FAQs & Tech Tips

MM News

NASA Racers! MM will support NASA road racers with $1,000 contingency prizes for the American Iron, American Iron Extreme, and Spec Iron at the 2019 National Champions. You must register to be eligible.

New! Read the article Maximum Motorsports Tames Fox & SN95 Mustang Rear Suspensions on FordMuscle.com.

MRT Exhaust! MM now offers premium MRT cat-back exhaust systems for 1996-2004 Mustangs.

New! for Street & Strip Mustangs! Big-bore rear wheel cylinders for 1979-1993 Mustang with 9" drum brakes. Improves braking when running big rear tires and front skinnies, and/or different OEM front brakes.

New! Swapping a Coyote into a Fox Mustang? MM's Hydroboost Conversion Kits allow easy installation of a 1996-2004 Mustang Hydroboost power brake assist unit into a 1979-1993 Mustang.

New! Swapping an IRS into your Fox Mustang? MM makes it easier with a brake line kit made just for this conversion. Bolts-in, with no cutting or flaring of brake lines. Designed to fit standard IRS brake hoses.

New! MM's billet aluminum Pedal Box Spacer for Fox Mustangs. Replace the breakage-prone OEM plastic spacer when converting to manual brakes or Hydroboost.

Canadians! Please read the latest about ordering from Canada/shipping to Canada.

/DRIVE
We've posted the parts list and link to the video of MM's Mustang in /DRIVE Tuner car Shootout

Maximum Grip Box, 1979-1993 Mustang
Actual product may differ from photo.

$5,398.14

  • Item # GB-1
  • Manufacturer: Maximum Motorsports
 

 

The Maximum Grip Box will completely transform the way your Mustang handles. This comprehensive, customized package does everything you need to make your ride reach its full handling potential. It stiffens the chassis, upgrades both front and rear suspensions, and features adjustable components so you can tune handling characteristics however you want. The carefully matched parts in the Maximum Grip Box will turn your Mustang into a world-class performance car-you won't believe how it performs. Our customers say it's like magic!

Each Maximum Grip Box is customized to suit your needs; it's not a one-size-fits-all package. We help you choose the right parts to make your Mustang ideal for your exact situation and driving style. Whether for the street or track, a Maximum Grip Box is the obvious choice when you've got to have the best for your Mustang. This is the package used by winners in the NASA American Iron series.

Install a Maximum Grip Box and you'll enjoy...
  • Dramatically increased traction, both when cornering and in a straight line.
  • Tunable handling balance to fit your driving style.
  • Amazing cornering stability and predictability.
  • Much quicker steering response.
  • Far less brake dive.
  • Greater comfort when cornering due to reduced body roll.
  • Amazing ride quality for a street setup-firm but not harsh, as expected of a high-performance car.
  • More chassis stiffness, giving superior ride quality and handling.
  • Ideal ride height, because it's adjustable to suit your preference.

Customized for your Mustang!
While the price displayed on this page is for the most basic Maximum Grip Box, with MM you don't have to settle for a standard package. Our talented Tech Associates will help put together a custom package to fit your needs perfectly. These are just some of the available options:

  • K-members for engine swaps
  • Front control arms for competitive road racing
  • Rear control arms for street, drag racing, or road racing
  • Torque-arms for moderate or big power
  • IRS swap
  • Swaybars for any situation

See the How to Order tab and the Options tab for info about all the parts in this Maximum Grip Box, along with the choices you have to make to get the set-up you want.

We highly recommend you take advantage of our Tech Associates' skill and experience to provide recommendations for your car setup by choosing "Maximum Grip Box Setup" from the options listed on the Technical Services page. This becomes a necessity when choosing a front or rear swaybar, or if you want to retain aftermarket parts already on your car. However, we can't help unless you provide the basic info about your car that we request in the Maximum Grip Box Setup Form linked on the Technical Services page!

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

Requirements

This Maximum Grip Box is designed for Mustangs equipped with certain specific items. While the GB-1 is listed for 1979-1993 Mustangs, 1979-1986 Mustangs must be upgraded to 1987-1993 V8 Mustang specs.

All 1979-1993 Mustangs must be equipped with the following parts to accommodate a Maximum Grip Box install:
  • One of these engines: 5.0L pushrod, 302, 351W, 4.2L, 3.8L, 2.3L, 4.6L/5.4L modular, 3.8L V6, 5.0L Coyote (2011-2014), or LSX engine.
  • 8.8" rear axle assembly
  • Spindles from a 1987-1993 V8 Mustang or any 1994-2004 Mustang. We have extensive Tech info about spindles.
  • An Oil Filter Relocation Kit is required for some Ford engines with an OEM oil cooler. This includes all 4V Cobra 4.6L and some 2V GT 4.6L engines, but not the Coyote engines.

