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Puddy46
Puddy46 HalfDork
6/29/24 9:53 a.m.

Really interested to see what the real world horsepower gains are for the 3 stage intake.  It's been steadily climbing my list of things to do to my E82.

 

roninsoldier83
roninsoldier83 HalfDork
6/30/24 10:58 p.m.

Well, I finally stopped procrastinating today and installed the DISA 3-stage intake manifold into my 128i. It isn't a "hard" job per se, but if you have small hands you certainly have an advantage. I unfortunately have giant caveman hands... in contrast, wife's tiny hands helped me out in a few different places, namely: 

-The hose that's next to the throttle body on the intake manifold- I couldn't reach my fingers to the back/bottom of that hose to release it to save my live! My wife had that thing disconnected in ~30 seconds. 

-The screws that attach the wiring box bracket to the bottom of the intake manifold... good Lord, you can't see the screws, they're surrounded by wires going all over and the bolts were tiny... after struggling for several minutes, I asked my wife if she wanted to give it a shot, and again, she got them screwed into place in no time flat. 

All in all, it took me/us right around 3 hours (my wife mostly just held the flashlight unless I couldn't get my hands somewhere). That was with me taking my time, cleaning out my new Euro airbox, installing a new filter in the new airbox, putting new gaskets on the intake manifold and throttle body, looking up torque specs for the manfold (3 sets in the book based on the thickness of the bolts- in my case they were M6 bolts), throttle body (couldn't find any) and "half strut tower brace" and cleaning up the garage. Nothing about this job is really "hard", just pay attention to all the hoses and sensors you have to disconnect/reconnect. With the exception of the rear PCV hose (y-shaped), I don't think I broke anything- and I bought an extra PCV hose for this exact reason (it's commonly broken- I broke mine on purpose just to get it out of there). If I had to do it again, there's a solid chance I could get it done in under 2 hours (assuming I have an assistant with small hands). 

Engine bay when I started: 



The junkyard 3SIM that's been sitting in my garage for almost a year now... it's a good thing this manifold is made out of plastic- at least it couldn't start rusting on me!



I spent some time cleaning this old thing up before I put it in the car: 





Old DISA valves that were in my junkyard manifold vs the new OEM DISA valves I bought from FCP Euro. Sure, they old ones might have still worked, but it was a high mileage X5 that was beat to hell in a junkyard... I didn't want to do all this work, just to have to pull the manifold and replace them, or replace them shortly thereafter: 





The USDM (left) OEM airbox, vs the Euro OEM airbox, which you can see is a completely different design: 



The Euro airbox comes with a conical air filter and is supposed to flow just a bit better than the USDM airbox. I put a new K&N filter into it: 



With the USDM airbox, you actually have to remove it from the car and open it in order to change the panel air filter: 



^^^^On the other side of the panel filter there's normally a charcoal air filter (I had already cut mine out) that supposed to take down on the smell of gas when you turn the car off, hence why we got the (inferior?) style airbox. Technically, the engine was designed for the Euro airbox and the USDM piece was an adaptation. 

With the OEM single stage intake manifold removed (right), you can see that the single stage manifold and the 3-stage intake manifold (left) are roughly the same size and shape. The only real difference is the DISA valves, which you can see the front one in the photo. The second DISA valve is in the back of the 3SIM (not shown in photo): 



The engine bay with the manifold removed: 



^^^It should also be noted that I moved the power steering reservoir out of the way (very easy) and removed the left/driver side strut brace in order to give myself a bit of room to work. 100% recommended as space in there is tight. 

The finished product with the new 3SIM and Euro airbox in the car: 



^^^Looks OEM... because, well, it is. People who don't know to look for the DISA valve(s) would have no idea this wasn't stock in the car. I certainly think the Euro airbox looks a lot nicer in the engine bay. Ironically enough the little accordion piece from the air scoops actually fits the Euro airbox much better than it ever fit the USDM airbox (it feels like it makes a better seal). 

Notes: 

-The wiring harness for the DISA and non-DISA cars are the same. The plugs for the DISA valves are actually mounted clearly to the single stage non-DISA OEM manifold. You literally just plug them in. I thought it might be confusing to know which one goes where, but the shorter wire (to the front/top DISA) doesn't reach to the rear/lower DISA, so you can't really mess this up. 

After the swap, the car fired up no problem and seemingly drives without knowing anything was changed. I haven't really gotten on it- I don't expect there will be any real difference. Without the ECU/DME knowing that the DISA valves are there, it won't open/close them... you need to tune the car/DME to let it know the DISA valves exist before you're going to see any real gains. 

