[rbryantaz]

BIMMERPOST / Classifieds

Asking Price:

None

Item Interest

Hello fellow N54 enthusiasts,

Recently I developed a B58 coil conversion kit for my 2008 335i which adapts the newer style coils used on the B58 engines.

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

The kits come with my "Fat Bunny" plates which screw into an existing and unused hole in the factory valve cover for each coil.




I am offering the conversion kits for $225 plus shipping where the buyer modifies the springs either using the internal resistors from the B58 coils.
Using the internal resistor is optional and is a simple process for using the resistor and springs from the original coils.

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


The kit can be ordered here:
N54 Fat Bunny B58 Coil Conversion Ordering Link


The kit comes with a longer replacement boots for the coils that uses a spring connector because the original B58 coil boots are not long enough to reach the spark plug.

The boots and springs I provide 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. The top and bottom b58 springs are swapped from their original coil/plug positions and the smaller spring (from the spark plug side of the B58 boot) is "screwed into" the spring I provide after it is cut in half.

This takes only a couple of minutes per boot. Take care when cutting the resistor out of the original B58 boot.

This shows how to modify the spring to use the resistors and the optional resistor delete adapter:



Some users have reported issues when running without resistor on other kits. I believe this was likely due to poor spring to coil contact. Using the resistor is an easy option if desired.

NOTE: It is critical that the bottom part of the spring is not modified so that it contacts the spark plug properly.

These custom 18ga copper wiring pigtails are included with solder shrink tubing. They match the stock colors of white/brown/orange for easy splicing.


Splice example:


They can be soldered using a simple lighter but I recommend using a heat gun.

This shrink was done with a lighter where heat was only applied until the solder ran and then to shrink up the tube. Results were nearly as good as a heat gun. If left too long they blacken slightly but no the splice is still sound (I did over heat this one on purpose to make sure it was "nearly fool proof").

(A heat gun was used on the left splice for the cleanest result)



Direct crimp/solder terminals are available but I really recommend using the pigtails. The connectors are a difficult crimp (I could not get the crimp tight enough with hand tools and still had to solder). It is also very hard to do the direct crimp without removing the harness from the car. The stock brown ground wires are also not long enough for a direct crimp. The pigtail gives enough extra length and are easy to install with just a heat gun or lighter.

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]

Hi everyone.

I have good feedback and results on the first kits and have also now developed a method to use the original 1k resistor in the boots.

I am going to offer the kit for $200 ($20) off for a limited time.

The kit ordering page is here: http://rbryant.freeshell.org/bmw_n54...onversion.html

Thanks for all of the support!

-Rich

[rbryantaz]

Quick update:

I had some suspension parts from another project going for black anodizing. I added the N54 fat bunny plates so I will have several black anodized plates ready to ship next week.

I will post pictures when I get them.

Thanks to everyone that has ordered so far!

I hope to see more reviews soon.

-Rich

[rbryantaz]

Here are is a picture of the latest anodized plates with a coil installed for illustration:



Next up N55 plates!

-Rich

[rbryantaz]

I got the next batch of N54 plates back from anodizing yesterday.

I will ship out all of the existing orders this evening. I have several sets in stock ready to ship.

Thanks to everyone that has ordered one!

-Rich

[Swedish Salmon]

Hi, would you be willing to maybe create a fully PNP solution? Or something close enough?

[rbryantaz]

Originally Posted by Swedish Salmon

Hi, would you be willing to maybe create a fully PNP solution? Or something close enough?

I understand the concern and plug and play is nice to have. Right now without adding significantly to the cost I don't think it is likely to happen with this kit.
Other suppliers have made custom connectors and I give them kudos for it. I think it was likely a big investment.


Depinning the connectors is about as close as I expect to provide to a true plug and play solution. It uses high quality automotive connectors and while there is some effort to de-pin the originals it results in a very good quality connection without cutting any wires.

Some customers have purchased connectors from another supplier and have spliced into those instead of cutting their harness.


Overall the best reasonable solution is to cut off the original connector and just splice the new pigtails in directly. A good crimp or solder connection will be more reliable than any connector and is also less bulky. It is possible to directly crimp on the connectors to the stock wiring but it is a lot of work and requires a bit of experience and patience. It took me a couple of hours to get mine right when I did the direct crimping on my car and I also ended up soldering the crimps. Soldering them was also harder than expected because too much solder wouldn't allow the terminals to fit into the connector. Suffice to say it was much harder and no better than splicing in pigtails. The professionally made pigtails have a very high quality crimp that is not something that can be consistently done with hand tools in the engine bay.

