E90Post
 


Studio RSR
 
BMW 3-Series (E90 E92) Forum > E90 / E92 / E93 3-series Powertrain and Drivetrain Discussions > N54 Turbo Engine / Drivetrain / Exhaust Modifications - 335i > Vishnu/FFTEC Single Turbo 6AT video/datalogs/vbox graph/pics



Closed Thread
 
Thread Tools Search this Thread
      03-07-2013, 07:19 PM   #1
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Lightbulb Vishnu/FFTEC Single Turbo 6AT video/datalogs/vbox graph/pics

Hi guys,
CupertinoSteve sent me video and datalogs from last nights 60-130mph vbox testing. They are worth seeing and can probably spark some good technical discussion (hence a new thread). First, here is a quick video from all of last night's runs:



If you look closely at the fuel level gauge, you can see boost/manifold pressure. As per the Procede's single turbo firmware, the fuel level gauge is scaled to read from 0-30psi, so 1/2 is 15psi of boost, 3/4 is 22.5psi of boost, etc,. The oil temp gauge is scaled to read from 20:1 to 10:1 which means that half is 15:1 and 3/4 is 12.5:1 and so on. The turn signals indicate methanol flow reaching the methanol flow target which is based upon PWM DC% from the fast-acting valve. A few tuners have suggested that our methanol control logic/hardware is unnecessarily fancy/expensive. But thats what happens when you treat methanol injection as if it were a real fuel system and only use race-quality components. It works reliably and properly as evident by all the single turbo cars on the road now making over 600whp on pump gas+meth. If you want to use gardening fittings/hardware to build a meth system, that's fine. But you are sacrificing performance and reliability for price. Don't let anyone tell you otherwise. The quality/functionality of a fully integrated meth injection system is revealed when something goes wrong, not when everything is working as it should.

And here some datalogs with some of the channels that we can disclose at this time:








Tuning/Tech Info:

-Post shift timing looks good. Never saw any ignition flatlines. Even on the runs were the car was boost 26+psi post shift.

-Boost above 6500rpm is tapered off dramatically as to reduce transmission stress in preparation for the upshift event. And boost target is dropped substantially during the gear change event itself. I can only imagine how fast the car could have possibly been if I asked it to hold full boost during the shift and with no top end taper. But this is a 100% stock transmission so until we need to push it hard, we'll go easier on it. Plenty fast enough. The boost drop between gear does make the boost ramp up at the beginning of 4th gear VERY fun. If you look at the video, you can see just how quickly the revs rise at the beginning of 4th gear!

-AFR is steady in the 10.5-11:1 range under full boost. Between gears it gets even richer due to the boost drop and negative ignition timing event. No misfire. Ever.

-Throttle blade is mapped to close between gears slightly to discharge unwanted boost since it's hard to drop boost that quickly through WG adjustments alone.

-If you look at the RPM graph in 3rd gear, you can see evidence of brief periods of wheelspin. That's 3rd gear with 275mm wide sticky drag radials!

-Methanol flow graph shows just how repeatable actual methanol flow is when you treat it like a fuel system (ie, constant pump pressure through a PWM injection valve). This gives us the ability to have actual methanol flow (read from an actual turbine driven flow tube) follow airflow/boost closely. This keeps fuel trims and AFR stable despite pretty abrupt changes in boost pressure at high RPM when the engine is most likely to get checked down from over-fueling and misfire. This cannot be done with a conventional meth injection systems (DO, CM, etc,.) due to the limited dynamic range associated with variable speed pumps/injection pressure.

VBOX graph


-Slope is pretty reasonable at -1.5%. I suspect if Steve were to find a stretch of road that had a the max allowable -3% grade, his times would have been in the 6.5-6.6 range but that's almost cheating

-Despite the boost drop/throttle closure/negative timing during the gear change, it's cool to see that acceleration is constant. That is, there are no flat spots that we would see in a 6MT car during shift where the clutch is pressed (or ignition cut) causing the car to coast or even decelerate slightly. At things equal, this gives the 6AT a big edge when it comes to multi-gear acceleration. Once we get to the point were we can hold full boost during the shift and don't have to taper boost above 6500rpm, the 6AT will straight up destroy a similarly powered 6MT in such a test of acceleration. Definitely something to look forward to.