Unfortunately, it would appear that the Bimmerlabs website is now down... that's unfortunate because they previously hosted the free 330i tune to activate the DISA valves... so unless you can find someone willing to share the map with you, it would appear the tune is now a pay-for-a-tune situation. Apparently I should have hopped on this last year. I just ordered a Bimmworks tune. They recommend you connect your car to a 30A battery charger to make sure the ECU/DME doesn't die during the process- so, I'm now waiting on a 30A batter charger to arrive before I start the tuning process. I read their instructions- honestly, they're pretty well written/easy to understand. The first thing they do is have to read the stock map and make a backup file so it would appear you can flash back to stock at any time. Fingers crossed that all goes well! 

Once the car is tuned, I'll drive it around for a couple of weeks to help the ECU/DME adapt (everyone seems to claim they make a bit more power if you give it time to adapt). After that, I'll be back to a Dynojet to see what kind of gains are made vs my previous baseline. 

In the interest of full disclosure, if you go the route I went, this isn't nearly the bang-for-the-buck power mod that the Internet would have you believe. I think the intake manifold was ~$33 from my local junkyard (remember to remove the throttle body to avoid being charged extra- doh!). New OEM BMW DISA valves, intake manifold gaskets, throttle body gasket and OEM BMW y-shaped crank case breather hose were a jaw dropping $894 from FCP Euro. Granted, there are much cheaper aftermarket DISA valves, but they have a much higher failure rate than OEM BMW DISA's. If the stock ones in your junkyard manifold are in good condition, that's where most of the money is spent. You then need a K+DCAN cable to flash/tune the ECU/DME- ~$87 with shipping... and unfortunately, with BImmerlabs down, free tunes are not a thing unless you trust someone online to send you the map, or you know someone... so, the Bimmworks tune cost me $373. So, for everything involved, we're talking about a total of $1387 spent. We'll see how much power it ends up making and if it ends up being worth it. 

It should be noted that if you skipped the 3-stage DISA manifold, you can technically make more power with the OEM N54 intake manifold. It needs to be modded a bit to make it fit (some trimming and about ~$50 worth of hardware), but it's a cheaper option that makes a bit more power with less failure points (no DISA valves). Unfortunately, since it's a single stage manifold, all of the power the N54 manifold makes is at the top end. Dynos show the 3SIM makes more power everywhere below 6500rpm vs the N54... but the N54 makes ~5hp or so more up top. The big cost advantage of the N54 manifold is the lack of DISA valves, which are the most expensive part of this equation. I went with the 3SIM as I spend the majority of my time on the road below 6500rpm where the DISA manifold has a large advantage. YMMV. 


In the meantime, while the tires actually got a good bit less squirely than they were a few weeks ago, to help with the floppy/worn out OEM setup, I actually just received a Bilstein B12 cup kit to tighten things up: 





^^^I decided to hold off on $3000 coilovers and give this much cheaper option a shot to see if I end up being satisfied or wanting more. I'll post my impressions post-install. 

roninsoldier83
roninsoldier83 HalfDork
7/1/24 5:50 p.m.

Today I installed the Whiteline rear subframe bushing inserts. Easy job- took less than 2 hours. Nothing fought me. Nothing complicated or hard to get to. 



Rear, rear subframe bushing (after dropped, looking from underneath):



With Whiteline inserts: 



Front, rear subframe bushings (after dropped): 



With Whiteline inserts: 




^^^They essentially just fill in the gaps in the OEM rubber subframe bushings. 

I went for a 20 minute drive down a twisty road, pitching the car around a bit... the rear does seem to react a bit quicker than it used to. Before whenever initiating a turn, the front end would turn in and the rear would take a moment to set before following. The time it takes for the rear to react seemingly just went down and the rear feels just a tad bit less squishy. It's not an "OMG, it's an entirely different car" experience, but it is a step in the right direction. I think it would probably be more noticeable if the suspension didn't feel so soft/worn out. 

Overall, for ~$50 in less than 2 hours of my time, I would recommend this mod. 


Unrelated: I've been driving the car around a bit since yesterday after installing the 3SIM and Euro airbox... I know the DISA's are in their "closed positions" right now without a tune- so I'm not sure what that means for the powerband... what I do know is the throttle response seems to be just a smidgen better and the car doesn't seem to fall off so hard up top, even without a tune. I'm getting very curious to see how much it changes with a tune so we can use these DISA's and make some more power! 

adam525i
adam525i SuperDork
7/1/24 6:08 p.m.

Looking forward to your review of the Bilstein/Eibach kit, that one is tempting me along with some camber plates in the front in my 330i. I like that the shocks are supposedly valved for the springs and the lack of adjustments has me thinking it will hold up better in our winters here. 

I ordered a set of the bushings inserts as well as they were on sale so I'll get those put in too.

I think the down low torque is the best thing about this motor, in one of these modern (aka heavy) cars it really helps them move. If I were swapping it into my E28 I'd be tempted by the N54 manifold for simlicity and track use.