One option that makes sense is to just purchase a second used coil/injector harness. This harness for the N54 is not hard to find and not expensive. An ebay search for "335i coil wiring bmw" shows 4 of them @ $49.95 with free shipping right now.

If I were ever to go back to stock I would just put a full used harness in.

Overall at this point splicing coil connection wires isn't the biggest modification that most of us have made to the car. Compared to installing inlets splicing the coils in is a minor mod.

-Rich

[rbryantaz]

VehicularDIY did a nice review of the kit here:

Thanks to everyone that has purchased a kit so far!

-Rich

[rbryantaz]

Thanks to everyone that has purchased these.

I have several sets in stock if anyone needs a set.

I have also added a new FS thread for the S55/N55 kit!

-Rich

[jadams161]

Great info. I was looking at running the B58 coils after battling coil/plug issues. I just ordered a kit to try out. looks like a great way to improve the ignition system on the N54. Can't wait to get it installed.

[Divszy]

Interested in this. Firing over a PM.

[rbryantaz]

Originally Posted by Divszy

Interested in this. Firing over a PM.

Replied, thanks for your interest!

These are in stock and ready to ship next day.

-Rich

[Bowenpuref3p]

I am currently tuning my f30 with a ps2 turbo and I’m having spark plug blow out issues with my factory coils. I wanted to go with the b58 setup and when I was researching nexsys version I fell upon yours. With nexsys there is a few week wait and I really don’t want to make my tuner wait that long. So I was wondering if you have the late n55 setup in stock and ready to ship? It will work for late n55 in a f30 correct? You don’t mention f30 on your retail website but since the engine is the same I assumed it would work fine. I emailed you as well through your retail website contact info but haven’t heard back so I’m posting here as well. I’ll pm you now also.

[rbryantaz]

Originally Posted by Bowenpuref3p

I am currently tuning my f30 with a ps2 turbo and I’m having spark plug blow out issues with my factory coils. I wanted to go with the b58 setup and when I was researching nexsys version I fell upon yours. With nexsys there is a few week wait and I really don’t want to make my tuner wait that long. So I was wondering if you have the late n55 setup in stock and ready to ship? It will work for late n55 in a f30 correct? You don’t mention f30 on your retail website but since the engine is the same I assumed it would work fine. I emailed you as well through your retail website contact info but haven’t heard back so I’m posting here as well. I’ll pm you now also.

Yes the late N55 kit works on the F30 N55 and even the S55.

Thanks for the order, I will get it shipped out tomorrow!

-Rich

[rbryantaz]

Some customers have purchased Eldor B58 coils with the expectation that they will be an exact match for the OEM BMW branded Eldor coils.

It turns out that the current version is not the same. The original part number was: 77460003 and the new version referenced here is: 77850002.

The new version is a different coil with a different resistor.

This appears to be a revision of the OEM version and it requires different spring/resistor modifications

(new version on the left, original on the right):





I have not ordered the Bremi, Bosch, or other coils yet to compare against.

-Rich

[GnomeChild]

Rich

If you offered this kit with direct plug and play connectors like they do with the fancy VTT kit I would buy it in a heartbeat, even at a higher price point! I like that each injector has its own bracket where as the VTT kit has a large bracket that houses all 6 coils.

I may just buy both kits to mix and match the elements of both of them that I like and sell off the leftover kit... If you are willing to sell just the 6 coil brackets, let me know!


EDIT
Also, if there is a way to modify the bracket design to move the coil mount "pin" to the bottom of the bracket instead of the top so that the coils point rearward instead of forward (like on the VTT/Nexsys kits) that would be amazing.

Clearly I have very many first world problems and too much time on my hands to care about such things


EDIT2
After rereading the thread, it never occurred to me to buy a second N54 harness to act as a sacrifice to splice the B58 connectors on... that would also leave the kit much less bulky and I would retain my old harness to revert to stock should the need ever arise. Now if only N54 Ignition wiring harnesses were as easy to find as you claimed
My only reservation would be the spring modifications themselves. The legit kits come with boots/springs I think already ready/modified to swap out from the B58 ones....

[rbryantaz]

Originally Posted by GnomeChild

Rich

If you offered this kit with direct plug and play connectors like they do with the fancy VTT kit I would buy it in a heartbeat, even at a higher price point! I like that each injector has its own bracket where as the VTT kit has a large bracket that houses all 6 coils.

I may just buy both kits to mix and match the elements of both of them that I like and sell off the leftover kit... If you are willing to sell just the 6 coil brackets, let me know!

While I understand the idea of wanting to just plug into the stock connector with an adapter overall extra connectors are generally worse than crimp or solder connections electrically. I also feel that they are bulky and get in the way of things. And yes there would be a cost to making them would increase the cost of every kit sold...

