A long time in the planning, I finally got my N52 DISA manifold and the time to install it. I've been planning to do this for close to two years and the pieces all fell into place over the last week. My local indy shop,
Bimmerworks, has had a crashed E90 330i parts car sitting in their lot for close a year. The owner and I talked and he was willing to part with the manifold for an excellent price, but only when he had the time to take it off. Being the outstanding shop that they are, they are pretty much constantly are working on a 1-2 month backlog of cars. Finally last week they shot me an email letting me know they were taking other parts off the car for an in-shop car and that I was free to come get the manifold when I wanted to.
From a software perspective I was waiting for Evolve to come out with their version of the N52 DISA tune. Knowing first hand the level of work they are capable of for the S54 and their outstanding customer service, there wasn't a question in my mind who was going to get my business. They are also the only company that I'm aware of that can tune our cars specifically for the Supersprint headers, as well as turn down(not off) the post cat O2 sensors so that they show both a ready and a pass signal to OBDII emissions plug testing.
Like my recent Supersprint header thread, this will be a mild DIY as well. I'll also be happy to provide insight to anyone working on the mod, but I won't be held liable if something doesn't work out! Mod at your own risk and know your abilities. Pictures will be worse though as I was taking them as I remembered to do so with gloved hands instead of another person who just happened to be hanging out in the garage with me.
Section 1: The Install
Tools:
1/4" socket driver
1/4" extension
T30 torx
T25 torx
11mm socket
10mm socket
8mm socket
6mm socket
6mm Allen key
Curved pick
Parts:
DISA manifold(should come with adjustors if used) 11617559523
DISA Adjustor unit outside 11617579114
DISA Adjustor unit inside 11617560538
4x manifold hex bolts w/ washer 07119903918
3x manifold hex nuts w/ plate 07129905541
6x(I think they come in a set) manifold gaskets 11617547242
Much the header install, you need to remove the cabin air filter cover, left and right upper panels, cabin air filter, cabin air filter frame, disconnect the wires/enclosure that run above the the valve cover, remove the valve cover, and disconnect a few miscellaneous plugs. Most of it is removable with the 8mm socket, though the valve cover is a 6mm Allen key. You also need to remove the airbox/piping which is held in place by two 10mm bolts and hose clamps with a 6mm head. After that take off the throttle body by removing the four 10(11?)mm bolts in each corner. Before you start it will look like this:
Here are all of your newly removed parts:
I also chose to suspend the wires that go over the valve cover with a pair of cable ties to keep them out of the way. Also don't forget to disconnect the 02 sensor wires on top of the valves.
Here's what I installed vs what I took out. The DISA version is on the right and the stock 128i manifold is on the left. You might notice a few differences which I will get into later.
After removing the initially mentioned parts you should be left with something like the picture below. At this point I took the time to label each wire I was disconnecting with its purpose. I also unbolted the power steering reservoir from mounting bracket and tucked it up from out of the way. No need to disconnect the power steering lines! Reach around behind the engine and disconnect the oil return line on the back. It will be the 3/4" pipe covered in 1/2" of foam with the pinch connector.
The longer DISA wire closest to the front of the car is for the DISA actuator under the intake runners. The shorter DISA wire is for the DISA actuator above the throttle body. You can remove the DISA wires and their cap/mount from the stock manifold by lightly prying the clip from the manifold and sliding them down. You also need to disconnect the wiring junction box at the base of the manifold from the manifold.
This plug on the throttle body frame is probably the biggest pain in the ass of the entire project. Hand access to it just sucks and it is the type where you simultaneously need to pinch it hard and pull off. It proved to be a rather awkward hand angle for me.
Don't forget to disconnect the plug on the back of the intake manifold closest to the windshield. While you are there you can also unclip the fuel line from the back of the manifold. There are two clips. The top one was easy enough to remove with a torx bit, but the lower one broke when trying to remove it. Fortunately, in all likelihood your new manifold will have a spare, mine did at least.
At this point you will be ready to unbolt the manifold. If memory serves there are three studs and four bolts into the block. I believe they are 11mm, but they could be 10mm. Either way, I chose to buy new hardware for the reinstall. The bolts/nuts are cheap, and if you read the BMW tech documents on the N52 that they sent to the service technicians, they stress this for any parts that come into contact with the aluminum/magnesium block. A few bucks here to save potential thousands later.
As the manifold comes off you will want to take it slowly so you can unplug the connections on the underside of the runners. Take it slowly and make sure you have unclipped any wires attached to the manifold. It should be pretty apparent when you can work it out and take it out. You should be left with a gaping rats nest that looks like this:
Earlier you may have noticed this on the DISA manifold. Previously the oil return unit was mounted on the manifold. For our varient of the engine it is mounted in the engine. Feel free to unclip this unit and toss it. Our hose varient for the oil return line hooks up without issue.
Remove the old gaskets using a pick tool and install your new ones. Once again, a few bucks here to save a potential hassle down the road. The new ones press in without any trouble using just your fingers. I plugged all the holes on my manifold when I got it to prevent any debris from entering the manifold and later the engine. I took them out as I placed the gaskets and then immediately placed it back on the block. I left the throttle body plug in place until I reinstalled that.
At this point you need to reassemble in reverse order. Only major changes are that you are plugging the DISA wires into their corresponding actuators as outlined above. Don't forget to remove the mounting caps that held them in place previously. It shouldn't take long as you previously labeled all the plugs and you are just playing connect the dots.
Overall I would say it is a 4/10 in terms of difficulty.
Section 2: Software Install
While not as glamourous as the nitty gritty of tearing apart your engine bay, I must take my hat off to a well designed product that Evolve offers. I simply downloaded my car data file, spec'd all the features I desired from Evolve, and emailed it in. They had the new profile ready to go in a day exactly as I requested it and the install was a breeze. It's hard to say more as it was a completely flawless experience.
Also, the low end torque they add is pretty absurd.
Section 3: Review
It's interesting. Unlike the headers I expected this project to make a big difference in terms of power, but I was still blown away by how much power this added. Between the header tune, the Evolve work, the 93 octane tune, and DISA manifold tune this car is putting down some serious power now. While I still need to get it dyno'd(and remote dyno tuned by Evolve), I suspect I'm sitting at close to 300hp now. Who knew we could get 100hp per litre from our little basic NA inline 6 in our bargain model BMW.
The car really feels like it has had the shackles of intentionally reduced power removed. I can see why they didn't ship it this way from the factory. It would be a bit hard to explain to the customer why they should get any of the other more expensive models when this one is such a visceral performer.
I think I can hear a sound difference but I need a bit more wheel time to be sure. Mainly I'm intoxicated by the NA power on tap that really pushes you into the back of your seat. Combined with the 40.4lbs of unsprung weight I just chucked from the wheels, I suspect I am at least on pace with a 135i in a straight line. In the corners we clearly have the weight advantage.
This really makes me want to square away the suspension with M3 bushings and a proper set of TCK coilovers...
