IRS Rabbit circle track car

[Chris V]

A project I've been working on...

[perrib]

Did you bolt the adapter to the stock rear axle mounts. It is a unique way to keep both rear wheels on the ground around corners. It is better than the idea I had to cut the stock axle in half and make it pivot since you get camber change.

[FJCamper]

Hi Chris,

You are doing some beautiful work.

Remember that the rear torsion-beam axle was the roll stiffness for the rear end, and on a front engine/front drive, you need mucho rear roll stiffness.

It appears you can do this to your advantage with a fabricated adjustable sway bar. A big one.

FJC

[Piledriver]

Devious!

[Chris V]

Did you bolt the adapter to the stock rear axle mounts. It is a unique way to keep both rear wheels on the ground around corners. It is better than the idea I had to cut the stock axle in half and make it pivot since you get camber change.

Yes, it bolts to the stock mounts...with additional mounts to come. In case it's a total flop or it gets mangled in a wreck we want to be able to throw a stock rear beam back on it.

I used two passenger side control arms, and set the right side up with nearly -5 degrees camber at full-compression...while I set up the left side with -1 camber at full-compression and around +3 at what we expect to be full-droop.

We've got to take a stab in the dark at springs and swaybars, the car I helped with last year ran 75lb springs in the back and a rear swaybar (not typical)...In his first season he finished 3rd in points and grabbed rookie of the year.

It's not my personal fancy, but at the same time the owner/driver of the car is planning on a 16V swap in a class that's primarly 8V - so there's a lot of new rules we must abide by. The car is one helluva guinea pig.

[FJCamper]

Hi Chris,

You just mentioned that rear swaybars (for the front wheel drives) were not typical.

They're available but most setups don't really need them. The torsion beam axle itself is like a swaybar.

Your design should really increase your rear grip. Just be sure to work in the roll stiffness somehow.

FJC

[Chris V]

2000 Jetta front bumper, new center windshield bar:

New dash bar, "Petty" bar, .032" aluminum dash with beads rolled in - access for gauges, new steering column, splined quick disconnect steering wheel, Simpson cam-lock belts, 8-AN fuel line runs through a 3/4" EMT on the passenger floorboard, 1/2" EMT for future re-wiring of fuel pump(s), lap counter transponder, radiator fans, and wiper:


Oil pressure, water temp, oil temp:

13x8 Aero wheel with 2" backspace - hiding behind it a Type III rear drum:

1780cc, CNC ported head, some big cam, adjustable cam gear, header, Holley 350 CFM carburetor, MSD coil and stock Haltech distributor, nice new aluminum radiator w/dual fans:


6-fuse electrical marine panel...relays so the switches in the car don't actually handle the current - (S) solenoid, (F) fuel pump, (IC) ignition coil and another hiding back there for the rear window wiper:

Solid mounts:

Tapped 1/2" NPT for water temp sender...other holes filled with pipe plugs, JB weld and cam followers :

Stock throttle cable - new mount on valvecover, heat shield on header - still need to get some exhaust wrap, oil pressure sender:


Well, that's about it...it's kept us busy and poor.

[Chris V]

Well after two race nights - and being tech'd about a half dozen times the officials called the car illegal for the class...Not because it was built illegal, but because the rules were rushed onto paper and it "should have been written so" that the car is illegal. I'll never be back to the track. It was fast through the corners - and it required absolutely no rear sway bar. The left rear tire temps were 20*+ hotter than they've been before at ~106*

[FJCamper]

Hi Chris,

Your rear suspension project has proven "how it is" is again different from "how it should be." No rear sway bar, plus the IRS works the tires harder.

So much for beam axles. They apparently are just cheap, not that effective.

I'm sorry about the tech guys. The racer's war with them never ends.

FJC

[Chris V]

Hi Chris,

Your rear suspension project has proven "how it is" is again different from "how it should be." No rear sway bar, plus the IRS works the tires harder.

So much for beam axles. They apparently are just cheap, not that effective.

I'm sorry about the tech guys. The racer's war with them never ends.

FJC

We had HUGE springs on the car too...a 400# RF 375# LF/RR and 150# LR

The rules stated a suspension must only have stock manufacturer (not model/year) components and use the stock mounting points...accomplished. They argued that the car is now trailing arm and it used to be a straight beam - when in fact we know it was a torsional beam/swaybar WITH tubular trailing arms... It's not like I made the car double A-arm... Another argument has been that if this is legal than the 'Ghias and Bugs should be able to run a double A-arm setup since there are several on the market that bolt-up - but the same person with that half-ass argument is missing the rule where it says stock steering box in stock mounting - yada yada yada - show me someone who's running a double A-arm car with stock Beetle steering box in the stock location

The last thing the tech who made the call said, "well since you mounted it in the stock location it should be easy to change back"

[perrib]

Sorry about the bad interpetation of the rules. It happened to us 33 years ago and goes on every weekend. Now it might be time to make the stock rear beam pivot in the middle.

[Chris V]

... Now it might be time to make the stock rear beam pivot in the middle.

I keep hearing that...and it still sounds beneath me...The car owner will probably go in that direction though.

[Chris V]

Old photo...rear end is still illegal...

[Chris V]

Some of Dad's old photos:

[ministockracer#7]

Chris, looking at those pics sure brought back some memories. Thanks for posting them.

Mike.