A V70 named Skrutten

[Konir]

Hi folks!

About a year ago a friend introduced me to the world of hypermiling and this forum. Been lurking ever since and during the last couple of months I've also been using the tools on here for keeping track on my fuel consumption. I really appreciate the time spent here, I've had a lot of fun and have learned a lot in the meantime!

My rust bucket is a Volvo V70 Classic(first gen v70) with 407.000km on the odometer since February 2000. She goes by Skrutten(tinpot, old and tired). We live in a hilly area outside Borås at the south western parts of Sweden where we do most of our driving. I would like to do more modifications on Skrutten but as of right now I'm trying to catch up with years of neglect, there is a lot of rust and rotted out bushings that I'm trying to fix at the same time as I need here for everyday use. Lot of late nights and weekend tinkering to keep us afloat. Skrutten is probably destined for the scrap yard but she is my first car and means a lot to me, and the longer I can do repairs the more experience I get.

At the moment I can't drive nor tinker. Confused a drill press for a merry go round in January. I had just filled the tank with the dino/ethanol juice we run in Sweden and didn't have time to drive more than 10km before the accident. Usually I'm the only driver of the vehicle but I asked my mother to use the car as much as she wanted during this time so that it wouldn't stand still for to long. When I'm able to drive again I'll head straight to the fuel pumps, fill her up, look at the numbers and see how she behaves when someone who don't try to hypermile is behind the wheel. Really looking forward to it!

My average MPG these last months is 32.67 which I think I can beat when the spring and summer comes. This autumn/winter I've driven a lot of bad back roads in fourth gear during late nights. When the days get longer, the visibility better and the road surface better I can use my fifth gear and plan my speeds better when it comes to hills and curves.
The best MPG's I've seen this car produce was 42.7 during a 160km trip on the flatlands last summer. Not something that I will be able to achieve at home, got to haul our bums up and down hills all day long. Go club Sisyphus!!

This is going to be my first post on the forum. Might look a little bit funny, got to befriend the interface and won't be able to embed pictures before I reach 15 posts.

I want to discuss some modifications later on but want to be able to embed pictures in the posts before I bring them up. Makes it a little bit easier to avoid misunderstandings. ^^

Have a good one folks and thanks for all the help you've already given me through your old posts!

Specs:
5 cylinder, 2.4 liter, 140hp, 5 gear manual gearbox, running 95 RON octane(roughly 91 MON U.S)

Weight reductions:
Ditched tow bar assembly
No second row seats
Removed AC-system
Skinnier tires(now running standard size winter tires)
No internal bed in the trunk due to ongoing welding
No reserve tire
No rear bumper due to ongoing welding
Lighter homemade high flow muffler
Most of the interior in the rear compartment stripped out

Aero:
Skinnier tires(now running standard size winter tires)
Added tray underneath engine
Dams in front of front wheels
Grill blocks, upper and lower
Removed mud flaps

Misc:
Low viscosity synthetic oil in engine and gearbox
Cancellation of factory cold air intake
Grill blocks to reach engine operating temp faster
Homemade high flow muffler running all the way from the cat to the rear end of the car, almost 3m as to retain a low sound volume while having a glass/steelpack design.
Iridium spark plugs

Planned mods:
Skinny tires all around
Air dams in front of the back tires and suspension
Belly pans, this car only have a small one at the very front from factory
New injectors
Aerodynamic wheel hubs from later V-50 Driv-e models(got them in storage)
True hot air intake
Funnel to direct air to/from radiator and gearbox
Maybe air curtains from the fog lights
Fill "bowl shaped indentation" behind door handles
Skirts for the rear wheels
Adjustments to the nut behind the wheel

[Konir]

A bit on my muffler:

It rotted out and was in to bad of a shape to patch it up any more. The standard maximum speed in "civilization" is 50km/h here, just a hair under what I was comfortable using fourth gear for. At 50 the car would start behaving sluggish and vibrate a bit so I always had to use third gear in towns and such. My train of thought was that a slightly less restricted exhaust system might just be enough to free up enough torque for 4'th gear to chugg along happily at 50km/h, it would make a noticeable difference in fuel consumption.

