Penske Racing Shocks Blog

The Most Common Racing Suspension Issues and How to Fix Them

Written by Aaron Lambert | Dec 27, 2021 3:10:00 PM

In the modern age, it's human nature to turn to Google when you're experiencing issues with, well, anything. 

When you're having trouble with your suspension setup, you could end up down a rabbit hole of forums and websites offering their thoughts and possible solutions. It can quickly become overwhelming, especially if you're not an expert on the finer details of your race car.

Your overall performance is tied to every component of your car working optimally, and once you've tuned your race suspension, there are common issues that might crop up. Fixing them doesn't need to be complicated. It will take some experimentation, but that's the fun part! The result is a car that handles how you want it to.

 

Common Racing Suspension Issues and Solutions

Successfully setting up a racing suspension depends on the driver's preferences. Common racing suspension issues can lead to frustration and loss of time and money.

Some drivers like a loose suspension and can handle a vehicle that moves around more, while others need a more stable platform. 

Which one are you?

The only way to find out is through trial and error. Below are 6 of the most common racing suspension issues and possible solutions.

 

1. "It's a Rough Ride."

If your complaint is about a rough ride, there are a couple of things to think about. Generally, it's because the springs are too stiff or too soft.

Springs

Cars sprung too softly will hammer the bump stop or even ride on the bump stop. When springs are too soft, you're more likely to bottom out - especially if you already like your ride height low.

Conversely, there's a misconception that stiff springs will make your car faster. A stiffly run car and a suspension that doesn't move isn't compliant most of the time.

Lastly, with no suspension, your tires have to do all the suspension work and can't create the maximum mechanical grip.

Shocks

Stiffer shock rates slow spring movements, while a softer shock rate allows the spring to move faster. If a shock is too stiff, it can cause the tire contact patch to bounce off the road surface over bumps, making your car feel less predictable.

However, too soft shocks will make the body of your car bounce after hitting a bump or rut. How do you find the right balance?

Solution

You need your springs to be soft enough to maintain contact with the track and provide a ride that strikes the right balance between comfort and performance. Race tracks tend to be smoother than regular roads, so a slightly stiffer setup would work.

Stiffer springs will make your chassis more responsive, improving lateral grip, and reducing travel.

You could also experiment with raising your ride height to avoid bottoming out.

Low-speed compression is essential for stability. With stiffer low-speed compression, you can have a softer spring rate offering more mechanical grip. It's a trade-off.

You could also choose speed and mechanical grip around a corner and put up with a bump. Some drivers are OK with that. There are specific sectors or areas of the track in any race condition where you can gain an advantage. Sometimes focusing on the handling in these sections can lead to lower lap times. That doesn't necessarily mean you will handle better at every corner, but sometimes maximizing one area will make you faster than your competition.

If the ride does feel too stiff, you can soften the compression damping, meaning your suspension will be more compliant, move around a bit more, and give you a more subtle feel. 

Tire temperature is an excellent indication of being too stiff or soft. Stiffer setups tend to increase tire temperature quicker, typically giving the tire a shorter life span. Where softer, more compliant setups take longer to increase tire temperatures but increase the tire's life cycle.

 

2. "My Car Feels Soft."

An unbalanced suspension lets your car move around too much, especially on corners.

If your car is too softly sprung, you can't control the attitude of the car or the load on each corner. Low-speed damping that's too soft coupled with a low spring rate makes for an unstable car.

Solution

A stiff spring needs the proper shock. If the car feels soft, increase the spring rate. If a stiffer spring feels better from a mechanical grip point of view and feels more stable, both will help your performance.

Sometimes a faster car isn't a better handling car, and the "balance" is typically more important for driver feel. A well-balanced car might be faster for an overall lap vs. a car with optimized handling that is not comfortable.

You could experiment with added preload, increase spring rates, or try a spring rubber.

Get comfortable and confident first, then worry about optimizing damping. Compression or rebound will affect how the car handles and tire wear. Your best bet is to try making adjustments and testing, working from a baseline until you find the optimum setup.

 

3. "My Brakes Don't Feel Stable."

Braking can sometimes be an afterthought because drivers think about going faster, not slowing down. But braking effectively and efficiently is essential, especially going into corners.

Nosedive

When you don't have enough front compression, you might nosedive as you enter a corner because you're transferring weight very quickly to the front of the car and overloading the front tires.

