Not necessarily my project, but this is the race car I work on in Fairbury:

http://www.kodakgallery.com/ShareLanding.a...w_photos_button

144 asked me for details on another site, so thought I'd repost here in case you guys were interested at all.



It's an 07 Rayburn Overrail chassis, with a Chevy 406 small block (i believe).

Engine is a steel racing block made for dry sump oil system (external oil pump/reservoir), 18 degree valve angle aluminum heads, other than that just standard high end NA race motor, 13:1 or so compression, big 4bbl carb, forged internals, about 8k rpm redline, msd ignition, using race gas. About 550-600hp.

We had an alumnium block, but, long story short, always run an external filter even when your engine builder assures you it's not necessary.

Here's my dirt track stock cars chassis 101 class.

For these cars, you have 2 options now, either the overrail or the underrail. That refers to the rear frame, whether or not there's a bar underneath the axle. Traditional race chassis were underrail for stability, but in the last 8-10 years they've been able to build overrail cars which allow for more travel in the rear axle by not having that bar underneath it, but they flex a little more. Our last car was an underrail, so this will be a neat change.

For suspension, there are a few options: 4 bar, Z link, swingarm, or some variety of leaf/monoleaf.
-- 75% of the people out there run a 4 bar setup, which is a bottom/top bar on each side, all connecting forward to mounting holes on the frame. You get kindof a V connection from the axle to frame. Coilover spring/shock mounted to the axle. Some of you will be familiar with 4 bar from drag racing.
-- Z link is similar using a coilover to the axle as well, but with the top bars mounted to the back of the frame behind the axle, instead of going forward.
-- Swingarm is a similar bar setup as Z, but the coilover mounts to a special bottom bar that goes forward, in about the middle between the frame and axle. This is what we use.

Z link/Swingarm tend to be a little better all around and easier to adjust then 4 bar, however you can't get the chassis quite as "dialed in" as with a 4 bar. But... with 4 bar, when you're out of shape, you're way out of shape.

Setting the chassis is crazy, depending on where you set the bars, you'll get a certain amount of rear steer, which you need at some points in the night but not others (depending on the track), and it also adjusts your body roll and axle positioning. But you have to think about how the axle responds under load, not where it's sitting when parked, and each side behaves differently. Geometry is huge, and it definately took us a while to get our heads around it. Remember that on dirt track you're always leaning right and turning left.

For instance, under load, most of the time you want as much weight on the left rear as possible, since you naturally roll towards the right rear. You do this by positioning the bars so the left rear moves forward under load.

If you look at the attached drawing, you can see how the axle responds. Note that the axle mounting points are not fixed; they are a "birdcage", a sleeve that goes over the axle with tabs on top and bottom for the bars, that rolls around the axle depending on axle height. Generally we keep the left side in the driving forward position, and then adjust the rear steer based on where the right side is. You always want some rear steer, but adjust the amount depending on how tacky/slick the track is (of course I dont remember which is which right now, think tacky=more).

That's the simple version, of course tuning it to track conditions and knowing which angles you need is the hard version. There's also a 5th bar that connects the center of the axle to the frame to keep it positioned correctly, and it's positioning changes as well with conditions.

If anyone ever wants a close up look/tutorial, let me know!

For those of you not familiar with rwd vehicles, here's a diagram of rear steer. By left rear steer, I mean the axle angling right, which turns you left.

Nice car. Where does it run?

I crewed on a friend's modified for a while. A lot of fun and a lot of work!

We run at Fairbury most of the time, but also hit Peoria occasionally. A couple of our sponsors are from (and race at) Peoria, so we like to hit the big shows over here too. It's funny how much better the competition is at Fairbury though.

We've been in Late Models for 2 years now (this will be the 3rd), and ran modifieds for lots of years before that. Have another good buddy that still runs Mods and tied for 3rd in track points last year out of about 25 regular competitors, http://www.curlracing.com/


http://www.fairburyspeedway.com

Had the car out last Saturday for practice day and it looked awesome. First time I've ever seen him drive into a corner without letting off. Most times had the car completely sideways before he even got to the corner and it stuck, and last lap just barely burped the throttle and it still stuck.

Only 1 more week till opening night, wooo!

On a side note, I got to play around on the 3/8 mile fairbury track with my 250cc Minisprint. Was a blast, but got an air bubble in the fuel line and lost power about 8 laps in. Hoping to be able to get it out and hotlap or something again before next years practice. If dad got some pics I'll get em posted.

What's a minisprint? Post up some picts!

The only pics I have are in actual picture format, so I'll have to try and bring them in and scan it. Was hoping the ol man would get some pics while i was on the track, but not sure he did. I have one at home from a couple weeks ago (at a distance), will try and ge tit uploaded.

Basically it's like this though:




It's a small version of a sprint car, runs tortion bar suspension and standard shocks, using a Honda 250R 2 stroke 3 wheeler motor. Loud, Light, and fast

I want one...looks like a hell of a time

Wife would shoot me though!

I was contemplating buying another one for $1300, but found out the guy was in Washington state ><

From Practice Day:






Was a lot of fun, especially coming out of a corner to see a hornet flipping in front of me

Update: Vaughan Racing finished 10th in the points at Fairbury Speedway this year, right there with some very fast high $$ cars. Season included 2 heat race victories, and 2 trips to the lock 8 race (fairbury locks in top 8 qualifiers to the feature, run the heat race for feature starting position), one of the lock 8 runs with 30 cars in the field. Hoping for some more sponsor $$ next year to pick up a few more horses and some better suspension components.

He'll be at Peoria this weekend, and then I'll be out helping him at Peoria for the 100 lap race on the 26th, if anyone wants to check the car out.

Pretty good!

Good luck with the sponsorship money, hopefully the year turn around and they'll be some extra funds out there.

well I'm mostly hoping we can get some more bucks out of some of our current sponsors. Mordue Moving and Digital Copy Systems are 2 of our primary sponsors; the owner of Mordue bought a car and basically gave a ride to another driver from Fairbury who had raced nationally. He didn't do well, and threw some of his trademark spoiled brat fits, and don't think that went over well with the ownership. Sooo... hopefully will be able to get some of that money or parts

Well, ran our last race of the year, 100 lap Peoria "Illinois State Championship", made the big race, out of about 40 cars, $500 to start, cool deal. Made probly 30 laps, until the trans cracked and siezed, snapped rear u-joint, broke yoke, bent driveshaft, bent 5th arm, fun stuff. Probly 2k worth of damage lol. Think I'm ready to swear off Peoria for good. Every time we're there we break something. 2 weeks ago snapped an axle, cost about $400 to get fixed lol.