Please get familiar with the parts included in the Maximum Grip Box, as listed on the Options tab. Most parts are available in multiple varieties. While it's pretty common to need help from an MM Tech Associate to decide which variety of any particular part is best for your Mustang, when you understand the basic options we can help you better.

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

Once you have a list of the exact parts you need, either place your order from this page and then type your list of parts into the Comments field located on the checkout page, or place your order by phone.

Keep in mind that customization also means that we can delete items from a Maximum Grip Box. If you already have some parts from another manufacturer, let us know and we'll check to see if they all play nicely together. On the other hand, if you're ready to load up your Mustang with a complete engineer-designed and track-tested handling package that will drop jaws, we'll hook you up.

The basic kit on this page shows the starting price. After you place an order, we'll give you a sales quote detailing all the parts you've chosen for your customized Maximum Grip Box, showing the current pricing.

What's my next step, you ask? Go to the Options tab. Or the Help Me tab.

Customizing your Maximum Grip Box means choosing the best combination of parts for your Mustang from the available options. Listed here are the options for each part in the Maximum Grip Box. You may be able to choose the most suitable part after reading through the descriptions in this section, but if you need help, knowing the available options makes your conversation with an MM Tech Associate go more smoothly. Just take it step by step, and all will become clear. Options appear in order of importance. Follow the links to the individual product pages and make note of your choices and questions.

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

Getting started
The heart of your Mustang's high-performance handling is the combination of springs and dampers. Spring rates should always be chosen first, before dampers, to suit your desired combination of performance and ride quality. In other words, the choice of spring rates guides the damper choice.

Springs
Front and rear coil-over springs are available in a wide range of spring rates. While an MM Tech Associate can help you choose, please read the coil-over section of our Guide to Choosing Spring Rates and Dampers first. The goal is to choose a front spring rate that's at the intersection point of optimum handling and ride quality. Your preferred mix of handling and ride quality, and the choice of front spring rate to achieve that, is the single most important decision to make.

TIP: If a soft front coil-over spring is most suitable for you, a stock-location rear spring will be a better match than a rear coil-over setup. An MM Tech Associate can match the rear spring to your front coil-over spring rate. Choice of rear spring type (stock location or coil-overs) will affect your choice of rear lower control arms.

Dampers Once you pick spring rates, the damper choice becomes easier. MM 3rd-Generation struts and shocks are available in 4 different series, with each matching a specific range of spring rates. This is detailed in our handy Guide to Choosing Spring Rates and Dampers.

Damper choices Coil-over Conversion
The dampers you choose affect the model of the coil-over conversion kits required. MM kits fit specific struts and shocks; we don't make an ill-fitting universal kit like the others. Choosing your dampers narrows down the choice of coil-over conversion kits:

Good work! Now go to the Options 2 tab.

K-member
Choose one of the 3 MM K-members available:
  • MMKM-1 fits 1979-1995 Mustangs with an OEM engine type: 5.0L pushrod, 302, 351W, 4.2L, 3.8L, 2.3L.
  • MMKM-2.1 fits 1979-1995 Mustangs with an engine swap: 4.6L/5.4L modular, 3.8L V6, 5.0L Coyote (2011-2014), or LSX engine.
  • MMKM-3.1 fits 1979-1995 Mustangs swapped with a 4.6L modular engine and a Hellion turbo kit.

Note: An Oil Filter Relocation Kit is required for most applications with an OEM oil cooler. This includes all 4V Cobra 4.6L and some 2V GT 4.6L engines, but not the Coyote engines.

Front Control Arms
Choose one of the many different MM Front Control Arms available.

