Drag racing requires a high level of vehicle optimization to be successful. There are numerous areas that can be tweaked and adjusted to extract the most performance possible. A proper front-end alignment is a must-have item in drag racing, but if you don’t have the right parts, it can be difficult to get the front end where it needs to be.
Project Number Cruncher’s front end consists of an interesting mix of OEM and aftermarket parts. Some of the parts the original builder used are less-than-ideal and made it difficult to give the Pontiac a proper alignment. We talked with the team at BMR Suspension about the issues we were having with the car. BMR sent the parts we needed to make sure we could get the best alignment possible.
Why Front-End Alignment Is Important
The three pillars of a front-end alignment are the caster, camber, and toe. These three measurements are important and we need to cover them before we dig into drag racing front-end alignment concepts. Proper front-end geometry is based on getting these measurements right.
Let’s kick things off by talking about caster. It can be described as how much of a forward or backward tilt a spindle has if you’re looking at it from the side of the wheel. When the wheel is tilted backward, that’s positive caster, and titled forward is negative caster. You measure caster in degrees, with the centerline of the spindle being perfectly vertical referenced as zero degrees.
Camber can best be described as how much a wheel is tilting in or out at its top. You express how much camber a wheel has in degrees, and it is measured off the wheel’s true vertical. When a wheel is tilting outward at its top, that’s positive camber; negative camber is if it has an inward tilt.
You’re going to see some pretty significant performance gains from an optimized and correct front-end alignment in drag racing, – Kyle Briese with BMR Suspension
Toe is the easiest front-end measurement to visualize. Toe is commonly defined as the difference in distance that can be measured from the face of a front tire and that of the trailing side of the exact same tire. When a vehicle has toe-in the front wheels will appear to be pointing in towards each other, while toe-out shows the tires pointing outward, away from each other.
Kyle Briese from BMR explains why these three measurements are so critical to a front-end’s geometry.
“Correct camber and toe settings create less rolling resistance and mechanical drag. Caster is adjusted to achieve a self-centering action in the steering, which affects the vehicle’s straight-line stability. You need the camber to be correct so you have plenty of grip, and so the tire is making as much contact as possible with the track. Toe is important because it makes sure the vehicle is going to go as straight as possible, this insures you don’t have to make any steering adjustments during a run.”
So, now we have a little bit of a knowledge base about front-end alignment measurements, let’s talk about why the alignment is so important. The front-end alignment is going to have an impact on how stable the vehicle is when it’s moving. The alignment also plays a role in how the vehicle is going to track and drive at high speeds during a run. The amount of rolling resistance a vehicle experiences can also be affected by the front-end alignment.
“You’re going to see some pretty significant performance gains from an optimized and correct front-end alignment in drag racing. Less rolling resistance and minimal steering input will help with MPH gains. Plus, the shortest distance between the start and finish lines is a straight line, so if you are turning the steering wheel you are losing time and speed. The alignment is also important from a safety standpoint. You don’t want to have a vehicle out on the track that is hard to control,” Briese says.
The Art Of Making Adjustments
Now that you know about camber, caster, toe, and why they’re important, it’s time to touch on how to make front-end alignment adjustments. Project Number Cruncher will be going to a shop to get its alignment after all the parts are installed, so we’re not going to get too technical with how you do an alignment. We take a deeper dive into the nuts and bolts of setting up a front-end alignment at home in this article here.
Briese explains how you should approach making adjustments to your alignment if any changes are made to the vehicle.
“Start with the rear and make sure it is where it needs to be, and check the thrust angle before moving to the front, as the front needs to be aligned off the rear axle. You want to set the caster and camber, then toe. After that, you can start looking at bump steer. There are a few things that people don’t think about when they’re aligning a front end on their own. You need to make sure the tire pressure is set, plus you want to make sure the vehicle is full of fuel, ballast, and the driver is in the car with all their gear on ready to go.”
Things happen and you might have to make changes to your vehicle’s alignment while you’re at the track. While this isn’t ideal, it can be done and is a good way to rule out chassis issues the vehicle might be experiencing.
“If you make adjustments at the track, you need a level spot. Some tracks even have chassis pad specifically for this. You want to make sure you can get back to where you started by using witness marks on any threaded adjustments and their jam nuts. It’s also important to take good notes and make small adjustments,” Briese states.
The Right Parts Are Important
We learned after our first trip to the track that Project Number Cruncher’s front-end alignment wasn’t ideal. The mix of OEM and aftermarket parts of unknown origins made it hard to put the perfect alignment on the car. We decided that the only course of action was to start from scratch and get the right parts under the front of the Pontiac.
The foundation for our updated suspension is a new K-member. This new tubular K-member gives us more adjustments and is set up for a manual steering rack. The 1-5/8-inch x 0.120-inch-wall and 1-1/4-inch x 0.095-inch-wall DOM tubing make this unit very strong, perfect for our setup.
The OEM A-arms that were still being used on Project Number Cruncher needed to go since they are heavy and lack any adjustments. By moving away from the OEM units, we are able to jettison some weight and make it easier to put a precise font-end alignment on the car.
“With A-arms, you are going to want something that is light, yet durable enough to handle the abuse of drag racing. Typically, most drag race A-arms are made of chromoly steel which is light but still strong. Also, some adjustable A-arms also allow you to adjust the track width of the vehicle. Pretty much all adjustable A-arms will give you additional alignment adjustability to be able to fine-tune the alignment for optimal specs for your application,” Briese says.
The final piece of our front-end puzzle was the manual steering rack. BMR makes a manual rack that’s a direct fit for our 1996 Firebird and its tubular K-member. The kit that BMR developed features a custom width that uses an extension that’s biased toward the passenger side. This relocates the steering shaft an inch toward the driver’s side and allows for improved header clearance. The BMR manual steering rack also gives us more adjustment options for the tie rods so we can properly set our bump steer. The manual steering rack that was on the car didn’t allow for this and it made driving the car a chore.
We’re looking forward to seeing what kind of improvements a proper front-end alignment will net us at the track. Thanks to the team at BMR we now have the right parts for the mission and shed some weight from the front of Project Number Cruncher.