[rbryantaz]

BIMMERPOST / Classifieds

Asking Price:

USD 150.00

Item Interest

Hello N20 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 N20, N55 and S55 engines.

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

N20 B58 Kit:


I am offering the conversion kits where the buyer modifies the springs and optionally can use the original resistors from the B58 coils.

The kit is $150 plus shipping for the N20 (2/3 the price of the 6cylinder cars). Shipping is $10 for the USA and $40 for international.

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.



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.

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