First decision
Choose Fox length or SN95 length:
  • The MM Fox length arms slightly increase the track width, moving each front wheel outward 1/4" compared to stock control arms.
  • The MM SN95 arms are longer than MM Fox arms and move each front wheel outboard an additional 0.9" over the MM Fox arms. Typically, competitive road racers use these to widen the front track for increased cornering grip. Note that extensive fender modifications are usually required with this option.
Second decision
Choose the offset. This refers to the fore-aft location of the ball joint relative to a stock front control arm:
  • Reverse-Offset: When installed with an MM K-member, this option retains the stock wheel base. Used to keep the tire in the stock fore/aft location, causing no interference between the tire and the front of the fender.
  • Non-Offset: When installed with an MM K-member, this option moves the front wheels forward by 3/4". Used to provide increased caster and slightly improved weight distribution. This option has potential for some tire interference (depends on tire size), but can usually be accommodated with minimal modifications that do not affect the exterior paint. We have instructions for the modifications.
  • Forward-Offset: When installed with an MM K-member, this option moves the front wheels forward by 1.5". Used to provide significantly increased caster and move the center of gravity rearward, this set-up requires significant fender modifications for tire clearance.
  • Drag Race: We omit the front swaybar endlink mount to reduce weight. This option is non-offset. See Non-Offset description above.
Third decision
Choose the pivot bushing material:
  • Urethane offers excellent performance and slightly less NVH than Delrin bushings.
  • Delrin is recommended for track-driven Mustangs due to much-increased longevity over urethane, along with reduced friction.
Making those 3 decisions will lead you to one of the control arms listed on these pages:

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

You're almost done! Now go to the Options 3 Tab.

Torque-arm
Choose one of 3 MM Torque-arm kits, using your Mustang's power level as the main decision factor. Be sure to follow the link on those Torque-arm pages to the Torque-arm Ordering Questions page. Rear Lower Control Arms
Choose the series of MM control arms. The primary difference is the horsepower rating.

If you're using stock-location rear springs instead of coil-overs, rear lower control arms with adjustable ride height are available in the Heavy-Duty and Extreme-Duty series, as well as a Drag Race series for Mustangs with big power.

Caster Camber Plates
Front coil-overs require steel caster camber plates with spherical bearings. Your Mustang's chassis year determines which MM Caster Camber Plates you'll need. Choose the main plate finish: either black powdercoating or chrome plating.

Subframe Connectors
Choose the finish of the MM Full-length Subframe Connectors:
  • Bare steel (you paint)
  • Black powdercoating

Adjustable Rear Swaybar
This is the one part that usually requires consultation to determine which size swaybar is best for your Mustang's setup. We highly recommend you get help from our setup engineer when choosing the rear swaybar. To do so, select "Maximum Grip Box Setup" from the options listed on the Technical Services page. Remember, we can't help unless you provide the basic info about your car that's requested in the Maximum Grip Box Setup Form linked on the Technical Services page!

Bumpsteer Kit
Choose the bolt-through kit that matches your front control arms (Fox or SN95). If you're swapping an SN95 steering rack into your Fox chassis, read SN95 Steering Rack Upgrade for Fox Mustangs.

Steering Shaft
Choose the shaft that matches your steering rack:
  • MMST-11 for Fox power steering rack.
  • MMST-12.1 for Fox manual steering rack.
  • MMST-13 when swapping to an SN95 steering rack.

Front Swaybar Relocation Kit
The MM Fox chassis Front Swaybar Relocation Kit (MMFSB-50) is required in all cases except when using the MM Reverse-Offset Front Control Arms. The swaybar relocation kit requires universal front swaybar bushings.

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

Just one more set of decisions! Go to the Options 4 tab.

Front Swaybar Bushings
You need to make a few decisions about front swaybar pivot bushings:
  • Which front control arms did you choose? The MM Reverse-Offset Control Arms do NOT require the Front Swaybar Relocation Kit, so use standard replacement swaybar pivot bushings.
  • All other Front Control Arms require the MMFSB-50 Front Swaybar Relocation Kit, which in turn requires universal front swaybar bushings.
  • After determining the type of bushings you'll need, select the correct bushing size for your swaybar diameter.
  • Note that some aftermarket front swaybars include new standard replacement swaybar pivot bushings.

Front Swaybar
While not included as standard in the Maximum Grip Box because the stock front swaybar is suitable for most uses, we can add a front swaybar to the package if you want. If so, we highly recommend you get help from our setup engineer with choosing a front swaybar. To do so, select Maximum Grip Box Setup from the options listed on the Technical Services page. Remember, we can't help unless you provide the basic info about your car that's requested in the Maximum Grip Box Setup Form linked on the Technical Services page!

Panhard Bar
Choose the surface finish of the aluminum rod: either the standard natural finish or a polished finish.

Steering Rack Bushings
No choices to make here; the MM K-member requires using MM's Aluminum Steering Rack Bushings (MMST-6). These let you install the steering rack higher or lower than stock.

Strut Tower Brace
Choose one of the two MM Strut Tower Braces for the 1979-1993 Mustang. Note that aftermarket parts such as superchargers and cold air kits may interfere with a strut tower brace and prevent installation.

Swaybar Endlinks
For standard front swaybars, the MM K-member requires endlinks that are shorter than stock.

