open planning new car
 

So as I'm past halfway on each of the 2 projects I'm currently working on, and can't work on at night right now, I've been planning a single-seater or inline-2-seater, custom fabricated frame, mid-rear engine, quasi-open-wheel (4-wheel) based on salvage yard used drivetrain and other major components.
Since it's generating some interest in another thread, I thought I'd open it up for everyone here in its own thread.
I know, this thread needs visuals.
Excerpting from that thread; "problem; side by side seating, rather than inline. That triples the total drag all by itself. Now I really want to get going on my own single seater or inline 2-seater, with either a 4G63T Mitsubishi engine or a turbo propane 22R Toyota engine in front of a V6 Passat transaxle."
" I've been trying designs in SketchUp Make, it is free downloadable 3d modeling. The Locost forum has great info for what metal is adequate, likewise plans for DIY CJ5 Jeep frames. I've done adapter plates before, getting either engine to that transaxle is doable. But enough about mine.
My reference to triple drag is not an exact scientific ratio, but is really obvious if you compare even something like the '83 RX-7 I'm building against something more like this: http://img546.imageshack.us/img546/3451/1326657812.jpg"
"I'm thinking most of my side-impact protection will come from nimble crash-avoidance, and secondarily from the overkill frame design I'm leaning toward, which has 2" x 2" mild steel square tubing of 1/4-thick wall thickness, along the occupant shoulders, on past the fuel cell, which would be between the occupants and the engine. The overkill steel would also go around the occupant compartment in other ways / areas, especially in front of the feet and something tubular curved overhead to meet the plexi canopy, if I can find a plexi canopy. Anyway, gasoline or propane will determine the firewall between fuel and human. I considered fuel in the lower frame, but then decided that's better for coolant hoses, brake lines, and possibly p/s if it proves necessary. These might all be braided stainless.
Still working on the fore-aft relationship between the driver's feet, the front suspension, and the radiator.
The bodywork is likely to be fiberglass formed over a hand-shaped wooden buck shaped by myself.
I need 60+ MPG HWY, I need it to spike at least 75 MPG at least twice, and it needs to be fun to drive anywhere, anytime, for under $10,000."
"Aircraft canopy construction
led me to:
Todds Canopies - Home
Their iceboat canopy is about what I was thinking if single-seat.
In fact, the whole back half of that looks good to me."

Also, not the entire frame will be such overkill steel, only the part around the occupant(s), and possibly some of the structure for bumpers required under state motor vehicle inspection laws.
I'll try to post sketches tomorrow.

Care to explain why you have chosen to limit engine choices to 1 of those 2 listed above? If you are making it all from scratch and plan to use as little steel and as much fiberglass, you could probably make a lean-burn 1.5 Honda fit and still be fun to drive. Or even a mid-sized motorcycle engine 750-900cc could work. It doesn't have to be stupid fast to be fun, especially if you plan on doing more turning than going straight when flipping the "fun switch".

How much would this thing weigh? Anything less than 15lbs per hp is fun, imo. Closer to 12:1 gets crazy fun. More than that and you'll just get yourself in trouble.

At 1500 lbs you only need 100hp to be fun. A honda 1.7 liter puts out around 125hp iirc, that allows for 1800 lbs.

Im guessing this thing is going to be around 1000 lbs. A modern 4cyl would make it insanely fast.

Can't find a subscribe button.

You just subscribed by posting :)

