Renault Master Minibus - Blank Slate

[Malvernmike]

Howdy All,

Following my first car (a Mk2 VW Scirocco Scala), I've always been keen on driving in a way that increases fuel efficiency - managing 72mpg in an unmodded 1999 Audi A4 Estate.

I've now got a Renault Master Van, and will be modding it to decrease fuel efficiency.

Currently, the van gets 26-31mpg.

At the moment ideas include;

Analyst Computer
Underfloor sheet
Rear Wheel Fairings
Removing Wing Mirrors - replacing with cameras & screens

I'll be keeping progress posted here, and would welcome any ideas, tips and resources that other members can provide. I am a product designer and work in a CNC & Fabrication Workshop so making/modifying parts is no problem.

To kick things off - can you guys help me source and install a computer and display that will allow me to monitor current, overall and trip mpg?

Examples of wheel fairings would be great, to give me an idea of how to go about making them and other useful considerations.

The effects of cruise control on mpg I understand - is keeping a constant throttle, such that the vehicle decelerates up hills and accelerates on descents, a good measure? I'm keen to install a hand throttle that would allow a constant level to be provided.

Thanks for providing a space to discuss ideas and progress.

Mike.

I'm new to the forum, so cannot display the image linked below. Would the following poster would be so kind as to [ img ] it.

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[focus1.6uk]

Welcome to ecomodder, Mike.

I find instant feedback really helps to improve mpg by driving more efficiently.

The van looks to be too old to have an OBD2 port which would allow a scangauge to be used, but an mpguino might be suitable with some wiring and calibration.

Removing or fitting smaller mirrors to replace the large ones it has should help a fair amount, as well as a simple air dam or a full undertray.

[Piwoslaw]

Welcome to EM, Mike

Originally Posted by Malvernmike

Currently, the van gets 26-31mpg.

Imperial? That's still quite good for a brick on wheels!

Originally Posted by Malvernmike

The effects of cruise control on mpg I understand - is keeping a constant throttle, such that the vehicle decelerates up hills and accelerates on descents, a good measure? I'm keen to install a hand throttle that would allow a constant level to be provided.

Most CC's keep a constant speed, not constant throttle. That's why they don't hurt much on flat highway driving, but in hilly terrain there is a much better technique, called Pulse & Glide. In short, you accelerate in such a manner that the engine's rpm and load is in the most efficient range, then throw the trans into neutral and coast, while the engine is either idling or off. To know where your engine's sweet spot is you should search for its BSFC map, but since these are hard to find a good approximation is to keep rpm around max torque and load near 70-80%.

BTW Is your engine a diesel or petrol, and is it a manual trans?

To your list of mods I would add a grille block to help warm up times, smooth hubcaps, and maybe a Kammback/boattail. The latter could be removeable, like this one:

(click for link to thread)
I've seen aftermarket cargo boxes for vans which could easily become boattails, just the angles would need to be improved:

[Malvernmike]

Howdy all, thanks for the replies.

Yeah imperial mpg - it's the 2.5 non-turbo'd diesel and gets driven pretty economically; even if I know I have to average 70mph to make a certain time. Generally I'll average 55mph, varying anywhere from 45-80mph depending on the hill.

Focus - yeah the instant feedback is a massive bonus, I like the added benefit of it helping induce a meditative state on clear motorways; it really gets you to focus on your inputs and also how the car's running and the road ahead. I've had some pretty deep experiences slipstreaming lorries with the instant mpg on.

Anyways.. the bus is 1999 and does have an obd2 port. I'll do some research on the scangauges.

As I mentioned, I'm planning on fitting two cameras to act as wing mirrors. Does anyone know of any legal implications of doing this? (here in the uk) It would be nice to keep the van fully legal, however that's not a main priority so long as the mods would be considered safe by most and are justifiable..

Can you guys recommend where might be the best place to mount the cameras? Mounting them on the sides of The front bumper would minimise blind spots and of course the bumpers are mighty easy to screw into and sculpt with various glassing/fillers.

Smooth hub caps are a good shout. Some aluminium sheet machined up would do nicely with recessed bolt holes and screwed directly into the steel wheels. Then there's the option of wire brushing it and getting my anodising chap on the case... Yum.

