Could use a little clarity on water/meth injection systems.

[feeshta]

Hello all. I'm a former 135i owner and probably future 135 owner(currently searching for the right car), and I have a few questions about water meth injection systems on the N55 engine in particular. I have done a good deal of reading and searching already, so please no "use the search" responses, I've tried that already.

So, I understand the basic benefits of the water/meth injection systems out there. I am personally primarily interested in the cleaning effect of these systems rather than the performance boosting effect, although the performance boosting effect would be nice as well. The main question I have revolves around the tuning of these systems, and their flexibility regarding the mixture used.

Personally, the idea of being able to simply run water in the system in order to avoid a @$600 walnut blasting procedure at @30K intervals is quite attractive to me. Such a system would not require routine runs to the store or online orders for fluid, and would cost virtually zero to operate. It would also be easy to refill while on a long trip or the like, as you could simply stop and grab some water anywhere along the way should the tank run dry.

That said, the idea of occasionally turning the wick up a bit with some methanol is also attractive, so system flexibility is something I am interested in.

So, what I am really wondering is how flexible are these systems when it comes to things like this? If you run the JB4 for instance, would you be able to have separate tunes for water only and water/meth mixture that are easily switchable? What happens if you should forget and your tank runs dry? Do you need to switch back to another map to avoid issues, or are things automatically integrated?

A possible complication here is that the delivery of the differing mixtures might require different delivery rates, and I am not completely clear on how easy it is to control this with the different injection systems. Would it involve something like adjusting some settings each time I switch back and forth? Also, how difficult is the initial tuning of these systems? It seems from what I have been reading that there is an initial tuning required to get them set up properly for your vehicle, as they are generally not vehicle-specific. Would I need to have a professional shop set it up for best results, or can I do it myself without much additional cost in equipment etc?

Any clarity you guys can offer on this issue would be very much appreciated.

[TUN3D]

feeshta > I've run meth for a number of years with the n54 engine. From the post, it sounds like you haven't really decided HOW you want to use the system. You have alot of ideas rolling around, with -- yeah -- flexibility in mind, but that's going to equal inconsistency. Here's what I can share.

For starters, Meth won't clean out your valves. It might, and I say that loosely, prolong carbon buildup a bit -- but it's inevitable. The piston head and combustion chamber will benefit the most from the steam-cleaning that takes place.

In terms of meth usage, as an example, some people in California only have access to 91 pump-gas and can't buy 93. Meth, in cases like that, helps to supplement fuel deficiencies.

In my case, I run 10 gals. of E85 over 93 (all day). My car is tuned for that. Meth will add very little (if nothing) in terms of power gains. It can, however, help lower my IAT's and improve timing.

If your serious about tuning and want your car to run the same/consistent way every time -- then you have to stick to a specific mixture, and fine tune the car for that. Otherwise, the JB4 system is very flexible and Map #3 will auto-tune. You can run whatever mixture you want with the JB4. 50/50 mix, rubbing alcohol, 100% meth, windshield wiper fluid, boost Juice -- whatever. You can literally piss in the tank and the JB4 will regulate it. That said, the car will be not run consistently, if you hop from one source/mixture to the other.

================

Practicality is something I always try to go buy in most things I do. Sitting there and manually mixing meth/water is a PITA. Not that I can't do it, but just don't have the time for it. For a while, before I started buying 5 gallon drums of 100% meth, I used to walk into CVS/Walgreens and raid their alcohol supply. I used to buy 4-6 containers of 91% rubbing alcohol and dump that into the tank. Evan that though, just became a mission over time.

Personally, if your gonna do it -- do it right. Use 100% Meth and buy the 5 gallon drum. Fill up once every couple of weeks (at home), no mixing, no headaches. Tune for whatever fuel is available in your area + the same consistency of meth. I like 100% because ignition timing drops off sharply at higher concentrations/%'s. You can also squeeze a little more power out of it. But again, it's a matter of preference. If you want to run water or cool-aid in the tank...it's up to you. Like I mentioned, the JB4 on Map #3 will sort it out for you.

For road trips, you'll be fine. Even with a very very heavy foot and dual Meth nozzles, a full 2 gallon tank will last a few weeks. Remember, Meth is only sprayed on WOT. Your not gonna be driving on WOT, the entire trip right? LMAO!

[feeshta]

Hmm, so there is no way to proactively prevent the carbon buildup issues? I had read in numerous other places that the water injection would simulate the normal fuel bath that intake valves see in a port injected engine. I understand that it can't be expected to clean the engine once the buildup has already occurred, but I had thought that it would prevent it building back up once you have the cleaning job performed once.

As far as tuning, the 350-odd HP I can achieve with simple mods like a JB4 and a down-pipe are more than enough to keep me entertained, and I don't want to negatively impact the reliability of my vehicle, as it will be my only car. I don't have any interest in drag racing, and the car is pretty close to the limits of it's chassis when it comes to putting down power on a tight back road as it is, so I don't feel a real need for massive power.

I'm mainly looking for a way to keep the car running cleanly and avoid maintenance issues. Having to take the car in every other year for a $600 procedure is not an attractive option to me at all.

