Spotted that Mountune are now offering this as a seperate item.

Might be popular, given the number of people on various forums who seem to suffer angst from not having the Performance Pack on their cars.😀

https://www.mountunestore.com/collections/mk8-fiesta-st/products/quaife-atb-differential-mk7-fiesta-st-copy-1

They are wonderful and worth every bit of their rather substantial price and effort to install. They not only improve traction during cornering but they also have the effect of calming down the stability and traction controls that are baked into the Fiesta and cause the brakes to become overheated in just a couple of laps. The stock stability controls are the most to blame for making the Fiesta ST a less than stellar track toy. The only reason that “big brake kits” were so popular in the States is because the stability controls put a tremendous amount of heat into the brakes, even if it is in the “off” t/c mode. The stock radiator and coolant reservoir is also not up to the task for track use. But nobody likes to say much about it.

Performance Pack including diff was standard on UK Mk 8/8.5 ST-3s from around late 2019, a £950 option otherwise**. Ford neatly solved any purchasing dilemmas by only offering the ST-3 for the last year or so.

(**The Performance Pack also included shift light and launch control for those who like to destroy their tyres and clutch. I understand launch control can be activated by Forscan.)

it does indeed do what it says on the tin, and I find it much more progressive than cars with LSD from years back.

Shortly after I got my car we needed to drive over the moors to Whitby, the road only just having been reopened after a late heavy snowfall. Its a tricky route in summer, so I'm thinking "this is all I need, driving over here in a 200ps fwd car with fat 40 profile summer tyres". It coped fine!

I want one for my 2016 Fiesta ST! But will have to wait until it needs a replacement clutch and pressure plate. If I don’t decide to sell it first. I have recently purchased a lightly damaged Mustang GT convertible that is fairly low mileage to repair and drive in the summer months.

The quaife differential is literally the only thing that the Fiesta ST needs added to it. The additional brake pad and rotor wear is something that I would not miss in addition to better handling. It’s a win-win situation.

The Mustang is a 1995 model. So it’s old enough to qualify for historic license plates and collectors insurance but new enough to have been equipped with four wheel ABS, driver and front passenger airbags and have a electronic fuel injected engine I think I am Finnished with the new “digital” cars. They are very powerful in stock condition but they are not repairable by DIY shade tree mechanics.