Close

Page 1 of 2 12 LastLast
Results 1 to 25 of 32
  1. #1
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8


    Yes Reputation No

    Revisit: How does DME maintain boost control

    Ok folks,

    I know for some of you this may be a trip down the memory lane, but I want to grasp a better understanding the particulars about EXACTLY how the MSD80 establishes boost control in the N54?

    As with any turbocharged engine, there are two, maybe 3 primary ways of controlling boost:

    * Wastegate actuation - by opening and closing the turbo waste gates, the ECU effectively controls the speed at which the turbos are spinning and therefore the amount of airflow and boost that they are delivering.

    * Diverter valves or blow-off valves - by opening or closing the DV/BOV the ECU has the ability to reduce or completely eliminate any boost pressure in the area between the turbos and the throttle plate.

    * Throttle plate - By shutting down the throttle plate, the ECU can completely cut airflow and boost, which effectively cuts the power of the engine.


    Now, this is all fine and dandy, but I want to dig more into what ACTUALLY happens in the specific case of the N54. Of course, I need your help and to see if I am understanding this correctly.

    So here is my train of thought about each individual components:

    1. Wastegates: Judging from all the logs I've seen, the MSD80 has a fairly sophisticated control over the turbo wastegates. Meaning, it is capable of adjusting via solenoids the waste gates anywhere from 0% to 99%. This is a very precise and granular level of control.

    2. Diverter Valves / Blow Off Valves - From what I can tell, these things are either fully opened or fully closed and nothing in between. Is this correct?

    3. The throttle plate is infinitely adjustable via a solenoid. ...and contrary to Shiv's belief, it can go up to 99% open.

    So, if all of the above is correct, it seems that a lot of the choppyness and a lot of the "lumpy" feeling comes from the diverter valves since they can't be actuated operated with the same level of precision, correct?

    As the weather is getting hotter, I am beginning to see a lot of choppyness and "lumpyness" with the Cobb tune running 4.01 beta maps. There are serious boost oscillations at full throttle. The engine output is becoming a lot less predictable when the heat starts to rise. I understand that with heat, the ECU must pull timing to prevent knock, but with Cobb, its almost feels that the engine is thrashing between the two states of max power and no power at all. Nothing in between.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  2. #2
    Join Date
    Jan 2011
    Location
    Pretty sure I am in Mexico
    Posts
    926
    Rep Points
    930.9
    Mentioned
    8 Post(s)
    Rep Power
    10


    Yes Reputation No
    Well the DVs only open during "overpressure" in the charge pipe in order to prevent a surge situation and they are completely mechanical in actuation unless you designed an engine where the vacuum to the DVs was ECU/DME managable. I doubt they are responsible.
    Never thought I would see the day...
    Click here to enlarge Originally Posted by Terry@BMS Click here to enlarge
    Life is so much more fun with a nemesis. I miss Shiv. Click here to enlarge
    Click here to enlarge

  3. #3
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    3 out of 3 members liked this post. Yes Reputation No
    Choppiness can come from the diverter valves when changing throttle positions, especially if your spring is too soft for your boost level. The diverter valves work using pressure, vacuum and a spring. When you get off throttle, you create vacuum in the manifold. There is a line that goes from the manifold to the top of your DV (this is the little guy on the top). When the manifold sees vacuum, the vacuum sucks the DV from the top. In the DV there is a piston that is pushed down with a spring. The vacuum created on top of of this piston sucks the piston up against the spring. This happens when off throttle. When the piston moves up air is allowed to go from the charge pipe back into the intake (or wherever the release line is going). When you get back on throttle, the manifold sees pressure. This pressure is now being pushed on top of the piston instead of vacuum. This pressure helps the spring push the piston back down against the boost pressure that is flowing from charge pipe to intake. Once the piston is all the way down, it blocks the air flow path from charge pipe to intake. This is how you keep boost.

    Anyone feel free to add anything I may have forgotten/missed, but this is how I believe the DV works from inspecting them. The DME doesn't really have control over the DV. The proper spring will help in driveability because if it is too soft, it may not be able to shut the piston as quickly as it should causing choppiness.

    Your choppiness could also come from the logic applied to control the wastegates. There is no magic forumla that directly converts an electrical signal into a precise mechanical movement. To solve this problem, people employ control logic, usually combing Proportional, Integral, and Derivate controls (PID). Without getting overly technical, the processor gives an initial input (in this case electrical) to move the solenoid. The ECU then reads what the error of the movement is compared to what it wants to see. The PID controller then employs its PID equations to try and control the rate of increase towards its goal, the amount it overshot its goal, and the time that the goal is overshot. Think of a regular x-y graph and you have a point somewhere on this graph you want to hit (horizontal line). You start from 0,0. Then you shoot at an angle towards this line, but you can't hit it directly. The line will go towards this goal at a certain rate (P-control), it will then overshoot the goal slightly and needs to be corrected back down (I-control). Last, it remains above this goal for a certain period of time and you may need to bring it down quicker (D-control). All in all - this is very tricky business. Hotter temperatures can cause the wastegates/solenoids to act differently than they did during the conditions that the initial controls were developed. This can cause inconsistencies. Also, inadequately designed PID systems will tend to have more error in some conditions.

    anyone feel free to correct me, it's been a long time since my System Dynamics and Controls course.

