TIGON Diesel Hybrid

[GreenHornet]

Hey guys,

I wanted to post this link to the Urba Centurion so you can see a nearly completed one on the road via youtube links on the site = Urba Centurion 128 mpg Diesel Powered Car.

This vehicle was one of my inspirations for the Tigon build as noted in an earlier post. There is estimated to be only 3 of these in the world. This is to bad really because this vehicle would be a pretty straight forward build and inexpensive if you were just sticking to a straight diesel and no added hybrid components like in the Tigon. The parts for a spitfire and GT6 are relatively inexpensive when compared to more modern vehicles. The parts are still made so very easy to get a hold of and they also offer many performance part upgrades for weight reduction.

The Tigon shares the same chassis as the Urba Centurion. Many of the parts on the Spitfires are interchangeable with the GT6. The main difference with the GT6 is the larger brakes and shocks to handle the straight 6 engine in the GT6 cars. This was one of my reasons for getting the GT6 vs the Spitfire. I liked the idea of larger brakes and front shocks with the GT6. This will help with the added weight up front for the hybrid components.

With 3 wheeled reverse trikes you want to shoot for roughly 70/30 or 75/25 front to rear weight distribution if you can. This helps the trike with stability in hard driving situations and lessens the chance for rollover.

[GreenHornet]

Some initial pics of the GT6 getting it home and tearing into it. The GT6 and Spitfires are notorious for turning into rust buckets especially in the floor pan. This GT6 was no different. I picked it up from a guy who had it outside for some time. I payed $500 for it. So far I have sold off $300.00 dollars worth of parts so I have recouped some of my initial investment.

The chassis was the main thing I was looking for. Surprisingly it was not in that bad of shape compared to how the rest of the body looked luckily for me. The GT6 cars are pretty rare much harder to come by than the Spitfires. So when I found one close to home I felt I needed to jump on it. So far it has worked out really well. Even if I do not sale off anymore parts I am only into the Chassis $485.00.

Today I spent much time getting the media out of the frame and coating it with rust proof primer. It is now sporting a bright yellow chassis with nice green shock towers. Pics of the rust proofed chassis I will have tomorrow.

Let the project begin!

GrenHornet

[GreenHornet]

Back from the sand blasters. I thought they did a pretty good job overall with the chassis it cleaned up real nice actually. Well worth the $200.00 blasting cost. They were done the same day in fact so that saved me in trailer rental fees which for 1 day came out to $29.95. This also saved me a great deal of time and headache trying to do the blasting myself. I also paid my friend $25.00 for his time helping me out for a grand total of $254.95 for the day. I bought $30.00 worth of primer yesterday and was able to coat the entire chassis and shock towers with it.

So to recap total costs for the chassis to this point.

#1. Chassis $500-$300 = $200.00
#2. Blasting = $254.95
#3. Primer = $30.00

Total so far minus paint = $484.95

[GreenHornet]

Here are some pics of the rust proofed chassis. I kept the main chassis yellow partly because I like the color and mainly because I will easily be able to spot grease, oil, and grime later on vs having a black chassis.

So what does this chassis weigh?

I estimate it to be somewhere around 150lbs at max. It would not surprise me if it weighed less than that. I can pick it up and man handle it fairly easy.

[GreenHornet]

So whats up next?

Now that there is a solid primer on the chassis and shock towers I will let it dry up and then give it another light coat. Once that is complete it will be ready for paint when the time comes.

It would have been best if I would have cut off all unnecessary steel from the chassis before the blasting, but I was a little undecided as to how much I will actually need during the rear swingarm attachment stage. So I just left everything in tact and will start to work on the rear swingarm attachment point design.

The rear swingarm will be bolted to the chassis at its pivot points and by the shock tower perch. There really is not much welding or fabrication that will be needed. A few hours of welding if that will be required to get the chassis rolling.

What needs to happen before welding the rear swingarm can start?

Front suspension, brakes, and steering, need to be installed so that I can attach the front wheels and tires. This will allow me to determine the ride height and get the proper angle for the rear shock tower perch and pivot points.

So its time to go shopping

[GreenHornet]

I thought I would take a sec to talk about the rear swingarm selection. I decided to go with a Honda Goldwing GL1800 swingarm for the project. While this is most definitely not the lightest swingarm money could buy it is however very reliable and virtually maintenance free. The swingarm is single sided for easy wheel/tire removal and is a shaft drive style swingarm.