-The power curve of the Single Turbo, despite the top end boost taper, is solid right to redline. Which means that there is no need to shoft-shift using the paddles. This means that it can ride out 4th right to 6800rpm automatic upshift point and hit 130mph without requiring a 2nd shift. This is a HUGE advantage of a turbo kit that makes power to max revs instead of peaking at ~6200rpm and falling above that. With high end power roll-off (tiny turbo syndrome) you can't take full advantage of gearing. And acceleration suffers.

-It looks like there is some wheelspin at the beginning of 3rd gear which suggest that with stickier rubber (or maybe a little less tire pressure), the car could run quicker. Steve did log a couple runs that were 1/10th quicker (6.7x?) but forgot to put the SD card back in the vbox after viewing the previous run data

If anyone has any questions/comments about tuning, hardware, what a badass CupertinoSteve is, etc,. feel free to post.

Keep the shiny side up,
shiv

Last edited by OpenFlash; 03-07-2013 at 08:04 PM..
Appreciate 0
      03-07-2013, 08:07 PM   #2
cupertinosteve
Second Lieutenant
United_States
16
Rep
227
Posts

Drives: BMW 335i
Join Date: Nov 2011
Location: Cupertino, Duh?

iTrader: (0)

@shiv - thanks for dissecting all the logs.

No comment on the last point, I thought that was our little secret.
__________________
Vishnu/FFTEC Single Turbo (58mm) 6AT ... 60-130 in 6.881 seconds
Vishnu Procede Rev.3, Vishnu PWM Meth Kit, AE Exhaust, Helix IC, Forge DVs, Wavetrac LSD
#### IT'S FOR SALE ###
Appreciate 0
      03-07-2013, 08:25 PM   #3
NY135ivishnu
Second Lieutenant
United_States
115
Rep
288
Posts

Drives: 2009 bmw 135i
Join Date: May 2012
Location: New york

iTrader: (1)

Quote:
Originally Posted by shiv@vishnu
Hi guys,
CupertinoSteve sent me video and datalogs from last nights 60-130mph vbox testing. They are worth seeing and can probably spark some good technical discussion (hence a new thread). First, here is a quick video from all of last night's runs:



If you look closely at the fuel level gauge, you can see boost/manifold pressure. As per the Procede's single turbo firmware, the fuel level gauge is scaled to read from 0-30psi, so 1/2 is 15psi of boost, 3/4 is 22.5psi of boost, etc,. The oil temp gauge is scaled to read from 20:1 to 10:1 which means that half is 15:1 and 3/4 is 12.5:1 and so on. The turn signals indicate methanol flow reaching the methanol flow target which is based upon PWM DC% from the fast-acting valve. A few tuners have suggested that our methanol control logic/hardware is unnecessarily fancy/expensive. But thats what happens when you treat methanol injection as if it were a real fuel system and only use race-quality components. It works reliably and properly as evident by all the single turbo cars on the road now making over 600whp on pump gas+meth. If you want to use gardening fittings/hardware to build a meth system, that's fine. But you are sacrificing performance and reliability for price. Don't let anyone tell you otherwise. The quality/functionality of a fully integrated meth injection system is revealed when something goes wrong, not when everything is working as it should.

And here some datalogs with some of the channels that we can disclose at this time:








Tuning/Tech Info:

-Post shift timing looks good. Never saw any ignition flatlines. Even on the runs were the car was boost 26+psi post shift.

-Boost above 6500rpm is tapered off dramatically as to reduce transmission stress in preparation for the upshift event. And boost target is dropped substantially during the gear change event itself. I can only imagine how fast the car could have possibly been if I asked it to hold full boost during the shift and with no top end taper. But this is a 100% stock transmission so until we need to push it hard, we'll go easier on it. Plenty fast enough. The boost drop between gear does make the boost ramp up at the beginning of 4th gear VERY fun. If you look at the video, you can see just how quickly the revs rise at the beginning of 4th gear!

-AFR is steady in the 10.5-11:1 range under full boost. Between gears it gets even richer due to the boost drop and negative ignition timing event. No misfire. Ever.

-Throttle blade is mapped to close between gears slightly to discharge unwanted boost since it's hard to drop boost that quickly through WG adjustments alone.

-If you look at the RPM graph in 3rd gear, you can see evidence of brief periods of wheelspin. That's 3rd gear with 275mm wide sticky drag radials!

