Adventures in dirt track racing...roundy roundy...

[YJ4Rox]

prepare for a long post, and I am no story teller like Silverzuk.

I know this is a wheeling site but I also know there are tons of motor heads that love racing of all types. I enjoy almost all forms of Motorsport. I found myself Totally burned out on wheeling, body won’t hold up to racing XC dirt bikes so I need a way to fuel my adrenaline addiction.

I grew up going to the dirt track races. We never had any money to race but always knew some people racing. Dad was even an announcer for a few years when I was in high school. I’ve been around it my whole life but never “into” it. Last year dad got an open wheel modified. His health isn’t the best so when he didn’t feel like racing it he let me jump in. I got several races under my belt in 2019 and I was hooked.

We built a shop late last year and on New Year’s Day I went to Richmond and picked up a new to me roller. A 2016 Shaw.

 

[SLOWPOKE693]

In

 

[YJ4Rox]

I immediately tore it down and called an engine builder to get on his list. I hashed out a “budget friendly” engine build that would fit the rules packages.

we run the sport mod class. 2500lbs with driver, Ump tires. Stock Holley 4412 2 barrel carb. Steel block and steel heads. No porting, 175psi compression hot, 3/8 rocker studs, no stud girdles...just to list a few.

 

[Tizken]

I'm going back the other direction now, got into micro sprints a few years ago since we have a track here in town that ran them. Selling all that stuff now to concentrate on the off-road racing again. Hoping to do an ultra 4 race or 2 next year along with some of the smaller series. My son is 15 now and wants to get a side by side to start racing with me. Changing it up once in a while is good, you always learn something new.

 

[YJ4Rox]

Now these bastards are about as 180 degrees from a wheeling rig as you can get. Everything is asymmetrical. It’s a chevelle front clip and a “parallel” 4 bar rear. I quote parallel because it’s really not when it’s set up right.

All of the tracks we run are high banked clay ovals, mostly 3/8 mile.

for the number nerds like me it’s completely fascinating. Roll center anti squat scrub rad etc throw out all the crawling numbers and thought processes.

right front runs negative camber, left runs positive. You also run a caster split left to right. Different chassis require different numbers but it can be as extreme as several degree positive on one side and negative on the other. You also run toe-put which was foreign to me.

Here are a couple Pics of front and rear.

 

[mobil1syn]

My son is 15 now and wants to get a side by side to start racing with me. Changing it up once in a while is good, you always learn something new.

as much as i despise those stupid little things, if he is serious and wants to put in the work he can be getting paid to race them.

 

[YJ4Rox]

Well those pics are all fucked up.

The rear end is a winters quick change. Centered with equal length shafts, light weight low drag center with magnesium bells and aluminum spool. we have to run steel tubes. I ditched the winters shafts and bought the Strange Oval axles. Both are gundrilled and different diameters to get better drive off the corners.

 

[YJ4Rox]

The dude I got the car from was mainly running and flatter 1/2 mile tracks so I went through everything to set it up for our rough little bull rings. New springs and shocks all the way around.

The plan was to test and tune in March and start racing in April. The Damn Rona hit and screwed that plan up. Engine builder was behind, it took him six weeks to get the crank but now worries since all racing was cancelled for April and May.

I took my time putting things together and bent up a new body. My first dirt body build. Luckily I have a buddy with a big ass sheet metal brake.

 

[YJ4Rox]

Picked up a sweet ass Jim Evans carb off a guy in Missouri.
Upgraded to aluminum wilwoods. gM metric calipers all the way around and a right front shut off for 3 wheel brake.

 

[YJ4Rox]

I did the responsible thing and spent my Rona stimulous in race tires

 

[YJ4Rox]

I picked up the engine in late May.
it’s just a SBC. 036 casting block with a standard bore.
forged 4340 light weight crank, forged H beam rods. Flat top pistons. Promax heads, stainless roller rockers.

 

[YJ4Rox]

Damn sideways pics.

anyways the trans is a Gen 2 Bert ball spline. For those that haven’t been around it the trans is a little different. You have low, high and reverse. High gear is direct drive, low and reverse are like 2:1. It’s also a reverse clutch. Don’t touch the clutch start the car in neutral or in low/rev. Put in low and push the clutch pedal down to engage it. You get up to about 3500rpm in low with the clutch depressed, left of clutch and gas and pull it into high. To shift back into low or slow way down blip the throttle and pop it into low, push the clutch back in to keep going.

they are tiny little trans, 42lbs with the wet clutch. You just have a flywheel and a coupler in the crank. Clutch is internal in the trans. Mine uses a band style friction/fiber. The gen 1 and other companies use a clutch stack very similar to a motorcycle.

 

[YJ4Rox]

The first test and tune wasn’t until the end of May. I had to build a fan shroud. Killed some tires testing. The car wasn’t bad but a lot different than dads. A much newer chassis with different geometry and a lot more HP was going to make the learning curve steep.

