redesign? what?

well, i made a choice today.

the gecko is about to hit the surgery table, and i barely have any parts. i am starting over, maintaining the same concept, but a radical redesign for four main reasons:

a) the most important reason for me is room. as it is now, it is VERY tight for two people. i want to widen it up a bit and have room for a hand operated shifter instead of paddles.

b) a frame that allows for longer front suspension which = a better ride.

c) i want to build a frame that easily accepts a removable hard top or targa top

d) weight reduction. with newly acquired information, i have realized a few unnecessary frame components., and im gonna redesign the frame with narrower tubing. two inch tube is huge.

Posi differential

well i found a killer good deal on a Posi (limited slip) differential. only $50 instead of the normal $400+.

so now i have two of the most crucial parts of the car. the diff, and the engine, both of which i got great deals on.

check it out!



now for those of you wondering how the heck im going to make this work with a chain driven vehicle, try and follow me here.

i'll take the ring gear off (the largest gear visible in the pictures) and bolt a sprocket in its place. now i will have something that looks like this:


next up is to create a cylindrical housing to hold grease and protect the delicate internals of the differential. a sort of sleeve that spans from the inside edge of the sprocket, to the inside edge of the opposing bearing. something a bit like this:

notice the smooth housing to the right of the sprocket? the inside of that is filled with grease that would normally be contained withing the differential housing on a car.

next step is to make a carrier. this would be a triangular plate on either side of the differential, with holes that the CV axle splines and come through and attach to the differential. the top of this triangular formation will be held to the chassis with two threaded rods that can be tightened and loosened for chain tension adjustments. the whole housing comes out like so:
this particular example has a disc brake mounted to the caliper, instead of brakes out at the wheels.

in a nutshell, thats a chain drive limited slip differential! lots of work ahead of me on this one!

Color!

played on rach's photoshop for a couple mins earlier. nothing fancy, but it just makes it that much more real :-)

Thank you Tony Pashley

you, sir, rock.

i got the book "How to Build Motorcycle-engined Racecars" in the mail and guess what? it kicks ass. every suspension problem i had, now gone!

thank you 1.3:1 to 1.5:1.

Tony Pashley, if you're ever in Spring, TX, come hit me up. i'll buy you lunch for being my literary hero.

Numbers

so here's a couple numbers that got my heart pumping a little bit just thinking about them...

i saw a similar car to mine...a FSAE car, and it had a 600cc CBR engine. compare some of these numbers:

600CC car:
74hp to the wheels
650 lbs
seats one
power to weight ratio--8.78 lbs per hp
0-60 time: 3.35 sec

non turbo gecko:
150hp to the rear wheels
900 lbs
seats two
power to weight ratio: 6 lbs per hp
est. 0-60 time: 2.8-3.0 sec

turbo gecko:
240 hp
935 (est) lbs
seats two
power to weight ratio: 3.75 lbs per hp
est 0-60 time: 2.2-2.7 sec

and they all get around FORTY MPG!

i love it :-)

Oh, such love!

So the car is little more than hand drawn drafts and an engine (and an ignition cylinder), and i'm already getting overwhelming support from nearly everyone that hears about it! My blog has TWO followers (woot) and check out this great support from 1000rr.net: (im gecko1000)
http://www.1000rr.net/forums/showthread.php?t=56778

the model continues to take shape:big thanks to terry tremmel for the tool loans! i'll be moving the engine and what other little things i have to the shop this weekend!

Teaser Shot

Here's a teaser for the final paint job (i realize i'm a ways off from that point, but here it is)

More scale model

so this little model is a great help for me visualize the final product. it's also helping me identify a couple of potential problems. and third, it's getting me a little bit of that drive back.

here's some more progress pics of the model:

Oh fun, an ENGINE!

Yes, I realize this is being posted right after the previous post, but i felt it needed to be separate. This post is to highlight my killer engine I have sitting in my living room right now. I found it from a guy on craigslist complete for only $800.

The engine is a four-stroke, four cylinder, fuel-injected motor out of a Honda CBR1000RR crotch rocket. The engine also features a dual-stage fuel injection system, meaning that at wide open throttle, fuel is injected in to the air intake as well as the cylinder heads, so the fuel coming in to the cylinders is already premixed with gasoline.

specs:

Displacement:	998.00 ccm (60.90 cubic inches)
Engine type:	In-line four
Stroke:	4
Compression:	11.9:1
Bore x stroke:	75.0 x 56.5 mm (3.0 x 2.2 inches)
Fuel system:	Injection. Dual Stage Fuel Injection (DSFI)
Fuel control:	DOHC
Ignition:	Computer-controlled digital transistorized with three-dimensional mapping
Starter:	Electric
Cooling system:	Liquid
Gearbox:	6-speed
Transmission type final drive:	Chain

all in all, the engine delivers about 150hp to the chain, and is capable of 300+ with a turbo and tuning.

I cut my thumb

Yea, so for those of you that are familiar with my custom headlights on my caliber...you know the turn signals are exposed. well, a rock flew up and shattered one of them, and when i was trying to replace it, the broken glass SLICED my thumb open. its pretty hardcore.

anyways.

Back to the Gecko.

Not much going on with it today. in fact i didn't even touch the model OR the plans. but i can show you a parallel wishbone (a-arm) suspension drawing that i did the other day just to show off my drafting skills a bit.

i referred to my RC car (Tesla) to get approximate dimension ideas--mainly the relation between upper control arm length and lower control arm length. I concluded that, when mounted on the same plane, the upper wishbone is 93% the length of the lower wishbone.
the drawing is approximate, but as close as I know how to come to a scratch built susp. The strut/spring was a doosey to draw.
here's pic:

Scale Model

I got a little more work done on the 1/18th scale model im working on of the gecko.


i'm trying to focus on suspension right now. I think i've narrowed it down for the front. I'm going to source off of a lotus kit car, using a package from the UK. like this. Still working on the back. I also bid on a limited slip differential on ebay. doubt i'll win tho. about to move my work in to the shop. Big thanks to OptiFlow and the Harlows for loaning me space!