West Fargo High looking for info.

[xtreamedrtbker]

Im a student at West Fargo High and my rec engines class is looking to build a sort of formula car. We have a 1991 zx-6 engine and we will be using 1020 dom for the chassis, as for that everything is still in planning. My major concern is with the differential, Im not sure where to start with this. Any information would be helpful on the differential or anything else.

[Igor]

Most teams here buy a Torsen differential and construct their own housing onto which the drive sprocket bolts directly.
For more ready made solutions you could try the diff from a quad.

As you're probably running the engine unrestricted you'll have far more power than the cars that univesities build. Please take some extra effort to make proper roll hoops, front- and side impact protection. Not sexy, but necessary to keep your project alive.

Good luck,
Igor

[drivetrainUW-Platt]

From a highschool side of things, unless machining/time/experince/money are sitting around in excess, I would consider a solid axle on a swingarm, think atv. Its simple, cheap and quick.

[js10coastr]

A solid axle would definatley make things easier, and would make the project more like a go kart. You'd want to look into castor angles on the front...

Otherwise, I think an open differential would be pretty easy to deal with. I'm not sure where to point you to get started, but those would be my suggestions.

[J. Vinella]

A spool could work too.
What I mean by a spool is; a traditional set up with a differential connected to CV joints, like most FSAE cars, but replace the differential with just a sprocket connected to a tube/bar. It has an advantage over a solid rear axle by having independent suspension.

[Bill Kunst]

Or mount the engine longitudinally and use a independent diff from a four wheeler. Then you can just offset the package to maintain the axle lengths and package other stuff next to the engine to balance your right:left weight balance. For a high school group, this would be great. If you go with a single, probably highly recommended for its simplicity, weight bias becomes much less of a concern in this layout. Run the exhaust down the right side of the car (passenger) and put the battery and fuel, other crap too, on the left side (driver). This should be really easy when it comes to drivetrain.

Oh yeah, use a arctic cat diff and it already has inboard brakes mounted to the diff housing, whabamm, another thing killed off the list.

Bill

[xtreamedrtbker]

We have already built a off road buggy using a 660 grizzly frame and a 550 nighthawk engine. So building this shouldnt be all that more difficult. I would like to have a differential with independent suspension in the rear. I have been looking into the Torsen, but building a carrier for it is the part that concerns me. We dont have the machining capability to make one, so I need to come up with a solution.

[NetKev92]

You should surf the gallery on the forum here like crazy. Where you may lack design skills, imitation is a good place to begin. Pick a car that seems to do well and try to understand why. The Formula SAE rules may also give you some good guidance on a roll cage and the side impact protection. I'd post some picture links, but you'll be better emulating the small FSAE cars than the bigger cars that I watch - unless you plan to do two seats or full bodywork. Google is your friend too. Some of the FSAE teams have great websites with pictures of cars that have finished well.

Rules:
http://students.sae.org/competitions/formulaseries/

[xtreamedrtbker]

The idea of using a atv diff would work and I can get my hands on a 500 Arctic cat rear diff, but having the engine offset sort of makes space tight. I would have to offset if fairly far to get the drive shaft angle to be fairly straight. I guess there is the option of setting the engine more centered and having a more extreme angle on the drive shaft.

[Bill Kunst]

Unless using a cv in the driveshaft, you will need to have two universals(at the sam angle) if mounting at an angle, as angular velocity will cause severe vibrations and destroy the drivetrain. As for the amount you would have to offset, that will depend completely on suspension geometry, track width, and the such. I guess I figured a sidewinder was probably easier to build for the students then a chain drive custom diffed car like most teams seem to do.

Anyway, good luck with this adventure.
Bill

[NetKev92]

Gratuitous links to Larger Steel Tube Frame Cars:

http://dsr.racer.net/chassis/stohr/gallery1.htm
http://dsr.racer.net/chassis/van_diemen/gallery1.htm
http://www.radicalmotorsport.com/
http://dsr.racer.net/chassis/merloy/page1.htm
http://dsr.racer.net/chassis/bcnu/page1.htm
http://www.khulsey.com/m_ouchi_maserati_birdcage.html

[FTC]

I think Taylor Race Engineering http://www.taylor-race.com/ sells chain drive differential assemblies for either quaiffe or torsen, I'm not sure which one.

[Dale Hahn]

xtreamedrtbker,

I am interested in your project. Please contact me with the details.

Best of luck,

Dale Hahn
Product Development Engineer
NVH / CAE Group
Arctic Cat, Inc.
(218) 681-9799 x4230 office
dhahn@arcticcatinc.com