Mission Possible: A Boxy 1984 Caprice Classic

[101Volts]

Originally Posted by xntrx

Should check the Cadi and Pontiac versions of the same era. Many had skirt that could be adapted. This would give an OEM solution and look that could be built upon.


I wonder how hard it would be to swap the back glass to the aero coupe style?



Fyi, the 6.2 diesel is a fairly easy swap (bolts in, but normal diesel conversion stuff like brakes, tank...).

So are the Pontiac Parisienne and Cadillac Coupe De Ville models what you're referring to?

Here's a photo of a 1986 Pontiac Parisienne with wheel skirts:



Maybe I can find some in decent shape in a junkyard.

And, What's involved in putting an aerodynamic glass on the back end? I'm aware the trunk will need to be shortened in such a modification.

As for the Diesel, Just for reference I realize you're talking about another motor and not the 5.7 that some of these G.M cars came with. An engine swap is definitely a possibility, But for now I'll use the stock motor. The car is close to 110k miles as is, I think I'd be able to get 23+ HWY if I stuck the right Diesel motor in though. And, I'm probably not going to tow anything with this car and it doesn't have a stock hitch.

Originally Posted by slownugly

Hard to say how much a trans swap would be worth. It would def show an improvement

Thanks.

[theicecreamman]

Originally Posted by 101Volts

So are the Pontiac Parisienne and Cadillac Coupe De Ville models what you're referring to?

Here's a photo of a 1986 Pontiac Parisienne with wheel skirts:



Maybe I can find some in decent shape in a junkyard.

And, What's involved in putting an aerodynamic glass on the back end? I'm aware the trunk will need to be shortened in such a modification.

As for the Diesel, Just for reference I realize you're talking about another motor and not the 5.7 that some of these G.M cars came with. An engine swap is definitely a possibility, But for now I'll use the stock motor. The car is close to 110k miles as is, I think I'd be able to get 23+ HWY if I stuck the right Diesel motor in though. And, I'm probably not going to tow anything with this car and it doesn't have a stock hitch.



Thanks.

Have you considered putting a TPI unit off an old F body on that old girl? They're probably giving them away right now. The 305ci version has small cross section runners that are long for more bottom end torque, and since you'll have complete control over the fuelling and ignition, you can tune that thing for max mpg. Then, of course, you could add some tri-y headers, small duals ( like 2.25" all the way out with catalysts, and an X or H pipe ).

[rmay635703]

Originally Posted by 101Volts

As for the Diesel, Just for reference I realize you're talking about another motor and not the 5.7 that some of these G.M cars came with. An engine swap is definitely a possibility,

Thanks.

A manual transmission does make a big difference if you EOC a lot, leaning a car of that vintage up (if you can) makes a bit of difference if done correctly.
Could check out the hundreds of dollars EFI systems floating around.

The diesels with a manual transmission (5speed variety) should top you out near 30mpg on the highway at low speeds. That is regardless of 5.7 or 6.2, also the 5.7 diesel can be reliable if proper precautions are taken, later goodwrench varieties could live a long time without even a fuel water separator, so one with a fuel water separator would likely be better.

Only benefit to the 5.7 over the 6.2 is if you get it free and because it drops in without motor mount work, beyond that it gets roughly the same FE (if your 6.2 if configured correctly) and is harder to adapt to a MT.

Cheers
Ryan

[cRiPpLe_rOoStEr]

With a manual transmission and a Diesel you could see some 35MPG in highway

[Miller88]

I think it would be awesome to get a car like that and put a 6.2 and manual transmission in!

[TurnpikeCruiser]

I was trying to do the same thing with my boxy boat at one time. Just overall driving like an old man got me 23-25mpg. I had the computer read 28mpg at one time, but rush hour killed that quick.

Do you know what kind of ratio gears are in the rear? If you're cruising on the highway mostly, 2.73s or even 2.55s will do nicely with a 4 speed auto.

I had skirts on my Marq, but that was before I was worrying about gas mileage and they got ripped off after an accidental off-road adventure.

[Superfuelgero]

Originally Posted by rmay635703

A manual transmission does make a big difference if you EOC a lot, leaning a car of that vintage up (if you can) makes a bit of difference if done correctly.
Could check out the hundreds of dollars EFI systems floating around.

The diesels with a manual transmission (5speed variety) should top you out near 30mpg on the highway at low speeds. That is regardless of 5.7 or 6.2, also the 5.7 diesel can be reliable if proper precautions are taken, later goodwrench varieties could live a long time without even a fuel water separator, so one with a fuel water separator would likely be better.

Only benefit to the 5.7 over the 6.2 is if you get it free and because it drops in without motor mount work, beyond that it gets roughly the same FE (if your 6.2 if configured correctly) and is harder to adapt to a MT.

Cheers
Ryan

6.2 is SBC mounts, and bellhousing. It will directly bolt up to what he has. They're dirt cheap as military drop out from the CUCV and HMMWV's. I've seen the come up several times on CL for 150-200 as complete drop outs. I almost went with a F-body 6.2/T-56 build instead of my VX.

OP- Not sure what's involved in the rear glass swap, never done it personally.

TBI is better at MPG than TPI. Smaller runners, and tuned for MPG.

[elhigh]

I guarantee you the underside of that car is an aerodynamic nightmare. You could do a lot of aero upgrade down there without changing the outward appearance of the vehicle at all. Air dam to start, just to start saving a few bucks.

As others have said, rear skirts were a factory option. If you go a little crazy with homebrew and make yours smoother/bigger, well, most people won't even notice.

One wonders whether a grille block, on this monster, could even have a positive effect.

Upgrade the induction to the '89-and-up TBI. According to Wikipedia this was done for fuel economy purposes, but the EPA's numbers tell me it didn't work. Can't hurt though. It'll be a lot easier to tune for leaner operation.

Subscribed. I'd love to see someone crack 30mpg at cruising speed in one of these whales.

[cRiPpLe_rOoStEr]

Another interesting option could be a Vortec 4800 out of an Express van. Or even the V6 wouldn't be the worst option at all...

[101Volts]

Originally Posted by TurnpikeCruiser

I was trying to do the same thing with my boxy boat at one time. Just overall driving like an old man got me 23-25mpg. I had the computer read 28mpg at one time, but rush hour killed that quick.

Do you know what kind of ratio gears are in the rear? If you're cruising on the highway mostly, 2.73s or even 2.55s will do nicely with a 4 speed auto.

I had skirts on my Marq, but that was before I was worrying about gas mileage and they got ripped off after an accidental off-road adventure.

I think they're 2.73s, Going by Automobile-Catalog.com.

I once had a grille block on this car but didn't check the economy while it was on since it wasn't driven much. The one tank I have logged in the Garage as of this post time is the first tank-to-tank measurement I ever got in this car, Before that we just did partial fill-ups.

I'm interested in the rear skirts and a belly pan. I'm also open to a Diesel with Manual Transmission conversion, But would like to do some other mods first and maybe get new tires; These things are probably 22 years old. (It sat in my grandmother's garage for a long time before we got it.)

Also, Here's a thought; Converting it into a hatchback for aerodynamic and storage purposes. Can I replace the rear seats with middle seats from a station wagon so they can be lowered for even more storage, Too? It's a thought, At least. I have the thought of adding a trailer hitch too, But I don't know what I'd tow with it.

And again, Would removing the pollutant controls from the car increase the economy? The car is already stinky upon start-up compared to newer cars, But I'm curious.

Also, I imagine I can add an air-bag system. And this car doesn't have cruise control as-is, I think that can be added too.

What is an induction system...?

*google search time*