Team, I moved on.
I thought the perfection for M2 is the FBO with STG1 turbo. See below.
http://f87.bimmerpost.com/forums/sho....php?t=1454381
Now is a different time and requires a different game.
1) The S55 powered M2 competition will be the new M2.
2) As you may or may not know, B58 DME is cracked. B58s will eat N55 M2 like a piece of cake.
3) Don't be surprised G20 M340i put down 370whp FULLY STOCK.
E46 M3 was the balance at its time. In 2016, 365hp M2 in E46 dimensions redefine the balance. Face the reality, new balance is soon to be 450~500 crank power with Cup2/Re71R. F platform can handle it. M4 GTS hooks up more than just fine.
The logical upgrade is the Pure Stage 2, a very proven solution covering full N55 spectrum. But in North America, what else do we really have ever since VTT DBB's failure to perform in 2016? Nothing.
Look outside of the USA, the German-made TTE460 is very high performing and just as reliable, and arguably the better turbo for pump gas because it's a step smaller so spools quicker. Two local TTE460 M2s walk my Dinan turbo with no sweat.
See where TTE460 gets you on pump gas.
https://www.facebook.com/tpsperforma...80403558816454
https://www.facebook.com/tpsperforma...66989296824547
TTE550, which is under testing, is coming soon. Keep in mind, TTE rating has always been in line with Dynojet WHP number, as has been proven all the time in VAG world.
However, I'm going for something more special - the G-Power 500hp turbo. G-Power is a top class BMW/MB tuning house in Germany that's best known for its E9X supercharger kit. 500hp M2 kit is their most recent release in late Apr. The key components of the package are the upgraded intercooler, downpipe, a stage 2 turbo (aka GP500) and a tune designed for stock fueling and pump gas.
Aside from all the marketing hypes, below are facts G-Power engineer confirmed in the written form:
1) GP500 compressor wheel, albeit significantly enlarged, is even LIGHTER than stock.
2) GP500 is close to TTE550 in term of flow capacity, and GP450 (M235i application) is equivalent to TTE460.
3) Everything is engineered and built in-house.
Frankly, I care more on spool up than flow potential at top end, because I'm not maxing it out anyway. I maxed out Dinan STG1 turbo octane wise. This time, I'll be taking the OEM approach, leaving headroom for power consistency under all circumstances.
Additionally, my tuning philosophy has always been - smooth torque build-up, middle range torque plateau, and top end power plateau, on pump gas and no meth. Clean and linear. Drive and maintain 100% OEM, just like a much more powerful car from the factory.
The most interesting part is, I am going to dyno test GP500 and PS2 on the same setup, same gas, and same BM3 OTS at 17~18psi level. That should be a good comparison.
A few GP500 pictures below. I'll update with my impression, tuning, and everything here.
----------------------------------Edit on 6/3 2018-----------------------------------------------------------------
Guys,
Installation of yesterday was a breeze. My mechanic started at 10AM when car was cooled down and job was finished at 8PM. An 8 hour job actually if we deduct 2 hours for the dinner and break. Not a single issue, never needed to "figure out how", never had a CEL to clear.
Now the turbo comparison.
See pictures below for GP500 vs PS2 (and vs stock for those who's interested).
Compressor: both PS2 and GP500 cut from forging billet. PS2 is a little bigger, as the opening is bored out to the edge of compressor housing. Also, PS2 seems to use factory blade design. GP500 has its unique in house 7 blade design and is even lighter than stock.
Turbine: Both are clipped type. Size is very close, maybe PS2 is slightly larger. PS2 also has a more aggressive blade pitch that trade spool up for less restriction. GP500 has a smoothly machined edge of blade that reduce restriction and weight at the same time.
To sum it up (through my untrained eyes), PS2 is more aggressive going all out for high boost. While GP500 feels more refined and advanced (for the price it asks it better be) and is screaming efficiency (at power range it's designed for).
Then the impression of GP500:
1) Exhaust note - The tone felt instantly deeper when I light up the car. Could be all in my mind, or the indoor resonance, I thought. Drove out of the garage and revved it up a little bit. My very discerning ear clearly confirmed it's a little louder and noticeably deeper. Oh...I'd be willing to pay 2k for sound alone
So did my mechanic think.
BTW, what freer flow turbine did to exhaust note is - less turbo restricted = more naturally aspirated. And, the more upstream the exhaust component goes, the greater effect it has on sound quality. Normally turbofold or header is the most significant sound changer in the entire exhaust system.
2) Turbo Lag - Let's be honest, 500hp or 550hp makes no difference to me but turbo lag does, to the point it makes or breaks the deal. Which is why I didn't do STG2 turbo much earlier.
First on the road, excited, I tried hard looking for it. Granted stock turbo and STG1 turbo aren't lag free to begin with. Thank god! GP500 lag was barely noticeable just like STG1 and stock. That was nothing remotely like my experience with my friend's 335xi PS2, the then 1/4 mile world champion 11.11@125mph. PS2 lag on pump gas was quite noticeable on the road, below 3k you have nothing more than a NA, though above 3k5 you're rewarded with a 911 turbo.