-Methanol flow graph shows just how repeatable actual methanol flow is when you treat it like a fuel system (ie, constant pump pressure through a PWM injection valve). This gives us the ability to have actual methanol flow (read from an actual turbine driven flow tube) follow airflow/boost closely. This keeps fuel trims and AFR stable despite pretty abrupt changes in boost pressure at high RPM when the engine is most likely to get checked down from over-fueling and misfire. This cannot be done with a conventional meth injection systems (DO, CM, etc,.) due to the limited dynamic range associated with variable speed pumps/injection pressure.

VBOX graph


-Slope is pretty reasonable at -1.5%. I suspect if Steve were to find a stretch of road that had a the max allowable -3% grade, his times would have been in the 6.5-6.6 range but that's almost cheating

-Despite the boost drop/throttle closure/negative timing during the gear change, it's cool to see that acceleration is constant. That is, there are no flat spots that we would see in a 6MT car during shift where the clutch is pressed (or ignition cut) causing the car to coast or even decelerate slightly. At things equal, this gives the 6AT a big edge when it comes to multi-gear acceleration. Once we get to the point were we can hold full boost during the shift and don't have to taper boost above 6500rpm, the 6AT will straight up destroy a similarly powered 6MT in such a test of acceleration. Definitely something to look forward to.

-The power curve of the Single Turbo, despite the top end boost taper, is solid right to redline. Which means that there is no need to shoft-shift using the paddles. This means that it can ride out 4th right to 6800rpm automatic upshift point and hit 130mph without requiring a 2nd shift. This is a HUGE advantage of a turbo kit that makes power to max revs instead of peaking at ~6200rpm and falling above that. With high end power roll-off (tiny turbo syndrome) you can't take full advantage of gearing. And acceleration suffers.

-It looks like there is some wheelspin at the beginning of 3rd gear which suggest that with stickier rubber (or maybe a little less tire pressure), the car could run quicker. Steve did log a couple runs that were 1/10th quicker (6.7x?) but forgot to put the SD card back in the vbox after viewing the previous run data

If anyone has any questions/comments about tuning, hardware, what a badass CupertinoSteve is, etc,. feel free to post.

Keep the shiny side up,
shiv
This is awesome!!!! Have you installed the single in any 135s yet?!?!
Appreciate 0
      03-07-2013, 08:28 PM   #4
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by NY135ivishnu View Post
This is awesome!!!! Have you installed the single in any 135s yet?!?!
Not yet. But we are about to ship out a kit to a 1M owner in France. We hope to do an in-house installation soon because there is nothing cooler than a 650whp 1 series.
Appreciate 0
      03-07-2013, 08:36 PM   #5
guru_method
Eating M3s for breakfast
guru_method's Avatar
No_Country
46
Rep
299
Posts

Drives: AW 09 135i M
Join Date: Nov 2011
Location: Dallas, TX

iTrader: (4)

That looks insanely fast!

What oct. gas?

Quote:
Originally Posted by NY135ivishnu View Post
This is awesome!!!! Have you installed the single in any 135s yet?!?!
Did you have to quote the whole thing?
Appreciate 0
      03-07-2013, 08:39 PM   #6
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by guru_method View Post
That looks insanely fast!

What oct. gas?
Just some good unleaded race gas. I think it's rated at 102oct with a MON of 99 or so. Running with 100% methanol mix spraying approx 1200cc/min into the FMIC end tanks.
Appreciate 0
      03-07-2013, 08:49 PM   #7
Dmacc
Colonel
200
Rep
2,799
Posts

Drives: 2011 BMW 1M
Join Date: Mar 2010
Location: So Cal

iTrader: (1)

Quote:
Originally Posted by shiv@vishnu
Quote:
Originally Posted by NY135ivishnu View Post
This is awesome!!!! Have you installed the single in any 135s yet?!?!
Not yet. But we are about to ship out a kit to a 1M owner in France. We hope to do an in-house installation soon because there is nothing cooler than a 650whp 1 series.
This is so so true
__________________

thanks to MGallop
Appreciate 0
      03-07-2013, 09:07 PM   #8
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Here's a post from Terry@BMS from another forum:
Quote:
So Shiv is basically saying he requires extremely precise control and flow data to achieve his single turbo tuning successfully. But when you look at his data you catch a glimpse of how the tuning is actually implemented. I've attached the datalog he posted with his comment above.