Honda: While I must admit the VTEC feature is as reliable as the sun itself, and their newer heads really don't need much porting, my own past includes UAW training, ASE pre-certs, plenty of automotive engine machining experience, including building, testing, and living with what I've machined and built to my own specs.
Honda is the one brand I shun above all others, least worthy of respect. Yes, I've driven several, none of them "lemons".
I've been into cars since I was a kid, it's my only hobby, and it is my obsession. May even be a major contributing factor to why I'm nearly 39 and never married. Plus I am a tested and proven genius, with an IQ over 140.
Granted, some designs just get MPG better than others, but I will not waste a single second putting economy over fun. And there's nothing fun about any engine that isn't cheap to improve the output of, and cheap to get. Much easier to get the MPG up, even with an engine that isn't among the best of it's type.
Huge power is fun, but along he way I've discovered for myself how lower power can also bring smiles, which is why I'm willing to consider the 'yota. It's the cheapest way to run adequate power on cheap fuel, and it is reliable. Parts can be had anywhere, anytime. It's the 350 Chevy of propane 4s. The 4G63T is common, has huge aftermarket support for more power, is a good design, and can make far more power on pump gas than such an application can realistically use.
I understand a max-effort GM Ecotec 4 can make 1200 HP, but I'm neither wealthy, by choice, nor crazy. In my youth I chased the dollar, successfully, and now I'm much happier.
Weight: I have no clue, nor do I much care. I'm not planning on narrow tires for daily fun, only for long trips and MPG tests. The rest of the time I'm thinking 315-width DOT-approved drag radials on the rear, and 315-width DOT autocross tires on the front.
Those are affordable, as are the 17" x 11" wheels.
The rear suspension is likely to be based on an '88 Pontiac Fiero, while the front suspension is likely to be based on the Ford Mustang 2 IFS that all the "street rod" community has so embraced.
Lastly for right now, I didn't have the opportunity to work on any visuals, sorry.

Update: I e-mailed Todd's Canopies for a quote, and I'm happy with his response: $ 425. He asked if I really want it that narrow, but I'm not sure if it is 15" or 20" as the width. Anyway, here's the reply I sent:
"Hello, Mr. Silver,
I was hoping the cost to be closer to the $500 price range than $5000, so I am now including your canopy in my plans. I really wondered if 20" was the width and 15" the height, or vice versa.
I'm thinking I'll need to get a canopy before finalizing the frame / chassis design, let alone any bodywork.
The single-seater idea is the minimum possible drag on the minimum possible frontal area, with a very reclined driving posture. No worries about claustrophobia, only clearing a safety helmet for an autocross. If I do inline 2-seater, then I may go for an untrimmed 76" with seating slightly more upright."

Oh, and much sincere thanks to everyone participating in this thread! It really does help.

http://ecomodder.com/forum/attachmen...1&d=1425748593

Ha! :)

Why? The ones that I've had have been solid cars, and the CRX was also quite fun!

-soD

After I logged out to start work, it occurred to me that I'd soon have everyone chiming in about the aftermarket support for Honda. I'm not saying any of you can't like Honda, I'm saying you'll never find me spending a single penny on anything by or for Honda, nor using any free Honda anything.
Nothing Honda can be built to 1200 HP, and while a 6.0L GM 400 RWHP LS2 V8 can do 35 MPG without deactivating cylinders, a Honda I4 can neither do a 70 MPG 200 FWHP 3.0L V6, nor a 70 MPG 200 FWHP I4, nor a 105 MPG 133 FWHP 2.0L I4 nor I3, thus no Honda is as efficient as the GM LS2, nor can be. Plus the GM was in one of those really low emissions classes despite the displacement and HP.
Admittedly IDK how my 2 current choices stack up, but getting the 4G63T to 70 MPG in this application with 400 RWHP and emissions-legal is no challenge, it just takes the right turbo, the right cat, the right gearing, and the right tune. The 'yota isn't even getting evaluated along these lines because I included it for the propane aspect.
That's why these 2 but NO Hondas for me.

2"x2"x1/4" is way overkill. You're building a lightweight car not a truck! No more than 1''x14g tube is going to be needed and probably less than that.

Space frames are relatively easy to analyse for strength. I suggest looking at Costin and Phipps book for a worked example. The book is old but the principles haven't changed.

Pure strength is not enough for safety (if that is the aim). You need crush space to provide the distance needed to reduce an impact acceleration. The frame just has to react that acceleration.

Rather than mess with adaptor plates a single engine and transaxle would be easier. The Audi 1.8T and Subaru EJ20T are readily available and have good aftermarket support.

Why build a chassis at all? If you can live with a single seat an older formula racer might provide the basis for a road car. I know there was a guy in Japan who registered an F3000 chassis for road use there. I'm sure that it has been done many times. Ford (Europe) has even done it:

https://www.youtube.com/watch?v=tmZMwk14r4c

With at least lip service to fuel efficiency, that one is a bit of us ecomodders I think; 1 liter displacement plus boost, light weight (485kg).

