Project 100 (custom enclosed Honda C90 targets 100 mph vmax and 100 km/L FE)

[Frank Lee]

Ha Ha "Quieter"!

I don't have weave at 85-90mph- hurray for excess weight!

[visionary]

Update 018

So I’ve just completed the basic prep list before my next test run, and I had a quick spin around the block on the machine to ensure I didn’t waste time and money on a venue hire fee, and hit problems.
Its been almost a year since I last drove it and today’s drive was like a fresh experience. So some aspects of the vehicle were quite a surprise – notably the weight and its effect on ground handling.
By “ground handling” I mean the time when the vehicle is not being moved under its own power. From the seated position, keeping the vehicle upright is no problem but it needs a parking brake since the force vector from the supporting leg tends to push the machine backwards.

The vehicle feels much heavier than I remember and it is extremely awkward to manhandle without a helper. This would be remedied by fitting a easily deployable stand and some handles or body features that enable easy holding, the smooth bodywork gives you nothing to work with.

Anyway, since I’ve been adding weight with everything that I’ve made, I thought it wise to check what it is now. So here’s a photo of the vehicle on cornerweight scales.



The results are –
Total weight (empty vehicle) : 205kg Front wheel : 85 Rear wheel :120
Total weight (me seated inside):274kg Front wheel :112 Rear wheel: 162

So it’s put on some weight and needs a diet. I’ve been making things in steel, for speed and simplicity and I knew things were heavier than ideal but it was still a shock to be over my target at this stage.

[renault_megane_dci]

Ouch !

[godscountry]

Originally Posted by visionary

Update 018

So I’ve just completed the basic prep list before my next test run, and I had a quick spin around the block on the machine to ensure I didn’t waste time and money on a venue hire fee, and hit problems.
Its been almost a year since I last drove it and today’s drive was like a fresh experience. So some aspects of the vehicle were quite a surprise – notably the weight and its effect on ground handling.
By “ground handling” I mean the time when the vehicle is not being moved under its own power. From the seated position, keeping the vehicle upright is no problem but it needs a parking brake since the force vector from the supporting leg tends to push the machine backwards.

The vehicle feels much heavier than I remember and it is extremely awkward to manhandle without a helper. This would be remedied by fitting a easily deployable stand and some handles or body features that enable easy holding, the smooth bodywork gives you nothing to work with.

Anyway, since I’ve been adding weight with everything that I’ve made, I thought it wise to check what it is now. So here’s a photo of the vehicle on cornerweight scales.



The results are –
Total weight (empty vehicle) : 205kg Front wheel : 85 Rear wheel :120
Total weight (me seated inside):274kg Front wheel :112 Rear wheel: 162

So it’s put on some weight and needs a diet. I’ve been making things in steel, for speed and simplicity and I knew things were heavier than ideal but it was still a shock to be over my target at this stage.

not that you want to build another vehicle but,if your happy with the ride and general handling,duplicate it in small diameter chrome moly or aluminum tube or square stock,using a spool welder with the mig to weld it.I remember reading about the 214 mpg Honda and that the body added 88 pounds,but had little affect on the overall mpg.But I can see in your case,the performance with that kind of extra weight might not be up to your needs ,for all around driveability .

[visionary]

Reply to Godscountry

The weight is higher than I had hoped for, but there are a multitude of reasons. The frame is built from 20x20mm box section mild steel because it approximates the flat-plane design and the section width that a production based composite monocoque would be made from. My initial material order was for 1.5mm wall thickness, but in a later order I allowed 3.0mm to be delivered. This was an error with two consequences, firstly the lighter material was used in the structural construction thus making it less than ideal. Secondly, the heavier material was used to make the less demanding upper sections with a weight penalty and no strength benefit.
However, I still feel that this is only responsible for about 30% of the over target weight. Most is due to the complexity of the design and equipment that I have chosen, and maybe I should just accept that I was too optimistic from the start. Either way, I have now started to focus on the mass of components and have taken steps to reduce weight where it can be easily achieved.

I’ve added a photo of the side braces now that I have taken a plasma cutter to them, its removed a significant amount of weight but I cannot do anything about the box section weight without re-making them from scratch.




As for driving, the extra weight will undoubtedly hurt acceleration but that’s not a major concern. The main purpose of this vehicle is to prove the point about the possibility of doing 100km on 1litre of fuel at 100kmh average speed, from 100cc displacement, outside of that goal I’m not much concerned with poor acceleration. The critical factor in this test will be aerodynamic performance and that’s where I will concentrate my efforts.

I’m already working on a 250cc single cylinder engine version, which will make for a much more usable daily driver. The extra mass will impact much less on an engine with 30hp and a six speed transmission, making it a much more enjoyable vehicle to drive, still not quick but OK, I hope.

[renault_megane_dci]

The only Japanese powerplant that I know of that fits your bill is the Honda NX 250.
It is only 27 hp though.

Actually that was my point : 4 stroke wise, anything over 100 hp per liter is starting to be not too efficient, not to mention reliability.

How about quads powerplant ?
Some of them do have a reverse.