Note how methanol flow immediately jumps up to 50% and remains there. Over the course of 2 seconds from 13 to 15 in the log boost drops from 24psi? to 12psi? (the log scaling is illegible), a swing of maybe 200whp, yet methanol flow goes down from 50% to 40%. So essentially, between 12psi and 24psi there is effectively the same amount of methanol being injected. In my opinion given the AFR and timing dip post shift he should probably inject that same amount of methanol at any boost level > 12psi and simply use the fuel pressure feedback to handle his fuel trims. But at the end of the day while he talks a big game on needing this "precise" control he clearly is not even using it himself in the most extreme single turbo example posted.
Terry fails to realize that the raw methanol flow signal is not linear with actual flow. This is due to "hammering" effect on the turbine as pulses of meth pass through it. This means that 50% DC does not result in 50% of max nominal meth flow data. In fact, if you spray the fast acting valve at just 15%, you'll see a nominal meth flow value of 30-35%. This doesn't matter. What matters is that the control device (in the case, the Procede) knows what nominal flow value to expect at any give injection DC%.

For those running a ProcedePWM and PWM meth kits, you can clearly see a compensation algorithm in effect by comparing Methanol Flow Target (Debug Byte 7) to different WGDC values. The relationship clearly isn't linear. Just another example of how seriously we take tune/meth integration and remove "slop" that others don't seem to mind. Thanks to Terry for giving me the opportunity to bring this up

Shiv
Appreciate 0
      03-07-2013, 09:09 PM   #9
turb0mik3
turb0mik3's Avatar
242
Rep
2,781
Posts

Drives: E90 335i Racecar
Join Date: Jan 2010
Location: San Diego, CA

iTrader: (1)

Garage List
2010 BMW 335i  [8.90]
I'm very impressed with the smoothness in which the RPMs climb. Keep up the great work!
__________________

HG Motorsports | Motiv Motorsport | Sparta Evolution | BBS Motorsports | Sabelt | JRZ |
NASA ST1 SoCal --- 554whp/487wtrq --- 3200lbs <<YouTube Channel w/ Race Videos>>
Appreciate 0
      03-07-2013, 09:19 PM   #10
NY135ivishnu
Second Lieutenant
United_States
115
Rep
288
Posts

Drives: 2009 bmw 135i
Join Date: May 2012
Location: New york

iTrader: (1)

What supporting mods are these cars getting in order to handle the power?

Lsd?suspension?bushings?

Have you had any customers who want the single turbo kit for the reliability standpoint? And don't need the enormous power gains?

My perspective of the twins is that they are a ticking time bomb.
Appreciate 0
      03-07-2013, 09:25 PM   #11
pits200
Colonel
United_States
547
Rep
2,590
Posts

Drives: 09 335i X-Drive Black Sapphire
Join Date: Mar 2010
Location: Pittsburgh

iTrader: (1)

Quote:
Originally Posted by NY135ivishnu View Post
What supporting mods are these cars getting in order to handle the power?

Lsd?suspension?bushings?

Have you had any customers who want the single turbo kit for the reliability standpoint? And don't need the enormous power gains?

My perspective of the twins is that they are a ticking time bomb.
So you want to spend 7-10k on the single to get your car to have the same hp as it does stock? Why even buy this car then, that literally makes no sense.
Appreciate 0
      03-07-2013, 09:51 PM   #12
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by turb0mike View Post
I'm very impressed with the smoothness in which the RPMs climb. Keep up the great work!
Thanks Mike! You need a ride in one some day
Appreciate 0
      03-07-2013, 09:56 PM   #13
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by NY135ivishnu View Post
What supporting mods are these cars getting in order to handle the power?

Lsd?suspension?bushings?

Have you had any customers who want the single turbo kit for the reliability standpoint? And don't need the enormous power gains?

My perspective of the twins is that they are a ticking time bomb.
No supporting drivetrain/suspension mods are absolutely necessary. Or at least no more necessary as they are with an FBO car. I'd recommend an LSD for starters as it will make the car a lot more fun to slide around if that is your thing (it is mine!). If you have a 6mt, a clutch/fw is a good idea as well.