I know, right? Here ya go:

http://ecomodder.com/forum/member-fr...11-5-38-12.png

This is Thee Holy Template, rendered as a open-wheel 4-wheeled car with minimal drag. I also have a design with enclosed wheels that could be scaled down:

http://ecomodder.com/forum/member-fr...-w-caption.jpg

What is the tire size again?

Update:
"I always state the dimensions length, width and height.

I've sat in airplanes with narrow canopies. Going from 20 to 22 inches wide makes a lot of difference to me, but I'll make whatever width you want.

Thanks, Todd"

You can do yours however you feel safe. Me, I see that new mass produced cars are designed to have a rigid occupant enclosure with crush zones before and aft. But the bumpers themselves mustn't crush. (State law for DIY vehicles.) So I can do likewise. Besides, the thinner the steel, the more difficult to weld.



Which is why I already stated that the overkill steel isn't for the entire chassis.

When did I ever care about easy? Easy doesn't show off my abilities to get my next career going. There are already enough experts specializing in turbo 4s of every make.

Again, this is showing what is possible for cheap, and making it safe. Enough that I'd be comfortable letting anyone drive it anywhere, anytime.

Build yours however you want.

Why the fourth tire behind the third?

Also, I don't understand this increasing the frontal area to get a big round bubble. I don't see much of this at the B'ville salt flats.

I'm trying to find a set of narrow 17" wheels I like, for when the 315/35R17s are inappropriate. To use the 17x11" wheels I need to end up with a 5 on 120.65 mm lug pattern, which is possible by adapting the front hubs from a 4X4 S-10 mini-pickup, which has been done before, but without good plans for copying. Getting the M2 hubs with that pattern is easy. But narrow 17" wheels with that pattern are not turning up in that pattern. Nor 18". Nor 19".
I could plug weld the hubs, drill and tap them for dual lug patterns, then use lug bolts instead of lug studs with lug nuts. This used to be common on trailers and on early Mazda RX-7s.
I'm insisting on 17" or larger so I can fit some impressively overkill-large brakes. Costs the same as puny brakes, so may as well ensure they never fade from boiling the fluid.
I think many of you are economy to the exclusion of performance, I've always been performance to the exclusion of economy, but as I near turning 39, I'm not as hardcore as when I was 18.
I've started some sketches, I'll post them in the next few days.
Please keep the ideas, comments, and questions coming.

The fourth wheel is so it could run as a Lakester instead of a motorcycle at Bonneville, similar to the Poteet and Main Speed Demon that runs two in tandem in the front.

Here's an earlier iteration that has a bubble top:
http://ecomodder.com/forum/member-fr...belly-tank.png

It's really quite narrow—the same width, height and length as a P-38 drop tank, just with a lower 'equator'.

Why not go to a 19" wheel? They were used on Ford and Chrysler in the 30s and MG in the 50s (w/ knock-off hubs). I think it was 28-31 Fords that had 4x19". You could fit BMW i3 tires that would be very appropriate for the vehicles weight, and they're 155-55/19 at 26" tall.
http://ecomodder.com/forum/member-fr...ncept-tire.jpg

Coker sells Rolls Royce tires that are much larger if you want to run big 'n littles.

I love good brakes as much as anyone, but I think you're going to have such large brakes with such a light weight vehicle that... well... things could get interesting in a panic brake, not to mention locked brakes are less effective. I think you may have a more effective brake setup using high-performance pads and not the "discount special".

My old car, 2000 Dodge Intrepid, could lock the brakes no problem. that was with 16" wheels, 225 section tires, single piston calipers, 3500lbs.

I understand you may want big wheels, but lets not say that massive brakes are necessary. You wanting them is a good enough reason to have them.

Air brakes. Dynamic winglets on the front axle to provide down-force.

In my own experience, the stock tire is 165R-15. Lot a lot of others, I ran 145-15s on the front; because it rolls [noticeably] easier and steers like a tractor. But what I found out was—downhill in the mountains you run out of tire before you run out out brakes. So I've gone to 165/50-15. It's the same width but has a shorter contact patch. My car is about 2000lb.

