How to build a muscle car for better fuel economy?

[Phoenix'97]

Originally Posted by Ecky

Thanks Funkhoss, your numbers speak for themselves. Conservative driving with engine-off coasting can go a very long way, and anything to keep RPM down, vaccum low and load high is going to improve efficiency.

Well I will certainly check out his modifications. Something is wrong with my set-up.

Originally Posted by Ecky

Anyway, the stock tires on your car have a circumference of 82.2 inches. A hypothetical hub motor that tops out at 500rpm at 24v will move your car along at 39mph, but will have a top speed of 78mph at 48v and 156mph at 96v. Electric motors play by different rules than gas engines do.

The question then becomes, how to have the electric motor kick on when my gasoline engine needs the power.

[Ecky]

Originally Posted by Phoenix'97

So are you still using the stock B-Body camshaft? I have been posting in other forums trying to figure out the best set-up for my F-body LT1 which gives me the additional low end torque I seek while also giving me more seat-of-the-pants feel that I have been desiring, which is why I have been so adamant about the TPI intake. I don't drive beyond 5000 RPM when I have my fun so I figured the TPI intake was a perfect fit.

How the heck are you achieving 46 mpg on a 4.11 gear ratio?! Even when my car was in the best of shape I never could achieve that kind of mileage, and I have tried everything from detuning and experimenting with sucking in hot engine bay air to try to improve my mileage. How?!

An engine kill switch, pulse and glide, and low top speeds. Conserving momentum?

There's a member on here who had a greater than 55mpg tank out of (if I remember correctly) an F250, or maybe it was a Ram 2500.

It's possible to get amazing numbers if you're willing to adapt your driving, but the moment you get on the gas, your economy will plummet.

[Ecky]

Originally Posted by Phoenix'97

The question then becomes, how to have the electric motor kick on when my gasoline engine needs the power.

I can think of a few ways. The most simple in principle would be to have a second "pedal" behind your gas pedal, so when it gets past a certain point, you start pressing the electric motor's throttle too.

Another method would be to tie motor throttle to manifold vacuum, so that the less vacuum you have, the more assist you get, and you get regen when vaccum is really high. Or, maybe you can tie it to throttle position sensor.

A really good system would probably take all of these factors and more into account (e.g. vehicle speed), and have some formula to derive how much assist you should get.

[funkhoss]

Originally Posted by Phoenix'97

So are you still using the stock B-Body camshaft?

Yes. It really does perform extremely well at low RPM. I could drive all day at 45 MPH and just under 800 RPMs at that speed (with my really high gearing). You'd be hard pressed to find a better low RPM camshaft for the LT1.

Except for tuning, and removing unnecessary accessories (power steering, A/C), my engine is completely stock.

Originally Posted by Phoenix'97

How the heck are you achieving 46 mpg on a 4.11 gear ratio?!

To clarify: I can achieve 46 MPG with my lightweight 2.14 ratio rear end. I've only done about 42 MPG so far with the 4.10 14-bolt axle.

And I think the difference there has more to do with the additional weight and parasitic loss, than with the difference in gearing, per se. I can achieve 46 MPG with the 2.14 axle even if I never go above 3rd gear.

Originally Posted by Phoenix'97

How?!

The point is that the biggest gains can be made with highly refined driving technique--especially P&G with EOC.

-Funkhoss

[Phoenix'97]

Originally Posted by Ecky

I can think of a few ways. The most simple in principle would be to have a second "pedal" behind your gas pedal, so when it gets past a certain point, you start pressing the electric motor's throttle too.

Another method would be to tie motor throttle to manifold vacuum, so that the less vacuum you have, the more assist you get, and you get regen when vaccum is really high. Or, maybe you can tie it to throttle position sensor.

A really good system would probably take all of these factors and more into account (e.g. vehicle speed), and have some formula to derive how much assist you should get.

Boy do I have a plethora of things to look into. I won't dismiss the hybrid technology but yeah, if it won't work the way I was hoping then that part I have to dismiss and admit I was wrong about it.

I won't go too crazy with this car.

[Phoenix'97]

Originally Posted by funkhoss

Yes. It really does perform extremely well at low RPM. I could drive all day at 45 MPH and just under 800 RPMs at that speed (with my really high gearing). You'd be hard pressed to find a better low RPM camshaft for the LT1.

Wow, because I was looking into getting the stock B-Body camshaft for my engine, and hoping that the TPI intake would give me that jolt of torque when I decided to let loose and have my fun with the car.

My motor is stock, I haven't done any ultra modifications to remove parasitic loss, and frankly I am nervous to. I am just focusing on what I can do to improve mileage without going to extremes, especially full blown aerodynamic modifications.

Thank you for chiming in!

[freebeard]

¿How?
http://ecomodder.com/forum/showthrea...mpg-33961.html

Now for the most important part...the mods. I've included both a "Cliffs Notes" summary, as well as a more detailed description, below. More pics are available here: Caprice Wagon - Album on Imgur

He gave you the link. And you thanked him.

I have been posting in other forums trying to figure out the best set-up for my F-body LT1 which gives me the additional low end torque I seek while also giving me more seat-of-the-pants feel that I have been desiring...

Anti-reversionary headers. Duh.

[Phoenix'97]

Originally Posted by freebeard

Anti-reversionary headers. Duh.

What kind of headers of these? I currently have aftermarket shorties on my engine, although I am not sure if my stock exhaust manifold was actually better...

[Phoenix'97]

Originally Posted by Ecky

I haven't looked much into the aftermarket, but a quick google search revealed this:

Vehicle Platforms | XLHybrids

Looks like it goes in-line with the driveshaft, but I can't tell if it has an internal clutch. If we assume it does, then the engine can be disengaged and you can creep along in stop and go traffic using zero gasoline (no fumes) and without any clutch wear or hitting your bearings over and over. When you pull away from a stoplight or are going up an on-ramp, the electric motor bump starts the gas engine (no starter, saves weight and is one less part to fail) and gives an extra 220ft-lbs of torque (from zero RPM) on top of what your engine produces to accelerate. When you get up to speed, you can either run on gas alone, or electric alone, or use both together when you want to pass. You can use the electric motor to brake the car, which prolongs brake pad life and puts your kinetic energy back into the battery, to be used to accelerate again later with zero fuel used. You can get rid of your alternator (saves weight, one less part to fail) and instead use a highly efficient DC-DC converter and a downsized 12v battery (lawnmower or motorcycle sized) to power the 12v components in the car.

It does add complexity, but it also subtracts complexity. By assisting the engine, you prolong its lifespan - there are examples of 400k mile Chevy Volts and 600k mile Insights and Priuses on their original engine, still running great.

Maybe it would be unreasonably expensive, but frankly I don't know how much the costs of your proposed engine modifications would be, and it might not be dissimilar. I expect you'd get both more power and more economy by putting an electric motor in the middle, and you'd still have your high strung V8 noise, too.

I totally missed this. Honestly, I would rather spend the money to have a business set this system up properly in my car than me trying to screw around and do it myself. I wonder how this system compares to the hub motor system offered by the University of Middle Tennessee. I am not sure if the XL hybrid only turns my rear wheels and hence I lose that nice front wheel drive aspect with the hub motors...

[freebeard]

If you have the time you could go back and reread the thread. It was created by and for you. Your Overton Window has been moved.

Here's a rabbit hole to dive down:
https://duckduckgo.com/?q=anti-reversionary+header

Big overlap at low ripp'ems.