[GnomeChild]

Has anyone run these?

https://www.ecstuning.com/b-kayser-p...6a145710n~kay/

Apparently they come on Porsches and are rated for 30+ PSI and are common upgrades on high power VW/Audis running higher-than-stock boost. People have mentioned them as an alternative to the upgraded spring-style diverter valves on offer from Forge or Turbosmart (of which I would probably end up going with Turbosmart if the 710ns don't work) but any google/forum search has only divulged mention of them, no one actually claiming/posting pictures of an actual setup

They are plastic construction, diaphragm style, plug-type fitting diverters and are not a plug and play solution for the N54 Diverters but those running aftermarket aluminum chargepipes would be covered for at least one of the plug ends (silicone tubing from OE style diverters on aluminum charge pipe). What are the diameters of the OEM diverters/710n plugs? I would just need some vacuum hose and it would complete the setup for nearly 1/4th the cost of the bullet/spring style alternatives

No
I will not just run a BOV

[GnomeChild]

After much deliberation, I have decided to undergo this uncharted/undocumented mod myself for the sake of anyone who may be in the same boat as me



I hope to achieve similar results to the Billet/Spring style kits that Turbosmart and Forge offer at a discounted rate but also looking as OEM as possible. If I only get stronger DVs out of it, I will consider it a success if I can manage to reuse the stock DV plumbing. The tubes may be made of plastic (vs aftermarket silicone piping) but it matches the engine bay well and has been proven to already be fairly stout/heat resistant. I have found some good deals on eBay that will make this all possible.

I will morph this into a DIY if I can achieve good results. It seems like a simple swap, but it would be nice to know it's finally documented that it is possible

[GnomeChild]

Reserved

[Dfbpurcell]

putting more plastic on an n54. genius.

[GnomeChild]

You're more than welcome to use RKX's Billet 710N instead

There are many reasons to stay with the plastic diverters systems
1) they don't require frequent, or any servicing at all (you just replace if they go bad)
2) they are cheap to replace
3) they look stock with no flashy logos and will fly under the radar of smog refs
4) they retain the diaphragm actuator instead of moving to a spring+piston style

Depending on who you ask, #4 is the only subjective, debatable point. However, I posted a spring actuated billet 710N by RKX which is the same exact price as the plastic OEM Kayser ones. There is literally no reason to be paying $350+ for any of the "legit" kits if you want to upgrade from the diaphragm actuator to billet spring/piston actuators

Ideally, Porsche guys have always upgraded beyond the 710Ns to Baileys DV30s which are the same dimensions as the 710Ns. Seeing as they went out of business in 2020 however, that's no longer possible. RKX is the next "budget" billet diverter if that's what you're looking to upgrade to.

I'm personally okay with the 710Ns myself

[GnomeChild]

Well boys

My box from Forge Motorsport came in today. Gonna pack it in on this mod, I threw in the towel












































































Jk, these are getting returned; I ordered them by accident

[feuer]

Oh this thread give me flash back of decade ago when people where trying different things assuming the DV on the n54 aren’t good. I come from Audi/VW back round and know these DV. Failure rate on both is very rare. I have seen them on n54 and will never forget because person used green water hose to attach them to the CP. Since they can be only mounted with a hose clamp and you want that oem look I suggest you get flat black clamps. You can paint clams that you have or even purchase them in black.

[GnomeChild]

The Porsche guys had some dog-ear clamps (the kind mostly used for coolant hoses and the same style clamps used for the steering rack boots) posted in a thread for these and I may go with those if the OEM diverter tubing is not a direct fit.

I don't intend to be that shoddy with this

[racerbruce]

well done gnomechild -
what's your thought(s) re oem dv's and that they create back psi @ the turbo(s) which can cause premature turbo failure vs bov technology.

[GnomeChild]

Admittedly, I am no engineer nor have I done extensive testing on which system is better/healthier for the turbos, but I know that diverters are meant to redirect boost pressures back into the inlets and help with spool on lift-off throttle

Depending on who you ask, there will be people who say absolutely do not get a BOV under any circumstances and there will be people who say the stock diverters are junk and do not help spool in any way, shape, or form. The truth usually lies somewhere in the middle of two extremes but since I appreciate the quiet and reserved designs of the stock diverters I will be biased by going the 710N route

There are BOV systems that can be setup to plumb back into the intake/inlets and act like diverters and there are diverters that can be set to VTA and make the "pssssh" sound, just like BOVs can. I think it mainly boils down to what type of valve do you personally want to run and how do you want it plumbed? I don't know if there is a definitive "right" answer and it might really just depend on your budget, build "theme", power goals, etc.