I believe the i3 tire is available in two widths, and in all-year and snow-tread. They're 26" tall. They're small but their designed to carry a maybe 3000lb vehicle. ...with good brakes.

I'd like mine on red Ford wire wheels. New ones that don't require occasional tightening, in red. I don't even like red, that's just the 'correct' color.

There's nothing wrong with the concept but take a look at the section and wall thickness of those cars (with safety cages). They're not even close to equivalent to 2"x2"x1/4" and they're not using that material as efficiently as a true space frame. Even more important, the lightest of those cars weigh more than twice what you will be aiming for.

The protective cage needs to react the mass of the car against the crush structure at the acceleration it crushes at in an impact. If the car is half the mass, the cage needs only be half the strength. F=ma in practice.

If you look for it you can find data on survivable rates of deceleration for human bodies. The rates vary with direction (on the body) and duration.

The tricky bit is designing a structure that will crush at the desired rate. Some racecar series have a spec. crush structure, at least for the front of the car. You might like to look for those. (The most accessible is probably FSAE.)

The design I proposed is a geodesic [prolate] sphere, which means maximum rigidity with minimum mass. By varying the member or skin thickness you can tailor the crushability.

And being spherical it would tend to richocet or deflect in any impact.

http://i1316.photobucket.com/albums/...psscuscvjg.jpg

http://i1316.photobucket.com/albums/...psshxslcbc.jpg

http://i1316.photobucket.com/albums/...psraoa5vqw.jpg

What, you guys want a narrowed Locost? I'd like to see it, but I won't build it. Mine needs to be driveable even after a crash, maybe except for a suspension / wheel / tire issue. Still, reuseable basic core.
What I'm needing is cutaway views, or plans, of the fronts of those old race cars that were still open-wheel on narrow tires. I'll post a pic or 2 in a few minutes.

In this first pic, the rear car, #30, that you can just see the front of:
http://i1316.photobucket.com/albums/...psdxrxrhgh.jpg
The front one looks daily useful, but also too bloated, plus with too much above the driver's shoulders.

Though this might be closer to my reality, if it had the grille opening larger:
http://i1316.photobucket.com/albums/...psnzab4dpu.jpg
But the driver seems too upright.

I hope "fair use" covers my posting these. This next one looks like a shape I can make, and this nicely:
http://i1316.photobucket.com/albums/...pskc5e526h.jpg

Here's where I should be in less than a year:
http://i1316.photobucket.com/albums/...psnm9hxvwv.jpg

And this also resembles my thoughts:
http://i1316.photobucket.com/albums/...pskrmzcsnj.jpg
But again looks to have the driver too upright.

Thank you! Excellent info!

They're a hindrance to MPG and to handling, lots of unsprung weight. I had an S-10 loaded, the front rotors were glowing orange at the bottom of the mountain, and those were stock 10.5" x 1" single-piston floating-caliper brakes. Not the stuff of Ferraris, but I didn't lose them.
However, I also rode one of my '78 Camaros ( I've had 3 of the '78s so far )
down a more moderate canyon, and totally lost all the braking power by the time I got to the bottom. Same brakes as the S-10, except 11". And any car can lock any size brakes, once, when they're around 70 defrees F.
I've experienced both ends of the spectrum, but neither of those were capable of use on a fast racetrack, where this single-seater may well see repeated 2g decel from over 190 MPH.
Now that I've found affordable Brembo 4-piston calipers, and discovered how to find matching rotor choices, I see no reason to surrender the peace of mind. That's how it seems to me. Building adapter brackets to mount the Brembos is easy. Brembos aren't the only best brakes, but they're better than anything cheaper.

I am completely in agreement with you about either a single seater or tandem seating vehicle. Frontal area is frontal area and really cannot be finessed like Cd. Obviously this is why high performance aircraft prefer tandem seating.

Do yourself a favor: call it a motorcycle. Much less regulatory hassle. 3 wheelers are almost universally considered motorcycles.

From an aero standpoint the “tadpole” wheel arrangement (2 front, 1 rear) is better as it lets your work to a very narrow wake area.