My car is a daily driver but it will see some autocross and time around Mosport when I feel like leaving the E28 at home.

roninsoldier83
roninsoldier83 HalfDork
7/1/24 9:08 p.m.
adam525i said:

Looking forward to your review of the Bilstein/Eibach kit, that one is tempting me along with some camber plates in the front in my 330i. I like that the shocks are supposedly valved for the springs and the lack of adjustments has me thinking it will hold up better in our winters here. 

I ordered a set of the bushings inserts as well as they were on sale so I'll get those put in too.

I think the down low torque is the best thing about this motor, in one of these modern (aka heavy) cars it really helps them move. If I were swapping it into my E28 I'd be tempted by the N54 manifold for simlicity and track use.

My car is a daily driver but it will see some autocross and time around Mosport when I feel like leaving the E28 at home.

I went back and forth on the Bilstein vs Koni setup. I've ran Koni's on cars in the past- I like the adjustability, but a few of the posts I read said the Bilstein's are essentially a bit stiffer than the Koni's set on full stiff. I like the idea that they're valved for the springs as well. I also know that Koni's start to lose some of their zing seemingly after 3-4 years, whereas the Bilstein's seemingly hold up well long term. I've got a set of brand new everything needed to refresh the springs/shocks/struts coming from FCP Euro. I'll be sure to post my impressions when I get them installed. If they don't quite give me the additional control I'm looking for, I'll likely trade up to a set of Ohlins next year. 

I went back and forth on the N54 vs 3-stage DISA manifold for a while. It's not my car, but here's a dyno with the stock single stage vs the N54 vs the 3-stage DISA: 



^^^It's not the most fair comparison, as I believe the stock single stage is lacking some of the bolt-ons that the other cars have, but I think the 3-stage DISA and N54 dynos are running the same mods on the same car. Either way: 

-Blue line= stock manifold
-Green line= 3-stage DISA manifold
-Red line= N54 manifold

My thoughts: 

-The 3-stage DISA literally has an advantage EVERYWHERE below around 6700rpm. 

-For autoX, I would prefer the 3-stage DISA manifold as I'm just going to be in 2nd gear just about the whole time anyway. Ditto for most canyon roads. 

-For a street car, there's no question, the 3-stage DISA is a better fit for me. 

-If you were drag racing (which, no thanks with this car), the N54 has a substantial advantage. 

-For road course work, I have mixed feelings. Coming off of the corner, I would think the 3-stage DISA would likely have an advantage on some corners, whereas the N54 on others... on longer straights, clearly the N54 is going to pull harder... but I feel like you're going to want to rev the car out to around ~7500rpm to see a noticeable advantage. My concern is that the motor wasn't designed to spin that high, putting more stress on an engine that was only meant to rev to around ~7000rpm, and adding a good amount of extra heat in the process. For a single hot flier lap, I think the N54 is likely the way to go, but not revving the motor as high with the 3-stage DISA is likely better from a longevity standpoint. BMW warrantied these motors with a 3-stage DISA manifold, whereas they never built or warrantied a high revving version. 

For the sake of simplicity, the N54 is surely the way to go. Although if my DISA's ever break, FCP Euro has a lifetime warranty, so it's just the labor that would be no bueno. 

I think the general consensus on the N52 is to keep it below 7500rpm, to which, the N54 manifold would be fine... but I'm not sure if that consensus is for track work or street driving. On the street I'm sure it would be fine, but I'm not so confident for 20+ minute lapping sessions at high elevation (I'm in Colorado- oil temps get a bit higher up here). 

I always liked the E28! What motor are you running in it? 

adam525i
adam525i SuperDork
7/1/24 9:56 p.m.

My butt dyno agrees with the green line above. Things start to fall off right at the top but otherwise it pulls really nice.

The E28 is a german 525i which came with a small, 2.5 litre displacement M30, I have since put in a M30B34 3.5 litre and since then rebuilt it with 11:1 forged pistons and rods, M30B35 head and a 290 dbilas cam all running through an ECUmaster black. Also has a set of headers and exhaust that I built. The motor wakes up at 4000 rpm and pulls really nice to 6500. If I were to race the 330i it would win if we were limited to 4000 rpm and the E28 would pull it from there to redline. If I were to put a more modern BMW engine in that car though the N52 would be it along with the 6 speed. I think the power/weight of that combo in the lighter E28 would be a a really nice, well balanced package. 

roninsoldier83
roninsoldier83 HalfDork
7/2/24 10:38 a.m.

In reply to adam525i :

That sounds like a fun E28- solid work! I just did some searching and the Interwebs says those cars only weigh about 2800 lbs- I didn't realize they were so light! Certainly a light car for a built 3.5L! 

