Mission Possible: A Boxy 1984 Caprice Classic

[kir_kenix]

There is a really, really nice mid 80's Caprice at the car lot I drive by everyday. The window says it has 55k, working AC, power windows/locks (didn't know they were an option in the 80's Caprice), and V8.

I'm kind of considering getting it and dropping a diesel + manual into it. It looks like a brand new car. I'll be following your progress with great interest!

[101Volts]

In this post there's not much to talk about as far as mods go. We got a new 5-year Battery in April. I'm getting a feel for the car with 35 Cold/39 Hot Tire Pressure with the stock tires and am gathering more data for tanks, I'm about 290 miles in to the current tank at this post time and have more miles to go before the tank is filled up and the car is inspected.

I was wondering, Are there any additives I should be using for this car since it has a carbureted engine? I use gas that has up to 10% Ethanol in it. I could use 100% Gas from a local gas station, However if it's the way it was a year or two ago it's still filthy; I was getting about 16 MPG on their pure gas one summer or spring day in the Caravan. I didn't even fill the tank up on it, I just put $5 or so of gas in! The lawnmower I tried to run on their pure gas wouldn't even run, Either. The lawnmower was very poorly maintained, But the point is when I used their E10 the mower ran compared to their pure gas which it wouldn't run on.

Here's a quote from the Orange Oil Tires Thread, Although I changed the quote a little bit for this thread:

Originally Posted by 101Volts

I've found that according to Automobile-Catalog (1984 Chevrolet Caprice Classic Sedan 5.0L V-8 automatic overdrive tire sizes (since September 1983 for North America U.S.)) These Yokohama AVID Ascends work (For the Caprice)

225/65 R 16 - 1.6% Larger than OEM - $106 Each http://www.tirerack.com/tires/tires....6ASC&tab=Sizes

225/60 R 17 - 2.0% Larger than OEM - $122 Each http://www.tirerack.com/tires/tires....7ASC&tab=Sizes

I also found this size works but these AVID Ascends offered are not 215s, They're P215s.

215/55 R 18 - 0.9% Larger than OEM - $126 Each http://www.tirerack.com/tires/tires....8ASC&tab=Sizes

Got suggestions?

[101Volts]

I'm still looking for advice on tires and asked at the Chevrolet Forum too. Do the sizes I posted in this thread fit the car without modification to the car? I'm cross-checking beyond reading what's on Automobile-catalog.

I do see this is a popular car model for putting large rims on.



As for news on Boxy, We have a trickle-charger on it now which is a nice aid; I started the car on the first crank and I only pumped the gas three times before I cranked it. I removed the mud-flaps too.

[dkunitz]

I don't have experience upsizing tires, but the consensus around here is that it's usually cheaper and lighter to only upsize the sidewall height and keep the 15" wheels you have.

Also, here's an updated aero template for you--the key to lining it up is the roofline, which isn't actually so bad

[The Other Andy]

Man, that is a sweet ride. In very nice shape too, it looks like. There's something about the big, boxy, American sedans (and hilariously large two doors) of the '80s that sits very well with me.

Good luck on your hypermiling with it.

[101Volts]

I'm still asking for help with the tire sizes. I posted on a Chevrolet Forum and hadn't received any replies:

Tire Size Questions for 1984 Caprice Classic Sedan - Chevrolet Forum - Chevy Enthusiasts Forums

Also, Now is time to figure out what engine heaters to use. I have a "Kat's 13150 1500 Watt Aluminum Circulating Tank Heater" in mind, Pictured below:

Amazon.com: Kat's 13150 1500 Watt Aluminum Circulating Tank Heater: Automotive



What else can be used - I know about Transmission and Oil Pan Heaters but what else is there, If any?

As for Oil Pan and Transmission Heaters, I've heard these Kat's Pad Heaters work pretty well. What do you think of these?

Pictured below is the "Kat's 24250 250 Watt 4"x 5" Universal Hot Pad Heater."

http://www.amazon.com/Kats-24250-Watt-Universal-Heater/dp/B000I8XDFS/ref=sr_1_2?s=automotive&ie=UTF8&qid=1402611444&sr= 1-2&keywords=engine+pad+heater



And I'm thinking, Higher than 25 MPG in this 1984 Chevy Caprice Classic Sedan? Yes we can. I'm also thinking of giving it a new dash cluster, Though not of this type which doesn't have Overdrive:



Gee, What's involved in something like this? These cars did come with vacuum gauges, As you can see on the far right in this photo. (The dash in the above photo is from a 1980 Caprice.)

It's been suggested that I override the air-pollution equipment on the car for higher fuel efficiency. Does this work? I don't have smog tests where I am now.

[rmay635703]

Originally Posted by 101Volts

I'm still asking for help with the tire sizes. I posted on a Chevrolet Forum and hadn't received any replies:

It's been suggested that I override the air-pollution equipment on the car for higher fuel efficiency. Does this work? I don't have smog tests where I am now.

For tire size put on whatever fits and matches your load requirements, those cars like the buick roadmaster seemed to be flavor of the day tire sizes.

You could look in the manual or on the options placard usually in the glovebox to figure it out.

In the end on a v8 its probably a wash whatever size you throw on there, on ours its seemed to be 225/75r15's that fit nicely.


Also defeating the pollution equipment has basically no affect on fuel economy in your case. Main reason people do it is because they don't want to buy a cat.

The only way I could see a "Defeat" actually doing anything would be to figure out how to lean out the car and likely your emissions would be better afterword anyway.

Cheers
Ryan

[101Volts]

How can the engine be leaned out? The Idle is lower than it was earlier (It was high, But not when this topic was created) and the car was harder to start and it would stall after it was first started it if the car wasn't given more gas. This was with the battery not being kept on a trickle-charger, Though. Speaking of which, Is there something that can cause excessive electrical use upon starting it? If it's not kept on a trickle-charger it's harder to start.

Also, This is a bit off-topic in hypermiling but how can the switch that turns on the dome light for the rear-right door be replaced? I tried removing it by un-screwing it but there isn't enough wire to pull it out far enough to replace it the way it is. Is it necessary to remove parts from the interior around the front-passenger's seat belt? I tried that too but there was something else in-between the wires and my hand.

Also on subject of the air-pollution reduction equipment, How can it be told if it needs to be replaced? The car is rather stinky upon start-up but is that due to the type of equipment used? Yes, The car is outside of an area with smog tests but it may not always be.

Question: 5w20 Full Synthetic Oil is already used in this car. Is an additive of aid such as the Lucas additive that makes oil even more slippery?

[101Volts]

If 225/65R16 and 225/60R17 don't fit with the stock wheel wells what can be done to make them fit? Larger wheel wells?

[rmay635703]

Originally Posted by 101Volts

If 225/65R16 and 225/60R17 don't fit with the stock wheel wells what can be done to make them fit? Larger wheel wells?

Why not keep the cheap, abundant, reliable and fuel efficient 15" tires that come on the car stock?

In any event those tires probably do fit, a few simple measurements would verify it, but they would cost more and have little benefit otherwise.

If they did not fit you would need to expand your wheel wells, but more likely a few spring spacers or air shocks would accomplish the same thing depending on what way you are having trouble.

As toward lean burn that is usually quite involved on an O2 controlled car such as yours. There are methods of tuning your paticular year and there is also a wideband device that allows you to lean the mix manually once you get on the road.

Likely more cost than its worth though.

Cheers
Ryan