Like I said...these are just my opinions...You can modify your car in whatever way suits your needs. More of an art, than a science anyway

To address your questions posed...

• Sprint Booster was applied after the tune and other performance upgrades...It essentially opens the throttle much faster now (AND YOU CAN FEEL IT INSTANLY..~$329.00)
• Fluids...To be clear, ALWAYs use fluids that meet the JLR Specs. There are cases, like the Engine Oil, where people figure Castrol Edge is close enough, or cheap out on Transmission fluid etc. You absolutely need to use the correct/best fluids when you amp up HP and you need to change it much more often...That is the moral of my comments. For Ex: Transmission should use ZF Lifeguard 8 (not fluids that sound similar...there are wear packages, and friction modifiers that make it run right, so unless you know better do not guess). Front and rear, V6 and V8 have various differential oils...Use the correct ones. Transfer case should be the Shell Tec TF0870 or compliant...Etc. You get the idea.
• As far as wearable parts....These things eat O2 sensors, check Cats also, Idler pulleys, and things like fuel filters and oil filters etc...Get good ones...don't skimp, especially with enhanced performance.
• Also there are a number of good additives that people have good luck with (not getting into a debate...just offering info of some that seem to work well). Due to the Direct Injection and potential to gum up and also putting the injector nozzle right in the combustion chamber, you should run Injector cleaner, cat cleaners, and Valve cleaners such as - BG44K/Techron, CataClean, and Intake Cleaners like CRC that have Polyether Amine (PEA) to clean the valves and engine top end respectively. Just running injector cleaner does not touch the top of the valves on GDI engine, nor does it do anything to clean the Cats.

DC

 

That ZF 8HP tranny has successfully been used for beasts up to 900 horses. The rating seems to change based on what the car manufacturer wants to bolt it to. The engine will grenade long before the tranny ever does.

 

100% Ko-Rect! Since I was doing a ton of research, and looking to purchase and install a new one... thinking I had 'sploded my ZF or TC, I did verify that they have several versions of the ZF for different applications. Just for general info...

Our cars have the ZF8HP70 HIS (Hydraulic Impulse Storage - for the start/stop feature...It is a canister device for stored hydraulic pressure to quickly engage clutches on start-up) These are rated at 700N-m - 516 Lb-Ft Tq.
There are also many other variants including ZF8HP45 - 450N-m - 332 Lb-Ft, ZF8HP50 - 500N-m - 369 Lb-Ft, ZF8HP55 - 550N-m - 406 Lb-Ft, ZF8HP90 - 900N-m - 664 Lb-Ft, ZF8HP95 - 900N-m - 664 Lb-Ft, and a few other specialty models. Also a few manufacturers have licences to produce their own versions (e.g. Chrysler).

Our 8HP70 (HIS and non-HIS) is shared with quite a few cars:

BMW 7 Series , BMW X5 50i, BMW 5 series , BMW 3 Series - 330d and 335d, Dodge Durango V8, Iveco Daily, Jaguar F-Type (V6 and V8), Jaguar XE 35t, Jeep Grand Cherokee 5.7L 8, Jeep Grand Cherokee 6.4L 8-cyl , Jeep Grand Cherokee V8, Grand Cherokee EcoDiesel, Ram 1500 V6, V8, & diesel, Range Rover Sport, Rolls-Royce Phantom, Maserati Quattroporte , Dodge Charger V8 , Volkswagen Amarok V6 TDI 550, Dodge Challenger V8, Aston Martin Vanquish, Aston Martin Rapide S ,Alpina B3, Alpina B4, & Great Wall Haval H9

The 8HP90 is in some High power cars and large cars like - Rolls-Royce Ghost, Rolls-Royce Wraith, Bentley Mulsanne, Bentley Continental GT, Dodge Challenger SRT Hellcat, Dodge Charger SRT Hellcat, Bentley Bentayga, Audi RS 6, Audi SQ7

Just sharing for general info.. It appears these things are pretty solid as UNHINGD states. There is very little documented on failures. Most common issue I have seen is a leak where the wiring harness passes through the case...Not much else.

DC

Picture of the HIS below - Stores the pressure to re-engage when foot is lifted from brake:

 

More info on the ZF...
https://www.dropbox.com/s/b7666doqb4...trans.pdf?dl=0