An N52 in that car would probably make for a fun ride in that chassis. I would imagine going from an iron block M30 to a magnesium/aluminum N52 would also save some weight over the front axle. I think the N52 is a pretty good fit for my ~3200 lbs 128i- shaving another ~400 lbs off of the car would make for an entertaining little rocket! If you decide to build it, you should definitely start a build thread. 

roninsoldier83
roninsoldier83 HalfDork
7/2/24 10:53 a.m.

To anyone considering this Bilstein B12 kit (basically Bilstein B8 shocks/struts and Eibach springs), while prepping to assemble the front struts, I made a few notes: 

-The strut top nut is 22mm. None of the spark plug sockets I have fit over it (of course they don't!). Fortunately, I do have a set of strut nut sockets: 



 

-The threaded rod on the top of the strut is 14mm (measured with my calipers). So, per Bilstein's instructions, it should be torqued to 54 ft-lbs. 

-The threaded strut rod hex size is 7mm... I have an allen key socket set, but unfortunately, my 7mm allen key socket is for a 3/8" drive and not even my smallest 3/8" ratchet fits inside the strut nut socket... I have a whole drawer full of allen key wrenches, but wouldn't you know it, not one of them is a 7mm (most of the common sets have a 6mm, then an 8mm, with no 7mm in between)... my word. So, I've ordered a long handle 7mm allen key. I also ordered a 7mm 1/4" drive socket (in the event the allen key snaps trying to torque the nut down to 54 ft-lbs). 



I don't believe in the "use an impact and send it" method unless it's absolutely necessary. There are a few different ways to torque these nuts down, but I just figured I would share in the event someone reads this and wants to order tools ahead of time. I ordered all the assembly hardware from FCP Euro on purpose, so I can assemble the front struts prior to installing them, to help break up the work load. 

roninsoldier83
roninsoldier83 HalfDork
7/4/24 11:17 a.m.

I received a few things in the last couple of days: 

-A box from FCP Euro containing all the mounts, shims, etc, needed in order to install the new suspension with all new hardware. 

-A 30A battery charger (recommended for the tune). 

-A headlight restoration kit. These 16 year old OEM halogens are rough! Driving around at night is like having an 18th century lantern taped to the front of the car. There's a good chance I'll also order some more modern LED bulbs to give me a bit more light. 




So, last night I started the first steps of removing the OEM tune and firmware files, which are needed in order to flash the car: 




Reading/removing the Tune file only took about ~8 minutes. Reading/removing the Firmware file took just over an hour. At this point, I've now emailed the files over to Bimmworks. They will take a look at the files and email me back a tune for my car. I'm not sure how long it will take- considering I've sent the files over on the 4th of July, I expect it might take some time to get my tune file back. In the meantime, it only removed a copy of the Tune/Firmware files, so the car still drives just fine. When I get the tune back from them, I'll be sure to load it into the car, take it for a spin and write down my impressions. 

Side notes: they recommended a 30A battery charger, which, I'm not convinced it was necessary. The charger I bought is supposed to be a "smart" charger that displays how many amps it's pushing at the time. When I first started removing the stock tune, I forgot to turn my auto headlights off (I had turned everything else off within the car) and it was seemingly pulling 14-16 amps. When I turned the headlights off, I noticed it was only pulling 6-9 amps the rest of the time, so the 30A charger might have been a bit of overkill (I have an old 10A charger that likely would have done just fine). 

When I initially connected the cable/software to the car without the charger connected, the software actually gave me a low voltage warning- which is a nice warning feature. I believe the software display said voltage was around ~0.5 V, whereas with the battery charger connected, it was around ~14 V. Translation: definitely use a battery charger! 

roninsoldier83
roninsoldier83 HalfDork
7/4/24 8:17 p.m.

Between today's festivities, I managed to use this headlight restoration kit on the E82 today: 



I won't bore you with the details, other than to say it's a cheap $16.88 kit off of Amazon that had decent reviews. The instructions were easy to follow and it probably took about an hour or so to knock out. 

Before: 



After: 




Interestingly enough, after we did the driver's side headlight, we noticed that the low beam bulb wasn't installed correctly and was pointed to the side, rather than pointed into the center light-spreader thing! It's undoubtedly been this way since I bought the car... no wonder the headlights have been so horrific. We re-centered the bulb and clipped it in correctly afterwards. I'm excited to drive this thing around at night to see the difference! 


Also: Jonathan from Bimmworks just sent me the new tune a few minutes ago! I literally sent them my files this morning- talk about fast turn around! I'm excited to get this thing flashed and ready to rip! 

roninsoldier83
roninsoldier83 HalfDork
7/4/24 10:27 p.m.

Well, I just reflashed the car and took it for a spin... first impressions: noticeably faster!! As soon as I gave it just a little bit of gas, I could immediately feel an increase in low-end and mid-range torque. The car feels considerably gruntier to say the least. Up top, it doesn't fall off as hard as it used to for sure, although it still doesn't feel like a top-end motor (coming from a guy that's been driving DOHC VTEC Honda's for years). I think BMW rates peak power with this manifold around ~6600rpm and I would say that's about right! Definitely pulls harder up top than it did before, but it's not a peaky motor, the torque curve still feels pretty linear. 