I don't think the stock turbos are granades under normal use. But the single will certainly be less stressful on the engine all other things equal. Will sound better too. Whether that alone is worth the entry cost is up to you. Personally, I could live with myself I had a 700hp car detuned to run 300hp
Appreciate 0
      03-07-2013, 10:19 PM   #14
BadBoostedBMWM3
Lieutenant
BadBoostedBMWM3's Avatar
United_States
334
Rep
557
Posts

Drives: e36m,F80,G80;TRX; 992 TTS; F95
Join Date: Nov 2009
Location: Louisville, KY

iTrader: (0)

I'm loving it. Very nice.
__________________
This is my signature...
Appreciate 0
      03-07-2013, 11:16 PM   #15
Ilma
Colonel
Canada
184
Rep
2,841
Posts

Drives: 2008 135i
Join Date: Nov 2008
Location: Mississauga

iTrader: (0)

Quote:
Originally Posted by shiv@vishnu View Post
Here's a post from Terry@BMS from another forum:


Terry fails to realize that the raw methanol flow signal is not linear with actual flow. This is due to "hammering" effect on the turbine as pulses of meth pass through it. This means that 50% DC does not result in 50% of max nominal meth flow data. In fact, if you spray the fast acting valve at just 15%, you'll see a nominal meth flow value of 30-35%. This doesn't matter. What matters is that the control device (in the case, the Procede) knows what nominal flow value to expect at any give injection DC%.

For those running a ProcedePWM and PWM meth kits, you can clearly see a compensation algorithm in effect by comparing Methanol Flow Target (Debug Byte 7) to different WGDC values. The relationship clearly isn't linear. Just another example of how seriously we take tune/meth integration and remove "slop" that others don't seem to mind. Thanks to Terry for giving me the opportunity to bring this up

Shiv
Funny......I was just corresponding with Jeff Howerton last week about meth sensor values versus flow rates, and he stated exactly the same thing......the relationship is non-linear.
Appreciate 0
      03-07-2013, 11:30 PM   #16
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by Ilma View Post
Funny......I was just corresponding with Jeff Howerton last week about meth sensor values versus flow rates, and he stated exactly the same thing......the relationship is non-linear.
Yep! When I was working on the Procede's progressive methanol control logic (with dynamic meth flow targeting), i had to really take some time to think about why i wasn't seeing a linear relationship between injection DC and nominal flow. And to verify that X% DC translates to a real X% flow, I measured flow into a container. I did this at 10, 20, 30, 40, 50, 60, 70, 80, 90% DC and recorded normal flow readings to create a response curve which the Procede's meth logic was based upon. Then when i added 2 additional nozzles for single turbo applications, I had to adjust the freq response curve accordingly for the ST firmware. It's work that most people don't see or notice but that's the best kind I suppose
Appreciate 0
      03-07-2013, 11:34 PM   #17
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Here's a post from themyst saying:
Quote:
Such precise methanol injection is so irrelevant given the wide adjustment range of fuel trims. When you can swing 34% in either direction, that leaves a HUGE margin for error. Which is why folks like me can run basic kits on this platform injecting 800cc of methanol at a low psi with no ill effects.

There is the issue of precise methanol distribution across cylinders, but once it mixes with the charge your bottleneck is the intake mani, and not the meth kit.

Aquamist is quality hardware and you are getting what you paid for. However, the inferior kits many of us have run for years also get the job done admirably.
1) Precise metering of methanol is NEVER irrelevant regardless of the factory closed loop fuel control's authority range. For a number of reason. First, there is a finite amount of time required for the DME to respond to a sensor and then make the an adjustment to injector on-time. During this period of time, the engine can easily see a couple dozen engine events. During short period of time, the engine is either running rich or lean. The amplitude of this rich/lean spike will be proportional to the methanol delivery error. I know themyst has stated several times that he doesn't care about partial throttle performance and that may account for his feelings regarding poor methanol control. But most people don't treat the throttle like an on/off switch and can easily feel the benefits of careful methanol metering. Not only from the seat of their pants but also in how long a tank of methanol will last before needing to be refilled. Also, all these benefits of proper metering become even more important as power levels increase. If you are taking about supporting a 600+whp N54 with a conventional on/off methanol system, you really need a reality check. Because I can assure you, you will not be driving a car that powerful with just two throttle positions.

