Vw pickup MAX mpg build!
 

1982 vw rabbit pickup 5 speed diesel. My goal it to get the maximum mpg out of this truck without swapping a newer engine, lets start with the engine, I plan on ceramic coating everything and using ceramic bearings, I want this engine to be able to use the lightest oil possible, I think it's also worth it to change the pistons , any other recommendations to internal engine changes? Transmission changes ceramic bearings/coated input and output shafts. To finish up this minimum friction drive line ceramic wheel bearings( might be part of the stage two build because of cost lol). Now to the valve train not sure what cam is best for the low rpm range a suggestion would be helpful, also what rpm should I try to tune this engine to mostly 55 mph driving. I have had a hard time trying to find the right header 4-2-1 not sure what's the best diameter for low rpm range either. If someone to recommend one with good build quality that would help a lot. Another question is if I put a air dam under the bumper do I still need to put a belly pan under the whole car or maybe just the back half or none at all? Does anyone know of information on building a aero cap on a rabbit specifically?

Welcome to the site. Sounds like a lot of work! What kind of mpg are you currently getting with it?

Ultra low tension oil rings.
File fitted piston rings.
A turbocharger.
And don't run oil that is too thin.
The ceramic bearings appear to be a waste of money on anything that turns slower than a 2 pole electric motor.
In a diesel, the stock cam is likely your best choice for low RPM.

Welcome to Ecomodder!

I found that your coefficient of drag is 0.44, which high but about right for a pickup truck.

I'm going to post a picture of a VW pickup to get an idea of what you're working with. vvvv

http://germancarsforsaleblog.com/wp-.../GTItrucka.png

An air dam will help divert air from going under the truck and somewhat block the tires off from the airflow, at the expense of increased frontal area. The belly pan, while more work, provides greater gains IMO. It smooths out bottom of the vehicle, which is usually very aero-dirty. Built right, it can prevent air from collecting underneath the rear bumper and cancel its "parachute" effect. Using both in conjunction would do nothing but help :thumbup:

On my Escort ZX2, I noticed a big difference in coasting and the amount of throttle needed at speed when I did a front and rear pan. You might can garner some ideas from my Aero thread in my signature. I have reduced aero drag by 18.5% with my mods.

I do not have any information on an aerocap specifically for a Rabbit truck. I suggest checking out some of the members with Toyota trucks in the Aerodynamics section. There is a lot of ideas and improvising in their threads.

The aero cap is probably where you'll get your biggest efficiency bang for the buck if you spend a lot of time at 55 mph. I'd consider starting there.

Or...

http://ecomodder.com/forum/attachmen...1&d=1433342678

http://ecomodder.com/forum/attachmen...1&d=1433342690

I think the tapered bed and the chopped top probably helped. But my gut says the front taper that exposed the front wheels is worse than stock in that area.

From: http://ecomodder.com/forum/showthrea...tml#post455297

49-53 I live in southern Illinois and I am pretty strategic on the roads I pic to drive lot of flat roads gentle slopes going in the right direction. Easy to avoid towns and I barely use my breaks. I just had a injector fail, and I decided to get the motor and tranny out and go threw it all.

Where do you think ceramic bearings is worth it from what I understand they can reduce friction 20-50 percent in certain places, and they last forever

For the rear belly pan I thought about lifting the car a inch in the back and putting in fins to guide air around the rear tires, is it worth it.

Is putting a turbo on it worth it. I might do it on the stage 2 part of the build a year down the road and a Giles pump but those two things would eat up most of my budget for the engine right now I want to put a thousand or less right now in the motor. And I don't want to chop the top I'm 6,2 and need the head room lol. Body wise I think I will make the aero back permanent and cut out the back window and move the metal back a foot or more and add cross braces to make the body stiff er. I plan on doing most of the little mods on this site. I would love to break 80 mpg in the stage one of this build, is this a realistic goal and maybe break a 100 on stage 2 after testing and fine tuning

1) Upgrade the head bolts. That's a known problem with those engines.

2) Absolutely do anything for the aero. I think the belly pan is the better way to go but if you want to start saving money immediately the air dam will start paying dividends right away.

3) Aero reduces demands on power, and that engine never had any power to spare. It'll feel a lot better on the road with the aero treatment.

