Wheel Hop: The Dreaded Mustang Suspension Issue

Wheel hop is where the rear wheels will hop or sort of jump, but very quickly and violently, almost as if the rear end is going to fall out of the car. It only occurs during quick acceleration at the line as the wheels are trying to put the power down. Wheel hop is caused by the rear wheels being allowed too much motion in relation to the chassis and struggling to get grip. 

Think of it like this. As you push the throttle, the wheels go into motion, but as the wheels move forward, the toe angle changes and you lost grip. As your Mustang loses grip, the wheels spin and your acceleration is drastically reduced which causes the wheels to go back to their original toe angle. The tires regain grip, and then the process continually repeats itself until you let of the gas or get out of the hole. It's a quick back and forth between accelerating and spinning the wheels which is caused by the change in toe angle, affecting the contact patch of the tires.

Answers to that question vary depending on your driving style. If you are a person who is interested in auto cross or just cruising around the streets, it shouldn’t have as large of an impact as it would for a drag racer. For drag purposes, wheel hop can be detrimental to track times. However, the fixes for wheel hop are generally the same for all applications. Owners can upgrade the tires, the vertical links, and even the subframe itself on the 2015 Mustangs.

While suspension can always be improved, wheel hop is one of those things generally attributed with an independent rear suspension setup. Wheel hop however, can be extremely stressful on a chassis/suspension setup. The constant change of tires spinning/not spinning puts a heavy load of strain on the vehicle itself. As a result, if it is constantly being applied to the car, parts will wear down quicker than if treated.

A good idea to consider first is to upgrade the vertical links. They're a simple upgrade that takes a handful of hours at the most. They allow you to launch harder and corner faster as well. Upgraded vertical links don’t deflect under load, and they increase the power output to the pavement by having good tire transfer. They are generally different bushing options for different applications and are a cheap upgrade for a lot of benefit. For most fair weather track goers, this is the most that one could need in certain cases.

Getting rid of wheel hop is not as difficult as some people tend to think it is. You need to readjust your 2015 Mustang’s suspension with a few readily available aftermarket parts that could be installed at home with a jack and the right set of tools. The main components you’ll want to consider to get rid of Mustang wheel hop are:

• IRS Bushings
• Vertical Links
• Toe Links
• Subframe Bracing 

Not only will these mods help to eliminate your S550’s wheel hop, but they will also work to give you improved handling in a straight line as well as around a turn.

From Ford, the S550 uses rubber IRS bushings that leave a lot to be desired in the handling department as they transfer a good bit of deflection and movement from the chassis. A good aftermarket set of IRS bushings will replace the stock ones with a urethane bushing that will greatly reduce wheel hop by cutting down on IRS differential movement. Generally these don’t cause too much (if any at all) NVH, but will give you a much firmer ride and launch.

Vertical links are to the S550 what lower control arms were to the S197 and previous live rear axle (LRA) Mustangs. The factory S550 vertical links are made from stamped steel which tend to flex under load/acceleration, causing wheel hop. A lot of aftermarket Mustang vertical links are made from lightweight and strong aluminum which will keep your rear wheels firmly planted, delivering power to the pavement. Another key factor in vertical links is their bushings. They're either a urethane or a delrin bushing that has a lower coefficient of friction and is much stiffer than the stock alternative.

A much needed upgrade for lowered Mustangs, toe links are the main issue in wheel hop and one of the most direct ways to address wheel hop. The stamped steel factory toe links are non-adjustable while aftermarket options are typically adjustable and made from strong steel, allowing you to dial in your S550’s handling. An aftermarket set of toe links will allow you to find that ideal setup with your suspension so even while under hard acceleration off the line, your toe angle will remain as close as possible to where it was while sitting still.

A large part of the S550’s wheel hop is a direct result of the subframe’s movement during off the line acceleration. To address this directly, many Mustang aftermarket parts companies have released subframe braces that stiffen the subframe up, eliminating any movement. Subframe braces will improve off the line acceleration (killing wheel hop), hard braking, and spirited driving, while not adding much weight at all.

Reviewing what we have covered, there are multiple ways to help aid the fight against wheel hop. Wheel hop is the constant change in traction/spinning of the tires that can be quite stressful on a Mustang’s components. Parts can be upgraded from vertical links, subframe connectors, lowering springs, to the tires themselves. Fixing wheel hop is crucial to drag racing times and has a large impact on the outcome of getting a Mustang moving down the track. To summarize:

• Vertical links are a great first upgrade
• Tighening up your suspension will help eliminate wheel hop
• Tires have a large impact on a car’s traction
• Subframe connectors can also be utilized and help with both handling and launching
• Leaving wheel hop untreated can wear down parts in a quicker manner than if fixed