2) By intake manifold bottleneck, I'm assuming he is referring to uneven airflow distribution at high airflow rates. This is reality on just about every stock intake manifold used in high boost/big turbo applications. This is one reason a proficient tuner will target a richer-than-normal AFR in these high hp applications. This is to account for some cylinders running slightly leaner than others. So when you read the average AFR of two banks of 3 cylinders, the richer AFR target means that even the leanest cylinder isn't running lean. The only important aspect of the methanol system is to ensure complete atomization before the meth/air charge gets to the intake manifold. When the methanol is in the gaseous state, it can mix homogeneously with the air. Keeping the air/meth ratio (and octane) consistent. This is why we use 4 smaller nozzles, injecting just 1200cc, mounted well upstream in the intercooler end tanks. 2 of the nozzles are even mounted on the hot size of the FMIC which means the meth injected gets vaporized instantly. The meth injected from the 2 nozzles mounted on the cold side of the FMIC still have several feel to travel before getting to the manifold. This approach, which we were the first to apply on this platform, is clearly superior to injecting a single M12 (or two M7) in the charge pipe just before the TMAP sensor.

3) I agree that Aquamist hardware is better than the rest. Not surprising considering their motorsport history. That is why our PWM meth system uses their flow meter, filter, FAV, nozzles, line, etc,. They work better than the conventional kits when mapped properly. The only way I can see that using the cheap stuff as "admirable" if you take the money you save and giving it to charity. Because arguing that something worse is "good enough" really just says that either you or your application is discerning enough to appreciate the difference. Sorry but it's true. This isn't a matter of having "allegiance" to a certain approach/product. It's about knowing how things work and being open-minded enough to learn as new data is presented to you. I'll be the first person to admit that I didn't understand what the big deal was a few years back until I implemented our first PWM meth kit and saw how much better it met performance goals.
Appreciate 0
      03-08-2013, 09:21 AM   #18
Ilma
Colonel
Canada
184
Rep
2,841
Posts

Drives: 2008 135i
Join Date: Nov 2008
Location: Mississauga

iTrader: (0)

Quote:
Originally Posted by shiv@vishnu View Post
Yep! When I was working on the Procede's progressive methanol control logic (with dynamic meth flow targeting), i had to really take some time to think about why i wasn't seeing a linear relationship between injection DC and nominal flow. And to verify that X% DC translates to a real X% flow, I measured flow into a container. I did this at 10, 20, 30, 40, 50, 60, 70, 80, 90% DC and recorded normal flow readings to create a response curve which the Procede's meth logic was based upon. Then when i added 2 additional nozzles for single turbo applications, I had to adjust the freq response curve accordingly for the ST firmware. It's work that most people don't see or notice but that's the best kind I suppose
When it goes unseen like that, many of us don't understand it either.

It's a journey to figure it out for sure.

It's nice when tuners share the details as best they can without exposing themselves.

Jeff made a comment that baffles me though......he did not recommend running 100% duty cycle on the FAV.

Does that make any sense
Appreciate 0
      03-08-2013, 09:28 AM   #19
JStang
Brigadier General
JStang's Avatar
562
Rep
3,625
Posts

Drives: FDB M3 CS
Join Date: Dec 2010
Location: St. Petersburg, FL

iTrader: (9)

And the haters go silent...Very impressive numbers! I have been in a ST car that went into limp due to the SMFW issue that was resolved. I hope to get another ride soon.

Last edited by JStang; 03-08-2013 at 10:32 AM..
Appreciate 0
      03-08-2013, 09:55 AM   #20
TTurbo335
Second Lieutenant
TTurbo335's Avatar
United_States
21
Rep
200
Posts

Drives: BMW 335i
Join Date: Nov 2012
Location: So Cal

iTrader: (2)

Crazy fast video didn't realize the rpm climb till you guys said something.. I was looking at how fast the speedometer was climbing. lol

other than the video
I see lines and some squiggly lines on a graph. I need a big turbo!!
Appreciate 0
      03-08-2013, 10:45 AM   #21
AlterZgo
Lieutenant Colonel
1538
Rep
1,665
Posts

Drives: 23 X3 M40i, 21 911S, 24 Taycan
Join Date: Sep 2010
Location: Gilbert, AZ

iTrader: (0)

Quote:
Originally Posted by JStang View Post
And the haters go silent...Very impressive numbers! I have been in a ST car that went into limp due to the SMFW issue that was resolved. I hope to get another ride soon.
I don't know about the haters going silent. It's funny... when a 6AT ST car has transmission/shifting issues, some people attribute it to Vishnu "tuning issues". Of course, now when there is a documented sub 7 second 60-130 run, many of those same critics come out an say stuff like Alpina flash FTW! and Shiv should thank cn555ic and wedge1967 for the Alpina flash, etc.

