My 57 drag Bug

[jacobnhra]

Gents,

I have a few, what you may classify as "elementary" questions about setting up a drag bug. I have a 57 that I'm getting ready to start on, this will be my first drag car build. This car will be a track only car(1/8 Mile as I have a track a few miles from the house). Just a little background on myself, I have a bit of experience building basic rail buggy's and dune buggy's so I have a good understanding of VW's. I'm looking to start out in the mid 8's which what little information I've read, shouldn't be too impractical(Your opinions would be helpful here). I'm looking at like a 1.5 year goal to be making passes with the car because I don't want to loose interest in the project. So I'm not necessary putting a budget on the build, I just want something practical to introduce me into the sport. I've always wanted to do it and I'm tired of looking at this bug sit.

My first question is, what would be better overall for rear suspension, adjustable coil over shocks and ladder bars or adjustable shocks and torsion bars?

What are the pros and cons to raising and shortening the rear torsion? I've looked at this a little bit but I feel like this is something not really necessary right now however I will be installing a weld in 8 point cage and am wondering if this is something I should consider doing now. Thoughts?

I appreciate all of your feedback I can get. I have a ton more questions but I want to take a few baby steps starting off so I can make some rational decisions on the build.

Thanks,
Jacob

[Chip Birks]

I have a heavy(2000 lb) street car that has run deep into the 7s. I ran stock 1960 torsion bars and spring plates, as well as oil shocks. The rear is lowered a couple inches. Front suspension was a stock width beam, with adjusters, again lowered, and used 90/10 front shocks for weight transfer.

I changed everything over the winter. New lowered 3 inch narrowed beam with dropped spindles, 29mm torsion bars in the rear with HD spring plates. Shocks all stayed the same. The car hasn't run faster or 60ft'd better than my previous best, but it no longer drags the deep sump on the ground when launching. It also feels quite stable at speed, so thats nice. I plan to put it deep into the 6's without much more than maybe some adjustable rear shocks. Torsion raise and narrow are on my wish list, hard to do gracefully on a real street car with back seat, I'd do it otherwise though.

[AZOffTheWall]

To get it to 60' better you need to weld in travel stops and preload the daylights out of the torsion bars, not very practical for a street car. Your other option is ladder bars and coils, also not very practical. Putting that pig on a diet will help too, it needs to lose a couple of hundred pounds at the very least.

[jacobnhra]

AZOffTheWall For a track only car, would you recommend coil overs and ladder bars over shocks and torsion bars?

[Chip Birks]

Are you hoping to run low 6s high 5s?

[Ol'fogasaurus]

Jacob, since you are a "rail guy" I feel free to interject here even though I am more of an off-road buggy VW guy now days as there are going to be a lot of things that are similar... in ways and a lot that are not. The same being between a rail and a pan buggy or bug: some things don’t necessarily transfer over too.

The VW bug is, like most cars are now days a unibody car, but with one main exception: the body is bolted onto the chassis/pan. There are 9 bolts per side, 4 across the rear, 2 on the shock tower and 4 in the Napoléon’s hat that are accessed from the underside of the car. I have been on the strip a few (few being the operating word here with $$$ being the main cause quickly followed by marriage) times with the last car being a unibody car. I did do the “frame tie” trick but later, when I was pulling the engine to change oil pumps, I ran into a problem… the car was “totaled” beyond what I was able to fix at the time (I didn’t know how to weld) so the body was scrapped. Basically what had happened is that the spot welds broke loose in the tunnel area between the torque boxes; the spot welds had broken lose and separated as torque was applied to the body.

First, the idea of a 1 1/2 year build because of the potential “loss of interest” being a great reason for the limit of time for the build (I’m well over 20 years on mine).

Just where are you on this build; e.g, how much tearing down or taking a part things have you done? If you have the seats and carpet out try taking a small hammer and go around the pan lightly tapping with the hammer and listening to the sounds it makes. You want to hear that metallic sound not the dull sound of rusted metal. I just went out and tried it on my pretty much completely rebuilt pan and was amazed on the different metallic sounds made in different parts of the pan and tunnel; I guess I pretty much ignored it during the build. I first installed the Brazilian pan halves (they are usually painted black) but they were so light weight I pulled them off and went to the heavier duty ones but they are still not the same thickness as the OEM ones are. I did add a 1” square tube down the body mount tunnel to add some strength.

