[rbryantaz]

BIMMERPOST / Classifieds

Asking Price:

None

Item Interest

Hello N55 and S55 enthusiasts,

Recently I developed a B58 coil conversion kit for my 2008 335i which adapts the newer style coils used on the B58 engines and was asked to create one for the N55 and S55 engines.

This is an adapter kit that does not include the B58 coils.


I am offering the conversion kits for $225 plus shipping.

The kit now comes with the springs already adapted so there is no need to modify them or install a resistor. Using the internal resistor is optional and is a simple process for using the resistor and springs from the original coils. Concerns about burned springs that have occurred on other kits are fully resolved with the adapted springs in this kit.

Here is a picture of the components of the kit laid out:

2011+ N55/S55:



Early N55 (pre 2011):


The kit can be ordered here:
BMW N55 and S55 B58 coil adapter kits

The kit comes with a longer replacement boots for the coils that uses a stainless steel connection spring and threaded spring connector. This ensures that the top side of the spring is long enough to make a strong contact to the coil and small enough to fit inside a variety of coil choices.

The boots and springs I provide also allow for very easy integration of the original 1k resistor from the B58 coil boots. The top and bottom springs from the B58 boot are used with half of the spring from my boots. This is no longer the recommended way to run the kit but it is also a fully viable option for customers that want to keep the factory resistor.



The extension spring in this kit is the same wire size as the original BMW coils and is designed to fully compress before the rest of the spring when installed (so the coils touch each other and ensure a tight contact to the coil).

Some users originally reported hearing about burned springs near the coil when running without resistor on other kits. This was almost certainly due to poor spring contact with the coils. It was likely a result of using the newer longer tube BMW coils where the spring did not fully reach the coil contact point (it has to reach a few mm deeper with the newer coils). This is not an issue with the springs in this kit.

I provide crimp and shrink butt connectors with the kit which provide a better connection than an adapter terminal and they are less bulky. The wires can also be soldered with shrink wrap if desired for more advanced DIYers.

I am also providing new stock terminals and wire seals so customers could return to stock if desired. I don't know why anyone would but it gives some peace of mind.

Direct crimp/solder terminals are available but I really recommend using the pigtails. The B58 connectors are a difficult crimp without the right tools.. It is also very hard to do the direct crimp without removing the harness from the car.

If you are unsure which kit to order these pictures may help:

The Later N55 and S55 have a "T" bracket to hold down the injectors:


The earlier pre 2011 N55 have a different bracket and a HEX plug in the middle:


Background on the development of the kit can be found here:

https://www.e90post.com/forums/showthread.php?t=1814915

Thanks everyone for your support on this project.

-Rich

[rbryantaz]

Here is some added information on how aftermarket B58 Eldor coils are not the same as the OEM version.

https://www.e90post.com/forums/showp...3&postcount=16

They are a different coil, resistor and spring setup so modifying the spring is not the same as the OEM B58 coil.

-Rich

[rbryantaz]

Here are some nice install pics on a 2011+ N55 engine.

This shows the benefit of splicing the wires and adding a ring terminal directly to the ground wires (removing the original ground wires instead of splicing them) for a very clean install.

Without the connectors the splices can be done inside of the wiring channel where they are fully out of the way and essentially invisible. The customer marked the front coil connector in each pair so that it is clear which connection needs to be made. this could have also been done as a marker stripe on the white wires (or a small piece of shrink wrap around the wire to mark it).



The back coil is a tight fit given the increased size of the B58 coil. To reuse the stock O2 sensor a non functional downward tab was cut off on the back side to clear the coil. This was along with the supplied spacer allows the original bracket to be retained.

The wiring channel was also very tight on coil #6 so it was trimmed slightly to make it fit.

[rbryantaz]

Bump for updates showing the latest pre-adapted springs.

Several customers are now running with the new pre-adapted springs that come installed in the boots.

There is no longer any need to modify the springs!

Thanks,

Rich