telepath

New guy here. Going to ask a lot of dumb questions all at once because I can't find much info online. Serves as a good introduction, I think.


To start, here's what I'm planning to do with the car (it's pretty vanilla):

Stage 0:

- Media cleanse of intake valves

- Waterpump/thermo replacement (with the all-metal body)

- General preventative maintenance

- KW Coils

- Some sort of brake kit (undecided, would love input)

- 359/M3 Comp wheels

- Maybe some M5 suspension goodies if I'm feeling gregarious


Stage 1:

- Jb4

- Dinan CAI

- Lots of goodies from VSRF (charge pipe, intercooler, downpipes, intake pipes, etc.)


Stage 2:

- Pure Stage 2 turbos

- Fuel-it LPFP

- "Phoenix Racing" plenum & port injection kit

- Custom exhaust


Drivetrain:

- ...


This is what I need some advice on. I have, in my head, a ~450-500whp (on pump gas) power goal that seems achievable with the stg2 boltons listed above (and a good tune, of course). I'm curious, however, if people know what the hard limits of the drivetrain are.


How much torque can the ZF 6-speed handle? Related, how much torque can it handle reliably (I know the answer is "what it's rated at the factory for", but I'm curious if anyone's driven a high-horsepower AT build for an extended period of time)?

How does the transfer case hold up? The front diff?


I see conflicting reports online of people's ZF boxes shitting the bed with a cone intake and jb4 and others who go big single and seem fine. Same goes for the transfer case and front diff. I understand that it's dependent on the health of each particular part but I am curious if there is a consistent pattern of failure at certain power levels.

Also curious if there are ways to mitigate potential failures with the ZF box. Not out of the question that the car could see a manual in it's lifetime but that's currently above my paygrade/abilities. I see promising development with ZF8 swaps so maybe that's something I'll explore, too.


I know this is a lot so thanks in advance to whomever takes the time to reply. Cheers.

NW E61

You are very much in the same boat I was when I picked up my '08. I have or had a good chunk of those mods on my e61 and though it sounds "vanilla" it really brings the car to light. There is good info on the forum and I suggest you check out Evan's build thread is a plethora of info along with other build threads on here.

Stage 0: I'd agree with all of those and that's a solid start
Rear sway bar is a must. The factory one isn't up to par the weight of the car and its a cheap/quick upgrade
As for brakes, the front M5 rotors/calipers are bolt on and are an easy upgrade. The rears however, not the easiest. After seeing Evan's nightmare I had my local shop do it and we marred an axle and broke a hub puller in the process. That being said, the stopping power is night and day. You will need 19's to clear the upgrade and don't forget it will change your wheel offsets.

Stage 1: I actually just took all those off to go single turbo Still debating on what to do but if you're interested in the parts, shoot me a PM.
D0wnp!pes - I ended up going with AR design since they looked like they flowed a little better. I was not a fan of the VSRF as they had a flat plate that looked very restrictive.
Intake - If you relocate the factory coolant expansion tank, it frees up lots of room to build a custom intake system. The factory plastic inlets are hot garbage IMO and no matter what "brand name intake" you have, it's not all that beneficial.
JB4 - I had one with all the bells and whistles and switched over to MHD and a Motiv Reflex with a custom tune. I will never go back to JB4 now. I am still working out some minor bugs on the Reflex but overall, this setup has a lot more power potential and safety IMO. Biggest thing for me was how JB4 had batch fire port injection vs the Reflex's sequential injection in addition to the Reflex's ability to control a lot more items (oil pressure input/safety, additional fuel control, flexfuel, etc..)

Stage 2: Lots of options available in this realm. Do your research and find the best fit for what YOU want. If you are only targeting 500whp, you don't need port injection IMO. A solid tuner and fueling will get you there but the stock turbos wont last long.
Exhaust - I would do this first. Again Evan has had many variations and probably has the most details / videos of exhaust notes.. I have been beyond happy with my setup. 3" all the way with 18" Vibrant resonator in the middle and a Vibrant Muffler at the factory spot in the rear.
Turbos - Pure or RB will have the best reliability. If you want to go single, just know it is not easy as it sounds....
Fueling - Fuel it has been my source and was very helpful in getting me with the setup best suited for my needs
Port injection - Again, research the Reflex vs Jb4 to ensure which "piggy back" you want. Couple manifolds out there to choose from. I have had zero issues with my Phoenix but the Evolution of Speed manifold is sexy AF. Or if you want to have a 2J look, go with a Doc Race but know you will likely need custom charge pipes fabricated as most manufactures don't build for the e6x chassis.

Drivetrain - I have a manual and have not found the limits yet. I've been told the transfer case doesn't like more than 600-650whp. I tend to run in RWD only and have not noticed any transfer case issues.


Welcome to the forum!
AJ

neilv

AWD front suspension is different than rwd(M5) so nothing works. In the rear most of it is the same other than the upper guide arms (the early M5/Z8 arms are the ones you want) have spherical bearings vs rubber and the rear sway bar is 18mm vs the 12mm stock on the wagon (M-sport rwd cars w/o dynamic drive will have 16mm might be easier to souce). Also E90 M3 front thrust arm bushings are a good upgrade if you want performance.

M5 brakes will bolt onto the front, rear you will have to swap out to rwd hub flange and add ~25mm spacer to get back to proper offset; rwd 535 or the V8 cars have brakes inbetween stock and M5 and can be easier to find/cheaper as well

Dj530

Not out of the question that the car could see a manual in it's lifetime but that's currently above my paygrade/abilities. I see promising development with ZF8 swaps so maybe that's something I'll explore, too. .[/QUOTE]
Putting a manual will lower it's torque handling capacity. Automatics handle more torque with the XHP tune unless you are will to throw cash at a manual tranny. I have recently picked up the 8HP tranny and just waiting for the weather to improve so I can do the swap. My 6HP in my Diesel has done just over 600 ft lbs on all stock internals and stock turbo.

The stock is able to process about 350 ft lbs before you start cuasing issues. Factory tune is capable of +300 lbs of torque if you don't have a boost leak. . . . . So it's not gonna be happy with your stage 2