What I liked about this swingarm is that its extremely easy to find them on ebay and around other sites. Many Goldwing riders convert there motorcycles to trikes and then sale off these swingarms at big discounts.

I purchased the entire rear swingarm setup minus a few misc bolts for $195.00 this includes the wheel,tire,monoshock, and complete rear swingarm and differential/driveshaft.

The weight of all these parts combined are 98lbs. So not to bad there but could be reduced big time had I went with a belt drive swingarm setup. The reason why I didn't was that I liked the idea of a little extra weight on that rear wheel for traction. Also a shaft drive is much more quit than a chain drive as well as more reliable with less overall maintenance. I also liked the fact that I can fit the low rolling resistance car tires on the Goldwing wheel to match the front tire diameter. Another nice feature of the Goldwing is its electronically adjustable monoshock.

All in all I think the Goldwing Aluminum swingarm is a nice compliment to the GT6 chassis and should make for a pretty solid 3 wheel platform that is light and stiff.

I included A few pics of the Goldwing components a few of which you can see on 3 wheeled reverse trike builds. I also included a quick mockup of a diesel motor mid engined and the rear swingarm. The diesel engine is close in size to the one that will be utilized in the Tigon build which was nice to get a visual idea of space requirements.

[GreenHornet]

This past weekend I took a little time to inspect the original front suspension components from the GT6 donor vehicle. Many of the components can be reconditioned and utilized. While there are performance upgrades for many of the components I don't see going custom on all of them as a big advantage.

Here is a list of some of the parts I will be upgrading on the front end:

#1. Shocks = The OEM shocks got the job done but they were not adjustable in anyway. The new shocks I will be going with are both ride and height adjustable. The shocks cost for the pair around $250.00 USD

#2. Springs = The new ones are stiffer and 1" lower than the OEM springs. The cost point is not that much difference between the two. The stiffer springs will help with the added weight in the front of the vehicle. They will also help with the aerodynamic profile of the vehicle being an inch lower. The cost of these are around $78.00 USD for the pair.

#3. Brakes = The OEM are heavy and non ventilated brakes with dual piston calipers. The new ones will be vented discs and 4 piston calipers. The discs are a little bigger than the original but lighter. The calipers are over half the weight of the original calipers. This brake kit also offers alloy caliper brackets that are also half the weight of the originals. The cost of this big brake kit is around $600.00 USD. Although I think the original brakes on the vehicle would be more than adequate for getting the job done I would still have to replace all of it and the price point is less than double. Not to mention the weight savings is pretty substantial. THe OEM calipers alone weigh in at 9.92lbs while the new 4 pistons will weigh 3.96lbs. I am a firm believer in quality brakes and think this upgrade is worth every penny.

#4. Hub and stub axle = Upgrading these components are essential if you are thinking about going with a larger wheel and tire. Since this is the plan for the Tigon this will be a welcomed upgrade. The new hub and stub axle are made out of Alloy so much lighter than the original and the bearings are uprated as well for increased life. The other part about this that I like is the fact you can specify a new pcd. This opens up the possibility for a much larger wheel selection than what is currently available on the GT6 cars. So with this upgrade you have decreased weight, added strength, and have a much larger selection of wheel options than you would otherwise have staying with the stock hubs. The cost of this upgrade is not cheap at $437.00 USD roughly but gives you quite a bit of advantages that makes it a worth while upgrade.

#5. Wheels = By going with the Alloy hub mentioned above this allows us to modify our PCD to a new modern wheel bolt pattern. The plan is to go with a 4 X 100 PCD which opens the door for many import wheels found on many common cars in North America. The OEM steel wheel that was on the GT6 was a 13 X 5.5 and weighed in at 18lbs. The new wheel selected for the Tigon is the Enkei RPF1 15 X 7 35mm inset at 9.85lbs. The cost of these wheels can be found for under $200.00 new. With this upgrade alone we are saving some major unsprung weight in the vehicle just under half in fact.

#6. Tires = If we compare the original tires on the factory GT6 to new modern tires of today it would be like comparing apples to oranges. Really not a fair comparison in the least. The plan thus far is to go with a Low rolling resistance tire most likely the Bridgestone Ecopias EP422. For the front wheels we will go with the 195/65/R15 at 19lbs and an overall diameter of 25" For the rear Goldwing rear wheel we will be going with Ecopia 195/55R16 at 19lbs and an 25" overall diameter as well. These tires can be had for under $120.00 USD.