I have problems with noise, it tires me really quickly. I wanted a high flow exhaust but still have a quite car. I did some reading and came to the conclusion that a glass/steelpack muffler uses the packing more efficiently if it is in close contact with the perforated core which harbors the main exhaust flow. When further away from the core, less energy is carried by the sound waves and therefore the packing does "less work" on converting the sound energy to heat energy, in other words, less muffling. A short but girthy glass/steelpack muffler should therefore be less effective than a longer but slimmer muffler with the same internal volume. This is a simplification, another aspect is that lower frequency sound waves travel further into the packing material, which makes a girthier muffler better at handling those. My solution was to make my muffler as long and as thick as I could without having fitment problems, starts about 30 cm down pipe from the cat and ends by the rear bumper. Not a perfect solution but it's what I could do with what I had, it gets rid of high pitched noise and what's left is a low rumble.

This was my first muffler build, took some trial and error regarding the shape. If I would do it again I would make the inner core out of sheets with larger holes(5mm) for a better muffling effect, I was afraid that the fiber glass strands would get blown out. After disassembling other straight through mufflers and packing my own I now realize that this probably won't be a problem with the long fibers used and the tight packing. The holed area of the sheets I used was only 33% of the sheet's total, the mufflers I dissected used a larger hole size which should land them at 40% "hole area".
The diameter of the inner core is the same as the original exhaust, which isn't what I intended. I planned to go a little bit smaller to tune the exhaust to my engine and driving style. But... I managed to take my reference measurement from the one and only "larger than original" piece of pipe welded in as a repair. Thought I put in a smaller diameter, landed on stock. 😉
The internal bends are smooth as seen in the picture of the assembled inner core. Just got really tired of fill welding and decided to make the first turn of the outer shell in one go. I also simplified the shape a little to make it easier for myself.

The hair is now a little bit shorter in places since I managed to set myself on fire while laying beneath the car welding mounting points on the muffler. No harm done but the next time I went to the workshop I noticed a couple of Wunderbaums hanging about.

The muffler is mounted and seems to work as intended. It isn't as quiet as stock but I can now drive at my target speed in fourth gear without problems. The old mufflers where both glasspacks but the fibers had detoriated at places and the bigger one wasn't a straight through design, the inner core did a couple of bends in it for a better muffling effect. It was really quite when it was in good condition!

Another note regarding glass/steel pack straight through mufflers. I think they probably work quite good on most hypermiling rigs. They are somewhat alright at muffling at low gas flow speeds but gets increasingly worse as the exhaust gasses speeds up with higher RPM... but that's not the bracket where most of us spend our time.

A stupid project, but fun giving muffler fabrication a go. 🙂

[cRiPpLe_rOoStEr]

There's a lot of room for improvements in this car, not to mention the opportunities for you to improve your mechanical and bodywork skills.

[Konir]

Originally Posted by cRiPpLe_rOoStEr

There's a lot of room for improvements in this car, not to mention the opportunities for you to improve your mechanical and bodywork skills.

Good way too look at it! I've been working on her for four years and driving her for three. Before that she spent a couple of years parked beneath a tree. Next big thing is to swap the clutch and subframe bushings. Never fiddled with a car clutch before, will be an interesting experience... and nice to get a break from all the rust patching I've been doing lately!

The part about her standing beneath a tree. When I first started using her she was more or less a rolling ecosystem. ^^

[cRiPpLe_rOoStEr]

Originally Posted by Konir

Good way too look at it!

I'm from Brazil so I see older cars still being daily-driven, either beaten the hell out of, or taken much good care of. Sometimes a fair share of makeshift fixes or upgrades and adaptations of parts from newer cars are required, but it's still quite common to see cars that Europeans often tell me they don't see anymore.