Here’s an idea I thought would work well with the tadpole arrangement.

Tilting Motor Works - High-performance trike kit for your Harley®

OK, this was developed for a motorcycle which presents an awful frontal area, but if you lengthen out the vehicle and have the driver sit low – behind the front wheels – you greatly reduce frontal area. Now this idea supposes the rider’s weight high above the roll axis and can be leaned with minimal effort. If you lower the riding position you lose all that moment needed to tilt the vehicle. You might need a hydraulic or electrical assist.

As for fairing it in you wind up with something like this.

Decopod Tri-Pod - an art deco aluminum bodied scooter from Randy Grubb

This thing is built on a Piaggio scooter with a narrow tadpole arrangement. Again it is clearly a motorcycle and too tall but again, it can be lowered. Notice he gets pretty good plan view shaping and with a canopy and a little more length to work with you could wind up with a very low-drag shape.

Grubb did not fair in the bottom but there’s no reason you couldn’t. Grubb is an artist, not an aerodynamicist.

Still with just a 150cc scooter engine/drivetrain his vehicle is low enough drag he can go fast enough survive on LA freeways. with a 600-900 cc engine it would be stupid fast.

As for mechanicals I always thought a Honda Gold Wing would be a good start. Very reliable and even has a reverse. Build you passenger compartment in front of the bike and apply a bulkhead to accommodate the tilting front end.

Seating position depends on how tough you are. Reclining is good for racers but after an hour your butt has had it. The bolt upright position common to pickup trucks is very comfortable even with relatively firm springs. I can drive my Ford all day long and still walk afterward. The trade-off is frontal area. Make your own value judgment.

I'll second your statement that the 22R is rock solid. If you don't need high revs it's about as dependable as gravity.

Which is not to say that it sucks.

I'm not too familiar with the hot rod side of the 22R but I know LC Engineering spends an awful lot of time building go-fast 22Rs so it isn't incapable. But if your rig's weight is low, then the 22R's abundant torque for its size down low in the revs will make it a big grin in the twisties.

Sorry, must have missed it where you plan to race it. By all means go for the big brakes!

Check out the classic Indy roadsters thread on the H.A.M.B. Open wheels are a drag, though.
History - Classic Indy roadsters: Most beautiful oval racers ever? | The H.A.M.B.

My thoughts on canopy width, if you plan to get your shoulders in go wider, plus wider more to include wearing a coat when you have to.

Side impact of your skull against the canopy is heightened the narrower it is.

Do you plan on wearing a helmet on the street? More room could help there as well.

All that said, keeping the weight down should help the physics of it all (acceleration, braking, handling), measure in safety and decide on how much or how little you can get by with.

A more upright seating position will help make you be seen, it's best not to get hit in the first place, right?

Those are awesome.

I have not seen that top one before.

What are the legalities of going with a four wheel car? It's more than using an automotive glass windshield, right?

If you get a Jones for something, and sit on it for years, eventually you gotta have it. Even so, reality never fails, so I may have to start with a propane 2 seater I don't love to afford the insane single seater I do love. Plus having not yet found the right lady to be my companion through the rest of my life is affecting this. If I'd found such a person, I might actually prefer a 2 seater.

I haven't thought it through. This was done to fit class racing rules. The motorhome could have the two hexagons facing front as six-sided cones with a twirling windshield wiper like Luigi Colani uses on his trucks.

Well, there goes your tandem seating. Here's a Colani micro-car with side-by-side seating and the spinning 3-blades wiper:
http://ecomodder.com/forum/member-fr...644-images.jpg

I guess the next step is to stop at Lowe's for some 2" x 2" wood for a living room mockup, with the most reclined racing seat I can find, and one of Todd's canopies.
Meanwhile I've been sketching some ideas for altering the front suspension.
And even if I had a lady, I'd still go inline, or she's not the one for me.

I have an option on an early-'90s 1.9L Ford, and I know they were better than average for MPG, plus they're a non-interference design. This may be what gets this build started.
And I found a good source for steel for the frame, around $40 per 10' length.

???

• Cross-section of the steel?
• How are you fixed for shop space?
• When will the canopy show up?
• Single seat or tandem?