3) Power - finally we're onto it. that's why it happens at all, right?
I started with OTS STG2 93OCT, which I flashed a few days back. That gave me a good perspective of how GP500 makes a difference over STG1 turbo. Let me put it this way - it reminds me of the day I drove my jb4ed 328i to pick up my new M2.
Read this - same map. same boost, same timing (Dinan turbo max out everything OTS map targets), GP500 pulls like a whole different car. The revving up was so rewarding that it never stop giving you more until shifting to next gear. On just OTS map, it feels similar to the BM3 STG1 tuned M4 of my friend which I drive all the time, maybe slightly less at mid range but slightly more at top end.
4) Datalog
30 mins road testing, aggressive driving, went back for oil/coolant leakage check - all perfect. I went to the highway for datalogging. As I said boost/timing was already capped out by Dinan turbo, GP500 made no difference of course in these areas. Sorry it's not a good time to share my full log, but one thing - I compare the spool up to STG1/stock turbo, I gave up 300~350rpm spool up, well...a tradeoff I'd love to do every day all day please! PS2 would be a 800~1000rpm delay.
I'm flying to USA on 6/7 and will stay till June end. I'll slightly tweak my map and be done with it for now. Next step is to build 2 of my friend the M2 PS2 when I'm back Shanghai. I'll do the comparison no worries.
Serious custom tuning will happen in Q4. Winter is a much better time for testing.
----------------------------------Edit on 6/6 2018-----------------------------------------------------------------
I lifted boost a little bit and data logged on a hotter day (30C or 86F). IAT ended up maxing at 115~120 from repeated runs. Those are some seriously high stress - 8~10 back to back pulls on 3rd~4th full gear, with 10 second in between for brake and turn around, short race track equivalent in term of engine load. My brake suffered and faded hard.
The good:
1) Timing was capped out up top on 98RON(93OCT) at flat 11 degrees across all 6 cylinders. I have good feeling I can handle 12~13 degree cap on even 120+ IAT if I stay 18~17psi, for which stock turbo would need ethanol or race gas to support. Keep in mind I'm talking 4k5~7k rpm.
There is easily 20+whp left in it for me, without increasing boost and stressing anything.
2) Fueling holds up well at 18.5psi middle range, which is surprising. There has been abnormity with my fueling (keeping up exceptionally well) since installing Dinan turbo, now similar goes to GP500. I've seen most if not all other N55s (bigger turbo or stock) rail pressure dipping hard on similar or less load. I think it has something to do with the trim. Dzenan and Halim agree with that, but hold different opinions to each other on why DME respond like that. Till this day, no one has a definitive explanation LOL.
At the end of the day, it's a good thing for me, I don't have to work to change it. On hot days, boost doesn't have same air density as it would when cool, and thus doesn't stress hpfp as much. I will refrain from increasing boost until HPFP upgraded if necessary at all with my goal in further tests.
The bad:
Boost curve isn't perfect. There is a little boost surge to 18.5+ at middle range and DME is busy adjusting to boost ceiling (like I said, one of the things I don't like about OTS). It took a while and boost settled from 6k+. Power delivery and drivability are not affected at all, it's been smooth as always. I just have more power where it's not intended, or maybe I need it and just have to let DME accept what turbo is offering. This is something beyond DME adaptation can fix. After all, OTS map is made for the stock turbo.
There will be an adjustment on boost curve, timing cap, and fuel pump. Boost curve is an easy tweak for a linear and smooth 17~18psi from middle range to redline, identical to what's thrown at Dinan turbo. Timing I see no issue either of capping out 12 degrees, passing which there is the diminishing return. The real challenge is fueling capacity, which I'll see in Q4.
Contrary to many, winter is the testing time for me. Because in summer, you're really testing turbo capacity and octane, both of which are many others' problem, not mine.
As such, I'll take a break with my car, and work on PS2 for my friends in early July.
BTW, the way she pulls, drives and sings - Is my babe the f*king all time greatest sounding turbocharged BMW L6? JK
I'm more in love with her than ever before!!!
----------------------------------Edit on 6/26 2018-----------------------------------------------------------------
I was offered a free HPDE by BMW China at Shanghai F1 circuit on June 25. So I did.
Shanghai F1 is a 5.4km(3.4mile) long, very horsepower and brake demanding circuit (think Monza with Italy). There are 16 turns and the longest straight is 1.2km(3/4 quarter mile). see this:
https://en.wikipedia.org/wiki/Shangh...tional_Circuit
Our group consisted of 1 E92 M3, 6 F80/82 M3/4, and 3 F87 M2. Each one of us did three 20-min sections.
It was a very hot day - the ambient 37.5C(100F) and 58% humidity (so it feels like 110~115F). One Jb4ed M4, melted his EWG wiring, went into limp mode in the first section and had to set to map 0 to finish the rest.
