LocostUSA.com

This topic will serve as my build log:

Well I have wanted a streetbike for quite some time, many of my friends have them, and since I am one of those one-upping kind of ppl, I'm 100% sure I would kill myself or be seriously injured on a bike, so I set out to get something relatively as quick as a 600cc rocket.

Last week I picked up a '03 ZX9R drivetrain and all the goodies to make it go, I.E. electronics, exhaust, radiator, fuel pump, etc.

I kinda want to build something similar to the Onyx Mongoose, http://www.onyxsportscars.f9.co.uk/id20.htm

but I want to styling similar to the new Lambo Reventon...I am quite familiar with CAD and 3ds Max, so with the two I can design a nice ride

I'm quite an avid car guy and have all the tools and skills to do this project, I'm gonna post everything I do up here so I can get input and criticism, as I want to do this quality and not like a kia (cheap and crappy)

I have got a few items together, to work off as far as designing for size

-4 gallon Jaz Fuel Cell
-Subaru SVX rear end (differential, cv shafts, brakes, hubs, etc)
-Subaru SVX front hubs and brakes
-Grant Alum. Racing wheel
-Bidding on Sparco race seats on Ebay

This car is going to be a chain drive mid-engined ride, so I'm going to machine a sprocket to bolt to the rear diff in place of the ring gear, and I'm going to use the stock carrier bearings with new plates to hold them

I have a couple questions to start,

-anyone with a mid-engine car using chain drive, the stock sprocket is 16 on the engine 41 on the rear, but I can get rear sprockets up to 50 tooth and front ones with 15, which would help my torque, as the car is going to be heavier than a bike of course, any suggestions?

-where can I get a good deal on Adj. Coilover shocks with springs that are light enough for a 950-1150lb car???

-lastly....am I crazy for wanting to have this car driveable by August (without fiberglass)????

hope to talk to you all....get pics up as I figure things out...

Sounds like a great project. I relate well to your "Add two wheels to my motorcycle so I don't kill myself" mentality. I love to ride and I'm quite confident in my own abilities to 'not kill myself' it's all those other idiots on the road who can't, won't or don't see motorcycles.

You certainly have your work cut out for you.
Are you nuts to want it driveable by August? That depends on how much time you have each week to work on it. The downside to a middy chassis is you don't have a design to start with.
I designed my own chassis and spent close to 200 hours planning, designing, drafting, buying parts etc. etc. etc. before I even started the build.
Since I pulled the trigger on building I work around 8 hours a week on it and I've been at the build for about a year (that includes completely tearing down a miata donor.) Do the math, that's 400 hours in shop time. And I'm still not even done with the chassis. I'm close, but there are a lot of mounts and tabs that take a lot of time.
Thinking about it now I've probably got 40 hours just in driving time back and forth to Metal suppliers, Home Depot, Fastenal, Norco Welding, etc. etc. etc.
I probably work slower than most, but I do this for the fun of building. I'm not cutting corners just to get it out the door.
I'd say if you can pull 30+ hours a week on it, you've got a roller by August. Anything less and you're dreaming!

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

Ditto what Rusty said.



And at least another 40 hours reading LocostUSA, right?

-dave "guilty" hempy

_________________
...nowadays people are so intellectually lazy and lethargic that they can't build ANYTHING with their hands. They'll spend hours watching whiny people marooned on an island, but won't spend a second adding anything to the world. -weconway
Visit my [Locost 7 build log]

Search for R1 ratio for some things to consider on ratio selection.

_________________
My reverse commuter trike build log: viewtopic.php?t=11384
Fitting glass and weatherstripping: viewtopic.php?f=23&t=6451
Growing various fruit trees, berry bushes, and wine grapes in zone 7b.

thanks for the help with the ratios in the other forum.....as I am using a chain drive still I will probably order the stunt sprocket set (cheap alternative to custom sprocket) which is a 15 front 49 rear which is a final ratio of 3.27 the stock is a 16/41 which is a 2.56 so this should help out with the loading

I plan on doing most of my driving on the street with just me and no passenger, so I think that if I can keep my car weight down under 1000lbs... I should be alright as I am basing my design around the
Sylva Riot R1 (400kg) 880lbs
http://www.sylva.co.uk/riotR1.html

and the Onyx Mongoose (420kg) 925lbs (but with a Rover drivetrain which is 200lbs heftier than my ZX9R)
http://www.onyxsportscars.f9.co.uk/id20.htm

I don't plan on having tires any bigger than 205/50/r16's ever

anyways I am working out plans and just picked up a small Lincoln MIG welder so I can tack things together as I go, I have a friend with a really nice MIG/TIG SnapON Welder setup which I will use to finalize welds on the frame

-for now I am looking for a decent set of race seats at a fair price
-I need a fuel cell...prolly order one off of SUMMIT racing
-Want to find a cheap set of front spindles, 5 on 114.3mm (4.5") with brakes, as the SVX rotors and brakes I have are HEAVY up front..we are talking 3 POT brakes with 1.25"wide rotors

don't ask me why I chose the Subaru SVX.....I guess it was convenient, but the subaru LSD in the rear and the rear spindles and CV's will work perfect for my setup

The bolt pattern is for heavier vehicles. 4x100 or 5x100 will have lighter rotating assemblies.

