I remember reading one of Smokey Yunick's cars resulted in a rule change in nascar (well many of them did, I'm sure, but I'm thinking of this specific one) was where he disabled the generator (I think it was a generator, not an alternator, but that's really of no consquence) in the original spot, and fitted one somewhere (possibly just below the bumper, but still inside the engine bay, but don't 100% take that location to the bank) else with an appropriately bladed propeller attatched to the front. At the speeds they were doing, it was more than enough to keep the battery charged. You'd probably be doing half the speed on average, so would need to use blade pitch to suit, but it might be worth a look. You could even have a manual switch that cuts out the std alternator for the economy run, but cuts back in for stop start traffic and the like.

if you want to get really serious about fuel economy you could use an EMIS system.
http://www.go-ev.com/EMIS-Desc.html
or incorporate a similar setup.
emis on youtube

Well I'm sure that the Aeromods & electrical charging mods produce benefits, but a second look will allow us to see just how much improvement is gained for the money & effort involved.

Electrics
Parasitic drag. This is the mechanical drag form the alternator just to turn it over. This will not change regardless of whether it is charging or not.
Electrical load. The electrical load is quite high at night, just after starting a cold engine as the lights & starter suck a fair bit from the battery & the alternator needs to replace any lost charge from the battery from the starting process, & to provide the electrical needs of the running car, but in broad daylight, after the battery charge has been topped up after starting, the only electrical load should be the ignition, blinker & stop lights, all of which is quite low & in the case of the lights, intermittent.

By all means, use a switch to cut off the field current, thereby stoping the alternator from charging as it will be cheap & easy to do, but I believe that the savings will be almost unmeasurable.

Aeromods. The shape of a B210 is fairly slipery anyway, however, unless you can make a slipery tail from some thick cardboard & duct tape which would be fairly easy & cheap, then this course of action looks like being a bit of a dead end for a car that is used very infrequently in economy trials, while spending the rest of its life as a performance car or an ice racer.

Permanant aeromods will be more costly, difficult to do & will leave a contraversial shape that not everyone will think of as being 'cool'
As for fuel savings, these aeromods are really only of significant benefit at speeds where the car was suffering from substantial drag in stock form.

At the low speeds that econo-drivers travel, I don't think that the aeromods really produce worthwhile benefits in the majority of cases, but if they can be done easily, cheaply, in a temporary fashion, & do not damage the car in any way, then give it a go.

EMIS. As the video clip shows us, the trucks in the clip can recoup the investment in two to three years of continuous day-in, day-out operation. This suggests to me a very high initial cost, & when used exclusively in occasional weekend economy runs, the investment would be recouped in about two centuries, so I suspect that the cost/benefit balance is not very favourable, particularly in a car that lives the rest of its life as a performance machine.
I wonder how much the extra batteries & the 48 volt charging system weighs, & how much edditional electrical load is imposed on the charging system to top up the batteries after the system has cut in after climbing a hill, for example.

Keeping in mind that these economy events are for sporting/educational purposes without big cash payouts for the winner, then very low cost improvements are probably the best path to follow.

Hmmmm, I wonder if some plastic rear wheel opening covers that are duct taped on will yeild in terms of efficiency. Worth a try I suppose.

EMS is just a type of hybrid motor assist system, very similar to honda IMA. But less efficient. And it requires OBD-II system and automatic transmission.

I think it is possible to gain measurable savings from aerodynamic mods. Yes, the B210 is slippery but only because it is small. It has a lot of drag compared to todays cars.

Have you tried the belly pan yet?

The EMIS system is on the right track but obviously not for the common hobbiest.
I hope in the future an AC system is available to unite the starter and alternator
to allow re-gen and electric assisted take off/hillclimbing etc.
If you have say 72volts of 6 x 12v 55ahm yellow tops that you charge at home they
wont need but to get re-gen to keep them healthy (not fully charged) for trips of 100klms using both fuel and E.

Although of small size and frontal area by no means is a 1200 aerodynamic on the other hand improvements can be made surely.

A honda crx of the early 1980s with a 3 vale CCV engine was capable 60mpg so the same car with aero mods and in eco-modder and better tires would likely get close to 80mpg+. The datsun on the other hand will need specialized lean fuel ratio capable EFI for starters. Maybe a KB10 would be a better body also :)

Right, aerodynamics are composed of two parts: frontal area and coefficient of drag. The first is more important. The B110 has 0.42 coefficient, similar to most pre-1980s sedans. B210 I have never seen a figure for, but I would guess it is not less than 0.40.

Regarding miles/gallon, the american gallon is smaller than the UK gallon. CRX did not get 60mph in USA, perhaps it did in the UK. 1989 Civic CRX HF got 52 mpg, a bit better than the 1978 Datsun B210 at 50mpg.

Good info DD, Im thinking if the b210 got 50mpg then the b110 with EFI
and some other mods for improved engine efficiency could be hard to beat.
An old goat I met at an gov. info session for fuel efficiency technology
grants has some crazy looking Renault 15 with with jet proof coated internals, exhaust system fueled by an LPG with small turbo.
It has the supposedly hemi style heads with crazy swirl style inlet ports
based on the Datsun design using very tricky welding and grinding.
Crank and most reciprocating parts are lightened.
He is a self employed mechanical engineer trying to get a grant for his
version of pre-compressed charge combustion process or something similar
and his wife drives an old bi0-diesel powered merc.
My ears propped up when I heard him speaking about the engine at tea break
after the information session. There are some wacky but wonderful people out there.

Yesterday I told a friend about this post and he said to me there is a guy cant remember the website name that built a system for a honda 2 seater car. They run efi type setup but they heat up the fuel to such and extent that they run on the vapour. The car can still do over 200kph. With normal driving it uses 2.6lt per 100km. So try and search for that site.

On the Alternator subject, it is somewhat common in racecars to run the Alternator under the car, driven off the pinion [via a belt] of the differential. Maybe this is something you could look into.

I lifted this pic off the web, so that you get the idea.



cheers

Gentlemen,

Thanks very much for all of your thoughts and input. There are some great ideas in this thread. I am starting to get things together and will soon post updates with pics. I have decided to go with removing the alternator completely for this event and have installed a new deep cycle battery. Obviously, I now want to lower every electrical load I can. I started with [temporarily of course] disconnecting the choke thermostat and fuel cut solenoid. I adjusted the choke wide open and removed the pintle from the fuel cut solenoid [so it will still idle].

I am fitting a shorter belt that I will "jump" onto my single row crank pulley and water pump.

I also bought two large sheets of choroplast [sign making material] that I will use to fabricate a smooth belly pan out of. Both side mirrors are deleted [again temporarily] as well as both wiper arms. The plexi glass headlamp covers will go back on as well as the 1/2 grill block and front chin spoiler from last year.

Lots of work and testing to do before the event on August 23rd. I will reinstall my wide band setup and try to tune it a bit leaner than the 14.7 to 15.0 to 1 A/F ratios that I ran last time out.

I will again be running 100 octane low lead aviation gasoline for the event [and throughout testing of course]. It has the advantage of having no ethanol added and is required to be "certified pure" for aviation use. I simply need it for the octane due to the higher compression, advanced ignition lead, hot thermostat, and hot air intake.

Mike