Zink Formula Vee

We're about ready for the first test run of the car.  We put some roller tires on it and took it off the table. 

It balanced pretty well when we grabbed the roll bar hoop with the hoist arm.  It was nose down maybe 2 feet.

Please excuse the mess behind the Zink.  We're painting the walls and we've moved everything around to do it. 

The pictures don't show it very well, but it's pretty nose-high right now, so we'll be fussing with the front ride height.

We just need to run the fuel lines, make up a temporary wiring harness to make it run, fill it up with fluids, and do one more check-over before the first drive.  We hope to do that tomorrow. 

Back in the day, everyone used 12" springs with some not very tough dampers and 100lb/in springs were common.  With modern dampers matched to the springs, I think heavier spring rates might be the way to go.  I just switched to 225lb/in springs with the dual-adjustable QA1 dampers and I've only done 1 test day, but I'm liking it a lot better than the 100lb setup.

In reply to Berck :

Thanks for another tip.  We really appreciate it.

We filled it with fluids, bled the brakes, cranked the engine until we had oil pressure, fixed a minor fuel leak, and it started very nicely.  There is no choke, so we had to hand-choke it (we used a putty knife to block to top of the carb opening).  Jack took a quick ride mainly in the parking lots of the shop and our neighbors, but did go down the street for half a block to run it through 1st, 2nd, and 3rd gears.

Looks kind of silly with oversize VW Bus wheels and tires, but now we know there are no major issues.

We threw all the remaining parts in it and put it on the scales so we'd have a good idea of weight.

We look like we'll be on target for the minimum weight of 825 w/o driver, maybe a tad more. 

We've been thrashing for the past few weeks because Jack's going to the VSCDA Gingerman Drivers School & Racing Weekend April 28-May 1.  We figured if we had the car running this weekend and pretty much finished (except paint) next weekend, that gives us plenty of time to fine-tune the setup and everything else.  

For paint, we're going to touch up the chassis with a brush and rattle can and run the body in gel coat with a meatball for numbers for Gingerman.  We'll blow it apart and paint everything nicely after a few races and some sorting.

Whew!  Plenty to do, but a little less pressure.

More progress and some detail pictures:

The dash had been cut off at some point so Theo made a new one. We think these new Stewart Warner gauges look sort of era-correct.

Except the back side of the tach, which is plastic.  Close enough.

For reference, this is the original dash in the other car. This car is a little earlier and has a different tube structure supporting the dash. 

Jack started working on the body mounting, which we hope to finish over the weekend.

I was at NAPA and they wanted me to try this new Bosch Lithium Ion battery.  They said the battery rep brought in some LS-powered truck and showed how well the battery worked even though it's meant for motorcycles, etc.  It's 3.5 lbs and we were going to use a 15lb Braille.   Napa said they'd take it back if we're not happy with it, so we're trying it.  Anyone have any experience with one of these?

Jack made the mount and it will fit the Braille if the Bosch doesn't work out.

The carb came from Quixote Racing in CA and the manifold came from Bigger Hammer Racing in TX, so we'll be able to give Bob his loaners back.   

Are you planning a structural front roll hoop around that dash?

The question with the battery centers around whether or not you're going to run a working generator.  Monoposto requires a generator, but other allow them to be gutted.  Mine is gutted and my experience with lithium batteries centers around the battery management software.  Most battery management software expects a working generator/alternator.  I tried one that started the car fine, but would disconnect a short while later.  It interpreted this as a "failed start" and shut down to save power for the next start.  Only, I need that power to run my ignition.  I'm running this one now and it works great: https://smile.amazon.com/gp/product/B07NVVPMST/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1  It doesn't have a fancy BMS, so it works fine.  Much lighter than the AGM motorcycle battery it replaced with more cranking power to boot.  I'm not sure how it compares in terms of total run time, but I can get a whole day out of it with hours of track time and many starts without charging it.  I've never tried to run it longer, I don't have any way of monitoring it, so I don't know what the limits are because I don't want to risk needing a tow back to the paddock.

Motorcycle experience with Li Ion batteries tells me that you need to be really mindful of charge voltages with them. On an old Moto Guzzi I modified, the manufacturer of the increased output alternator I used recommended an adjustable voltage regulator that allowed no more that 13.7v. Here's a short article to support this: https://adventuremotorcycle.com/tech-n-tips/rmstator-mosfet-voltage-regulator

Other than voltage regulation, I have a battery that will fit in my pocket but doesn't hesitate to kick a big twin that uses an automotive style starter right over. I'm a fan. 

Not sure how we haven't talked about Vees, but it's cool to see you guys working on these! My dad's solo Vee was a Zink copy, and he had tons of information on it, but sadly that went with the car when it was sold last spring. Not sure how useful info on a clone that was setup for solo would be, but I am still in contact with the current owner, whose uncle was the original builder in the 80's. Keep up the great work!

Nick N.

Please keep posting FV and other VW road racing stuff ,

There is tons of stuff on the web for VW drag racing  , not much for road racing.

From what I remember about my motorcycle lithium battery swap, I needed a Li-ion specific voltage regulator. I also have a Li-ion specific battery tender. Otherwise I've heard they tend to ignite if not properly regulated.

Fascinating.  

@Berck, We are planning on another hoop at the front that we'll figure out with a little more of the packaging and body fitting done. You've been giving super useful advice, so if you have thoughts or pictures, we're listening.

@Berck, Mezzanine, and machinenbau, Thanks for the notes about batteries.  We are running a generator and do have a charger that says it's compatible with Lithium Ion.  We'll keep everyone posted about how it works. We'll be taking a spare Braille AGM from another car along as a backup.

@californiamilleghia, Thanks for the validation that it's worth posting this thread.  Too much VW trivia in people's heads and not enough on the internet.