Solution

Increase the front compression to limit weight transference. Springs and shocks go hand in hand, so you could also increase the spring rate on your front springs to limit nosediving.

Rear Pitching up

If you nose dive, the rear of your car will pitch up, which could be a combination of not enough front compression or not enough rear rebound.

Solution

Increase rear rebound and front compression, and try them independently. If you change both simultaneously, you won't know which one helped.

Setup is too Stiff

If your whole setup is too stiff, the suspension doesn't move or dive when you brake, and your tires become instantly loaded. Once the tires meet the maximum load they can handle, they will lose grip.

Solution

Soften springs and compression damping.

 

4. "I'm Struggling With Understeer."

Turning the steering wheel harshly or at speed might result in your front tires losing traction, forcing the nose of the car to slide wide across the track or 'push,' typically as you approach a corner.

A corner comprises three different sections: Entry, Mid-corner/Apex, and Exit. If you don't go into the corner well, you won't recover well.

Entry Understeer

As you enter a corner, you'll start to steer and apply the brakes, loading the front end of the car. If your front compression is too stiff and you load the front tires too quickly, when you turn the wheel, you've reached the maximum weight the tires can take, and they won't grip, causing your car to slide.

Solution 

Make everything softer on the front by reducing low-speed compression and making the front springs softer,  allowing the front to move slightly more.

Apex Understeer

As you enter the corner, the weight transfers to the car's front, but when you move into the corner's apex, the weight will start shifting to the car's rear.

Solution 

Increase front rebound to stop weight transferring too quickly to the rear and losing grip in the front, allowing you to turn. Decreasing the rear rebound would have a similar effect.

Exit Understeer

Once you're back on the throttle, through the apex, and trying to steer, the car might not go where you want it to go. Your front rebound might be too stiff, making the front end feel like it's locked down because there's no weight transference.

Solution

Reduce front rebound and retest. If you reduce the rebound too much, the weight will transfer backward too quickly, meaning your front tires lose traction. 

Increase rear compression if the weight transfers too quickly. Make the balance better, but be warned, you'll take grip away from the tires, and it's usually driver-dependent.

 

5. "Oversteer is a Problem."

Oversteer is when your car rotates more than the angle requested by your steering input, causing the rear tires to slide sideways as you enter a corner.

Entry Oversteer

Front compression is too soft. As you brake entering a corner, and the car pitches forward, the rear of your vehicle will feel light and, as you turn, want to come around. 

Solution

Increase front compression, especially low-speed, to make it a little stiffer and slow down weight transference. Stiffening your front springs has a similar effect.

Apex Oversteer

As you get back to the throttle, if the rear springs are too stiff, the rear tire can't take the same load as it does in the front and gives you the loose condition.

Solution

Decrease front rebound and soften your rear compression or spring rate. Remember, some drivers like a loose car and can control using the throttle; others don't.

Exit Oversteer

Once you're back on the throttle and you hit it hard, you need to reduce the front rebound to allow you to load the rear tires harder by transferring the weight. If you can't load the rear tires, you'll lose traction.

Solution 

Reduce front rebound and reduce rear compression. How much will come down to making minor adjustments and testing. Find a balance.

 

6. "My Racecar Isn't Handling Well."

Lack of confidence in your car's setup leads to poor performance. Finding the right balance between stiff and soft springs and suspension is paramount.  

The wrong setup also leads to tire wear. Aggressive, stiff suspension burns your tires up, and too-soft suspension doesn't allow your tire temperature to reach optimum levels, meaning loss of grip.

When your car is underdamped/overdamped and not controlling the sudden input, you won't feel confident that you can handle the car.

Solution

A compliant setup. Your suspension should fully absorb the impact of any bump at any speed to keep your tires in contact with the track. You can achieve the desired setup by testing and retesting. In our experience, springs and shocks are often set up too stiff.

Another often overlooked element is the sway bar. They help your car handle turns and prevent body lean, but they're like a band-aid. They can also mask what you're trying to do with your shocks and springs.

Sometimes it might be worth disconnecting the sway bar to see if it improves drivability. If you don't get results from adjusting shocks and springs, take the bar away and see if the driver notices improvements.

 

It Takes a Team Effort

Now that you know the most common racing suspension issues, the best way to overcome them is by working with suspension experts to optimize your setup. Just buying the right parts isn't the whole solution.

 

This detailed webinar sheds more light on common racing suspension issues and how to solve them.