Hello everyone!

So I've continued to to do reading and research and at this point, have literally read through hundreds of posts and archives over at roadfly and this forum all in the attempts to try and figure out which E31 car is right for me.

Based on everything I've read I think I can safely say that the 96-97 840ci is the clear winner.

Why?

As a daily driver the car must be reliable. OBDII cars seem to meet this requirement better then the pre-95 cars. Additionally parts availability is better for the 840 and insurance is cheaper. So far so good...

The thing that really sold me however was the fact that the OBDII V-12 cars really cannot be tuned for more power beyond the expensive (and mediocre) 'superchips' upgrade. While the 97 840 can be Dinan chipped to remove the speed limiter, and increase hp and torque (albeit modestly).

The final bit that truly sealed the deal was reading a post on roadfly made by 'Ahmed303' where he substantiates that with both Dinan chips plus the addition of plasma coils he threw down a stunning " 248HP and 290ft-lb of torque at the rear wheels" with his 840 O.o HOLY SMOKES!!!!! As far as I can tell, that exceeds the performance that one can expect to see out of a stock 97 850ci.

Now it's possible that I've been chewing my bubblegum a bit too hard and have become misinformed. If so, please do not hesitate to correct me and show me the error of my ways.

Ahmed303, I would be grateful if you would chime in here and provide me with any other details or things that I will need to do on my 840 to realize the same gains that you made with your 840.

Collectively the cost, reliability, maintenance and performance have utterly sold me on the late 840's as being the superior car for me personally.


On a side note, I hope I have not been a nuisance with my endless stream of questions. Thanks for allowing me to pick your brains and conduct my research! I am a serious car guy and I've always taken very good care of my cars. I plan on making sure the E31 gets the same treatment ;-]

Attack Vector......Yes that was my car and was dynoed at a collective event.

Just to give you a quick history of this 840Ci. My brother-in-law was the original owner of the car and I was the second owner. Since I needed financing the car was consigned through Bell BMW in NJ.

Anyway, I have taken great care of the car as I have seen my brother-in-law doing the same. It was maintained at a regious level. A synthetic oil change (After the first 10K miles) at every 5K miles using Mobil-1 15W50 initially and then RedLine Synthetic 15W50. I have always used Shell Premium Gasoline with a bottle of 12oz Techron every 4th or 5th fillup.

Tuning wise, I have had the following when the car was dynoed producing those numbers:

1. ITG TriFoam Air Filters (Drop in Replacement).
2. Ignition Solutions Plasma Ignition Coil set (Currently http://www.okadaprojects.com)
3. Dinan ECU
4. Dinan Transmission Chip

Also I have just done a bi-annual fluid flush (Coolant, Brake, differential) along with a Transmission fluid flush about 8K miles prior to the event as I did not believe in a lifetime fill BS. I also had a fresh set of Spark Plugs (BMW Stock) and new batteries (Interstate MTP-93). My intake and exhaust was stock aside from the Chrome tips.

At that point I was very close to Supercharging the 840 but I ended up selling the car for a business venture and bought the 860 after the venture payoff. I still miss the car. It was a beast to drive when the roads were not busy (Manual mode sprints) and the Steptronic was a blessing when they were busy (Full Auto mode). I have also done Autocrosses with the car in Sport mode when I needed to concentrate on the upcoming twists and turns rather than shifting without sacrificing much. IMHO, the 5HP30 is one of the best Auto tranny ever made with very low parasitic loss.

The cost was a different issue, I worked on the car myself somewhat and the dealer for things that I did not have the time or tools. The reliability was great as it was my daily driver for over 2 years. I even drove it in light snow a couple of times with Michelin Pilot Sport A/S tires as was fine. However I did not venture out when it snowed over 3~4 inches.

My final thought is that BMW underrated the M62 engine specs and with a good maint plan the M62 engine mated with 5HP30 can be a great powertrain for any machine.

PS. I wish I still had the documents to scan and post but I have given all the documents (and all the awards the car won) to the new owner. He is in AZ and does ot seem to be connected to any of the forums.

Ahmed303, Thanks for the great information regarding the history and buildup of the 840. I am thrilled that my wild speculation was not totally off-base. I honestly am suprised that other 840 owners have not traveled the same path with the OBDII 840's to realize those incredible gains. You seem to be a bit of a pioneer, both with the 840 and now with your V-12 monster!

I can certainly respect the work and diligence that went in to maintaining the car. Having personally owned a small collection of rare and unusual sports cars over my life I am no stranger to having to do most of the work myself and also commit to massive amounts of self-education about the nuances of my cars. I honestly feel that the 840 will not be nearly as frustrating to care for as some of the other cars I have owned.

One final question,

*** see edit below **** What is this 'lifetime fill' that everyone keeps talking about on the transmission?! Is this some reference to the fact that once the transmission starts to leak there is no way to correct the problem with a gasket or seal replacement? I find this very hard to believe. I mean if there's one thing I've learned while working on cars it's that, if it leaks... you can fix it. However it seems that this problem was isolated to just the OBDI 840's? I don't seem to remember reading about 'lifetime fill' problems with the steptrontic units?