4) I think 80mpg might be achievable but only under a very specific usage envelope of steady, modest speeds on the flat. I remember Popular Science reported about 70mpg at 45mph in a Rabbit Diesel; the Caddy's longer profile will put it in a better aerodynamic position if you add the kammback aerolid.

On the air dam could I make 2 small ones in front of the wheels to just guide air around them and let the belly pan do the rest. And minimize the the amount of surface space in the front and let the belly pan pic up the slack.

Weight reduction wise I am thinking using a plexiglass material for the front and side Windows and making the side Windows stay up permanent and taking out all the junk in side the doors, swapping the exhaust manifold for headers. The interior is all ready stripped and I plan on only having one racing seat in the car. Using a fiber glass hood. Is there any where else I can shed some weight besides going on a diet

I want to thank every one for the information so far. Does anyone know of a aftermarket injector with better fuel atomization?

Also I can drive 45 most places no problem very few people on the roads where I live and we have really nice back roads too in my area.

This is an indirect injection engine, my guess is the injector is designed to stream onto a hot surface in the pre-chamber for atomization. An injection designed to atomize might not work very well at all.

That makes perfect sense, I should of done a little more research before asking, thank you

Are you talking about ceramic wheel bearings or engine bearings?
Aside from roller lifters and roller chains, you are not going to find any type of roller bearing in most engines.
If you want to put ceramic bearings some where on your engine, put a ceramic ball bearing turbocharger on it.

In my next engine build I am going to convert it to a roller lifter cam and also try to convert the cam "bearings" (which are actually bushings) to rollers too. This is done by installing traditional cam bearings wrong (so cam bearing oil port does not line up with the with the hole, blocking off oil cam bearing oil flow, normally this is disastrous) Then the cam bearing journal is turned down on a lathe to the diameter of the inside of the rollers. When you put it together the roller bearings are splash oiled by oil being flung off the crank.

Propane or methanol intake fumigation.

Roller bearings I thought I might find them in the transmission but I am still working on getting it out in the next day or to but I think there should be at least one tapered roller bearing but I won't know until I get it apart and I was planning on doing ceramic wheel bearing. Also please forgive me on any confession I might cause on my writing abilities, I am on a cheap mobile device and it can be difficult at times

Welcome to Ecomodder. You've set yourself an interesting project.

You've hit on the reason I wouldn't start with the Rabbit/Caddy myself. What I would do in your place is take off the doors, hang a set of two-door doors, and move the B-pillar and rear bulkhead the rest of your 'foot or more'. Done right it could look factory and solve a problem the extended cab wouldn't.

There's all the other things to do of course (ceramic bearings: marginal gain with some fragility) but to get a real gain right out of the gate: a v1.0 aerolid. If there isn't one for the Rabbit then you get to be first. :thumbup: Anything you do, you can do in a removable form, at least until you ditch the full width tailgate and boattail the rear of the body. What everyone tries to do is fit The Template over the pickup box as best they can. In thinking about my own case (the aircooled Beetle) I separate it into the narrow, tapered upper body and the wider, rounded lower body and treat them differently. Examples:

http://ecomodder.com/forum/member-fr...four-tails.jpg

If you consider the upper right case as substituting for your pickup, then the others are all possible options. Lower right—truncated Template (no added length), lower left—full boattail (not effective below the beltline and—if you do the math—the full length is brutal but you get to start at the B-pillar, ust like the Beetle) and in upper left is an interesting case: a bubbletop-tonneaued full boattail. That could cover the bottom part of the backlight, if you keep that. It would show nicely, but be pretty ineffective except as a wake filler, which is not nothing.

On the 4-2-1 header, once again you can be first. If you look at a blood vessel or Oak tree branch you'll see the 'primary' bulges before it splits into the 'secondaries' (reversed in exhaust flow). If someone manufactured a header using a hydro-forming process (like they use on Chevy truck and Har-Dav frames) to correctly/scientifically model the interior shape, to fit across the A-1 to A-6 generations, then they'd have an immense market to sell into. I suspect motorcycle exhausts are probably made this way now.

If you can find them and they are not stupid expensive, go for it.
Wheel bearing if properly setup really don't create much friction to start with. Plus wheel bearings are operated at relatively low speed, usually turning less than 900rpms at 60mph. But that all depends on tire size and actual speed.