Frankly, I don't know if the flash helped signficantly or not, but I think it's disingenuous to blame shiv for "tuning issues" when it was a transmission issue initially, then when the transmission issues are resolved, claim that shiv's tuning had little to do with this and the success was all due to the Alpina flash.

If the only holdback to great high-speed performance for 6AT STs was the lack of the Alpina flash, wouldn't that acknowledgement by the critics just negate all of their initial criticism about the alleged Vishnu "tuning issues" in the first place?
Appreciate 0
      03-08-2013, 12:45 PM   #22
OpenFlash
United_States
1736
Rep
17,960
Posts

Drives: A Lot
Join Date: Sep 2006
Location: SF Bay, CA

iTrader: (0)

Garage List
Quote:
Originally Posted by Ilma View Post
When it goes unseen like that, many of us don't understand it either.

It's a journey to figure it out for sure.

It's nice when tuners share the details as best they can without exposing themselves.

Jeff made a comment that baffles me though......he did not recommend running 100% duty cycle on the FAV.

Does that make any sense
Perhaps that may have something to do with atomization. Or more maybe something to do the transition that occurs when the FAV goes static at ~85%. Above that point you immediately get 100% flow. I've played around will all sorts of methanol mapping strategies. With the baseline maps, i tend to err on the conservative side (lots of meth) since I don't always know what other settings the customer is using. But you can get smoother performance with better ignition timing/fuel trim behavior if you moderate DC as a function of airflow and keep DC between 12 and 85% With the single turbo maps, we go static (>85%) at high RPM/high boost since there is so much airflow and injection volume is probably more important than anything else. Aquamist has no released larger 1.2mm nozzles which we hope to try out soon. With them, we could keep the FAV from going static in the 62mm 650whp applications and still get the injection volume we like. Definitely on my to do list

And here is another response (from my last post regarding the nonlinear relationship between flow meter signal and actual flow) from Terry@BMS:
Quote:
With all due respect, sounds a bit like BS. The flow sensor turbine only returns a dirty frequency, which is then filtered and linearized by its controller, in this case the procede control unit, to provide a meaningful data output. For example a 0-100 variable that corresponds to 0 - 2000ml/min of methanol flow. So now handling this basic function of a flow sensor is "taking tune/meth integration seriously" and "removing slop that others don't mind"? Do you even read the stuff you write? I think you might have been a used car salesmen in a prior life.

So the output in your log if you've done your job properly is supposed to already be linearized. Are you saying that you're still working on it? Even if we are to assume you have intentionally entered a non-linear scaling in the output for some unknown reason, doing so would reduce the flow resolution, further making our case that the level of data you claim to require is not being used.
Looks like Terry didn't understand what I said and instead chose to attack me. I'll try to put it in simpler terms. The methanol flow channel in the Procede datalog isn't linearized/modified in any way other than a very gentle smoothing function. It represents the frequency output (0-5v square wave) from the flow meter's hall effect sensor. No trickery there. He can confirm this himself easily. What is modified is the methanol flow target value that the procede expects to see at various RPM/load combinations in order to transition to more aggressive tune settings. This target value already accounts for the nonlinearity between injection DC and actual flow. So, in summary, we apply our algorithm to the flow target, not the flow input from the flow meter. Anyone can easily verify this by comparing Debug Byte 7 (flow target) at various Methanol Injection DC% values. You'll see that they are not linear. Not sure how that can possibly sound like "BS" if you Terry takes the time to actually research/test what I said

Cheers,
shiv

Last edited by OpenFlash; 03-08-2013 at 12:56 PM..
Appreciate 0
Closed Thread

Bookmarks


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off



All times are GMT -5. The time now is 06:17 PM.




e90post
Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2024, vBulletin Solutions Inc.
1Addicts.com, BIMMERPOST.com, E90Post.com, F30Post.com, M3Post.com, ZPost.com, 5Post.com, 6Post.com, 7Post.com, XBimmers.com logo and trademark are properties of BIMMERPOST