@Nick, I very seriously considered your dad's car when it was for sale.  It was really well done and a great value.

Back to work...

The body just needs a few more fasteners and it's properly mounted.  We've also moved the whole operation from the back room to the main shop floor as we go into the home stretch.

I have only a fleeting familiarity with Formula Vs (mostly, they piqued my interest from the periphery while working on other types if race cars).  But I find myself very eager to keep up with this thread.  I'll soak up as much as you share...Thanks!

I mainly worked on the front beam today.

I pulled the spindles and trailing arms in preparation for painting and putting the offset spindles on.

VW details: These screws and lock nuts hold the trailing arms on the torsion leaves and also hold the torsion leaves in position in the beam.

Formula Vee details:  Normally, there are torsion leaves in both tubes of the beam, but that would create too much spring rate as the FV weighs about half of a Beetle.  So the top leaves are replaced with a sway bar and the bottom leaves are dialed in for spring rate and ride height.  We'll be getting some guidance from Bob and other FV guys for the dialing in. 

I've also been painting the stuff that isn't black, black.  I'm using PPG DP-90LF epoxy primer with two thin coats (reduced 2:1:1 with DP401LF catalyst and DT870 reducer) . After this season, we'll be blowing the car apart for shinier paint, but for now we want a little rust prevention with the ability to see cracks or flaws.

Since Berck brought up gutted charging systems, here are more details. The black chassis came with a gutted generator, but the VSDCA requires us to have a charging system so we won't use it on this car.

This was originally a 6V generator that someone gutted. The armature was removed with just a shaft remaining to drive the fan.  The fields are gone.  And Speed Holes galore!

There is a little weight difference between the gutted generator and the stock 12V one we're going to run.

Also, fan details:

At some point, VW doubled the number of blades in the fan.  FV guys like the fans with fewer blades as they are lighter (I forgot to weigh but will later) and supposedly less drag.  

I love all the tricks and trivia these FV guys are teaching us.

So much cool information here!
 

Thank you Carl. 

Are you using the small diameter 12v generator which is the same diameter as the 6v generator .

hard to tell from the picture !

In reply to californiamilleghia :

I didn't know there is a small diameter 12V.  This one is a larger diameter one and I've changed the generator stand/oil fill on the engine.  What cars used a small diameter 12V?

Carl Heideman said:

In reply to californiamilleghia :

I didn't know there is a small diameter 12V.  This one is a larger diameter one and I've changed the generator stand/oil fill on the engine.  What cars used a small diameter 12V?

Some 356c models and  industrial motors , there were also some made by Bosch Brazil,

they are a little hard to find , but seem to show up out here at swap meets , they have a remote voltage regulator on the firewall.

Carl Heideman said:

@Berck, We are planning on another hoop at the front that we'll figure out with a little more of the packaging and body fitting done. You've been giving super useful advice, so if you have thoughts or pictures, we're listening.

I don't have anything to offer here, mostly in this case I was hoping maybe you did.  Mine's original with the fairly beefy-looking dash/integrated front roll hoop thing, but I'm totally unconvinced that it's sufficient.  I think plenty have survived rollovers that way, but I'm wondering if something else should be added.

Man, I didn't realize the weight savings from gutting the generator was that big.  That, plus the fact that you're adding extra drag to power the thing...

I highly recommend some sort of system to detect when you've lost the fan belt.  If you're running a CHT gauge you might notice it in time, but you'll have roasted a cylinder by the time you notice an increase in oil temp.  I run a universal pressure sensor tapped into the fan shroud calibrated to about 1" of Hg.  I think.  Unless it was 1" of H20.  Piped to a giant warning light on the dash. It flickers at idle but goes off above that.

As you've probably discovered, we run fan belts very loose, some people grease them to increase slippage.  In the old days, people would rig up a system to toss the belts on the final lap; this is now illegal.  There are people who do things like hook up a can of lubricant to spray the belt for a "push to pass" system, which may not be technically illegal, but sure seems like cheating.  No matter what you do, even a fresh belt fully tensioned will start slipping around 3,600rpm (somewhere near the beetle redline), so we go through belts pretty quickly.  I have better luck with the smooth belts, which are somewhat tricky to find as most of the available ones are segmented which tend to flip on me.  Oh, and once a belt flips, it's done--don't try to run it again.

Berck said:

Man, I didn't realize the weight savings from gutting the generator was that big.  That, plus the fact that you're adding extra drag to power the thing...

Its not just the guts that weigh a lot , it's that the large 12v housing is about 50% heavier.

Berck said:

I highly recommend some sort of system to detect when you've lost the fan belt.  If you're running a CHT gauge you might notice it in time, but you'll have roasted a cylinder by the time you notice an increase in oil temp.  I run a universal pressure sensor tapped into the fan shroud calibrated to about 1" of Hg.  I think.  Unless it was 1" of H20.  Piped to a giant warning light on the dash. It flickers at idle but goes off above that.

Since we're running the charging system, I'm planning on a HUGE idiot light/charge indicator.  If it lights up, the belt is probably off.

We've heard a lot about belt tension etc..  Thanks for adding to that.

Berck said:

I highly recommend some sort of system to detect when you've lost the fan belt.  If you're running a CHT gauge you might notice it in time, but you'll have roasted a cylinder by the time you notice an increase in oil temp.  I run a universal pressure sensor tapped into the fan shroud calibrated to about 1" of Hg.  I think.  Unless it was 1" of H20.  Piped to a giant warning light on the dash. It flickers at idle .......

Do you have a picture of how the sensor mounts .? And how you  wired it ?

Sounds like a great idea for any air cooled VW - Porsche - Corvair etc
 

Thanks