Street Kart Project, 120rwhp

[Jbrocks]

So me and a buddy of mine decided its time to start our long future of car/project building with this. I have a 90's gokart, nothin special, from sam's club. My father got it for me when I was a kid for around $100, so it has some sentimental value. I know what I want to do with my life now, and this seems like a pretty good place to start. We're beginners with go-karts, but have a vast collection of car knowledge between us, and a history of working on them.

So lets get down to business. What my goal is, is to complete this whole project by Spring of this year. I want to replace almost everything on it, minus the frame, with better components. Now I'm aware I'm going to need to reinforce the frame at somepoint, and I'll cross that bridge when I get to it. But what needs to happen primarily is an engine swap. I had my mind set on a 302 V8 from a 70's firebird, but realisticly that wont happen. It just doesn't have the surface to support something like that. So, its looking like I'm going to go with a 1.5 liter-ish i4, putting out around 120rwhp. This will in turn give me somewhere around 2-3lbs per hp. In between a Porche Turbo and a veyron Thats all thanks to the 100lb chassis.

Anyway, the mods that I figure that im going to have to do are new braking system, engine install, tire/rim swap, accelerator/brake pedal re-configure, and my biggest problem, a substitute for a transmission. I got the idea from a combination of a monster truck (1 gear) and any Lamborghini >80's (longitudinal engine). To clear it up: i4 engine mounted parallel to rear axel, 1 gear.

So my first question to all of you is: What should I use to get the power to the wheels? I dont want to use a trans, because I simply don't have anywhere to put it. I was thinking of a high resistance chain, but I don't want to jump into buying anything just yet. So if you have any tips/advice, feel free to post away, and ill keep all of you guys updated along my journey of a project


Ill upload some pictures/stats of what Ive got now shortly. Thanks

 

[streetlegalkarts]

Great idea!

I'm starting a similar build. you can find me on youtube. I wish you the best of luck and cann't wait to see it come together.

I intend to use a 5-6 speed harley trans. for my build. but my power sorce is a bit diff.
I like these trans. for a couple of reasons. one, being they can take a beating and not blow up. and two, i want to use a pnuematic or electrical shifter, leaning more to electric. up/down buttons on the streeing wheel!

anyway, if you dont already have a you tube channel get one share it all and maybe make a buck or two. and we can colaborate as we build.

 

[Jbrocks]

sounds good, best of luck to you too. I do have a youtube so ill hit you up on there. you can shoot me a friend request @ brockwell92

 

[j.concepcion54321]

well recently at my school theyre rebuilding the elevator with new parts, and they use a chain system. Its a masssive chain and i think one of those could work, or im almost positive heavy duty motorcycle chain and sprockets will work. good luck man with the build, do you have any pics yet? whos gonna be the brave soul to ride this thing when its done?

 

[Doc Sprocket]

With a drivetrain like that, you're going to need a lot more than "frame reinforcement". While this sounds like a very interesting project, I would strongly suggest you consider a total scratchbuild. By the time you've brought everything up to snuff, you will have practically built the whole thing anyhow. Often, it is easier to build something anew (frame) than try like he// to reassign something existing- especially with such radical plans.

Furthermore- you're overlooking a few things.
*The factory axle is not going to be sufficient for that weight or HP.
*With that much power and weight, a single, rear brake will not suffice. Nothing short of four wheel, hydraulic brakes are going to reliably stop you.
*None of the frontend componentry will do, either- Bearings, spindles, knuckles, rod ends, tie rods, etc.
*You've overlooked clutching- how do you propose to accomplish this?

My suggestion to you is to go a little more conventional. Build a new frame, and install a motorcycle engine. This will be smaller, lighter, easier to mount, include clutch and transmission. No, it's not as "original", but there's a reason it has been done.

 

[mrfreyguy]

Anyway, the mods that I figure that im going to have to do are new braking system, engine install, tire/rim swap, accelerator/brake pedal re-configure, and my biggest problem, a substitute for a transmission. I got the idea from a combination of a monster truck (1 gear) and any Lamborghini >80's (longitudinal engine). To clear it up: i4 engine mounted parallel to rear axel, 1 gear.

So my first question to all of you is: What should I use to get the power to the wheels?

I have seen snowmobile CVT's used in some dune buggy's. As long as there set up right they can handle a decent amount of hp and be fun at the same time.

 

[Jbrocks]

Ok so thanks everyone for sharing your opinions and advice, I'm gonna respond to everyone to the best of my ability.