On the tunnel: check the three main piercings, the shifter hole, the e-brake hole and the access hole for the sifter connector to the transaxle for cracks as on one of my buggies the e-brake hole was cracking to the point where additional welding of it shut could not be done.

I would weld the seams of the frame head as the three pieces are spot welded together and they can break lose with all the torque that could be applied on a hard launch. Off-road buggy guys often use the frame connectors to add additional support for the frame head. I would also weld the seams on the shock towers on the front beams.

I used to ride with a guy who was a VW factory trained mechanic and it was his suggestion to add at least two more, per side, connectors to add additional support for the pan to torsion tube connection. Stock there is the connection at the tunnel and a small hoop connection on the lower side of the shock mount casting on the torsion tube that supports the end of the pan. For both hard riding and a lot of torque the additional supports should be added.

When you launch hard the transaxle is busy trying to keep it’s guts from flying everywhere and the mount for the transaxle and engine are busy doing a conga line/”shake your bootie” dance which can be fatal for both the mounts and components they carry. The standard fix is to add a Truss Bar which is also known as a Kaffer Bar or a Traction Bar by some. Basically it ties the two shock towers together and also adds a direct support to the “Pickle Forks”/trans mount. If you had a IRS unit I would recommend the Mendola version; more expensive but adds an additional pair of connections to the trailing arm pivot bolts. Rails guys usually solve this same problem by adding a transaxle mount connectors directly from each of the transaxle mount tubes to the upper side tubes. I would also recommend welding the seams of the transaxle mounts together also. Spot welds are suspect in old metal cars and cars that are hard worked.

That is about as much help as I can realistically give. I hope it helps some.

Lee

[Ol'fogasaurus]

001.JPG

Just for reference/something to think about: this shows the heavier duty pan halves I installed which also shows the tubes I put into the body mount tunnels for some additional support. I almost forgot: the holes in the tube are crush sleeved which means that tubes were added and welded in place. More strength and it helps keep the moisture out of the tubes. The ends were also welded up solid too using a short block of solid square tubing.

Lee

[Ol'fogasaurus]

Many, many years a go I saw some pictures or film showing the top/roof of a car wrinkle as the initial loading during launch was spread around the car via the roof. One side of the front lifted while the rear torqued to the other side which is why I mentioned the stiffening to the pan I did for on the sand or off-roading.

If I did it again I would go to 1 X 2 X 0.090 wall tube. Square is OK but the rectangular tube would be better with the long sides vertical. I tried to see if I could find some of them again but I did run into this: http://www.aircooled.net/vw-drag-racing ... lkswagens/ I hope there is something in here that will help.

Lee

[gbaker770]

If the car has torsion bars currently you do not want coil overs. The spring or torsion is only meant to hold the rear of the car up. The shock controls the loading and unloading of the rear suspension. Best investment I ever made was putting good shocks on my car, it went from very inconsistent 1.50-1.70 60' time which were all over the place (very dangerous) to consistent 1.30-1.40 60' times in an 1850 lb street car.
Lots of people have gone really quick with stock and heavy torsions. Most drag guys step up to at least a 29mm bar.

[Chip Birks]

If the car has torsion bars currently you do not want coil overs. The spring or torsion is only meant to hold the rear of the car up. The shock controls the loading and unloading of the rear suspension. Best investment I ever made was putting good shocks on my car, it went from very inconsistent 1.50-1.70 60' time which were all over the place (very dangerous) to consistent 1.30-1.40 60' times in an 1850 lb street car.
Lots of people have gone really quick with stock and heavy torsions. Most drag guys step up to at least a 29mm bar.

What shocks are you running Gavin?

[gbaker770]

Custom Afco coilovers by Menscer Motorsports.
My car does not have the torsions in the housing.

[gbaker770]

IMG_0331.JPG

[gbaker770]

Leaves like this now.

IMG_0360.JPG

[Chip Birks]

Custom Afco coilovers by Menscer Motorsports.
My car does not have the torsions in the housing.

Back halved?

[gbaker770]

No, has old style heim joint/spring plate setup. Lummus used to use them back in the day and lots of off-road guys use them. Fits relatively in stock place but eliminates the torsion bars and beefs things up.
Not trick by any means but it works.
I'll see if I can find a pic.