Update: Quick feedback on BMS stage 1 and DINAN sway bars

[(H)]

Dear All,

Couldn't wait to pick up my car from Princeton BMW today. Colin and Mike (and everybody else) did a great job as always. New disks and brake pads and Michelin PSS all around (if you wonder why after 15k miles, see my previous post http://f10.m5post.com/forums/showthread.php?t=1028104).

But besides the regular upkeep I was obviously most excited about the two latest mods, the Burger Motorsport stage 1 piggy bag tune and the DINAN sway bar set.

Don't be surprised, my overall initial feedback is disappointment on both. Maybe I simply expected too much.

1) BMS tune
BMS told me that it might take 3-4 days for the car to fully "embrace" the tune and for the tune to take full effect so maybe I shouldn't judge yet. Remember when you first drive the F10 ///M5 and you thought "crap, this is amazing". I expected a similar experience from the un-tuned car to the BMS stage 1. And that is probably wrong. I do feel more pull across the rev band in 2nd gear and some more pull in high rev 3rd gear. I don't feel any difference in any of the other gears. It doesn't matter to me that objectively it might make a difference. If I don't subjectively feel a considerable difference it's not there. But then again, it's a $500 piggy bag fix. So maybe again, I should a) give it some time and b) not expect to be blown away.

2) DINAN sway bars
My aim was to considerably reduce body roll. My initial reaction after installation and set to max stiffness: Complete fail. Almost no reduction in body roll whatsoever. I couldn't feel much of or any difference in ride quality in comfort settings and not much either in sport/sport+ settings. Despite the fact that it seems easy to replace the bars, it still turned out to be a 5 hour job all in all so at a total price tag of $1,600, I am not really sure if this is a meaningful mod.

Maybe sleep over both, drive a lot more and report back on Monday or so next week ...

Meeeh,
(H)

[Fantasm]

1) you will need to give it a few days and several hours of driving time. it will not be an increase you can very easily notice by butt dyno normally. however, i do know when its kicked in or not.
FYI: The BMS kit isn't sold or advertised as a "subjective" upgrade, its sold as an actual factual HP/TQ increase -- if you want to verify it, remove BMS - DYNO, re-add BMS - DYNO. You will see where in the torque and hp curves the new power comes in. Don't forget adding catless or low cell cat DP's will also give you a ton more power with the BMS.

2) no reason to have gotten the dinan sways. too small of difference to have noticed ever probably. you would have been better off getting some coilovers for $1000 and $500 install and that would've been a HUGE difference... even the $1000 coilovers (megans, KW H.A.S. , etc).
My recommendation: Sell the Dinan sways, buy the KW H.A.S. kit = HUGE difference.


in regards to the BMS, when I fill up with 100oct gas it takes a bit for it to recognize the full power. I can always tell the difference between 91oct and 100oct, but it takes like 2 days. there is considerably more torque and then it drops off again if I dont keep using 100oct.

im saying that because im used to 91oct and BMS already, and I get more HP by just putting in 100oct - so its similar to how it would be if I removed or just added the BMS on a stock engine.

[shahano]

Interesting. Thanks.

[RPiM5]

I think Stealth.Pilot was the only other person I know running Dinan Sway Bars with non-Comp Pack Suspension. But also (H) you have the 19" wheels. When I upgraded to the Competition Package Sway Bars and Eibach Lowering Springs, I noticed a pretty big difference in the handling and demeanor of the large F10 chassis. I could feel all of the changes, less body roll, sharper turn in, a little more steering feel, etc...

Also with the BMS tune, it does take a little time. When I first installed my BMS I went for a 500 mile drive. I could definitely tell the difference when the ECU adapted. I was and still am only running 3.2psi over stock and I can always feel a big difference in torque and horsepower.

Just give it some time.

[Used2be]

Originally Posted by (H)

Don't be surprised, my overall initial feedback is disappointment on both. Maybe I simply expected too much.

2) DINAN sway bars
My aim was to considerably reduce body roll. My initial reaction after installation and set to max stiffness: Complete fail. Almost no reduction in body roll whatsoever. I couldn't feel much of or any difference in ride quality in comfort settings and not much either in sport/sport+ settings. Despite the fact that it seems easy to replace the bars, it still turned out to be a 5 hour job all in all so at a total price tag of $1,600, I am not really sure if this is a meaningful mod.

Maybe sleep over both, drive a lot more and report back on Monday or so next week ...

Meeeh,
(H)

Interesting report, I have the BMW CP bars and felt a definite improvement with them in conjunction with the standard M5 suspension. I would have thought the Dinan would be at least equal to that. They are tubular and the diameter is very close to that of the CP bars. Most of the torsional resistance is obtained from the outer metal of any sway bar, and I don't know the wall thickness of the Dinan bars, but I'd think they would have been of a larger diameter being tubular compared to the BMW CP bars to be a stiffer bar as they claim. Or perhaps the grade of steel used is different and that accounts for a less than favorable review? But Dinan's claim was only a comparison to the smaller, stock M5 sway bar......for the price difference it doesn't seem worth the expense. It would be informative if you could find an M5 equipped with the CP bar to drive and compare.

[(H)]

Dear All,

I spent the last three days in a 2014 ///M5 non CP with 20"s. This was a rental from Hertz in LAX. I spoke to Hertz HQ and they confirmed that the car was bone stock with no modifications or restrictions/limiters in place (with the only exception that DSC off was disabled, only MDM possible ;-(. The car had 9000 miles on the odometer so it was slightly less driven than my own.

With this comparison I now have to dramatically revise my initial assessment.

a) the BMS stage 1 makes a huge difference across all gears and the entire rev band. My butt dyno registered a considerable difference in pull and elasticity. I will see how it feels when I am back later today in my car and experience the difference the other way around.

b) the DINAN sway bars must make a considerable difference because even with the 20" wheels on the rental, I felt more body roll and less overall handling stability. Oversteer (as much as I could test with MDM) was much more prevalent. I can tell you that with this experience, I really think that BMW should reconsider the US specific oversteer setup on the stock M cars. While I understand that the general US consumer appreciates oversteer in daily drivers, I would assume that the majority of ///M customers would prefer the European specs on their cars. I will in fact talk to my dealer and see if they can convince BMW NA for a retrofit on my car (upper control arms etc.) at a reduced price or better yet - free of charge but labor.

Hope this update helps.

[Fantasm]

Actually, most cars are built with a higher amount of understeer for the general consumers for safety reasons.
The oversteer is much appreciated by performance and enthusiast drivers.

Looks like previous drivers of your rented M5 can't park either as the front passenger wheel is fucked up badly lol.

[(H)]

Thanks @Fantasm, of course I mixed up the two and meant the annoying understeer. Goodness, must be sleep deprived!

Also kind of you to assume that previous renters messed up the wheel and not me ;-)

[Hawkeye1]

I have a '13 non comp pack with the Dinan sway bars and springs. The difference was very noticeable to me, especially the sway bars, which are stiffer than the comp pack versions. Mine are set to the midpoint, which is intended to set the car's balance to 'neutral' with modest understeer at the limit. I've never taken the car to the limit, so I'll take them at their word. I'll be at a track in a couple of weeks. 328 and 335 models will be available for use, but I'm tempted to put my car out there and see what it feels like to slide a car with that combination of size, weight and grip.

Anyway, added Dinan Stage 1 last week. Saw about half a second and 4 mph improvement at the drag strip afterward. Butt dyno is hard to feel. The car was already ridiculously fast. My biggest disappointment is that it appears the price dropped $500 this week. I've asked the dealership to refund the difference. I'll post the results of that conversation...