Racing Secrets Revealed

First Impressions - Tenhulzen 4-Wheel Alignment System

by Roger

First Impressions - Tenhulzen 4-Wheel Alignment System

WIth the right caster, camber and toe settings, even the most mildly tuned track cars will turn some very impressive lap times. If you get your alignment settings wrong, $10,000 coilovers and custom control arms won't save you from the ignominy of last place. Believe me, I've been there.

Because of this, I've accumulated quite the collection of alignment and setup tools over the years, from my first set of toe plates to my arsenal of camber gauges to this surprisingly useful QuickToe tool. But none of the tools in my collection could effectively measure thrust angle (the alignment of the rear wheels relative to the car's actual centerline) or check all four wheels at once, which meant that once a year, I would have to take the Prelude on a long journey to the one person I trust to do alignments on my racecar. Enter the Tenhulzen 4-Wheel Alignment System.

What is it?

The Tenhulzen 4-Wheel Alignment System works using the age-old string alignment method. For those of you who aren't familiar with this method, the idea is that if you surround all four wheels of the car with a rectangle of string, you can measure the toe of each wheel against the true centerline of the car. This is critical in ensuring that the steering wheel will be centered when the car is going straight and that it won't try to drift in one direction when you let go of the wheel.

Although there are a number of other systems out there, including the popular SmartStrings system and this low-buck DIY method using jackstands, the Tenhulzen system offered a few unique features that piqued my interest. For one, the strings are mounted on a standalone rack rather than on the car itself. Big plus if you don't trust the straightness of your racecar's body panels (which you shouldn't). Also, the system comes with its own hands-free camber/caster/toe gauge that attaches to the wheel using metal "fingers" which are designed to stick onto any kind of wheel between 12"-20", regardless of whether they have curb rash or are made of aluminum. That was enough for me to put the $500 down to have one shipped to my garage.


Some Assembly Required

The press photos on the Tenhulzen website show the rack being used to align an Ultima GTR, a British-manufactured sports car known for being very wide for a kit car. So it was quite the surprise when the whole kit arrived, disassembled in a thin cardboard box no larger than a bass guitar: Even more surprisingly, the whole package was super light, weighing in under 15 lbs.

Unpacking the box results in the usual heap of tightly packaged angle aluminum arms, hardware and instructions to piece it all together. Assembling the outer frame was a straightforward process needing just three tools: a 3/8" socket, ratchet and the allen key that came with the kit. Putting my good friend Chris in charge of the assembly made the process even easier.

Unfortunately, the instructions provided with the camber/toe gauge had us thoroughly confused. I blame the pictures in the instruction booklet, which are too close up and hard to make out in black and white. We ended up piecing it together based on photos of the finished product from the website. If you run into similar problems while assembling your gauge, these photos of the completed product may help:

Front, side and rear view of the handheld camber / toe gauge, for reference purposes. You will need a 7/16" crescent wrench and a set of small allen keys to put the handheld gauge together.


Handle With Care

During the assembly process, we also discovered why the system was so light. All of the non-load bearing components of the system are made out of thin, flexible sheet aluminum. The center sections of the outer frames have long slots cut into them so that the width of the frame can be adjusted to accomodate cars of different widths. It turns out that if I press my finger against the metal in that slotted section, I can bend it pretty easily:


After playing with this for a few minutes, we drew two conclusions from this:

  1. While this is pretty amusing, it probably doesn't have any imapct on the use of the system. This slotted portion is doubled up against another piece of angle aluminum, so this piece won't bend like this when it's assembled. If used correctly, this section is also non-load bearing, so there's no reason to worry about it.

  2. The metal pieces of this system won't tolerate being banged around in a tool box or being stepped on by a careless mechanic. It would be wise to store this kit away from the hammers, spare tyres, and other heavy things that could potentially tweak the frame.

I'm actually happy that the engineer who designed this setup prioritized light weight over rigidity. I can only imagine what this setup would cost and weigh if they made it out of the same 1/4" thick steel like half of my Longacre tools. Astronomical and ponderous are the two adjectives that come to mind. What club racer wants to pay for that (and carry it around)? The guy who designed this system seemes to understand what people like us really need and what we can do without.


More than the Sum of its Parts

A closer look at the assembled product really shows just how much thought they put into the design of this system. Getting the system ready for an alignment is a breeze. Thumb screws make adjusting the frame width a snap.The reusable elastic strings store neatly onto spools mounted on one of the two frames. There are thin slits cut into the sides for the strings to hook into and clearly printed numbers virtually guarantee that you'll put the strings at the right height the first time. No tape, no pencils, and no spacers needed for this setup. Everything you need is cleverly built into the rack.

The built-in spool and the small notches cut into the frame are tiny details that takes a huge amount of frustration out of the whole setup process.

The hands-free camber / toe gauge is also a triumph of ingenuity packaged into a compact aluminum frame. I tested the hands-free-ness of this gauge against every wheel and tyre combination I had in the driveway, from chunky Hoosiers on aluminum race wheels to the knobbly 18" M+S shod-wheels on my FJ Cruiser to the skinny 16s on my wife's Subaru. The "finger" adapters that Tenhulzen has built into this gauge work exceedingly well.

The digital gauge used for measuring camber is one of those generic square box angle finders, which is adequate. It does have magnets on three sides though, and the gauge has a nice steel shelf for it to snap on to after a quick zeroing on the ground. My garage floor is 0.5 deg off level throughout the whole center section, so being able to zero the gauge and quickly take a camber measurement is a huge deal for me. It's features like this that make the difference between a pleasant setup session and a frustrating cavalcade of re-taking measurements.

Turn the gauge sideways and you'll see two metal rulers for measuring toe. The rulers are permanently mounted onto the gauge handle and swivel easily from a fully stowed to a 90 degree position. Compared to the metal straightedge that I normally use for string alignments, this will probably be a dream to use.

These little aluminum fingers are what makes all the difference. I wish all of my other alignment tools used these little guys.


Impressions and Thoughts

My first impression of the Tenhulzen 4-Wheel Alignment System is that it's a unique DIY alignment tool designed by someone who knew exactly what racers need. It's chock full of features that are designed to take the petty frustration out of setup work and I can appreciate every bit of it.

I am a bit wary of the thin aluminum used in the rack and the gauge though. Will this clever piece of engineering withstand the rigors of abuse by a careless club racer? Find out in the Hands-on review when we use it to give the CRX Si a whole new setup.