Never fiddled with a car clutch before, will be an interesting experience...

Sure it will be an interesting experience, yet not exactly so pleasant. But it's good to learn how your car works, so you're less likely to get stranded not knowing if you could eventually try some makeshift in order to limp home safely.

[Konir]

The oldest cars in daily use over here are about 30-35 years old. We put salt on our roads during the winter so the corrosion is really bad at times, cars without sufficient protection from rust from factory usually "melts away". The older part of the active vehicle fleet over here is mostly Volvos since they have the needed protection, they rust as well but at a slower rate so that you can keep up with the need for repairs.

It would be fun documenting the makeshift fixes and adaptations you mention. Might not be all that interesting for a culture where it's common, but here it's inspiring and impressive! We could need some of that "make it work" mentality!


The doctors gave me thumbs up for driving again this week, had my first drive yesterday and I felt really free! Drove to the gas station and filled up what fuel my mother had used up while borrowing the car. She drove about 240km and landed on 25.12MPG. She mostly drove to her work a 7km highway stretch away. I figure that the high consumption stems from the short trips, oils never reaching operating temperatures and such, and to some degree her pedal work. She complained that my car is slow, says a little about how she drives. ^^

[cRiPpLe_rOoStEr]

Originally Posted by Konir

The oldest cars in daily use over here are about 30-35 years old.

I often see Volkswagens around 50 y.o. still being driven normally in Porto Alegre.

We put salt on our roads during the winter so the corrosion is really bad at times, cars without sufficient protection from rust from factory usually "melts away".

Salt on the road is not an issue here. I'm not even sure if it's actually used in any place in the regions where snowfalls are less uncommon.

The older part of the active vehicle fleet over here is mostly Volvos since they have the needed protection, they rust as well but at a slower rate so that you can keep up with the need for repairs.

Not to mention they were made there. Just like the VW Beetle used to be made here until '86, and later from '93 to '96. But anyway, repairability is as important as how long the vehicle would last before needing such repairs.

The doctors gave me thumbs up for driving again this week

What happened?

[Konir]

Originally Posted by cRiPpLe_rOoStEr

I often see Volkswagens around 50 y.o. still being driven normally in Porto Alegre.

Not to mention they were made there. Just like the VW Beetle used to be made here until '86, and later from '93 to '96. But anyway, repairability is as important as how long the vehicle would last before needing such repairs.

What happened?

That's really cool! Is there a large production of spare parts for older VW-models in Brazil to help the fleet stay afloat?

I got stuck in an old industrial drill press. Snapped the lower bones in my left arm and messed up the fingers on the right side. Stupid mistake, but could have gone worse.

I've looked up my how to do a clutch change on my car by the way. I like to tinker with old Soviet-Ukrainian motorcycles in my spare time and it seems like the experience will be quite similar, but the parts will be bigger and harder to reach. It will be interesting, doesn't feel quite as intimidating now!

I can't really tinker quite yet but I think a better version of this will be my next test(attached pictures). I don't have the dexterity in my fingers to make a good version of it right now, but I'm curious to see if it affects cabin noise in some way. The door handles are really easy to remove as well, thinking about removing the ones on the back doors later on. I don't use them much and when I do I can probably stand the hassle of opening them from the inside.

[cRiPpLe_rOoStEr]

Originally Posted by Konir

That's really cool! Is there a large production of spare parts for older VW-models in Brazil to help the fleet stay afloat?

Sure there is still a reasonable amount of aftermarket, yet it's mostly provided by suppliers not affiliated with Volkswagen nowadays, and quality of the spares may not be so consistent among different suppliers. Not to mention some very specific parts becoming harder to source, then it might be inviting to look out for some adaptations with modern parts. Once a guy from Santa Catarina told me he did an entire subframe to fit transversely the engine and gearbox out of a 1st-generation Audi A3 into a Beetle.