 

[YJ4Rox]

Jackson Ohio planned a Sunday day race with no fans so we loaded up and headed west. A new car on a new track in the dry slick. Hell I spun out in hot laps. The car was way too loose and not responding to changes. I switched out the 6.18 gears to 6.27’s to try to keep it up on the bars more but I couldn’t get the car to stay planted on entry.

after that race and upon further inspection I had broken two Bolts on the LR lower shock mount and I had too much drop on the LR chain limiter. The damn shock mount was just pivoting so I had no damping when trying to sit the car, then it would immediately jump up on the bars and chain. It made it VERY hard to drive. I hit at least to infield tractor tires but managed to squeak out a 7th in the feature.

 

[665.0coupe]

Nice! You get a lot of good parts compared to the IMCA sportmods that I'm use to. I helped my buddy for a number of years. We have to run a 9", mini spool only, 3 link (or 2 bar as the dirt guys call it), pan hard behind the axle, no floating rear calipers, OEM iron calipers, no brake shut off, stock front lower control arms, shitty IMCA hoosiers, and a 602 crate engine.

Your sport mod is better equipped than our modifies

 

[YJ4Rox]

Nice! You get a lot of good parts compared to the IMCA sportmods that I'm use to. I helped my buddy for a number of years. We have to run a 9", mini spool only, 3 link (or 2 bar as the dirt guys call it), pan hard behind the axle, no floating rear calipers, OEM iron calipers, no brake shut off, stock front lower control arms, shitty IMCA hoosiers, and a 602 crate engine.

Your sport mod is better equipped than our modifies

we have one track that runs very similar sportmod rules to yours. 9”, Saginaw trans, no MSD, hei only and a vacuum rule to keep the cams small. They always have 25-30 cars but those cars aren’t too competive anywhere else. We have damn good car counts almost every night. I skipped Saturday they had 39 sport mods.

our modifies are awesome but so high dollAr they might as well be running super lates. Top mods around here are 800+ Hp and have bad ass shocks. $35k mullens motors and $6k in shocks. When it’s slick our top sport mods are only a couple tenths off the top mods on lap times though and that’s with off the shelf $80 integra shocks that haven’t even been dyno’ed.

 

[665.0coupe]

we have one track that runs very similar sportmod rules to yours. 9”, Saginaw trans, no MSD, hei only and a vacuum rule to keep the cams small. They always have 25-30 cars but those cars aren’t too competive anywhere else. We have damn good car counts almost every night. I skipped Saturday they had 39 sport mods.

our modifies are awesome but so high dollAr they might as well be running super lates. Top mods around here are 800+ Hp and have bad ass shocks. $35k mullens motors and $6k in shocks. When it’s slick our top sport mods are only a couple tenths off the top mods on lap times though and that’s with off the shelf $80 integra shocks that haven’t even been dyno’ed.

We can run a Saginaw or a Power Glide. I forgot about the HEI only, and a rev limiter. There are no vacuum rules on the open engines, I think just lift rules.

I wish we could get those kinds of car counts. Last Friday there about 30 total between sport mods and regular.

There is a track pretty close that runs USRA modifieds. They get better stuff like you get. IMCA did allow quick changes in the mods a couple years ago but they are still pretty restricted. I've never seen anyone run Fox shocks locally so that's cool to see. The current big money shock packages here are bulb top Integra and BSB's.

 

[YJ4Rox]

So with the shortened season We raced every Friday and Saturday we could. My crew is my wife and with it just being the two of us it’s a lot of very long nights. It’s a ton of work just like any racing, you really do get out what you put in. I don’t want to just be driving around I want to be as competitive as possible with my small budget.

wifey is a trooper, she helps bleed brakes but can’t see over the cowl.

 

[YJ4Rox]

We can run a Saginaw or a Power Glide. I forgot about the HEI only, and a rev limiter. There are no vacuum rules on the open engines, I think just lift rules.

I wish we could get those kinds of car counts. Last Friday there about 30 total between sport mods and regular.

There is a track pretty close that runs USRA modifieds. They get better stuff like you get. IMCA did allow quick changes in the mods a couple years ago but they are still pretty restricted. I've never seen anyone run Fox shocks locally so that's cool to see. The current big money shock packages here are bulb top Integra and BSB's.

We see a lot of fox and Bilstein shock packages. There is a good mix of lift vs pull at cars too. My buddies Elite has a sweet Fox package on it. Actually the guy I got my Shaw from stepped up to an Elite. Maybe that’s why we see a lot of Fox stuff because Nick Hoffman is just Down in NC and specializes in Fox.

 

[Black Sabbath]

anyways the trans is a Gen 2 Bert ball spline. For those that haven’t been around it the trans is a little different. You have low, high and reverse. High gear is direct drive, low and reverse are like 2:1. It’s also a reverse clutch. Don’t touch the clutch start the car in neutral or in low/rev. Put in low and push the clutch pedal down to engage it. You get up to about 3500rpm in low with the clutch depressed, left of clutch and gas and pull it into high. To shift back into low or slow way down blip the throttle and pop it into low, push the clutch back in to keep going.