I prolly won't do it then, I read all the propaganda from the ceramic companies lol and I want to take it to the MAX! so I was a little more easily influenced by some of there bs, but this is why I am running this by the ecomodder community to point out some of the holes I can't see my self . Thanks for the knowledge

Tires with less rolling resistance most likely have more benefit then those bearings

the Mk2 big bumper covers from around 1991-92 can be morphed onto a Mk1. I've seen it done. Might be worth it to do a little google searching on that and project sipster that has been mentioned. Take what they did, make a aero bed, low RR tires, moon hub caps and I bet you could beat them.

Oil, use Shell rotella T6 synthetic 5W40. If you go too thin, bad things happen to VW motors. You might be able to use Redline MTL in the trans to cut down on lube drag there.

IDI motors do not respond well to propane injection from what I hear.

Injectors: A good set of balanced injectors with proper new heat shields is probably the best way to go.If you are already talking with or going to go with Giles, he can sort that all out. I've had 3 injection pumps done by Giles. I wonder if he still posts the video he did with my 1.6 TD pump? I was the first in E TN with a Giles pump. After the local shops drove my cars, they now send their pumps they want done right to him. It costs some $$$$ but they are spot on, install it and forget it. He is best one to discuss and set up your needs for fuel economy with the injection system.

You do know about the VW GTD forum? VWDiesel.net The IDI, TDI, and mTDI source.

Look at the techtonics tuning downpipe and exhaust. Uses the stock 2 hole cast iron manifold with a decent sized piping. Not too big to ruin exhaust velocity hurting torque, but a bit better flow to not choke the motor. most 4 into 1 or try Y headers for VW are aimed at top end HP. you want torque and efficiency.

What exact transmission code do you have? You have tons of gear ratios to choose from. How high would you like to gear it? Trans from 1975 to 1998 and beyond will bolt into the Mk1. The later you go, the harder to get the linkage and clutch sorted out but it can be done.

There is almost too much info to dump onto you all in one post. I wish you luck in the project. :thumbup: I have a TDi into a 1981 Scirocco S project that is floundering from too many other projects.

Ted thanks for the detailed information, I have lots of friends in Knox, I went to Nashville auto diesel college, you live in a beautiful state. But as far has 4-2-1 headers go I have seen some that are 1.25 in diameter but I have not found one with very good build quality yet. I will find out what my trans code is today and post it. I still need to go over some of the information you posted and check out that forum .

That is what everyone says about IDI motors and propane.
Mine ran fine on propane, but I was only trying to run about 10,000 to 12,000 BTU/hr (not really that much) on a 389 cubic inch diesel.
Don't worry about finding small headers, that is a gas motor thing. The diesel will do fine on 1.625 or 1.75 inch headers.
Big exhaust doesn't hurt fuel milage on a diesel engine like it does on a gas motor.
The more air you can get in and out of them the better. Where with a gas engine, the more air that goes into it, you need the same proportional amount of fuel to go in there too. Diesels only burn the fuel they need, stuff all the air you want into them, it will only further increase power and fuel mileage.

You should get a turbocharger. On my current engine when I turbo charged it I picked up 2 to 2.5mpg when I added the second turbo charger it increased fuel economy form 0 to 0.5mpg. I do not believe adding the second turbo and intercooler hurt fuel mileage.
Now that doesn't sound like much. But I was only getting 17 to 19 mpg with out the turbo.

bearings
 

I would recommend that you GOOGLE ultra-low-drag bearings/tribology.
There are some fine articles about micro-finishing and synthetic lubes vs efficiency-economy.
You may decide that the ceramic bearings would provide savings lost in the signal-to-noise ratio of testing.Only lab testing could convince an onlooker that a savings could be realized.:o

I can not find online where my transmission code is located and I don't see it in my Bentley services manual there is a good layer of grime all over the transmission so I can't find it with a flash light if someone could tell me the location I would be very grateful

Found it it's FF

I have a gift of information to those that read this thread on the alternator delete one negative is the aero penalty when putting conventional solar panels on the roof ,, well now they have boat solar panels that are just a few mm thick and are strong enough to walk on. A 50 watt 20 amp panel is 150 , number to is the heavy deep cycle batteries that put off dangerous gasses and there cost is high, the cell phone towers have lithium ion batteries get replaced every two year new they are over 700 bucks but you can find them used from 15-100 bucks they are 1/3 the size and weight of a deep cycle and you guys know other the other benefits of lithium

They also have a 10 year warranty

Other benifets of lithium, as in they are not currently recyclable?