***edit: Okay. I apologize for my previous ignorance. I just figured out what 'lifetime fill' means. I had never heard that expression used. So Lifetime Fill simply means that the fluid put in to the gearbox at the factory remains in the gearbox for the life of the unit, correct? If so... wow that's stupid. Why would anyone design a gearbox so that the fluid cannot be flushed?! This seems like a recipe for disaster.

Okay, so I am revising my previous question... Ahmed303, how do you flush the gearbox fluid if the transmission is sealed? Better yet, how do you fill it back up?



More info would be great!

Thanks guys!

OK. Here is the skinny on the Lifetime Fluid:

When BMW filled the Transmission fluid for the Automatic Transmission it was marked as a "Life Long Fluid". There is a speculation that it got translated loosely from the "Long Life Fluid". My take on it is that there is NO lifetime fluid. I recommend changing it at between 60K~70K miles and every 3 years or 36K miles thereafter. I however do not recommend it if the mileage is over 100K miles as the tranny fluid is already too sludged up and new fluid may introduce leaks and such.

I did mine and others did theirs as well with great results. It will cost about $600 from the dealer to do a Tranny service (Flush, Filter, etc). Some dealers may refuse to do it before 100K miles but they may have other motives. Even the Transmission maker ZF recommends the Fluid change. http://bimmer.roadfly.com/bmw/forums/e31/6143735-1.html

You can do a search on RoadFly on "lifetime fluid" and will find people doing this and having good results (Smoother shifting, etc.).

I had mine done at the dealer but Here is a procedure I found which should be the same for the 840 (http://www.e38.org/zf-5hp30-service.html)

How much did the ignition coil kt set you back? I cannot find any info for 840 M60 or M62 applications on their respective website.

I am wholly intrigued :D

I bought them from a friend for $350 while they retailed for about $750 at the time. SInce ISI sold the technology to OKADA the price doubled (Link to Applications). (http://www.okadaprojects.com/usa/applications_files/Applications.pdf)

They are expensive but they will give you the last few HP and Torque you are trying to squeeze out. Also if you can get someone to program your ECU to add 3% more fuel and the use of a High flow TB from Dinan you should be able to produce a lot more power as these coils ensure a complete fuel burn.

Search RoadFly for Plasma Coils or Ignition Solutions and you will find discussions.

Keep an eye on E-Bay. I have seen plasma coils for sale there.

Excellent info, I really appreciate it. I'm on the hunt.

Any extra horse I can add to pull my wagon, the merrier.

Ahmed303, Thanks for the additional info.

As far as the extra 3% fuel goes... This doesn't sound like much. How did you come up with this value? Was this a finding from the results of your dyno pulls? If so, were you able to see if running the plasma coils puts the engine at a dangerously lean threshold?

I wonder if adding slightly oversized injectors would rectify this without having to go through the brain damage of an experimental EFI tune that explored boundaries beyond the Dinan ECU update? Of course, I'm speculating out of ignorance here, but some engine ECU's are set up to compensate for changes in fuel and air concentrations within a spectrum, and are therefore considered to be 'adaptive' systems. If the aperture and flow rate of the injectors was slightly increased would the ECU compensate for this and make the necessary adjustments to engine timing (retard / advance) to allow combustion to take place, albeit at a richer fuel density? Or would the system freak out and not know how to handle the new injector size?

As I said, pure noob speculation on my part. I know very little about EFI and engine tuning technology beyond the basics.

As far as the Dinan throttle body goes, where can I get this part and how much does it cost? Dinan makes no mention of it on their website for our cars.

Again, thank you for all this great information! :-]

Ahmed303, Thanks for the additional info.

As far as the extra 3% fuel goes... This doesn't sound like much. How did you come up with this value? Was this a finding from the results of your dyno pulls? If so, were you able to see if running the plasma coils puts the engine at a dangerously lean threshold?

What I meant to say is that the 3% fuel increase in combination with the High Flow TB. The Dinan TB provides between 3% to 5% increase in Air Mass and thus the recommendation of the 3% fuel increase. Now that is from what I have seen from the 2000 BMW 740iL I owned for a brief period. Plasma coils does not introduce any additional Air and I ran my 840 without any increase in fuel or air and the A/F Ratio stayed between 12.8 and 13. I had plasma coils on both cars.

I wonder if adding slightly oversized injectors would rectify this without having to go through the brain damage of an experimental EFI tune that explored boundaries beyond the Dinan ECU update? As far as the Dinan throttle body goes, where can I get this part and how much does it cost? Dinan makes no mention of it on their website for our cars.

Again, thank you for all this great information! :-]

The 840 injectors are fine stock and nowhere near it's capacity or atleast that is what I was told. I did not play with the injectors themselves. The oversized TB is for the 740's and should work with the same M62 equipped 840. Dinan stopped offering them for the 840 when they stopped offering the Supercharger system (Yes Dinan had a SC System for the 840 and TT for the 850 in 3 stages).

