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The Z1 SP Differential is now available for pre-order. As a show of appreciation for our early adopters Z1 is offering pre-order discount of $100 off available only to the first 15 differentials sold! (Limit 1 per order)

The Z1 Motorsports Fully Built R190 Limited Slip Differential Upgrade is a complete sealed drop in differential assembly for all '14+ Q50 and '17+ Q60 models.  Fully Assembled with the Z1 SP-Pro helical LSD, new OE bearings and seals, and custom tailored to your specifications of gear ratio and fluid type, this drop-in solution saves you the trouble of trying to locate a qualified local driveline shop with the required specialty tools needed to properly assemble and set-up your limited slip differential. Gear ratio upgrade options are also available for some models below!

Choose to pay the refundable core charge to avoid downtime OR send in your rebuildable differential core first, and we will ship your custom built differential sealed up and ready to go. Just add the included fluid, install, and enjoy!

Z1 Street Pro LSD

Z1 Street Pro R190 Limited Slip Differential was produced exclusively for all 2014+ Infiniti Q50 and 2017+ Infiniti Q60 models. The nature of the factory open differential leads to dangerous conditions especially in high power, high boost cars. The benefit is not only on acceleration, significant improvments are experianced in corner entry, overall cornering stabiliy, predictability when driving the car at the limit, and lead to a generally safer and more controlled driving experiance.

The Z1 Street Pro Limited Slip Differential is a helical unit that delivers dramatic improvements over open differentials given its considerably greater ability to distribute torque to both wheels. With its internal gear design, it boasts exemplary street manners and is operationally quiet when compared to clutch type differentials that have a tendency to chatter or clunk when cornering at low speeds because of axle bind. The Z1 Street Pro Differential exhibits no axle bind and provides smooth operation in any circumstance. Seriously, your wife won't even notice you upgraded this thing. Because of the internal construction the Z1 SP is low maintenance (only regular fluid service intervals) and ensures exceptional life span with no special fluids or friction modifiers needed. Red Line or Motul differential fluid available in the options below.


  • Robust Build Quality
  • Great Street Manners
  • No Special Maintenance
  • No Noise - Chatter Free!
  • No Special Fluids or LSD Additives Required
  • Improved Power Delivery and Handling
  • Ready to Install: No Break In Or Setup Necessary!
  • Includes Your Choice of Fluid (Optioned Below)


Fluid Type

Red Line 75w-90: Red Line Gear Oils and Transmission Lubricants are designed to provide excellent low-temperature shift-ability and improved gear protection at higher temperatures. Efficiency improvements between 1-5% are typical. The synthetic base stocks used have tremendous thermal stability and provide the best film strength available. The unique combination of base stocks and additives allow Red Line gear oils to carry higher loads compared to petroleum lubricants. The stability of these products allow them to be used for extended periods.

Motul 75w-90: 100% synthetic lubricant for hypoid differentials with limited slip system operating under shocks, heavy loads and low revolution speed or moderate loads and high revolution speed. 0% shear loss: Unshearable oil film in extreme conditions. Very high lubricating power which decreases friction and wear. 90 grade at hot temperature to provide outstanding oil film resistance at hot temperature and/or to reduce gear noise. Fluid at low temperature to allow comfortable gear shifting.

Motul 75w-140: 100% synthetic racing lubricant based on Ester-Technology For all hypoid differentials with limited slip system, gearbox with integrated limited slip differential, mechanical transmission, synchronized or not synchronized gearboxes, transfer gearboxes This is the fluid we run in our Global Time Attack and Spec Z race cars and recommend for heavy use.

Select Your Gear Ratio

There are THREE different gear ratios used in the 2014+ Infiniti Q's, depending on powertrain and trim model.

2.611: This is the original gear found in all Hybrid Q50 models. This offers the lowest acceleration with the greatest benefit in fuel economy. This gear ratio is ONLY currently available as a build with core supplied first.

2.937: This is the original gear found in 2WD 2.0t and all 2WD / AWD 300hp 3.0t (Non-Red Sport) models. The 2.937 gear is available as an opgrade from the 2.611 for hybrid owners using the options below.

3.133: This is the original gear from the Q50 and Q60 Red Sport, as well as the AWD 2.0t and 3.7l models. This gear provides better acceleration over the 2.937 gear found in the 300hp 3.0t models and is available as an upgrade in the options below.

Optioned below, select your gear ratio using the above chart as a key. It's important that the CORRECT ratio is selected, as this will specify the gear ratio used when assembling your differential. Z1 offers the 3.133 Red Sport gear ratio as an upgrade to all 2WD models (with 2.6 or 2.9 factory gear) for an additional charge. If you have a hybrid model with the 2.611 and wish to upgrade to the 2.937 gear, the 2.9 Gear Upgrade option is available in the options below as well. If you choose to pay the core charge and return your original differential after installation, you MUST send your original differential with the correct ratio selected in the options. If the differential you return does not have the ratio matching your option selection (with exception to those selecting Gear Upgrade) a $300 core fee will be subtracted from your core charge and you will receive only a partial refund.

3.133 Ring & Pinion Gear Upgrade option is applicable to 2WD models ONLY! AWD models must select original ratio. Failure to do so WILL result in extensive and expensive damage.

If you are unsure what gear ratio is in your Q, give us call or ask us in the product questions below. Please be sure to have year, model, and drivetrain type available.


  • 2014+ Infiniti Q50 Sedan
    • 2WD and AWD 2.0t
    • 2WD and AWD 3.0t
    • 2WD and AWD 3.5l Hybrid
    • 2WD and AWD 3.7l
  • 2017+ Infiniti Q60 Coupe
    • 2WD and AWD 2.0t
    • 2WD and AWD 3.0t

*This differential does NOT fit 2014-2015 Q60 Coupe* (Click HERE for applicable R200 LSD)

Z1 Built Diffs are currently assembled to order. Z1 expects built differentials to ship within 2-3 weeks from the original order date assuming core charge has been paid or core has been recieved.

Have questions?  Need assistance or clarification?  Give us a call Mon-Sat 9am - 6pm EST at 770-838-7777 and we will be happy to help.

Available Options:

Core Charge:

Fluid Type:

Gear Ratio:

*** This item does not qualify for any additional discounts or promotions ***

$1,698.00 $1,598.00

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