no reason (once they got the programming ability, which I would say was a late 80's thing), so you've got to figure out *why* it's running too rich or too lean there. It's like: Why run 11:1 air-fuel ratios at high load? It costs power, uses fuel, and doesn't add to engine safety... Oh wait I have cats and they overheat after 30 seconds without the low egt made my running rich.

Sequential injection can only get so much when you're not running massive injectors, and injectors have only improved so much since, especially for two-valve heads (four valve heads now have injectors that have two-cones that point at each inlet valve and timing so that at low loads they can put the entire charge through an open valve)

Spark control in the aftermarket basically hasn't changed since the late 80's so you get screwed over with not being able to use the dual-knock sensor with 4-method closed-loop spark control factory cars got around 2005. There's one Australian car which has an increase in high load torque of about 7% by running premium fuel simply because its spark management and knock detection is so damn precise. No such luck for the aftermarket. Program your ignition, have a knock sensor if it pings, no real continuous octane detection and optimisation.

Well, this is where things may get interesting. The second-generation LT1 has a horrible optispark distributor ignition system. I do intend to perform a coil-over-plug DIS conversion which utilizes LS1 coils and the LS1 ECM. I am not sure if this ECM will allow more tuning ability with a DIS ignition system but I need to research it.

BLSTIC commented that I should use the latest equivalent fuel injectors for my car since they are likely able to better handle tuning for leaner fuel mixtures and they are more accurate in their fuel delivery versus 1980's era fuel injection technology.

When looking for a camshaft, I am going to try to find a happy balance between performance and fuel economy. I was recommended on other forums to use modern camshaft lobes versus off-the-shelf camshafts, so I need a custom grind. I want low end torque that kicks in at 700 RPM and falls off around 4500 to 5000 RPM, which is exactly where the TPI intake manifold drops off with airflow. EfficiencyLover mentioned Rhoads lifters on the intake side of my valvetrain for variable valve effect. This might be an interesting modification and I would have to see what the engine builder thinks of it since I won't be using a big cam, rather a very mild stockish style cam, maybe something that comes close to ZZ4 or Crane227 performance. For the TPI intake, I was suggested on another forum that my exhaust valves will need more lift on their end so 1.6 I believe for them and sticking to 1.5 for the intake side. mhayes mentioned 6.2'' long push rods.

So, clearly I have a LOT to look over and research in order to determine what would be best for my set-up. If a smooth and complete underbody tray with rear diffusers is not too complicated and expensive to have done, the aerodynamic benefits along with wintertime driving protection from the salt is also an added bonus.

With regards to a plug-in hybrid kit, if I am unable to find something that turns my front wheels and permits electronic assisted all-wheel drive, I am not sure if an inline drive kit would be worth it.

Technology | XLHybrids

[freebeard]

My mechanic's Camaro has the cowl induction hood.


https://www.octanemotorsports.com/1998-2002-chevy-camaro-4-cowl-induction-fiberglass-heat-extractor-hood-p-3429.html

This is similar to what aerohead did with his T-100 that he ran at Bonneville.

If a smooth and complete underbody tray with rear diffusers is not too complicated and expensive to have done

Here's the one I like:



The outer fences run from just inside the rear wheel and tire and curve outward to the outer edge of the rear tire. With a flat roof, you still have a diverging duct. Here are some others. Bombshell Betty of course:



Straight fences. Then there was Lucra (they were burning lucre):



I asked him about that difusser and he said it had been proven out in a wind tunnel. It has four fences but appears to have winglets or something connecting them.

edit;
Then there is this; the first difusser that really impressed me:



That's a lot of fences, but it's on a mid-rear car. They do diverge though.

[JSH]

Originally Posted by gumby79

Not to mention you have to go to the New York version of C.A.R.B.and get your transplant certified that you did it right. This is not cheap.

New York exempts cars older than 25 years for emissions testing so in 4 years NY won't care what he does. Phoenix97 is a sophomore in college and the timeline to start this project is once he has graduated and paid off his student loans. No doubt by the time the car is finished it will be exempt

Originally Posted by gumby79

Any reduction in harm to the ecosystem is a gain.

