open planning new car

[some_other_dave]

Originally Posted by cosmick

Honda is the one brand I shun above all others, least worthy of respect.

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

-soD

[cosmick]

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.

[Occasionally6]

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).

[freebeard]

I know, this thread needs visuals.

I know, right? Here ya go:



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:



What is the tire size again?

[cosmick]

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"

[cosmick]

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.

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.

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.

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

Rather than mess with adaptor plates a single engine and transaxle would be easier.

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.

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:

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.

1 liter displacement plus boost, light weight (485kg).

Build yours however you want.

[cosmick]

Originally Posted by freebeard

I know, right? Here ya go:



What is the tire size again?

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.

[freebeard]

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:


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.


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

[ksa8907]

Originally Posted by cosmick

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 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.

[freebeard]

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.