Kohrt Racing

Drag Racing Team

Project 68: Improving power to the ground


The next major project at hand in its goal towards the strip for Project 68 is putting power to the ground and working towards the rear end. Drag racing requires two basic concepts, making power and putting it to the ground effectively.

Now, unfortunately, this is not a Dana car, however, a beefy 8 3/4 Mopar will do the trick for now and has Project 68 in the right direction. After evaluating what was around it, however, it was clear sweeping changes were needed for the 30-year-old out-of-date pieces.

Out with the stock axles including a bent driver’s side and in with new 35-spline Moser Axles. I’ve always been a fan of Moser Engineering’s work from afar so it’s exciting to finally get my hand on some of these for myself.

After getting the appropriate bearings on, I made sure to draw a straight marker line on the axle before installation. This gives me a quick and easy evaluation of the twist on the axle the next time it’s out with hope the line is straight and true. Drag racing creates a significant amount of torque and axles twisting is no bueno!

Since I had the axles out, of course, the center section became the focus as we went to 3.91 gears and a new differential.

Initially, by default, I’ve always had the Eaton Detroit Locker on race cars in the past, but after talking to friends at a local driveline spot, Front Range Driveline in Colorado, I was talked into the Eaton TrueTrac, and boy am I glad I listened to their advice.

For a street/strip application, the TrueTrac system seems to be a mix of straight-line power and ease of usage on the road. Acting as an open on the road but locked while applying horsepower. This is seriously voodoo-level work.

Described by Eaton on their website. The TrueTrac is a “helical-gear style, limited-slip differential that maximizes wheel traction and enhances driving characteristics. Maintenance-free, it features smooth, automatic operation in forward and reverse. Its versatility makes Detroit Truetrac the ideal traction solution for almost any type of vehicle.”

It’s all that and some wrapped in a small application that I’ve been very happy with. It knows to transfer power when it’s slipping on one side. Someone smarter than me could probably explain it better, but I know it as a piece that’s executed perfectly and no clicking or destruction of rear tires to boot on the street (locker users know the struggle) this may be the best part I’ve put on the car thus far.

Next up is brakes. Upon purchase of the vehicle it was old, rusty drums all around, and since we’ve done the axles, gearing, differential and setup new lines it was only fitting we go all the way with new disc brakes.

After a nightmare attempt at cutting corners with a cheaper brand, I have to thank my friends at Summit Racing for helping me out immensely in swapping out the junk for Wilwood rears. Since we’ve gone through the trouble of disc all around and new lines, of course, a fresh new master cylinder completes the brakes project.

Following the concept of my purchase with Moser where I was always a fan of Wilwood from afar. I’m a first-time purchaser of Wilwood and I’ve been a fan so far. I’ve heard of dragging pads from fellow racers but have yet to experience any sort of situation. They stop well, went on easy and look great in the process. For front disc brakes, I went with Classic Industries with plans to switch to Wilwood in the future.

Now you can’t talk about improving power to the ground without talking about tires and suspension! With the full system planned for the future, I’ve gone with the split mono-leaf spring from Caltracs with the intention of the full system going on in the near future. Along with this, I’ve thrown DOT Drag Radials from Hoosier on the car. I have always liked the Hoosier brand for traction and air retention. They’ve never steered me wrong and I continue this usage. The 275/60R15 or 28×10 tire fits snug to the spring so a spacer is added to give a little more space between spring and slick for comfort during usage.

The rear-end is the often forgotten piece in the puzzle when it comes to a race car. Exciting to report back a strong rear-end performance and stout consistency with no tire spin during our first season of racing!

Project 68 is a life-long dream of Mopar fanatic and second-generation drag racer Ronnie Kohrt to build from the ground up a 1968 Dodge Charger to drag race across the country. It’s a behind-the-scenes look at the grind of restoring a car without the glitz and glam of big money, a large shop or a race team. Just a middle-class guy with a passion for horsepower and vehicles.


September 2023