Never been around circle track and I am sure there must be a reason, so why the reverse clutch setup?

 

[YJ4Rox]

Racing Friday and Saturday was wearing me out. I was third in points at the Friday track and leading the points at the Saturday track. I decided to start taking fridays off and focus on points.

I got tore up by idiots driving over their head a few times. Three different times I got T boned by someone spinning in the high line.

 

[Byro]

I dig it, love watching the guys run the cushion, come in hot as hell and flick the car and never lift.

 

[YJ4Rox]

Never been around circle track and I am sure there must be a reason, so why the reverse clutch setup?

I’m honestly not sure but the internal clutch has less rotating mass. Also Nothing to explode in the bellhousing. Plus higher classes run a reverse mount starter and accessory drive. Tiny little flywheel and a splined coupler. A little drive belt runs off the coupler and turns a two stage pump, fuel and power steering. That gets everything off the front of the motor. Ideally you want less weight in front of the mid plate. So starter ps and fuel pump all on the bellhousing.

 

[YJ4Rox]

Some random pics

 

[SLOWPOKE693]

When I lived up in New England we built and raced paved short track cars. I've driven everything from a 4cyl charger car all the way up to super late models with decent success. I've always wanted to race a dirt car though, looks like a ton of fun sliding around out there. I moved to Texas 4 years ago for work and am surrounded by dirt tracks and chassis builders. Wife gave me the green light to buy one and go race but I somehow ended up building a SxS for short course racing. The alure of jumping 100' table tops won out.

I've looked at a few local sport mods set up similar to yours. The suspension and chassis dynamics blows my mind. Complete 180 from what I learned and know about setting up a paved oval track car!

I'll be watching this thread.

 

[YJ4Rox]

Couple more

 

[SLOWPOKE693]

I’m honestly not sure but the internal clutch has less rotating mass. Also Nothing to explode in the bellhousing. Plus higher classes run a reverse mount starter and accessory drive. Tiny little flywheel and a splined coupler. A little drive belt runs off the coupler and turns a two stage pump, fuel and power steering. That gets everything off the front of the motor. Ideally you want less weight in front of the mid plate. So starter ps and fuel pump all on the bellhousing.

Our paved oval super late model stuff was all reverse mount Tilton stuff. Only difference was we had to run an external 5.5" clutch in the bell housing and our transmissions were Saginaw 3 speeds with first gear removed. So basically a L-H-R box.

 

[YJ4Rox]

When I lived up in New England we built and raced paved short track cars. I've driven everything from a 4cyl charger car all the way up to super late models with decent success. I've always wanted to race a dirt car though, looks like a ton of fun sliding around out there. I moved to Texas 4 years ago for work and am surrounded by dirt tracks and chassis builders. Wife gave me the green light to buy one and go race but I somehow ended up building a SxS for short course racing. The alure of jumping 100' table tops won out.

I've looked at a few local sport mods set up similar to yours. The suspension and chassis dynamics blows my mind. Complete 180 from what I learned and know about setting up a paved oval track car!

I'll be watching this thread.

It’s different but similar. Rear and left % will be a little different and it’s all about rear steer.

it’s all about rear steer on dirt. I’ll get into what does what on my chassis one day. For me One of the hardest things has been anticipating how the track is going to change through the night.

the hot thing now is putting them on a pull down rig to get dynamic loading.

 

[YJ4Rox]

Running the cushion is fun I but reallllllly found a love for the dry slick. The slicker the better.

Last weekend was sprint car night so the track got super slick. It was so dang fun. I was fighting in the top 5 the whole race. I bumped the wall on the back stretch on the last lap. It shot me left so I tried diving under the 4th place car in turn 4. Ended up spinning out. I had to go for it, can’t settle for fifth. Well fifth sounds better than 16th

id have to count but we have ran more than 20 races. I hope to squeeze in a couple more before the weather goes to shit.

I had a couple of bad Races and second gained a bunch of points on me but I ended up with the track championship my rookie year. I led some laps Here and there and had a bunch of top 5s. No wins on the year yet which is extremely frustrating.

I tend to qualify shitty which I really need to work on. Well there are a ton of things to work on. I still really don’t know WTF I’m doing.

lots more to post.

any questions fire away. It seems like there are too many secrets and it makes it hard for people to jump in and race. I’ll answer the best I can.

its good redneck fun

 

[SLOWPOKE693]

the hot thing now is putting them on a pull down rig to get dynamic loading.

To a certain extent technology has ruined racing in my opinion. Buying your way to the front of the pack is easier today than it ever was due to technology.....


Are you allowed to groove your tires? Im running the same tires in the 27.5 x 8.0 x 15 size and grooving is allowed at the track im racing. Any pointers would be greatly appreciated.