Popular additions:

That's it! That's the last decision to make. Now place your order, either by clicking the Add to Cart button and then writing your list of part numbers in the Comments field on the checkout page, or by calling us. When phoning, please have your written list of parts (and any questions) in hand.

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

Feeling a little overwhelmed by the choices required to set up a Maximum Grip Box? If you really want the best for your Mustang and the fun of driving a truly awesome car, hang in there. It's really not so difficult. Even if you don't have extensive knowledge of automotive engineering and handling dynamics, have no fear! We're here for you.

First, familiarize yourself with the choices listed on the Options tab. You can probably make many of the required decisions on your own before you contact us just by knowing some basic information about your car. Next, select Maximum Grip Box Setup from the options listed on the Technical Services page and fill out the Maximum Grip Box Setup Form. We do charge for this service, of course, but it's refundable when you buy a Maximum Grip Box directly from MM.

Once you send us your completed Maximum Grip Box Setup Form we'll lead you through the step-by-step process laid out in that form, answer your questions, and help you decide which parts are best for your Mustang.

If you autocross, open track, race, or would like to retain some aftermarket parts you already have, you'll require a higher level of technical help than most people. Thus, your Maximum Grip Box Setup Form will go to our setup engineer.

We look forward to talking with you. Here's to transforming your Mustang from sloppy to spectacular!

  1. Read the Description tab.
  2. Read the How to Order tab.
  3. Make the choices on the Options tabs to the best of your ability.
  4. If you get stuck, deploy the Maximum Grip Box Setup option on the Technical Services page.

What does the Maximum Grip Box do?
It dramatically transforms your Mustang's handling to a level far beyond what basic bolt-on parts can do. When you want your Mustang to handle well (unlike the average Mustang), you need the Maximum Grip Box. MM's Engineering Team designed it to improve the tires' grip on the pavement, which means faster and more stable cornering, which means more fun!

Fits
1979-1993 Mustangs equipped with certain specific items.

All 1979-1993 Mustangs must be equipped with the following parts to accommodate a Maximum Grip Box install:
  • One of these engines: 5.0L pushrod, 302, 351W, 4.2L, 3.8L, 2.3L, 4.6L/5.4L modular, 3.8L V6, 5.0L Coyote (2011-2014), or LSX engine.
  • 8.8" rear axle assembly.
  • Spindles from a 1987-93 V8 Mustang, or any 1994-2004 Mustang. 1996-2004 spindles are preferred. Read our Spindle Tech.
  • An Oil Filter Relocation Kit is required for most Ford V8 engines that have an OEM oil cooler. This includes all 4V Cobra 4.6L and some 2V GT 4.6L engines, but not the Coyote engines.
1979-1982 Mustang K-member Mounts
  • These model years have a unique distance between the two holes at each rear lower frame rail mount. You will need either stock nut plates from a 1983-2004 Mustang or four nuts and thick flat washers. Minimal grinding may be necessary on a 1979-1982 Mustang's rear mount to match its wider hole spacing to the narrower spacing of the slots on the MM K-member (matches 1983-2004 Mustangs).
1979-1984 Mustang Steering Rack Mounting
  • Mustangs built from 1979 through 10/1/84 have 14mm bolts holding the steering rack to the K-member. You'll need a pair of 1985-2004 Mustang 12mm steering rack mounting bolts and nuts to attach the steering rack to the MM K-member. Caution: Some aftermarket companies sell SAE bolts for this application, but they do NOT fit. You must use the OEM-size 12mm metric hardware.
Steering Rack Notes

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

We're working on FAQs for this product. If you have a question, please use our Contact Us page to email your question. We'll answer your question by return email, and also consider it for possible addition to this FAQ section.

How do I choose which springs to use?
In general:
Choose springs that provide the handling characteristics and ride quality you want from your Mustang. Here's how to determine that:

  • The front spring rate MUST be chosen in conjunction with the rear spring rate, rear spring location, and rear suspension configuration.
  • Decide on your performance goal.
  • Consider how you'll use your Mustang most of the time, and optimize it for that type of driving.
  • Consider what level of ride quality you want. Then decide what (if any) compromises you'll make to achieve your performance goal.

In general, start by selecting a front spring rate that's appropriate for your Mustang's intended use. Then pick the rear spring rate to match, taking into account the rear suspension type (4-link, torque-arm, etc.).

More specifically:
See the MM Guide to Choosing Spring Rates and Dampers.

Which MM dampers go with which springs?

Befuddled? Impatient? Hopelessly lost? See the Help Me tab.

The individual parts in this Maximum Grip Box each have their own instructions. See the product pages for part numbers, and then look up the part numbers in the instructions index.