But, I would like to take a moment to apologize for mixing up information between my 740 and 840. But If I still had my 840 and the 740, I would have swapped those mods under careful observation until the SC. But what I said still stands based on the same engine platform (M62)

Please, no apologies required!!! I am just delighted with the wealth of information that you've posted. Honestly, your various posts amongst the message boards have yielded the most conclusive evidence that the 840 is really a bruiser in hiding. Even without the extra air and fuel from the Dinan TB, I would forever be happy with the numbers that your 840 was putting down. You've given other 840 owners a great target to shoot for on what I see as a very reasonable budget.

Too bad that Dinan does not support the E31 the way they used too with the turbo and SC packages, but alas... those would've been way out of my price range, and honestly... I've hard it up to my eyeballs with forced induction. I'm very much looking forward to the simplicity and reliability of NA power.

Thanks again!

What I meant to say is that the 3% fuel increase in combination with the High Flow TB. The Dinan TB provides between 3% to 5% increase in Air Mass and thus the recommendation of the 3% fuel increase. Now that is from what I have seen from the 2000 BMW 740iL I owned for a brief period. Plasma coils does not introduce any additional Air and I ran my 840 without any increase in fuel or air and the A/F Ratio stayed between 12.8 and 13. I had plasma coils on both cars.



The 840 injectors are fine stock and nowhere near it's capacity or atleast that is what I was told. I did not play with the injectors themselves. The oversized TB is for the 740's and should work with the same M62 equipped 840. Dinan stopped offering them for the 840 when they stopped offering the Supercharger system (Yes Dinan had a SC System for the 840 and TT for the 850 in 3 stages).

But, I would like to take a moment to apologize for mixing up information between my 740 and 840. But If I still had my 840 and the 740, I would have swapped those mods under careful observation until the SC. But what I said still stands based on the same engine platform (M62)


So the Plasma coils should give better/greater spark = performance/efficience! Are they a more condusive wire? A Performance applicator!

Thanks,

840ways to C

Anybody tried Bavarian Auto's peformance coils?

So the Plasma coils should give better/greater spark = performance/efficience! Are they a more condusive wire? A Performance applicator!

Thanks,

840ways to C

No wires (Unless you are talking about conductor inside the coils). The M62 runs Coil over Plug system. The Plasma coils generate a better Secondary and subsequent spark to ensure a complete fuel burn in the chamber. Now coupled with a good Air-Filter (ITG, BMC, etc.) you get the best bang (Pun intended).

It is almost like a Capacitor for very powerful Audio system where the normal power is delivered from the batteries but when it needs the extra juice to execute the big Bass it uses the capacitor. In the case of the plasma coil it is constantly storing the charge and applying it to the next spark.

Watch this video and see the multiple full sparks after compression (http://video.google.com/videoplay?docid=-5815350492893860613&hl=en)

Anybody tried Bavarian Auto's peformance coils?
Put them in my 840 ,with Denso Iridium plugs to replace Bosch +4 plugs.
I did one change at a time and the coils and plugs improved overall drivability

248HP and 290ft-lb of torque at the rear wheels" with his 840 O.o HOLY SMOKES!!!!! ;-]



Faisal, bro... what am I missing here? Why does a 282hp @ 5700 rpm car go to 248hp with these mods? Is it a typo or is there some measurment designation missing/misinterpreted by me?

Faisal, bro... what am I missing here? Why does a 282hp @ 5700 rpm car go to 248hp with these mods? Is it a typo or is there some measurment designation missing/misinterpreted by me?

I believe that's 248hp rwhp and the 282 is at the crank. since the org rwhp is around 220 I think that's about a 30hp gain over stock

I believe that's 248hp rwhp and the 282 is at the crank. since the org rwhp is around 220 I think that's about a 30hp gain over stock

That is correct. The posted HP and Torque is at the wheels.

If you consider a 70 HP and 85 lb-ft of Torque loss for the Steptronic Transmission (ZF loss measurement), then the HP at the Crank is 248+70 = 318 HP and the Torque is 290+85 = 375 lb-ft.

Now the most common method people use is 20% drivetrain loss. In that calculation the HP is 1.25X248 = 310 HP and 1.25X290 = 362.5 lb-ft of Torque.

Either way it a decent gain over stock 282 HP and 310 lb-ft in Torque.

I appreciate the clarification, thanks guys-- :)

Faisal, 'plasma coils + 840ci bmw' bring this post in the top two for google so probably good to keep the info as clear and accurate as possible. I was just searching for spark plugs...really :help!!!!!!!!!!!!

Hey, are these numbers 'pre-SC' or after? I thought you had that baby SC'ed?

Pre SC. I almost went to SC but then sold the 840 and got the 860

Ah, okay!

One of these days my car is not going to have such a high burn rate for my 'fun money+time' with its needy little hissy fits. Then the real fun will begin, which is why I am tracking this conversation. (:

hi guys just thought i'd chime in for all the 840 owners and soon to be owners that is it may take a while to make our cars perform but it's well worth it it's taken me over 2 years and alot of set backs to get mine to where it is today and right now i am looking like I will be right on track to have my 840fi out of the shop in Feb which will be the 3rd anniverserry of it being mine. so keep planning and reading. almost all I know about my car comes from this board.