As soon as we turned down the street and I gave it a little bit of throttle, my wife commented immediately on how much faster it felt. There's no mistaking the difference. 

Did it give giant tuned turbo car gains? No. But for what is essentially a regular bolt-on on a smaller displacement NA motor, I'm very pleased with the gains. I'll be driving it around for a few weeks (to let the car adapt) and putting it on a dyno to see if the numbers match my initial impressions. 


The tuning process almost gave me a heart attack! You essentially have to flash the DME twice: once for the base firmware in order to unlock the DME so you can tune it, and a second time to flash the performance tune. Quick notes: 

-When I initially tried to flash the "unlock" firmware it gave me a low voltage warning, despite being hooked up to a charger and the charger showing my battery was almost full... when I tried to flash it, it failed and said it couldn't communicate with the ECU/DME! The panic immediately set in!! The car wouldn't start... my laptop wouldn't communicate with the DME/ECU... FML. I spent several minutes troubleshooting, which, the folks at Bimmworks actually send you instructions that explain what to do if a crash happens- which, they actually worked! 

-Because of the crash, I had to "Restore" the ECU/DME. Before getting to that point, I pulled out the K-DCan plug and saw that one of the pins somehow got bent! WTF?!? I straightened it out, inserted it as carefully as I could and prayed for the best... which, it worked! Restoring the DME took about ~40 minutes or so... 40 minutes of me staring at the screen on pins and needles, but it worked. Once I had that done, I still have to upload the "Unlock" firmware... again, on pins and needles... ~27 minutes later, it's almost finished and all of a sudden, I get a warning from the software telling me voltage is dangerously low!! I have a charger hooked up, it says my battery is full- WTF?!? It takes the Unlock firmware... 

-I then upload the Tune file... which uploads in under 2 minutes! Again, towards the end, I get another voltage dangerously low warning... this damn thing is going to give me a heart attack! 

The car takes the tune, status says everything is normal... I go to start the car... and it won't start!! It sounded like a low battery, so I put a jump pack on it and it fires up with ease! No check engine lights, idles like stock, runs a good bit stronger than stock! All is well, but man, I don't want to have to do that again. 

The good news is that once you go through the long process of uploading the "Unlock" firmware file, you apparently never have to do it again and can just upload the much quicker Tune files without issue. 

Overall, while stressful, a solid result. The Tune absolutely worked (I could feel it immediately) and their instructions were top notch. I've been putting this off for almost a year now and I'm glad it's done! 

OHSCrifle
OHSCrifle UberDork
7/4/24 10:47 p.m.

Interesting that ECS offers a 3-stage intake with new DISA valves for the 128i .. but no reflash. Wonder if the local BMW specialists would do that  or is that illegal now???

I also wonder if it would trip any smog checks..

https://www.ecstuning.com/b-assembled-by-ecs-parts/intake-manifold-upgrade-kit/11617559523kt3/

...Wondering mostly because this rambling testimonial teased me into buying one and I'm researching the snot out of it before I fly to pick it up in 8 days. 

roninsoldier83
roninsoldier83 HalfDork
7/5/24 8:08 a.m.

In reply to OHSCrifle :

Good question. I know I saw some guys on the E90 boards say they passed smog in California with the free Bimmerlabs tune, which, it's literally an OEM 330i tune, so that's not shocking. I'm not sure about the aftermarket tunes... I have no idea if they trigger anything that would fail a smog check. If you can find the Bimmerlabs 330i tune, its legal for sure. 
 

Worst case scenario, I have a copy of my extracted stock tune on my laptop. If I fail emissions next year, I'll flash back to the stock tune. I suspect uploading it would be like uploading the 3SIM tune, which took less than 2 minutes. I suppose I'll find out next year! 
 

I should note that my 128i is probably in a position where I would feel this tune/manifold to a greater degree than some others. Namely because it's a manual coupe 128i with minimal options- so it's noticeably lighter than a convertible or E90/92 3-series and has a lower drivetrain loss than an auto, presumably. The only N52 powered car that's lighter that I'm aware of is the Z4 manual (by about ~100 lbs). YMMV. I've chatted with some 3-series folks locally that didn't describe as much of a difference as I noticed... but regardless, it's seemingly still a worthwhile modification. 

roninsoldier83
roninsoldier83 HalfDork
7/5/24 8:29 a.m.

