Does this look like fun or what!

http://www.hyperracer.com/

Looks almost like a cross between a go kart and a car.

"The Hyper PRO Racer features a state of the art, race bred, Yamaha WR450 cc environmentally friendly 4-stroke engine, 5 speed sequential gear box, 4 wheel cross-vented disc brakes with billet milled 4-pot aluminum brake calipers, Ohlins aluminum bodied race shocks, optimum weight distribution and feather weight design. All this adds up to lap times that compete with the big boys."

It sound anemic (when compared to a car), but it really scoots in this Top Gear video. http://www.youtube.com/watch?v=3L0cN_2h0Tc

Pretty sweet, but 30K?

Yeah, not bad for a turnkey with that speed.

You can buy a looooot of car for 30k....

Interesting front suspension design. Single A-Arm...

what A-X class would that fit in?

I'd rather build my own for that kinda money

That's front suspension is what I've been trying to figure out.

I guess that due to the weight and limited movement it is sufficient, but doesn't that introduce a lot of camber change? No way to keep the tires flat.

I'd been shot down over any idea of introducing a suspension in a go kart in a number of conversations with go kart people so I'm glad to see that I was right.

I haven't seen any shots of the rear suspension, only some shots of a roll bar end link.

the suspension is VERY odd. Especially with a single shock in front?

A question for the tire gurus. Is this 6" tire really such an awesome choice?

And what would an equivalent shifter kart cost you?

I found some pictures of the rest of the suspension. Front single swing arms like that are pretty common on cheap RC cars--not with a single shock though. I imagine it works okay with very limited movement.

carguy123 wrote: A question for the tire gurus. Is this 6" tire really such an awesome choice?

I'd be thinkin' 10" wheels

The answer to the question no one asked.

When I bought my (used) CRG shifter, new ones were about 8,000. Not sure about current prices.

30 seems a little high. Would sell my CRG if anyone is interested. and YES! TONS of fun.

Fascinating. I want to drive one, badly.

That said, there are some trade-offs with the design that have me pondering which situations it would really be suited to. The single front damper/spring seems like an unnecessary compromise (but what do I know, lol) and I have to wonder what kind of rpms those go-kart tires would see at road course speeds. Didn't the Tyrell P34 have problems with that due to the small diameter tires? I guess it isn't exactly pushing F1 speeds anyway (circa '76). Looks absolutely killer for autocross.

Despite my ramblings, it's an awesome design exercise.

And yes, it does look like fun.

Matt B wrote: Fascinating. I want to drive one, badly.

I'd like to drive on WELL.

The small size is what got me wondering if a larger tire like a 10-13" wouldn't be better. Dwarf car tires?

what I can't work out is why they went with a single A-arm front end? it would only require four little tabs on the frame and you'd have a lot easier time keeping the tires flat on the ground through the whole range of suspension movement, and you could mount the ball joints vertical so you could change the roll center really easily (move around spacers to raise or lower the ball joints relative to the bottom of the chassis). I do like how they did the front brakes though, mounting them inboard of the spindles rather than right beside the wheel, puts the rotor in the airflow better and cuts down on the scrub radius needed

EDIT: upon closer examination of the front end, it's a monoshock, no swaybar, but that's ok because it doesn't look like the rod the secondary pushrods are bolted to can rotate at all, apart from maybe bushing flex. I'd have just forgone a lot of complexity and stuck two short shocks on there, you don't need a shock with 5" of stroke if you're only designing around 2-3" of suspension movement, stick an itty bitty shock on there (mountain bike shocks come to mind, the VT FSAE team runs Cane Creek Double Barrel (read: Ohlins) shocks all around on their SAE car) and be done with it, then get the CG down really stupid low and put the roll centers sorta close to the CG at ride height so you have a lot of inherent roll resistance. the rear end, I'd rob a Polaris Raptor 525IRS of the IRS bits and then do a really obnoxiously long trailing arm rear end (look under the arse-end of a new mini, then imagine half-shafts in there and you've got it) to get awesome forward bite and good side bite, run a single brake rotor beside the rear sprocket, and do whatever you want as far as rear shocks and mounting. I really really need to get my hands on a welder... I've got a feeling I'd be better served to actually build half the crap I come up with than just talk about it

Slyp_Dawg wrote: I do like how they did the front brakes though, mounting them inboard of the spindles rather than right beside the wheel, puts the rotor in the airflow better and cuts down on the scrub radius needed

Check out these inboard front brakes on a D/SR

As much fun as it looks, there's too much weight up high. Looks like it would have lots of roll in the corners. I'm also thinking a shifter kart is much cheaper and faster. The plus is that you can flip and be protected, but I can also get that with a Bandolero car for $7,000. Price seems way out of control. For $30,000 I can get a Star Mazda formula car.

ncjay wrote: As much fun as it looks, there's too much weight up high.

How do you get that?

fasted58 wrote:

Slyp_Dawg wrote: I do like how they did the front brakes though, mounting them inboard of the spindles rather than right beside the wheel, puts the rotor in the airflow better and cuts down on the scrub radius needed

Check out these inboard front brakes on a D/SR

Why do this? Surely what you gain in reduction of unsprung mass you more than replace with overall added mass and complexity?

For the Hyperacer you have to have it inboard of the wheel as the wheel is so small, but why for the D/SR

I've never understood the fad of monoshocks. It seemed to be the in thing in the early 90's for F1 then trickled down to the lower formula, but it seemed to die out by 95 or so. I've never understood the how/why. To me it looks like you end up with normal springing and damping in bump/rebound, but essentially zero roll control at the front except for anti roll bars. Can someone smarter than me explain the whys and how's please?

Oh, after a couple of apparently negative posts I absolutely love the concept of this thing. It may be a bit pricey, but don't forget it's from down under. If this were made/distributed in the US I'm sure it would be cheaper.

It may not fit into any existing class structure, but as an autocross or track day type toy it seems a great concept. Small, light, easy to transport, low running costs yet insanely fast. Looks like massive fun to me.

carguy123 wrote:

Matt B wrote: Fascinating. I want to drive one, badly.

I'd like to drive on WELL. The small size is what got me wondering if a larger tire like a 10-13" wouldn't be better. Dwarf car tires?

Dwarfs run 13 inch tires.

You know, looking at some of the videos it appears to have essentially infinite roll resistance with a very small amount of bump/rebound compliance. If it's got infinite roll resistance the camber change caused by the swing arms is negated.

Adrian_Thompson wrote: It may not fit into any existing class structure, but as an autocross or track day type toy it seems a great concept. Small, light, easy to transport, low running costs yet insanely fast. Looks like massive fun to me.

You just described a shifter cart...