As I'm a (pedal-powered) bike rider (Trials by profession, as well as mtb and touring), the bus regularly gets used to cart around bikes as well as people, hence I want to build a secure bike rack for the back. This would tie in very nicely with a Kammback.. I'll get sketching that one up.

Am I right in assuming that engine-off during coasting in this vehicle (manual gearbox, not auto) will be absolutely fine? I'm well aware of the lack of p/s & servo brakes, but I haven't done it much since discovering the gearbox in an old A6 avant I had, blew up a week after selling it - I learned the hard way that engine-off in an auto isn't a good idea!

Cool, the mod list is coming along well;

Scangauge
Cameras + Screens
Hub caps
Kammback bike rack
Underfloor tray
Rear wheel fairings

Thanks for the help so far!

[Piwoslaw]

Originally Posted by Malvernmike

Am I right in assuming that engine-off during coasting in this vehicle (manual gearbox, not auto) will be absolutely fine? I'm well aware of the lack of p/s & servo brakes,

The main things that might keep you from EOCing are an auto trans and a turbo, so you do not have much to worry about.
You probably don't have electric p/s (and probably won't want to invest in a swap), but usually it isn't needed at highway speeds.

As for brakes, there should be enough vacuum in the system to allow at least 2-3 full presses of the brake pedal. If that is not enough of a safety margin, then you can either swap the vacuum pump for an electric model (made for electric cars, for example), or add a vacuum reservoir to your brake lines, like these:
Homemade PVC Vacuum Reservoir
Auxillary vacuum reservoir

Did I mention that the Kammback/boattail are ideal for highway speeds? (wink, wink)

[Malvernmike]

Haha yess yess.. I suspect out of all the mods listed it will have the biggest effect (apart from perhaps a Scangauge), and will also have the added benefit of being able to house the bikes. I currently have to put the bikes outside every night to set the hammock up to sleep in..

I'll also make it such that it fold in on itself to allow me to 'nip' into those 'tiny' parking spaces.

What sort of % increase in mpg might I expect from a well designed ~1.25m long Kammback?

M

[Piwoslaw]

Originally Posted by Malvernmike

What sort of % increase in mpg might I expect from a well designed ~1.25m long Kammback?

I saw 7% @ 100 km/h from my ~50cm long partial Kammback plus rear wheel skirts.

Those who have done a full length boattail report 15-20%, iirc. That's just the reduction of fuel consumption from aerodynamics alone. The improved coasting will allow you to take better advantage of other hypermiling techniques, so the overall increase in FE will be greater.

BTW Have you looked into a trans swap? Maybe there is manual6-speed, or a taller top gear to reduce rpms on the highway?

[cRiPpLe_rOoStEr]

Originally Posted by Malvernmike

it's the 2.5 non-turbo'd diesel

If you could get a turbocharger, that would help a lot. IIRC the factory-turbocharged 2.5L engine had direct injection, which also increases the fuel-efficiency, while this one is an IDI...

[Malvernmike]

I was discussing the option of a turbo with a colleague yesterday.. It does seem like a good option, but I'll have to do a lot more research and learning.. The option of finding a more modern 1.9tdi and fitting that appeals more, but it is a vast amount of work, which I'd rather spend converting the whole thing to electric drive with minimal batteries and a diesel generator some colleagues are working on for the MOD.

Piwoslaw - that's great.. If I could see 20% gains, that would save me £1,000 a year! Definitely worth putting some time into a Kammback.

Likewise on the gearbox side of things, I feel it's beyond my knowledge/scope of time investment at the moment.. My first priorities are making this thing nice and slippery!

[cRiPpLe_rOoStEr]

Originally Posted by Malvernmike

I was discussing the option of a turbo with a colleague yesterday.. It does seem like a good option, but I'll have to do a lot more research and learning.. The option of finding a more modern 1.9tdi and fitting that appeals more, but it is a vast amount of work, which I'd rather spend converting the whole thing to electric drive with minimal batteries and a diesel generator some colleagues are working on for the MOD.

I'm not so much into hybrid drivelines, but that would be an interesting project. BTW if you were going with minimal batteries seems like it would worth to take a look at the Chevrolet Volt traction layout, which still uses the internal-combustion for auxiliary motion when the batteries charge is still too low