For reference, the only difference between the 330i and 328i is the 3-stage intake manifold and tuning. The fine folks at Car and Driver tested both: 

2006 330i:

60 mph: 5.6 sec
100 mph: 15.3 sec
1/4 mile: 14.3 sec @ 98 mph

 

2007 328i:

60 mph: 6.1 sec
100 mph: 16.4 sec
1/4 mile: 14.8 @ 95 mph
 

https://www.caranddriver.com/reviews/a18202661/2006-bmw-330i-road-test/

https://www.caranddriver.com/reviews/comparison-test/a15148731/2007-bmw-328i-vs-2008-cadillac-cts-di-2008-m-b-c300-sport-2008-infiniti-g35-sport-comparison-tests/
 

roninsoldier83
roninsoldier83 HalfDork
7/5/24 2:53 p.m.

So, I've been having an annoying time with an airbag/seat belt light combo on the dash. 

About 3 months ago, I went over a bump/dip in the road (I think it might have been a manhole cover or something) at speed. Nothing crazy, but as soon as I hit it, my seat belt and airbag lights came on the dashboard immediately. When I got back home, I checked the codes and found a code for "belt force limiter, left". I did some digging and it looked like it was the driver's side seat belt. I cleared the code and it went away...

Fast forward a couple of weeks, the next time I went over a light bump in the road, the lights/codes came back. This time, I figured I would actually replace the seat belt. I found a brand new one on eBay and ordered it. In the meantime, I cleared the code again (due to my OCD/not wanting to look at the lights on the dash) and the lights went away. The seat belt got here, but the light never came back. It's been 3 months and the code for the driver's side/left seat belt never returned, so I never bothered replacing the seat belt (it's still sitting in my garage). 

About a week ago, I was on my way to a friend's house to help him wrench on his daughter's Corolla. He lives out in the country. I came up over a crest in the road and there was a giant pot hole that I didn't see early enough to avoid... sure enough, as soon as I hit it, my airbag/seat belt light came back on. When I got back home, I checked the codes: "belt force limiter, right"... WTF?!? This time the code was for the right/passenger side... no code for the driver's/left side, only the right side this time... 

I tried to clear the code multiple times and it never cleared. So, I ordered the right/passenger side seat belt, thinking this time it really was the problem. 

I had assumed this was all somehow related to the accident the car had been in years ago... I'm now not so convinced. 

The right/passenger side seat belt was due to be here today. So, in anticipation, I removed the right side interior pieces to access the seat belt. For the record, it wasn't very difficult- only took about ~5 minutes or so. 

Before the UPS truck arrived, I figured I would watch a couple of YouTube videos on replacing the seat belt, just to make sure I didn't miss any super secret BMW assembly steps. While searching for videos, I stumbled upon this video: 

https://www.youtube.com/watch?v=NsC73a2R_CI

^^^This guy claims his seat belt/airbag lights have nothing to do with the seat belts/airbags, but only come on because a sensor on the battery comes loose... he recommends just using some electrical tape to secure the sensor to the battery... I wish I would have found this sooner... I followed his advice, it only took a few seconds, and sure enough, I was able to clear the code/lights. This is the sensor I speak of: 



^^^It's on the back side of the battery, in the trunk. 

I essentially now own 2 new E82 seat belts that will hopefully just not be needed lol. I think I'll likely keep them though, just in case. 

Now I just need to track down the newly acquired interior leaks that occur when I take the car through a car wash lol... While I still enjoy driving the car, I'm convinced that older BMW ownership isn't for the faint of heart lol. 

adam525i
adam525i SuperDork
7/5/24 5:42 p.m.

Just keep going older and they get a lot simpler!

That's interesting that you had issues with low voltage even with the charger connected and they seem legit with you having to boost the car to get it going. I ran into a similar situation bleeding my brakes while running the DSC pump with it running down the battery. I wonder if you connected the charger directly to the battery instead of at the jump terminal under the hood if that would have helped. I also wonder if some of your main battery connections aren't as good as they should be.

 

roninsoldier83
roninsoldier83 HalfDork
7/5/24 7:03 p.m.

In reply to adam525i :

You're probably right about going older! Although I think I've been spoiled by owning a plethora of Japanese cars over the past couple decades. Ironically enough, my S2000 is the same year as my 128i (both 2008). I've owned my S2000 for almost 5 years now. In 5 years, I think I've had 2 issues total, even though I used to autoX it regularly: a sticky clutch about ~4 years ago- I bled the clutch, problem solved, never stuck again... and it had a gas cap message once- I ended up replacing the gas tube and it never happened again. Granted, the S2000 has lower mileage, it's never been wrecked and has likely been a garage queen all it's life, so maybe not an apples to apples comparison, but man, these German things are finicky compared to most of the Japanese cars I've owned over the years! 