Well, I'll be putting up some pictures of what it is now shortly. And I did some more research. It looks like what I need for a chain is a size 30ish roller chain, that should be able to handle more than the amount of power I'll be using. Also, to the clutch difficulty brought up, I have a centrifugal clutch on there now, and I believe I can do without one on the final build. When idle, its going to require constant braking to keep it stationary, so I'll most likely install an E-brake equivalent so I can exit the beast while its running. As for the brakes, I have something drawn up I'll post in a few minutes, I'm uploading that now. And for the rear axle I'm just going to find a whole new one, weld a gear on there and the braking mechanism which you will see shortly. It wont have a differential so turning is going to be a bit noisy, but I can live with that. I want this to be as low tech and primal as possible.
Now, for the question as to who the brave soul will be first driving this, that will be yours truly

Thanks again guys

 

[Jbrocks]

layout

Sorry for my lack of artistry, but this is what I've come up with for the overall layout. The cage and frame for the most part isn't shown. Basically one rear axle, with one gear and brake disc mounted straight to it.
Just as an FYI, the only reason I'm doing this and not a scratch build is because I love this thing, If I wanted to do a scratch build I'd just build a ratrod, not a gokart. To me, this whole thing is about building something special to me, and unique to everyone else, something that hasn't been done too much. Something that makes you think, its so simple it just might work. Big engine on little car, every engineer's dream.

Anyway, here's the basic layout of the final build, actual pics of current on the way

 

[Jbrocks]

Current

Here's what Its starting out as

 

[Jbrocks]

And the rest

 

[racerc2000]

I agree stock a 120hp engine will tear the axle apart and your going to need sizable tires not only for traction but weight.

one option although pricey would be a micro sprint rear axle

I believe its 1 7/8" and the wheels are on splines. it also opens up a huge variety of wheels also. mostly 10" diameter as per the sprint but any width you could dream up and tires are 18" tall slicks or you can use some of those 205/50 10 golf cart tires.

whats the weight on that 3cyl? I could see having a piece machined up that bolts to the crank and is keyed for say a 1" or larger clutch/torque converter.

another thing to look into is the old 70s honda 600 coupe or s800 coupe

it was some FWD some RWD but it was a 600cc motorcycle engine chain drive

had a strait axle aith sprocket to motor and doesnt have to be all pretty and in cases but you get the idea. and its showing you just how sturdy a 600cc build about your HP would need

 

[everblade]

All IO can say would prob be obvious to you, But I'll give a go anyways. A FREAK 100 HP ENGINE WOULD TEAR THAT THING TO PIECES! If you were to chop off the passenger side seat you could fit a motor cycle motor there I think. Then you'd still have room for the tranny. But I still think a motor cycle engine would rip that thing up.

 

[redsox985]

Putting 120HP into that kart would be like building a roll cage from paper clips.

 

[Jbrocks]

Yeah I'll definitley look into the trans/chain ideas you guys gave me. You're loads of help, seriously.

But anways, in response to the few comments that suggested this was unlikely or improbable:

it just wouldn't be as fun if it was gonna be easy now would it?


the trickiness and difficulty is what I enjoy, straightforward and simple things don't excite me as much as stuff like this does, ya know? I guess I'm just weird like that.

So this weekend, I'm going to cruise around for some materials I'll need, look into getting the roller chain or whatever I decide to go with, and talk to my welder friend and see when I can get it in there to start its "beefing up". If i can get around to it Im also gonna start removing all the old parts that need to be, down to the chassis.

Just as an inquiry, how much do a set of gokart slicks usually run? I know ballpark how much, but if anyone can give me a range it would be great. I can kinda guess though, I have a set of 315 semi slicks on my camaro, and they ran me about 300ea.

 

[fowler]

id just start from scratch
a bike engine will just be stupid fast and the frame will fall apart at speed
a car engine will have the same issues as a bike but be hugly over weight and no reinforment to the frame will hold it

although
as everblade said u could fit a bike engine in the passenger seat
but bike engines have built in trannys
that would allow u to install a swing arm at the rear

it goes with out saying suspension is a must in this project

 

[streetlegalkarts]

i agree with fowler. and beside power/ton is better with a bike motor anyway. and they get better mpg's.

 

[racerc2000]

gokart slicks are usealy in the 30-65$ each range for rears. but your limited to around 12" diameter on 6" rims

if you went the micro sprint way... 18X10X10 slicks will run you about 80$ each. up to about 100$ for 21" tall

205/50/10 golf cart tires. dot legal on/off road tires if your lucky can get a pair for under 100$ on the bay


if you mod that frame to work with this power at least Ide suggest doubling up the base tubes.

http://www.youtube.com/watch?v=3CQfom3ceCk
turned into
http://www.youtube.com/watch?v=bZIK2bZp6BU&feature=related

but you see the chassis reinforcement that went into it. you could do the same to yours.