#7. Alloy Steering rack mount = Manufacturer states "Rigid mountings mean that all steering inputs at the wheel are transferred directly to the steering rack - no effort is wasted compressing soft bushes. Fitting these mounts will result in sharper steering and provide better feedback through the steering wheel - they will also never wear out!" For the cost of $29.45 USD this is not a bad upgrade especially as it eliminates maintenance while improving performance.

There are a few other upgrades I am considering but will wait until I have the vehicle complete and tested out before I change things up. I think the upgrades I have listed above for the cost will be more than adequate to bring the vehicle up to a modern performance level while not breaking the bank. Now you can get an idea of the costs associated getting the Tigon to a rolling chassis level. At this point its fair to say to get Tigon rolling its around $3,200 USD estimate. This is a pretty fair estimate as I currently have $500.00 into the chassis and $200.00 into the rear swingarm. This leaves me around $400.00 to get the swingarm mounted to the GT6 chassis and for all the other small low cost parts.

This project is not a dirt cheap project by any means but should still be far less expensive than any hybrid sold currently around the world not to mention will have far superior fuel economy and range! My original budget goal for the completed project was under $14,000.00 USD. So we will see if we can get there! I think at this point I am giving myself a fighting chance despite all the added upgrades.

Well its time to get back to the grind,

GreenHornet

[GreenHornet]

Today I started working on the top view of the Tigon. Still much work to be done on it but you can get an idea of the general aerodynamic shape I am going for here. The body design if you are wondering is a heavily modified Fiat Turbina. There are some improvements I have made to the body design as you will start to see as the sketches become more refined.

So where did I get this idea anyways?

I purchased the Urba Centurion plans many years ago which gave me the original idea of creating my own body shell and utilizing a donor chassis. The plans also pointed me into the diesel direction as the energy source. Although the Urba Centurion is a solid design that achieves over 100mpg, I thought it could be made much better performance wise and improved upon aerodynamically.

The original only had a 17hp 3 cylinder diesel in it for propulsion which gave it a horsepower to weight ratio of 1200lbs/17hp = 70.5 ratio. I think this was fine for the time but for today's standards I think you could use a lot more on the low and top end. For a quick comparison the Geo Metro XFi had a Horsepower to weight ratio of 1,621lbs/49hp = 33 with 58 torque @ 3,300rpm. So its safe to say the Urba Centurion could use a little help in the acceleration department. The Urba Centurion topped out at 65mph which to me is to slow for our modern freeways. The plans do not state the 0-60 time but I estimate it to be very slow to say the least! The Geo Metro again for comparison sake can theoretically hit 100mph and many individuals have stated getting it up to 88 to 90mph.

The Urba Centurion was not meant to be a speed demon by any means and I am not trying to build the Tigon as such either, however I feel as though the Tigon needs to have better acceleration than the Urba Centurion and better acceleration than the Geo Metro. In order to achieve this I new I would have to do a major update to the general plans of the Urba Centurion. So that is exactly what I am doing. When I decided to move forward with the plan I came across another plan set of a person who turned an Opel GT into a diesel hybrid. This sparked my interest into hybrids and I have been researching them ever since.

For many years I was dead set on an all electric Tigon, but my practical wife stepped in and thought for the first prototype it would be good to go the hybrid route. This way it has the opportunity to appeal to more people and I tend to agree. I have always loved the idea of driving on electric helping to decrease my carbon footprint but also driving on biodiesel or recycled petroleum products. So why not build the Tigon to do both? I could not come up with enough reasons not to so the Tigon Hybrid was born and will in fact be the first prototype.

After reading and studying the Urba Centurion and other plans I felt as though it was time to create an updated modern plans booklet. You can absolutely learn a lot from the Urba Centurion and other plan sets, but I felt the plans had potential for expansion into theory and component selection. These are 2 areas of the Tigon plans I will definitely expand on.

In order to achieve my performance goals and range I new that I would have to go diesel with electric. I almost went all diesel with a VW 1.4L 3 cylinder TDI but I liked the idea of using electric in town to much and felt the combination of the two would be overkill. Then I stumbled onto the Smart for two CDI .8L turbo diesel. Now I thought this would just about be perfect but quickly realized that if I was going to be making a plan set for this vehicle it would need to be practical for people here in the US to get the parts for it. So both of those engines would not work as they are both illegal in the US currently.