I have a theory about the battery situation... when I first hooked the charger up to it, it was showing around 80% and charging. At a certain point, it stopped charging and said the battery was full. I'm wondering if after the battery was full it just stopped charging? I considered hooking it directly to the battery, but the instructions specifically said not to unless necessary. Fingers crossed I don't need any long battery draining ECU work in the future! 

roninsoldier83
roninsoldier83 HalfDork
7/5/24 7:06 p.m.

I got the front Bilstein struts assembled today: 




I had to get creative with my vice to get that top nut torqued down to 54 ft-lbs! 

Fortunately, no struts to build in the rear. I've never been a big fan of strut assembly. 

roninsoldier83
roninsoldier83 HalfDork
7/6/24 6:07 p.m.

I got the front struts put in today: 



The first one probably took 1.5 hours, figuring all the things out, whereas I think I had the second one in, in under 30 minutes. 

I'm a bit beat up, so I left the car on jack stands in the garage. I'll get around to doing the rears in the next few days or so. 


Unrelated: I might have also found my interior water leak. I think it might have been my passenger/right side sunroof drain tube. I spent some time messing with it today with a piece of wire and an air compressor- it seems to now be draining much faster. I ended up pulling most of the passenger/right side interior trim out, as well as one of the plastic underbody panels to locate the bottom drain tube, which actually wasn't that bad. I'll monitor it and see how it holds up to the car wash. 

roninsoldier83
roninsoldier83 HalfDork
7/7/24 6:23 p.m.

I put the rear suspension in today: 

 

It took a bit over 2 hours to get this job done. It's a simplistic job, but takes a bit more muscle than the front if you're working alone- mostly just getting the spring seat arm to line up with the knuckle while raising the spring seat arm. 

I measured both the thickness of the front and rear springs, and it appeared the Eibach springs were close to ~1mm thicker (as per my digital calipers), despite having similar spring rates as the OEM Sport springs. 

After I was done, I took it out for 30-40 minutes to try and get an impression... which, honestly, it wasn't a huge change. Turn in is a bit quicker. The car feels just a bit more planted, maybe a minor reduction in body roll, but it's not exactly a night and day difference. The change in ride quality is minimal to say the least. The Bilstein setup probably still rides smoother than my other 2 stock suspension cars (2008 Honda S2000 and 2021 Mazda 3 Turbo). It would be easy to live with daily. 

While knocking out the front yesterday, I noted a bit of play in my front right endlink. I'll replace them soon. 

I've concluded that these tires are a bit softer than I would like- I can feel the tires sidewalls roll over a bit on tighter corners. I'll be eager to test this setup with a set of sticky rubber (likely next year). 

There's not much of a difference in ride height thus far; which, shouldn't be surprising, as my old suspension was a little tired. I'll give it some time to settle. 


I'll get an alignment soon, continue driving and post more long-term impressions. 

adam525i
adam525i SuperDork
7/7/24 7:31 p.m.

Just to be clear, did your car have factory sport suspension? Edit - just went back to your first post and see that the car did have sport suspension. This sounds like I'd be very happy with this package on my E90 with the non-sport suspension, just annoyed it pushes me up a class at autocross.

I think I'll try to get an internal spring compressor for the rear before tackling that job again, I found those control arms/springs really fought me putting things back together so I'll try to make that a bit easier.

roninsoldier83
roninsoldier83 HalfDork
7/8/24 10:04 a.m.

In reply to adam525i :

You are correct, my car came with the factory Sport suspension. The Internet told me that the spring rates of the Eibach springs were very close to the OEM Sport spring rates, so I shouldn't be shocked that it wasn't a huge change in handling. I was thinking/hoping that the more aggressive Bilstein B8 shocks would have made a bigger difference than they did. Don't get me wrong, so far they feel excellent for a car you could truly drive everyday in comfort, but the car is just a smidgen softer than my stock S2000 (well, kind of stock, it does have a CR front bar) and Mazda 3 Turbo. Admittedly, both of those cars are on the stiffer side of OEM vehicles. I'll try the Bilstein's out on track/dodging cones with some stickier tires before I make any final judgments- as the car didn't start feeling this soft until I threw on these all-season tires, so the softness might be more tire related than suspension related. 

I did some more driving last night. Body motions do seem a bit more controlled and turn-in is just a bit quicker, but for whatever reason, while making harder turns, the steering doesn't load up quite as much as I would like it to- it feels a bit light. I'll give the suspension some time to settle, then get everything aligned to see how much of this is related to me throwing off the alignment a bit. 

Are you autocrossing with the SCCA? Technically, you could just buy the OEM Sport springs on eBay, buy whatever shocks you want to go with them and convert your car to a Sport package car to avoid getting bumped out of the class. I suppose you might have to upgrade sway bar(s) and maybe add the Sport seats, unless Sport springs were a standalone option on the E90? I will say, the OEM Sport seats are excellent if you can find a deal on them. I'm not sure how much you want to invest into it, but converting to a Sport package car with whatever shocks you want would avoid bumping you out of the class while gaining a significant bump in handling. 