But I use them.
DIY: BYOB, for more power, a lot less weight - Diesel Place : Chevrolet and GMC Diesel Truck Forums

I think a solar panel bed cover would work rather well as opposed to attaching a solar panel to the roof of some vehicle and using a huge aero penalty.

Their would not be a aero penalty at all with the boat solar panel they are like 3.5 millimeters thick basically a then piece of plexiglass that can contort to the shape of the body panel it's glued to this would be especially beneficial to someone that does not have a truck,

If you build the bed out of solar panels you would be limited to making it flat angle s. I think the boat solar panels are all around better. As far as the lithium batteries not being recycled , chances are by the time that batteries go bad in 8 years or longer the infrastructure will be built to recycle those batteries. Buy that time the hybrid car batteries of today will be being retired thus causing the demand for the batteries to be recycled and giving time for new technology to be developed to make the recycling a easier cost effective process.

Really looking forward to the final result here. I had an early 80's Rabbit truck when I was in high school. It was a rust bucket that burned a ton of oil, but it got great mpg even with a 17 year old driving it.

I hit 50-ish mpg on multiple trips to Michigan from central Nebraska. I attribute that mostly to the rust cutting weight to a bare minimum and the fact that it would barely do 65 mph...usually requiring a hill of some sort. I loved that truck, and it would literally burn anything I put in the tank (or crankcase lol).

Have you already ordered parts, or still looking? When you get to that point, please post a complete parts list...we love that stuff around here.

I plan on taking pictures at every stage of the build I want to make it as easy as possible to follow in the foot steps of this build. Right now I am still taking every thing apart and I am still working on a part s list

The thin, conformal panels can fit to rounded shapes, but you're still limited by the rectangular outine. See what they do on the solar race cars.

You could use a full tonneau with a curved V-shape of clear plexiglass all the way to the end of the bed (for great visibility) and have a flat roof to put the solar panels on that that could even extend like an inch-thick cab-over over the cab for increased area.

I don't know the cost difference between using plexiglass compared to fiber glass but on my truck I planned on making it kinda like the hatch door on a crx having a 6 in strip of plexiglass going over the top of the tail gate, with a crx I did not think visibly was bad at all with a similar design, also would plexiglass weigh more then fiberglass? The boat solar panels are a lot small dimensions I think I might be able to fit 2 50 watt ones on my roof but I think one would be enough or I can put it on the hood of the truck

I was thinking plexiglass for a secondary backlight, like the 1948 Studebaker Starlight coupe. The shape would be more like the Rumpler Tropfenwagen than the Template.

At EVTV Motor Verks Store: you can find a flexible 120watt/$245 panel:

EVTV Motor Verks Store: Flexible Solar Panel 120w, Solar, Boat and Golf, 120wsolarpanel

Those are make in China with American-made individual cells that are 3 watt/$8.95

EVTV Motor Verks Store: 1 Sunpower Cell, Solar, Boat and Golf, sunpower

Its a small world. My brother went to NADC and my nephew-in-law is going there now. :thumbup:

Finally at a place I can post some links.

For exhaust options, the best choice for Mk1 cars is at Mk1 VW Performance Exhaust Systems 1982 should have the dual outlet cast manifold so the twin downpipe that attaches to that (hope your studs are not rusted solid) and the 2" stainless pickup system would be great if cost is not a concern. I've ran the aluminized in TN and it will last here. Not sure how it will last where you are. Aluminized is cheaper than the stainless, it performs the same but wont last the same years as SS.

I had a feeling you would have the FF. There are supposedly some diesels running around with a 4.25 final drive instead of the stated 3.89 final ratio. Not sure if myth or fact. You already have one of the tallest geared transmissions. Only thing taller is one with a 3.67 or 3.65 final.

Lots of transmission info at Gear Up!
and 020 GEAR RATIOS The gear charts can help with engine RPM, tire size, and speed estimates. There is an excel spreadsheet on the bottom of the scirocco.org/gears page that you can mix and match all kinds of ways. I still think your best bet with the trans is just change the fluid, make sure your CV's are all in good shape and work on efficiency elsewhere.