I did offer "de-pin" setups that change the BMW connectors to a standard automotive grade connector by removing the terminals from the OEM proprietary connector shell and sliding them into a standard one that uses the same terminals. I sold some of those adapters but demand has been for the splice connectors instead. I even had one customer buy custom de-pin connectors and decide to splice instead to keep things slim and clean.

I haven't heard of anyone wanting to go back to the original coils after installing these. There is no reason to ever go back to the stock coils. That means that splicing the connectors in is the best solution.

By far the cheaper option if you don't want to cut the harness is to buy the connectors from precision raceworks and splice my connector into that, their replacement coil harness is only $50 IIRC.

As a counter point a used n54 or n55 OEM wiring harness is usually less than $50 so on ebay or a junkyard. If someone did want to remove them to sell the car as stock or something the best way would be to just swap the entire modified harness with a used one and sell the kit or put it on a different car....

Originally Posted by GnomeChild

EDIT
Also, if there is a way to modify the bracket design to move the coil mount "pin" to the bottom of the bracket instead of the top so that the coils point rearward instead of forward (like on the VTT/Nexsys kits) that would be amazing.

I don't think I will be changing the connector position. I designed them to be forward facing so that the connector is easy to depress and pull out of the coil.

If they were on the back side it would be more difficult especially for the back coils. The factory engine cover fits unmodified with the current position so I would argue that it is the best of both worlds. The mounting bolt would also interfere with the stock wiring sleeve if it were done that way so it would have to be removed which is undesirable IMO....

Plus if I did that the BMW logo would be backwards on the OE coils! That just wouldn't be right would it?

Customer install Photo:


-Rich

[GnomeChild]

We've hashed out the replies in PMs but I thought this would be an interesting place to mention/ask this

In your OP and VehicularDIY's video you both show the process of preparing the spring to adapt to N54/N55 style plugs, but what would the process be for those of us wanting to go with B58 plugs instead?



The "squat" looking spring that is meant to go into the top of the new N54 boot adapter is plundered out of the bottom of the B58 boot and is meant to contact the different terminal on the B58 plugs in B58 applications. Can the spring assembly simply be installed upside down and achieve the same results except have the correct contact spring for the B58 plug terminals?

[rbryantaz]

Originally Posted by GnomeChild

We've hashed out the replies in PMs but I thought this would be an interesting place to mention/ask this

In your OP and VehicularDIY's video you both show the process of preparing the spring to adapt to N54/N55 style plugs, but what would the process be for those of us wanting to go with B58 plugs instead?



The "squat" looking spring that is meant to go into the top of the new N54 boot adapter is plundered out of the bottom of the B58 boot and is meant to contact the different terminal on the B58 plugs in B58 applications. Can the spring assembly simply be installed upside down and achieve the same results except have the correct contact spring for the B58 plug terminals?

I have had customers use the B58 plugs without any issues. The length to the terminal is pretty close overall because the ceramic is longer as you showed. I have been meaning to change to B58 plugs myself but haven't gotten to it yet.

The spark plug side of the spring should not be changed for these plugs because it needs to move correctly in the boot (there is a 12mm or so pocket for the spring to compress and expand in inside of the boot). All of the spring mods are on the side away from the plug to avoid changing the way the spark plug side moves in the boot pocket.

Customers have said that the spring make a good contact with the terminal and no real modifications are required.

It might be good to round out the top terminal on the plug slightly with a file to match the conventional plug terminal profile to keep the spring centered but customers have said that they haven't needed to do it.

The feedback has been that the B58 plugs just work with it.

-Rich

[rbryantaz]

Hi everyone,

I just wanted to share some developments to make it even easier to to use B58 spark plugs with this setup and to minimize the spring modifications.

I have added an option for the spark plug side of the spring to ensure that the B58 spark plugs are well centered.

A special set screw is simply screwed into the spring. If used with the newest eldor coils with their resistor the only modification is to cut the spring to 53mm and squeeze the top spring turn tight to ensure the best contact with the resistor.

There are three options, cut the spring in half to get two 47mm springs and stretch it to 54mm a few turns below the resistor side and use the resistor (it will compress back slightly to 53mm), cut the spring to 53mm, use a resistor delete screw in adapter.

Original style Eldor Coil and resistor setup on the left, new style on the right, resistor delete in the middle.


I recommend pinching the resistor side of the spring slightly to give it an extra secure connection:


I also have B58 plug adapters that screw into the bottom of the springs if running a B58 plug is desired.



Here is a shot of the B58 plug contact with the new setup:


Here is the contact point from inside of the boot:

[rbryantaz]

Bump for some improvements and simplifications on the springs and for B58 spark plug adapters.