Agreed

Originally Posted by gumby79

Any reduction in fuel consumed is a gain.

Here I disagree. Only mods that reduce fuel economy AND reduce or at least do not increase vehicle emissions are a gain.

[JSH]

Originally Posted by Phoenix'97

...I just think that it will cost too much. This coming from the guy spending thousands to modify my car into a V8 hybrid plug-in, lol.

What is the budget for this project? Seems that would be a starting point for people to offer reasonable advice that meets your budget.

[JSH]

Originally Posted by Phoenix'97

The car is White and came that way from the factory. When I have the car resto-modded, I am thinking of having her painted Mystic Teal....
Attachment 23414

Nice looking car. I had a poster of a Firehawk on my dorm room wall when I was in college. Life happened and I never got it.

[freebeard]

More than you could reasonably want to know about Mystic Teal:

GM / General Motors Mystic Teal / #1e394f Hex Color Code Schemes, Charts, Palettes, Paints & RGB / CMYK / HSL Conversion

One of my favorite color names is Dark Bright Teal, because it's so mystical.

[Phoenix'97]

Originally Posted by freebeard

My mechanic's Camaro has the cowl induction hood.

I have been debating on whether or not to convert my factory WS6 hood into a cowl hood, which would mean sealing off the air inlet nostrils and opening up the back side to vent air in. For the winter time it would be beneficial to keep snow and salt from entering the engine bay, so I would need custom inserts that are removable for the spring and summer to reactivate the hood. Since I am using a somewhat restrictive air box with an equally restrictive paper air filter, the added airflow will be a benefit, so I am going to keep the ram-air hood functionality but it does need modification for the LS1 air box I am now using.

Originally Posted by freebeard

As far as those diffusers go, what I plan on using won't be nearly as large as what those aero cars are using in these pictures! The smooth wheel covers may look neat on my car, although I have been trying to imagine what baby moon wheel/hubs would look like as well on my car, lol. Probably not too good but definitely giving a vintage homage look with marginal wheel streamlining.

[Phoenix'97]

Originally Posted by JSH

What is the budget for this project? Seems that would be a starting point for people to offer reasonable advice that meets your budget.

I am not going to say. Just as you do during an accident YOU NEVER GIVE OUT A FIGURE BEFORE CONSULTING A LAWYER OR YOUR INSURANCE COMPANY!

A good amount of money will be invested into my LT1 to modify it as per the suggestions I have received and with the addition of increased friction reduction where applicable. The engine builder will be the guy to give me the low down on what he thinks will be wise alterations and which ones may end up blowing holes in the block while testing and tuning, lol.

[Phoenix'97]

Originally Posted by JSH

Nice looking car. I had a poster of a Firehawk on my dorm room wall when I was in college. Life happened and I never got it.

Yeah. I got that aftermarket LS1 style hood a long time ago for my then 6-cylinder automatic Firebird of the same year but in dark green. The hood is poorly shaped and I am just using it right now because I wanted to see how the car looked with this aggressive hood.

Honestly, I miss the sleeker style of the Firebird/Formula and this is why I am going to give her the cosmetic make-over to a Firehawk, but without the official tags on the door. I have a special name in mind to have painted in that location. The mystic teal, that metallic bluish cyan color, suits the transformation of this Phoenix into it's next life and into a plug-in hybrid, depending upon how this project goes.

[freebeard]

My vote is for the cowl induction. It sucks on what's left of the high-pressure area at the base of the windshield. And acts as a bug deflector.

Originally Posted by DuckDuckGo

Houzz Color Guide: How to Use Teal. ... Teal pops with bright white, ... More crisp white, earthy browns and dark teal. Absolutely gorgeous.

You can regain the hood space, and instead of the Firehawk/chicken, use an airbrushed Teal duck.

I showed examples from Bonneville, but not everybody wants a tail-dragger. I expect you'd want to address the departure angle and round off those sharp tips. The main considerations are the curvature and the reasoning behind fences.

For the wheels and tires, I'd look to the hyper-efficient cars like the VW XL-1 and the BMW i3. They use the tallest and narrowest tire possible. Use the wheel offset to flush the tire out to the body side.

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