[feeshta]

Just now saw your edit. I had started to reply, then got distracted by a phone call and finished later.

I understand what you are saying about simplicity. If I were going to be doing the full-on meth injection, I would probably go that route. The thing is, if there is no real cleaning benefit to it, then I would probably avoid the issue altogether. For my driving preferences, WOT is not all that often a part of the equation other than highway on-ramps and the like. My "fun" driving time revolves around extremely tight rural back-roads, and as such throttle response and wideband torque availability are the main areas I would seek improvement in. Chip and down-pipe would probably be my best bet to achieve those goals. On the back roads, if you have an opportunity for WOT, it is usually limited to an extremely short area, so it's not a major factor in the overall driving experience.

Most of my time and money is probably going to go into sorting out the 135i's understeer issues and getting the chassis sorted, as that will be the largest single performance factor for my personal experience.

[6MT_Addict]

Originally Posted by feeshta

Hmm, so there is no way to proactively prevent the carbon buildup issues?

You can pick up a BMS Oil Catch Can. This will help extend the interval between walnut blasting, but buildup is inevitable.

http://www.burgertuning.com/BMW_335_oil_catch_can.html

From the sounds of it, meth/water injection is not really worth the time or effort based on your driving habits and goals with the car. I would save the $$ and invest in a kit to clean out the valves yourself - it will cost less than $600 all in anyway. If you plan on keeping the car for a while this will pay for itself time and time again. Bav Auto has a great DIY video, the process takes about 6 hours.

[feeshta]

Originally Posted by 1AddictsAnonymous

You can pick up a BMS Oil Catch Can. This will help extend the interval between walnut blasting, but buildup is inevitable.

http://www.burgertuning.com/BMW_335_oil_catch_can.html

From the sounds of it, meth/water injection is not really worth the time or effort based on your driving habits and goals with the car. I would save the $$ and invest in a kit to clean out the valves yourself - it will cost less than $600 all in anyway. If you plan on keeping the car for a while this will pay for itself time and time again. Bav Auto has a great DIY video, the process takes about 6 hours.

Yeah, I saw that video. It's quite the process, but it would be worth the effort to avoid $600 or more of expense, and especially for peace of mind to know that it was actually done and done properly. There are a lot of shady folks out there, unfortunately. The catch cans don't seem to actually do all that much from what I have been reading, but I will probably put one on anyway.

All of this makes me wonder if it might not be easier to simply eliminate the EGR system from the equation, as that is where all the carbon is coming from as I understand it. Not sure what that would entail from a tuning perspective. I am sure it is probably illegal, but then so is a catless down-pipe and it seems everyone is running those.

[6MT_Addict]

Originally Posted by feeshta

All of this makes me wonder if it might not be easier to simply eliminate the EGR system from the equation, as that is where all the carbon is coming from as I understand it. Not sure what that would entail from a tuning perspective. I am sure it is probably illegal, but then so is a catless down-pipe and it seems everyone is running those.

You can just vent it into the exhaust, like they used to do. It is illegal in most areas due to emissions, but I don't think this kind of thing is checked during emissions checks. Some people here have done it, I've read about it but not in depth. A quick search should yield results but I'm sure some sifting will be required. I picked up a BMS OCC and will be installing soon, unless dumping the excess oil into the exhaust is an easy thing to do.

[feeshta]

Originally Posted by 1AddictsAnonymous

You can just vent it into the exhaust, like they used to do. It is illegal in most areas due to emissions, but I don't think this kind of thing is checked during emissions checks. Some people here have done it, I've read about it but not in depth. A quick search should yield results but I'm sure some sifting will be required. I picked up a BMS OCC and will be installing soon, unless dumping the excess oil into the exhaust is an easy thing to do.

Now that I think about it, that would not work either, as the PCV system is still going to be bringing gunk into the intake. You would have to bypass that as well, which might have other unwanted results from a tuning perspective, as you I don't think you would be able to accuratly meter air anymore.

I'm not seeing a reasonable way around this. Then again, I would guess if there was an easy way around it, the manufacturers would have found it by now. I was hoping the injection was it, as manufacturers would be hesitant to apply such an approach to a stock car due to the fact that most owners don't want to be bothered with another maintenance item, and a large number would simply ignore it. It's the same reason they don't offer oil catch cans. I guess that was wishful thinking though.

It is a bit crazy that more people are not aware of this issue. I guess when GDI engines start hitting the Honda accords of the world, the general public will start to take more notice.

[6MT_Addict]

Originally Posted by feeshta

Now that I think about it, that would not work either, as the PCV system is still going to be bringing gunk into the intake. You would have to bypass that as well, which might have other unwanted results from a tuning perspective, as you I don't think you would be able to accuratly meter air anymore.

Have a read: http://www.e90post.com/forums/showth...518306&page=28

[feeshta]

Originally Posted by 1AddictsAnonymous

Have a read: http://www.e90post.com/forums/showth...518306&page=28

Not sure if I stepped into the middle of that convo or what, but I read the whole page and it still isn't completely making sense. Might need to start from the beginning, but don't have the time at the moment. Thanks for posting it though.