BMW 1 Series Coupe Forum / 1 Series Convertible Forum (1M / tii / 135i / 128i / Coupe / Cabrio / Hatchback) (BMW E82 E88 128i 130i 135i)


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      05-27-2020, 10:14 PM   #1
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Drives: 2011 BMW 128i
Join Date: Mar 2019
Location: LA

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3SI Upgrade Experience

Hey folks,

I did my 3SI upgrade over the holidays and I wanted to check in on experiences that people have had with doing this upgrade. I used BMW genuine DISA valves with the MSV80_S8608441_x28i_to_x30i_NoMAF.0da tune from bimmer labs. I have a 6 speed, non-SULEV.

Now I've read varying HP upgrade amounts with 20 on the low end and 40 on the high end, with most people/places claiming 30-40 (not sure why there would be a range here).

I do feel that the car has slightly more torque, but I'm not sure I'm experiencing 30hp-40hp more. I would think I'd feel it even if it was 20hp more and I wouldn't have to be questioning am I feeling it.

Can folks who have performed this upgrade chime in?

Thank you!
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      05-27-2020, 10:37 PM   #2

Drives: 128i Sport
Join Date: May 2015
Location: Toronto

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I will say the car improved over the first week or so with driving. It's also an adjustment period in your own brain, it's not like upgrading a turbo car where you get new software and there's a huge whack of torque now with more boost.

What I noticed is that as I drove the car in normal situations like my commute, it "surprised" me as I wasn't thinking of the tune/upgrade/3SI, just making my normal drive.

Second - the engine "breathes" above 4500 rpm way better than before, that's where if you (once warmed up of course) run it through the gears, the HP is quite apparent. That along with healthy torque bumps in the 2K-3K range, and 3K-4K range.

What I definitely notice is the DISA "transitions' at 3K and 4K, where you get torque "Dips".

Long story short, reset adaptations, drive the car a few days and you'll notice the power, it's quite apparent.
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      05-27-2020, 10:56 PM   #3
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Drives: Sedona 128
Join Date: Apr 2011
Location: Ottawa On Canada

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I had planned to do the 3SI this year but may put it off due to many factors, not least of which is covid19.
I intend on measuring (in time) my acceleration in 3 or 4 gears. For example 20-35mph, 35-50mph, 50-70mph before and after conversion.
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      05-28-2020, 12:25 AM   #4
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Drives: 2010 128i
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I don't think you're getting 40 HP from a 3-stage DISA manifold alone. Maybe that much with headers, too. My car has intake, headers, exhaust, and tune and dyno'ed at 238 max HP - assuming 15% drive line loss, that puts me at 280 HP at the crank, optimistically. The DISA manifold is certainly part of that, but the headers (and of course the tune) play a big role as well.

The other thing to think about is real life. A dyno measures peak HP, so what? What about power delivery in real world conditions? In my opinion, one of the main values of the DISA manifold is that it optimizes power at three distinct RPM ranges such that the power band is significantly broadened. You feel that behind the wheel, more so than peak HP.

I hate to say it, but if you're chasing raw numbers, you bought the wrong car. It will never look as impressive on paper as a 135i, or a million other cars on the road. But a 128i with the right mods can be extraordinarily balanced and responsive, and really be capable of more than most of us are able to take advantage of.
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      05-28-2020, 06:09 AM   #5
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Drives: BMW 128i ZED Package
Join Date: Jan 2018
Location: New York City, NY

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If you're expecting a mind-blowing difference then this won't be it.. however if this is a road in your upgrade path to what this particular vehicle is fully capable of then yeah it makes sense to do this and is one of the better things to do in order to engage the car more.

Like others have said, after attributing for drivetrain loss and other variables that affect power on many different dyno sheets posted here about 15-20HP is fair to say on this upgrade alone. Couple that with headers, MILVs (silicone tube, a better intake/carbon delete, maybe scoops wouldn't hurt), and a better exhaust set up to funnel all that through and maybe you'll max out at the 40 total.

Smart for getting genuine DISA valves. I did the same thing (got them new from FCPEuro just in case) as well, the only used part I used for the part was the manifold itself.

Yes, like Bob mentioned above me, this car won't give you that out of your pants feeling the N54/55s do BUT you did get this car for a particular reason as many of us on this forum did. I am more than satisfied with the job done and is leagues better than the car was when I first drove it. I did not feel the power come through until I had put a couple of miles/a tank of gas in the vehicle but the car did feel more responsive above 4000rpm. I also did hear the "whooosh" of air flowing through the valves. Cabin sounded a bit more aggressive and throatier and is an overall joy to drive, torque does improve and you feel it especially at WOT. Going full bolt on makes me more than happy at the moment and haven't considered the FI route yet.

Can't report on how the 3SIM feels from bone stock alone as I had gone from stock to AA headers, exhaust and tune to 3SIM and MILVs, StageFP tune in that order tune at the time.
Mods Done: AA Exhaust/Headers | 3SIM | MILVs | StageFP Dyno Tuned | Euro Box Intake Swap | LCI Blackline Tailights | OEM Euro Bi-Xenon Swap from Halogen | Rear Bumper M-Sport Swap | Rear PDC Retrofit | BMW OEM CF Diffuser/Spoiler | BMW Front Aero Kit | Supersprint Sec 1 Cat Delete Straight Pipes

To Do: Ohlins R n T Suspension | Front/Rear Sway Bars | M3 Front Control Arms/Bushings

Eventually: AT -> MT Swap (!?)
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      05-30-2020, 08:59 AM   #6
Just one more taste...
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Drives: 2013 128i 6MT MSport
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Originally Posted by NorthernDancer View Post
I had planned to do the 3SI this year but may put it off due to many factors, not least of which is covid19.
I intend on measuring (in time) my acceleration in 3 or 4 gears. For example 20-35mph, 35-50mph, 50-70mph before and after conversion.
The only thing that really matters is the MAF reading. There are so many other factors when timing those things but if you can log the Peak MAF reading, you’ll know for certain how much additional air is allowed through the engine, which directly relates to power
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      05-30-2020, 05:01 PM   #7

Drives: 2013 128i M-Sport
Join Date: Mar 2019
Location: Indianapolis, IN

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Like others have said, it's not going to knock your pants off by any means.

However, with the tune I've noticed above 3/4k RPMs the engine really opens up with the DISAs kicking in. I never really drove my car much prior to this above 4K RPMs, usually shifted up between 3-4. Now I'm constantly revving her out because the power gains on the upper RPMs are very noticeable -- IMO.

Maybe try the StageFP tune, I have no experience with yours but for me the difference was night and day. It removed the sluggishness. I also have a BMS pedal tuner which I don't need to use anymore since the tuned throttle response is much better. With the pedal tuner it's just too much and I fear it may not be very "compatible" with the tune.
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      05-30-2020, 05:26 PM   #8
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Drives: 2010 128i 6MT Sport Pkg. 18"
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2010 E82 128i  [0.00]
Very happy with this mod. A lightly used DISA manifold w/ A.A. tune. Great across the range, better bottom end and a strong bump around 3500 rpm. Not a lot of power options for the N52 , this is probably the best.
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