I hear ya on putting the control arms/springs back together! I used a jack to raise the spring perch arm- but getting it to align with the knuckle while jacking it up was a pain in the neck! A second set of hands would have made this a much easier job- specifically having someone jack up the arm while I guided it into place. I found that I really needed to loosen the rear camber bolt quite a bit so I could move the spring perch arm laterally to line it up. My lower back is not happy with me today, after my battle with that damn spring perch arm yesterday. With a 2nd set of hands, I could have probably seated the springs/re-connected the spring perch arm in less than 1/2 (maybe 1/3rd) of the time and with far less pain involved. 

roninsoldier83
roninsoldier83 HalfDork
7/8/24 11:04 a.m.

Unrelated: I think part of the car feeling more "floaty" with the new tires might be my fault. I think I might have set pressures too high based on the car's GVWR. 

A lot of the posts I found over on 1Addicts show people weighing the 128i on a scale around ~3100 lbs (although it's tough to find people that post cross weights). By contrast, the GVWR on the inside of the door reads as follows: 

-GVWR: 4134 lbs
-Front: 2028 lbs
-Rear: 2249 lbs

I know this is with the vehicle fully loaded, but that's typically what manufacturers go by when they recommend tire pressure. 

The tires in question (Continental ExtremeContact DWS 06 Plus), in stock sizes (205/50R17 front & 225/45R17 rear) are rated at a load index of 93W front and 91W rear, with a max pressure of 51psi. So, I did the following math: 

Front: 93 index is 1433 lbs, multiplied by 2= 2866 lbs, divided by 51 (psi)= 56.1960784 (rounded). If I divide the front GVWR (2028 lbs) by that number, it comes out to be close to ~36psi (cold). 

Rear: 91 index is 1356 lbs, multiplied by 2= 2712 lbs, divided by 51 (psi)= 53.1764705 (rounded). If I divide the rear GVWR (2249 lbs) by that number, it comes out to be close to ~42psi (cold). 

I'm now thinking the problem is that the fully loaded GVWR is roughly ~1000 lbs heavier than the car likely weighs. With my wife and I in the car, it's likely closer to the ~3400 lbs mark. If I calculated for a weight of 3400 lbs, with a rough 50/50 weight distribution (1700 lbs on each end), math would suggest front pressures should be closer to ~30.25psi and rears around ~32psi. 

When I get some time, I'm going to drastically lower the tire pressures, to see if that helps the car feel more planted and connected. This honestly should have hit me sooner. Oops. 

adam525i
adam525i SuperDork
7/8/24 12:55 p.m.

Basically my 330i is my daily driver but it is also playing backup to the E28 for autocross/track duty. If the E28 isn't ready or I feel like a more comfy ride to an event the E90 will go instead (E28 lacks AC and is very stiff). I'm an instructor now with our chapter so I'll be heading to the track regardless of if the track car can attend.

Both autocross groups the springs would push me out of stock, one of them with SCCA rules and the other their own simpler set. Pretty annoying when I'm running Indy500 300 tw tires and zero plans to get a set of whatever the hot tire is right now. I guess the set of fixed camber plates I already ordered will do the same regardless of the springs lol.

Sport seats are on my radar, I need to sit in a set to see how I fit and if they gain me any headroom as it's a bit tight with a helmet on right now. 

roninsoldier83
roninsoldier83 HalfDork
7/8/24 2:48 p.m.

In reply to adam525i :

I can't speak for the other autocross group, but in the SCCA I thought it was legal in the Street classes to convert your car to another trim package/option available on the same car. Although I believe you have to convert everything from said package in order for it to be legal. According to this PDF, it looks like the 2006 330i Sport Package added the following: 

Sport Package:
• 149-mph top-speed limiter
• Sport suspension calibration
• 18 x 8.0 front/18 x 8.5 alloy wheels, Ellipsoid design #162 • 225/40R-18 front / 255/35R-18 rear W-rated performance tires10
• Sport front seats with manually adjustable thigh support, power-adjustable backrest width 

chrome-extension://efaidnbmnnnibpcajpcglclefindmkaj/https://www.billswebspace.com/e90PIB.pdf

^^^Technically, as long as you added everything from the package, it should be legal in Street, unless the SCCA changed the rules over the past couple of years? And since you can change wheels in Street (+/- 1" diameter, same width, within 7mm of stock offset IIRC), you can add whatever wheels you want, within those specs. Although the 149mph top speed increase might be a bit tough to "add" (maybe the Bimmergeeks software can just disable the top speed limiter?), but the suspension portion (OEM sport springs/sway bars) should probably be pretty cheap on eBay. The seats (and wheels, depending) would probably be the most expensive item(s). 

Although the fixed camber plates you ordered make that all completely irrelevent lol. 

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