light weight car? suggestions (for removing weight from 81 VW Rabbit diesel)

[Ryland]

If you really want to go to an extreme and mod a VW, get one of the convertibles and put a Diesel engine in it, the car you have is a unibody and cutting in to the body will make it weak, convertibles have a stronger sub frame, of course the draw back to a convertible is that they tend to weigh more because of the reinforcements that are needed when you don't have a roof.

I agree with what everyone else has said about not making mods that can't be undone, after all you have a car that when it was new had an EPA rating of nearly 60mpg while being a 4 door hatch back.
But if you really do want to make your 1,900 pound car lighter, I'd start with unsprung weight.
You are also going to see an improvement with better/faster glow plugs, a block heater and smoothing out the underbody air flow.

[JethroBodine]

In my opinion, don't worry about weight, concentrate on aero. I live in hilly country( Vermont) and use the hills to my advantage. With an added passenger( my son who weighs 260 lbs plus), I see little overall difference in mileage, more going uphill, longer coasts going downhill, pretty much a wash.
I know that the MKI and MKII are a bit different, but there are a lot of similarities.

I would suggest an upper grill block, full belly pan, and, if you really want to get wild, put a tail on that wabbit.

If you have the 4 speed, your top gear ratio is the same as my 5 speed with my re-geared 5th. If you have a 5 speed, there are options for re-gearing 5th here that might benefit you.

Keep (V)Dubbin'!

[baldlobo]

buy one of these

Trabant - Wikipedia, the free encyclopedia

1,653 lb, and a 4cyl will fit in it; there's an outfit in toronto that sells them

[ecomodded]

A 1990's Toyota Tercel hatchback , cheap, light,reliable and fun.

[nimblemotors]

Can you do some ABA testing to determine how much 250lbs difference makes? Or add another 100 to test 350 lbs.

It is not a wash going up and down, you don't recover the lost efficiency of the engine from going uphill, and if you have to brake going downhill it is worse.

Originally Posted by JethroBodine

In my opinion, don't worry about weight, concentrate on aero. I live in hilly country( Vermont) and use the hills to my advantage. With an added passenger( my son who weighs 260 lbs plus), I see little overall difference in mileage, more going uphill, longer coasts going downhill, pretty much a wash.
I know that the MKI and MKII are a bit different, but there are a lot of similarities.

I would suggest an upper grill block, full belly pan, and, if you really want to get wild, put a tail on that wabbit.

If you have the 4 speed, your top gear ratio is the same as my 5 speed with my re-geared 5th. If you have a 5 speed, there are options for re-gearing 5th here that might benefit you.

Keep (V)Dubbin'!

[drmiller100]

for market research, if you could buy a car body and put your running gear into it, what would you pay?

it would be a 2 seater, tandem, with huge doors for easy in and out.

total weight would be 1100 pounds ready to go.

Would you pay 3000 for it? 5000? 10,000?????

[81rabbitdiesel]

hi guys,

Thanks for all the responces. Its been an internal battal as far as cutting the car up to make it lighter. With the responces i think i will leave the car as it is and just to what project sipster did.

Everything takes me a while to get done, partly due to financial situation and partly due to some of my physical limitations. I did move my fuel cut off switch to my gear shifter to make it easier to get to and i like it there much better. the car has really tall gears in it already I was told it has the tallest 5th gear that vw put in them, and driving the car makes me a believer of that.

the grill block worries me a bit but im going to start doing it in small implements. I have a couple of small pieces of plexi glass i can cut to make the headlights smooth and was thinking that maybe blocking the lower grill portion first...............I mean if i did a bumper type airdam (Bumper to 4 inches above the ground) it would have the lower grills blocked anyways.

thanks again guys.
Don

[Grant-53]

Years ago Chrysler engineers determined for each 100 lb loss in weight, a 0.1 mpg gain was obtained. This applied to larger cars with higher Cd. Test by adding weight. I would not carve on the unibody or eliminate all forms of bumper for safety sake. Substitute lighter materials and eliminate parts not used. A lighter battery, wheels, and seats would help so long as you don't sacrifice satey or comfort. Big gains are from aero mods and driving techniques.

[JethroBodine]

Nimble and Grant- With Pulse and Glide techniques, there can be an advantage with the extra momentum. There have been quite a few posts on here where they will say that their best trip on their favorite road was with extra weight in the car. I also have taken data on all my car usage with load descriptions and ambient temp., and found that there was less difference with weight than temp.. Just my vehicle, my roads, and my experiences.

[jtbo]

If one has silly amounts of cash, Volk wheels might be worth to consider, in Rabbit's size single wheel weight is under 3kg, tires can be heavy too, so one could save a lot of weight with good tire choice.

Replacing rear glass with plexiglass or thin not transparent plastic might be possible, depending regulations on your area.

Problem with cutting the car is that body is self supporting structure without separate chassis so if one would make it more like 2dr short pickup with aero bedcover, that would require some ingenious support structure that would not kill driver when one is rearended by blind fellow motorist.

If driving is at city, weight has meaning, but if highway, then weight has less meaning, in Rabbit's figures, as starting weight is so small, that it is not possible to cut it to half like with some bigger cars it is possible.

In rallying, most crazy ones use acid treatment to make sheetmetal thinner, but they have rollcage and sometimes fibre parts, like hood and front fenders, doors from glassfibre or if money is no object, making those from carbon fibre might provide some weight savings. Gains are however bit questionable, at least at highway.

Suzuki Alto, that is something that was before Geo Metro (early 80's) I believe? Weight something around 600kg, putting rabbit motor to such might be easier and more beneficial as weight reduction of Alto might put it to 500-600kg with rabbit motor and getting rabbit to that weight would be really difficult, also Alto would have less frontal area too, finding one might be challenge though, they did rust a bit. I think Alto is hypermini class or something like that, it is a lot smaller than most others I know, almost any other really.

Besides, nobody will ever miss Alto, but Rabbit is icon, don't cut that.