Seems like there are quite a few options to consider and none of them are mutually exclusive since they can all be setup in such a way that they act like the "other side" of the spectrum. It really might just come down to personal preference and what your goals are

Someone with more knowledge than I on how these systems work is more than welcome to come by and prove me wrong

[racerbruce]

Originally Posted by GnomeChild

Admittedly, I am no engineer nor have I done extensive testing on which system is better/healthier for the turbos, but I know that diverters are meant to redirect boost pressures back into the inlets and help with spool on lift-off throttle

Depending on who you ask, there will be people who say absolutely do not get a BOV under any circumstances and there will be people who say the stock diverters are junk and do not help spool in any way, shape, or form. The truth usually lies somewhere in the middle of two extremes but since I appreciate the quiet and reserved designs of the stock diverters I will be biased by going the 710N route

There are BOV systems that can be setup to plumb back into the intake/inlets and act like diverters and there are diverters that can be set to VTA and make the "pssssh" sound, just like BOVs can. I think it mainly boils down to what type of valve do you personally want to run and how do you want it plumbed? I don't know if there is a definitive "right" answer and it might really just depend on your budget, build "theme", power goals, etc.

Seems like there are quite a few options to consider and none of them are mutually exclusive since they can all be setup in such a way that they act like the "other side" of the spectrum. It really might just come down to personal preference and what your goals are

Someone with more knowledge than I on how these systems work is more than welcome to come by and prove me wrong

thank you gnomechild for the well thought out response and rationale; i too am no forced induction expert and seek knowledge from those with experience on this topic (and all topics relating to the care of bmw's).

perhaps others can add to this thread regarding diverters, bov's etc.

[GnomeChild]

racerbruce

After thinking about it more, I have come to the theory that I don't believe the stock diverters would exacerbate turbo wear. On setups with excessive backpressures (turbo systems with no BOV or Diverters) typically you with hear "compressor surge" as boost pressures depressurize on closed-throttle and travel back through the turbo housings in reverse, causing them to spool in reverse. Obviously, because of the stock diverters, N54s don't experience this.

Frankly, the issue with N54 diverters is that they leak at above-stock boost pressures and there have been reports that they top out even as low as 1Bar (~14.7psi). That is literally Stage 1 boost targets! People have been known to run nearly 25psi on the stock diverters but what they don't know/realize is that a lot of performance could be getting lost due to leaky diverters! Their tune/turbos could very well be producing and boosting up to nearly 2 bar and losing some due to leaky diaphragms!

That is the issue that this DIY/pet project of mine is looking to solve. I don't intend to push much beyond MHD Stage 2+ (about 18psi) and stock diverters will be adequate for this boost target, as many have already verified and experienced; it is well documented how many people run JB4/MHD stage 2+ without having to upgrade their diverters. However, just like in the B58 coil thread, more overhead is a good thing. I would rather run 18psi through diverters rated for 2bar vs running 18psi through diverters only rated for 1bar; even if they "work"!

Again, if my theories are off-kilter I welcome absolutely anyone more knowledgeable than I to chime in and redirect towards truth. I'm sure a dedicated Tuner or Engineer are much more thenically knowledgeable on these systems than a shadetree mechanic swapping around parts!



I have also done a little bit of work today on this project. My 710N diverters came in and I have snapped some progress pics of at least the "prototyping" stage. I will update this thread in a few hours with all the pics and measurements I have taken for everyone's benefit. I have a few more projects to attend to while it is still "daylight" but I will be back. I trust there will be a little something special for everyone in my research

[Tambohamilton]

Originally Posted by GnomeChild

After thinking about it more, I have come to the theory that I don't believe the stock diverters would exacerbate turbo wear. On setups with excessive backpressures (turbo systems with no BOV or Diverters) typically you with hear "compressor surge" as boost pressures depressurize on closed-throttle and travel back through the turbo housings in reverse, causing them to spool in reverse. Obviously, because of the stock diverters, N54s don't experience this.

Just to iron this out a bit...

Without a diverter or BOV, boost pressure *spikes/increases* on closed throttle (throttle plate closed but turbos still spinning fast). The resulting "compressor surge" that you can hear (people at least used to erroneously refer to it as "wastegate chatter" ) happens because airflow through the compressor stalls, flows backwards until the pressure drops sufficient for forward flow to restart....and repeat, rapidly. The net result is that the turbo decelerates quickly, but it won't spin in the opposite direction ever.

Disclaimer; also not a turbo specialist, but was lectured at university by a chap who knew a few things about them.

[GnomeChild]

That seems about right and thanks for the correction

I have found a quick video that also summarizes the concept of "compressor surge" and can be helpful for anyone else who wants a more visual representation of the concept

[racerbruce]

great video gnome - helpful!

[racerbruce]

another perspective - https://blog.moddedeuros.com/blowoff...iverter-valves

bmw n54 engines do not have a maf and have a map.

[GnomeChild]

Yes. Originally, before I created the thread, I came upon the same findings. It was one thing that swayed me toward sticking with the diverters. However as you specified, N54s have a MAP, not a MAF: it measures pressures, not airflow, so my fears became unfounded. N54s will be unaffected by the traditional "running rich" on throttle-off that MAF equipped cars will face. But by that point I was already committed to only upgrading the stock system

[studio54]

Originally Posted by Dfbpurcell

putting more plastic on an n54. genius.

Why not? Plastic is fantastic.