So I settled on a 2 cylinder .79L 19hp V twin diesel that is both cost effective and legal here in the states. It holds an EPA Tier 4 rating and I have no problem importing the engine through customs. The company I am getting the engine from also has a 10kw genset based on this engine that is EPA certified as well so perfect for the series hybrid design option. This diesel is more efficient than the original Urba Centurion Diesel and more powerful. This component selection really sets the stage for the rest of the vehicle. The weight of the engine is only 126lbs compared to 181lbs of the Urba Centurion. So not only is it more powerful and efficient it also weighs 55lbs less.

The electric component of the hybrid drivetrain will use a brushless design. Not completely set on whether to go PMAC or BLDC. I thought I had it all figured out until the company I was going to get the PMAC motors from has backed out for whatever reasons. So I may have to go the BLDC route which I have all ready contacted numerous suppliers and have some solid options lined up at affordable pricing.

The Urba Centurion had a curb weight of 1,200lbs. I felt I could easily knock off 200lbs or more to the design with modern materials, 3 wheeled platform, and better component selection. So far I am sitting at 611lbs diesel only and 706lbs with hybrid components. So it looks promising at this point I can definitely knock off 200lbs to the Urba Centurion design. The vast majority of the components have gone into the weight calculation thus far. There really is only small minor parts that have not been accounted for. So I feel pretty good so far with my design weight.

The lower weight gives me some options I would not have if the vehicle was 1,200lbs. First I can go with a smaller electric motor and battery bank. This opens the door for a 20kw peak motor to be used for traction purposes. You would find this size on motorcycles and smaller electric vehicle builds. Do to the low weight and enhanced aerodynamics of the Tigon this small of a traction motor is very possible. This further cuts weight and costs. The voltage range I will be utilizing will most likely be 120V. A brushless water cooled 20kw DC motor I have been looking at weighs 35lbs and has more torque than the Geo metro engine by a longshot. The motor will put out over 55hp peak. So very light, compact and powerful electric motor. looking at the numbers if we can in fact get down to 1,000lbs curb weight and we can safely put out 55hp peak we have a hp to weight ratio of 18. This is far better than the Geo metro or Urba Centurion not to mention we have instant torque available at 0 rpm perfect for in town use or getting onto the freeways.

The body design was taken from the Fiat Turbina one of the most aerodynamic cars of all time. It just so happened that the Turbina had very similar size specs as the GT6 I used for the donor chassis. So I have been studying the Turbina as well as general vehicle aerodynamics and incorporating what I learn into the Tigon body design. At this point I think I have a pretty solid body design being sketched up definitely needs to be refined but has a good profile and modern look going. The Tigon definitely does not have your normal 3 wheeled trike feel to it. In fact it looks more car like than trike and this was part of my goal. I wanted to have a 3 wheeled trike that has an all year round cabin rather than open cockpit like most of the 3 wheeled designs you see. This creates more versatility I believe and is more practical for the majority of people to use as a commuter vehicle including myself.

Tigon will definitely not be the answer to all of our fuel problems, but it will provide a good option to help reduce them responsibly. I hope as this build thread continues you all will find it interesting and helpful.

GreenHornet

[NeilBlanchard]

Here's the Fiat Turbina:



The 0.14 Cd is great, but the Panhard LM64 was 0.13 in 1964, 10 years after the Turbina. There are some amazing MG's from around then, as well.

I'm confused - is this going to be a 3 wheeled vehicle?

[GreenHornet]

Hey Neil,

The Panhard LM64 is pretty awesome thanks for sharing it! It is hard to believe that car could go 155mph with only a 2 cylinder engine. Just goes to show how much aerodynamics can have on a vehicle. I wonder what the curb weight was of that vehicle?

The Tigon is going to utilize a 3 wheeled reverse trike platform. So unlike the Urba Centurion which utilizes only the Triumph Spitfire chassis the Tigon will incorporate the Honda Goldwing rear swingarm into the GT6 chassis to make it a reverse trike and quite unique. Despite it being a 3 wheeled vehicle I am trying to go with a more 4 wheeled aerodynamic profile.

I hope this cleared up any confusion take care,

GreenHornet