I expect the rotors are separate from the hubs. Slip on rear rotors in that pattern with aftermarket calipers should lighten your load, though the spindle/cv stub axle adds some weight to the rotating assembly. The hubs concentric ring needs to closely match the rotor center hole id.

_________________
My reverse commuter trike build log: viewtopic.php?t=11384
Fitting glass and weatherstripping: viewtopic.php?f=23&t=6451
Growing various fruit trees, berry bushes, and wine grapes in zone 7b.

yeah 4x100 hubs brakes and uprights would be nice all around....I want to make this thing lightweight and I think to do so I'm going to have to ditch all my subaru crap.....

when i first decide to start this project (last week)....I had no idea that so many ppl had made light cars with bike engines, I am quite surprised and relieved to know that there are ppl like me trying to do the same thing, hopefully with all this advice around I can save some time choosing parts and such....

For cheap shocks, make sure you check out bike shocks. I'm building an Ariel-Atom style car with an end weight of around 1200 lbs, and I'm using Yamaha R1 bike shocks all around. The spring rate is 500 lbs an inch, so if you're going to do a bellcrank system, it's easy to get 4-6 inches of travel and a natural ride frequency between 1.5 and 2.5. If you want less travel, I believe r6 shocks are essentially the same shock with slightly less travel and a little bit cheaper. Plus, they're double adjustable.

Good luck on your build!

_________________
"I've just been paid a visit by Q. He wants to do something nice for me."

"I'll alert the crew." (Picard and Riker)

well i just picked up a set of fiberglass race seats weight 18lbs a piece with mounts. I hope to get them shipped in next week sometime.

Major change: My buddies and some guys on this forum have got me seriously thinking about a 1+1 middy, I always thought it would be cool to do, but never liked the idea of a cramped passenger area......but due to some new ideas on keeping wheelbase short and still giving the passenger space I might change my mind.

The idea was that you could make space on either side of the driver seat for the legs of the passenger...and since the seats I just got are not much wider than the driver, and the fact that I want a low car means that you will be sitting fairly laid back.... the passengers legs will remain low, thus they can go alongside the driver without disruption....

Keep in mind that these are merely ideas, I will test the idea about a 1+1 when I get my seats in, hopefully it will be reasonably comfortable, and within a decent wheelbase range, I would like to experience driving in the middle...could be fun.

Well, I will get some pics up of my seating tests so I can get some feedback....

The Rocket that Gordon Murry designed uses the 1+1 driving position. Check out http://www.jaylenosgarage.com/cars/RocketCar_shell.shtml he has one in there.

_________________
Before you judge a guy walk a mile in his shoes. Then when you judge him, you've got a mile head start and you've got his shoes on:)

I believe his new Caparo T1 is also a 1+1 of sorts. It is a staggared 1+1 so the passenger sits behind the driver, but both her legs go to one side. That way you still keep your wheelbase short but you get the visibilty (and novelty) of sitting *almost* in the middle.
This is the best picture I could find of the cockpit

_________________
In God We Trust... All Others, Bring Data.

Miata based, custom chassis build in progress. First Drive!!! http://locostusa.com/forums/viewtopic.php?f=35&t=2269&start=375

How about this one...

got my seats last friday and have decided to do a 1+1 car. I setup the seats to the most comfortable angle and at the correct distance from the pedals that I have setup in my sketchs, the passenger will not be as comfortable as the driver will be (she will have her legs on either side of the driver seat, as per the LCC Rocket) but will be much more comfortable than a Rocket passenger as I am going with a little longer wheelbase and pushing the driver slighly forward. I am trying to figure out my rear differential setup, and I desperately want to have inboard brakes, but since I am trying to keep the car locost I am struggling with a setup.

The gas tank will be located above the differential...(only a 5 gal..13"x13"x8") and the radiator will be in the front of the car. I have some sketches on paper that I am trying to scan in, and I will soon have my 3d model complete so I can post pics on here soon.....

Are there any common IRS setups that have a centered diff with bolt on CV shafts (inboard bolts)?

I only ask because if so I could maybe fab up some inboard brakes then.

well here is my original sketch...its to scale, but before I got my seats, so this has a 90" wheelbase, but after I set up the seats, in order for the passenger to be comfortable I need to have a minimun 95" WB.....sorry this is a picture of the sketch...scanner doesnt work

In board brakes are a good idea. What does the diff you have look like? I am not sure how you make an adapter. Transaxles usually/often? have side covers that bolt on behind the CV joints. These make places you can bolt an adapter. Someone makes brake disks that have the CV bolt pattern.

Here's a picture, but it's hard to see. I don't know where the rotors come from.

I think side by side makes more sense for a passenger. "She" will not enjoy being staggered to the back. It's nice to be able to talk with your passenger, look at them and share a smile etc. There is no performance gain that makes it worth a really unusual arrangement. If you really need to go fast, buy or build a track car. It's not sensible to drive fast enough to make odd seating arrangements worthwhile on the street.

I think the real seven's were 39" wide...

_________________
Marcus Barrow - Designer of Car9, an open design community supported sports car for home builders!
SketchUp collection for LocostUSA: "Dream it, Build it, Drive it!"
Car9 Roadster information - models, drawings, resources etc.