Stock DVs (plastic) are maybe and probably fastest to react than some over priced and fancy Forge or any other brand aftermarket DVs.

[GnomeChild]

Yup, the plastic diaphragms are actually the quickest on the market. The billet upgrades that run $350+ with the piston style plungers are more stout but they are subject to more heat soak and they are grandpa slow in comparison. Nothing reacts as fast as the plastic diaphragms! Your spool will thank you!


That being said, I have returned with the promised update



The 710Ns came today and I got straight to work. I haven't actually ordered anything from VRSF, that was just the box that the eBay seller shipped my pre-LCI chargepipe and stock Diverters in



I started by laying down my workspace. The stock diverters with piping on the left and the 710N Kaysers on the right





As you can see... at first glance they are extreeeeemely similar



I managed to get the pipes off the stock diverters but it took a substantial amount of force. I basically wrapped the stock diverters in a microfibre towel and "stood" on top of them as I pulled the plastic tubes off. Will some elbow grease and "lifting with my legs" I was able to deadlift the pipes off

To my surprise, the stock diverters and 710Ns are the exact same dimensions, except with different flanges



Even the diaphragms are built the same. At this point I actually started to get a little scared that they actually may be the "same" diverter so I tested them out and you can definitely tell that the 710Ns take more force, almost twice as much force to open the diaphragms over the stock diverters. The 710Ns are definitely in a different league



So I stuck on the OEM piping and it... sorta..? worked...?



As you can see, the piping sorta "deformed" and took the shape of the previous stock diverters. Due to the nature of the flange on the 710Ns, you can't quite get them to seat all the way. They also don't seal, no way, more like... loosely fit. It's entirely possible that if I can manage to get the piping to fully seat that they may seal on their own and not require any additional clamps

I did a little digging and it seems like even new OEM diverter piping has those "grooves"





I was contemplating buying a new set and seeing if fresh plastic would mold/flex better and actually seat correctly. It's entirely possible that after so many heat cycles, the plastic piping is "set" in that position, but having to buy a second set of diverters just for the plastic piping would drive the cost up of this mod and defeat the purpose. I was pressed for time and I still have a few... experiments.. I want to try, so I left it at that. The purpose of today was just to see if the stock diverter and the 710N diverters had similar sized flanges and could adapt to the OEM piping, which I consider a major success

Lastly, I wanted to give something to the aftermarket community so I took some quick measurements of the flanges



Chargepipe side



Piping side



The Porsche guys were saying that the flanges were 24mm which I have effectively confirmed. The flanges are just under 1" in diameter. That means those of you running aftermarket/silicone inlets will still be able to use these and adapt them to your setups, you'd just need to source your own 1" vacuum tubing. Forge sells their tubes at 350mm for the front diverter and 400mm for the rear diverter, so you could probably get away with buying about 2.5' of silicone/rubber vacuum tubing and making two tubes out of it; would probably cost less than $10

Lastly, I posted these in the "WDYDTYCT" thread but I think they also deserve an honorable mention here too:



I made sure to buy upgraded diverter seals. The stock chargepipe and diverter tubings all have O-rings at the flange ends (where the grey "twist-cap" is) and after some time the rubber wears down and degrades. Often times leaky diverters are actually just leaky O-rings. I wanted to ensure that my new 710N diverters will be leak free so I went ahead and ordered upgraded seals. If you are running the stock setup, you need 4 total, but upgrading to 710Ns using the OEM piping as I'm trying to do, you only need 2. The O-Ring store had a 15 ring minimum order however, so I just ordered 20. I will probably keep 2 sets of 2 for me but the rest I will have available for sale (soon).


All in all, I consider this "prototyping" phase a massive success. I will experiment more with how to get the 710Ns to seat fully next weekend, but it seems as though my proof of concept has indeed been proven successful for the first phase of this mod

[racerbruce]

well dne gnome!
your linear and calculated approach is commendable.

great pics and love the old-school dial indicator vernier caliper for critical measurement of id and od.

we await next weekend's update!

[racerbruce]

on the topic of off-throttle boost and what to do with it....

turner motorsport's narrative of dv's vs bov's....of course written by a co that sells product (but in fairness sells dv's and bov's)....

"All of the tuning in the world is only as good as the weakest link. More boost in your 135/335 is great! But you will soon learn that some of the factory hardware is not up to the task of handling that extra pressure. One of the first things to fail and cause a boost leak are the factory boost diverter valves. This allows boost to "leak" out of the intake stream and a loss of power from the engine. This ECS Tuning chargepipe upgrade includes a blow-off valve in place of the factory diverter valves. The BOV is higher quality than the diverter valves and will exit intake air to the outside instead of putting it back through the turbo system (which will reduce strain on the turbos). This aluminum chargepipe is also much more robust than the stock plastic factory pipe and the connection to the throttle body is stronger, eliminating another failure point of the stock pipe."

[Tambohamilton]

Clearly the solution is to have both; quick diverters and slow but effective bovs.

Only semi-joking there