We have been discussing de-tuning DOHC engines by Atkinson timing their inlet.
Might be a good way to use some bigger capacity engines.

[CFECO]

I would vote for a WR 250 Yamaha engine, electric start, supposed to be very reliable, with high compression. It could be detuned some with different grind on the cams, but if running a Carb, leaving the Intake open late does not seem like a good idea, as you'd be pushing air-fuel mix back out of the carb. With enough computers the Prius can do it by adjusting the fuel injection.

[renault_megane_dci]

The more the power out of an engine, the more it is tuned for high rpm and that often means compromising reliability.
There are some 4 stroke on which you need to replace the piston every 12 hours (RMZ 250)

The implications of dephasing the inlet have been discussed in "Atkinsoning motorbike engine" and yes, it requires FI.

Might be more cost effective and fuel efficient than detuning an engine ...

[CFECO]

By "detuning", I was thinking grinding the cams so there is less overlap, so less AF mix out the exhaust, while keeping the high compression a key to Efficiency. I do not know the specs of the cams stock, but this is the "Enduro" version of the Higher performance Motocross engine in the YZ250F.

[XprizeRoadTrip]

Originally Posted by visionary

Update 018

So I’ve just completed the basic prep list before my next test run, and I had a quick spin around the block on the machine to ensure I didn’t waste time and money on a venue hire fee, and hit problems.
Its been almost a year since I last drove it and today’s drive was like a fresh experience. So some aspects of the vehicle were quite a surprise – notably the weight and its effect on ground handling.
By “ground handling” I mean the time when the vehicle is not being moved under its own power. From the seated position, keeping the vehicle upright is no problem but it needs a parking brake since the force vector from the supporting leg tends to push the machine backwards.

The vehicle feels much heavier than I remember and it is extremely awkward to manhandle without a helper. This would be remedied by fitting a easily deployable stand and some handles or body features that enable easy holding, the smooth bodywork gives you nothing to work with.

Anyway, since I’ve been adding weight with everything that I’ve made, I thought it wise to check what it is now. So here’s a photo of the vehicle on cornerweight scales.



The results are –
Total weight (empty vehicle) : 205kg Front wheel : 85 Rear wheel :120
Total weight (me seated inside):274kg Front wheel :112 Rear wheel: 162

So it’s put on some weight and needs a diet. I’ve been making things in steel, for speed and simplicity and I knew things were heavier than ideal but it was still a shock to be over my target at this stage.

It's good to see people like Visionary actually doing this, building from scratch and learning the design challenges involved in the delicate balance between weight, strength, performance, efficiency and safety. When I saw Edison2's Xprize car, it was a powerful example of designing for that balance on the front end as much as possible and minimizing compromises from there out. As Ron Mathis said,

There are only two absolute virtues for an efficient car: the first is light weight and the second is low aerodynamic drag…everything else is a desperate compromise.

Edison2 has taken heat from Ecomodders because their vehicle isn't available yet as a kit or production model. But in terms of learning how to this from scratch, they're a great example of how dedication to physics and best practices creates desirable results. In my opinion, I believe the Very Light Car will be come a kit car in one form or another sooner vs. later. Ron Mathis drew the vehicle such it could be easily mass produced or assembled as a kit, and I've spoken with him a number of times. Few may know this, but he really believes in the VLC as a kit for several reasons; it makes too much sense not to do it.

FYI for those who haven't seen, here's where the Xprize Very Light Car ended up for specs, from this page: Edison2 - X Prize VLC

Dimensions & Weight

Overall Length 167"
Overall Width 79"
Height 53"
Wheelbase 100"
Front Track 70"
Rear Track 70"
Curb Weight 830 lbs
Engine Placement Rear Engine
Luggage Capacity Up to 22 cu-ft
Standard Seating 4 Passengers

Engine

Type 1 Cylinder, DOHC, Turbocharged
Displacement 250 cc
Max Power 40 hp
Max Torque 29 ft-lbs
Fuel E-85
Control Strategy Extensive Exhaust Gas Recirculation

Drivetrain

Type Rear-Wheel with Differential
Transmission Manual Sequential, Auto Clutch Option
Number of Gears 6 + Reverse
Features Full Neutral Disconnect
Hybrid Option Electric Drive / Power Take Off Capable

Chassis & Suspension

Chassis Steel Tube Frame w/ stressed skin
Steering Rack and Pinion
Turning Radius 18'
Front Suspension Type Edison2 Proprietary Design
Rear Suspension Type Trailing-Arm with New Force Mgmt
Front/Rear Shocks Adjustable Gas-Pressurized
Front/Rear Springs Coil
Brakes 4-Wheel Water Jet Cut Disc
Anti-lock Brakes Capable
Stability Control Capable
Fuel Capacity 6.5 Gallons

Performance

Fuel Mileage 129 MPGe (highway) 110 (combined) in on-track testing at the X Prize
0-60 mph 14.2 seconds
Top Speed > 100 mph
Range > 600 miles

Interior

Heat Heating System with Defrost Function
Air Conditioning Conductive Cooling
Windshield Wiper 3 Speed with Intermittent Function
Audio System Ipod Dock Sound System