I pushed pretty hard and made the fastest lap of the day. I am not a pro racer. Though holding the national B class racing license, I'm not your average driver either. Brake rotor temp, at pit after cooling down lap, is still 800+C/1500+F. I think I didn't cool it well, as I still wanted to push at my cooling lap LOL. Tire temp is 80C/176F@37psi. My front is still stock PSS, it did a pretty nice job overall, though a little understeer was experienced.
From datalog the IAT maxed at 130+F (timing is capped out most of the time), oil/coolant temp is below 240F. At the end of the last section, my fuel tank had only 30km/14mile fuel left. The car ran rock solid.
The 1.2km long straight on such a hot day was the best place to demonstrate M2 M4 power difference.
Stock M2 reached 215kph at brake point.
FBO Flashed M2 on stock turbo barely see 225kph.
Stock M4 ZCP is 235kph. (10kph makes a big difference)
My car and one BM3 STG2 M4 did 245kph, the fastest of the group.
Above numbers were gotten with air con turned on.
----------------------------------Edit on 7/1 2018-----------------------------------------------------------------
Guys, I'm installing a M2 friend Pure Stage 2 and BM3 OTS.
I think I have the best BMW turbo installer in China here...PS2 was done in 6 hours, holy crap...that's even including one hour for lunch and break. Not a single mistake. Not a single issue.
It surprises me that M2 PS2 in 2018 version is quite different than 2016/2017. It has not only a better fit and finish but also, more importantly, an updated design of BOTH compressor and turbine which you can clearly see, comparing the attached pictures to the ones I posted earlier.
I cannot comment what difference this smoother and nicer looking compressor would make, but turbine is definitely a freer flow design. There is a cut, which is new, on the blade edge, which is trading spool up for less back pressure, as exhaust partially bypasses turbine rather than pushes or gives momentum to it. It seems Pure is really trying to upper the power or efficiency game, trying to compete with all these new STG3 turbo.
Powertrain wise, this M2 is FBO geared minus fueling.
ARMA carbon fiber intake
Pure Inlet Pipe
TIC and CP
Wagner Evo2 Competition IC
Catless Downpipe
3D Design Catback
Pure Stage Two
BTW, he also has KW club sport 3 way, AP Pro5200 brake kit to accommodate 18" BBS RI-A on 265/285mm P Zero. And anti roll bar & etc. Pretty track prepared.
I loaded OTS STG2 93OCT (the one everyone is using) to the new PS2 and test drive it. Despite of the fact that OTS isn't tuned for radical spool up and new PS2 seems to give up a little spool up, I felt this M2 PS2 is more responsive than the 335i PS2, 1/4 mile world champion, of my another friend. PS2 has really improved over these years (only 3 years actually) in terms of everything.
To make no mistake, lag was felt. I could tell my friend wasn't particularly satisfied with PS2 power until we have open road for deep throttle on 3rd gear and a little 4th. Once PS2 gets on boost, torque blew him away, which is comparable to GP500 at these boost level as expected. The power even broke traction of his 285mm P Zero on downshift to 3rd, something he never imagine remotely possible with stock turbo. In fact he's already been used to having full traction on 2nd with FBO stock turbo.
Additionally, as long as PS2 isn't completely off boost, throttle on/off response is sharp, which has a lot to do with the great DCT. That, in conjunction with the outright power, makes it easy to forget the lag in building up boost.
Regarding power, one thing I want to add - Monstrous torque, everyone can have it with stock turbo on a tune designed for it. However, how hard it comes is how quick it falls as rpm goes up. You short shift wishing to stay on power as if you're trying to gloss over your blemishes at upper range. This is the point - with STG2 turbo, you'd only wish gear is longer so there is more you can explore.
I was trying to log a few full 3rd and 4th gear pulls. I knew without looking, everything logged on OTS would be capped out with PS2. I only wanted to check the lag in spool (compared to GP500 and stock/STG1 turbo), boost curve and rail pressure. However, it started to rain and was going to rain for next 10 days or so (raining period of the year). We'll log when possible.
Below is a log of my car (GP500) I grabbed on my way back home. There was a window rain stopped and I found dry road under elevated road. It was on 3rd gear. Not enough road for 4th gear.
GP500, ambient = 32C/90F, 80% humidity.
18~19psi
Pump gas 98RON (AKI93)
http://www.bootmod3.net/log?id=5b38d28fd10b437334792d1b
Mighty GP500 and mighty HPFP of mine!
Despite how poised this GP500 handles the superpower (for a pump gas N55) as log shows, I'm going to dial it back a little LOL
Cheers.
----------------------------------Edit on 3/4 2019 -----------------------------------------------------------------
Me and my friend (the one I sold my old Dinan Turbo to) put our cars on the roller.
Fuel is RON98 (US AKI 93OCT).
GP500: 17psi, 5th gear
Dinan Turbo: 17psi, 4th gear (because 5th showed slightly less due to heat).
There are some 2psi of headroom (that I tested last summer) in the octane and fuel pump that I left there with my GP500. Because for my daily and track map, I want consistent power.
Dinan turbo is pretty much octane limited, running 17psi under max 95F of IAT that we saw.