  4. #4
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    GeorgiaTech335Coupe,

    Thanks for the clarification. That's what I figured. I know how the PID systems work after recently reading alot about it. I honestly feel that the fully mechanical, vacuum operated DV/BOV in the N54 are vastly inferior to the electronically controllable alternative. An electronically controlled diverter valve will have close to infinite adjustability and therefore it will provide much improved driveability. For an example, here is the N75 diverter valve for the 1.8T VW/AUDI engine aka. "the Neva' Loose". This is now almost 15 years old:

    Click here to enlarge

    So I guess for us N54 owners, it really boils down to proper tuning. Sadly, I still think Cobb has a lot to work to do before they can deliver a smooth predictable software in all conditions. Click here to enlarge

    I am going to be doing some extensive logging next Saturday @ Gingerman race track. My plan is to send all the data to Cobb and have them figure out why all this is happening.

    I'll play with ATR when it comes out, but if that does not fix the issues, then I might go back to GIAC again. ...or sell the 335 and get an M3
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  5. #5
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    The other thing that bothers me is that whole PID business. Why do we need to have it altogether? Why does it constantly have to chase an ideal line if it is ALWAYS deviating from it? Honestly, this is the first turbo engine ECU that I've seen that uses PID control system. Why is this any better than the more traditional way of tuning turbo engines via direct maps....
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  6. #6
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    2 out of 2 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    GeorgiaTech335Coupe,

    Thanks for the clarification. That's what I figured. I know how the PID systems work after recently reading alot about it. I honestly feel that the fully mechanical, vacuum operated DV/BOV in the N54 are vastly inferior to the electronically controllable alternative. An electronically controlled diverter valve will have close to infinite adjustability and therefore it will provide much improved driveability. For an example, here is the N75 diverter valve for the 1.8T VW/AUDI engine aka. "the Neva' Loose". This is now almost 15 years old:

    [url]http://c1552172.r72.cf0.rackcdn.com/50488_x800.jpg[.img]

    So I guess for us N54 owners, it really boils down to proper tuning. Sadly, I still think Cobb has a lot to work to do before they can deliver a smooth predictable software in all conditions. Click here to enlarge

    I am going to be doing some extensive logging next Saturday @ Gingerman race track. My plan is to send all the data to Cobb and have them figure out why all this is happening.

    I'll play with ATR when it comes out, but if that does not fix the issues, then I might go back to GIAC again. ...or sell the 335 and get an M3
    I haven't seen the specifics of the electronically controlled DV and haven't run the calcs on the standard mech controlled either, but I think that the mechanically controlled ones would act faster if setup properly than the electronically controlled. With the electronically controlled, you may have more error and more time from when the DV 'sees' the change in throttle position (vacuum/pressure). Where as with the mechanical DV, it sees these changes almost instantly.

    Maybe some pos rep to keep me sticking around here?

  7. #7
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    I rep'd you. Sorry, I tend to forget to use the rep system on this board.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  8. #8
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    The other thing that bothers me is that whole PID business. Why do we need to have it altogether? Why does it constantly have to chase an ideal line if it is ALWAYS deviating from it? Honestly, this is the first turbo engine ECU that I've seen that uses PID control system. Why is this any better than the more traditional way of tuning turbo engines via direct maps....
    We need it because when you input x amount of current/voltage to some kind of device to make it work, it cannot automatically go to Y result. It has to start moving. Think of a motor that is at a stand still. You want it to go to Y rpm, so you turn a knob that calls for it to go Y rpm. The motor has to start turning to get up there, then has to slow down to Y speed. This cannot be done instantly, but takes a finite amount of time (this is called the transient state). Well, if the motor could take 10 hours to get to Y rpm, then it probably would easily be able to stop when it gets to Y rpm. The problem is we want that rpm and we want it NOW! So the motor ramps up at a very high rate. Well the problem with this is that once we get close to Y rpm, we want it to stop on a dime. Not happening with all that created momentum. So the rpm overshoots Y a little and now we need to bring it back down. Then we have to figure out how quickly do we want to speed him down? IF its too slow then it takes forever, if its too fast then we go under Y rpm. All this crap is controlled by corrections of the PID controller. The bottom line is to blame it on physics. But we love physics, so we will forgive her.

  9. #9
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    The other thing that bothers me is that whole PID business. Why do we need to have it altogether? Why does it constantly have to chase an ideal line if it is ALWAYS deviating from it? Honestly, this is the first turbo engine ECU that I've seen that uses PID control system. Why is this any better than the more traditional way of tuning turbo engines via direct maps....
    Electronically controlled wastegates provide much more control and fluidity. A good PID system will never be felt. It's all in the genious of the design(er). There are lots of forms of controls in all different things that you use. Your electric oven has a form of control to get to its called operating temperature, although much more basic than what we are talking about here.

  10. #10
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,219
    Rep Points
    9,374.4
    Mentioned
    655 Post(s)
    Rep Power
    94


    2 out of 2 members liked this post. Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    The other thing that bothers me is that whole PID business. Why do we need to have it altogether? Why does it constantly have to chase an ideal line if it is ALWAYS deviating from it? Honestly, this is the first turbo engine ECU that I've seen that uses PID control system. Why is this any better than the more traditional way of tuning turbo engines via direct maps....
    I have a full plate this AM so not able to read the entire thread, but the OEM uses a PID system to control boost. As does any form of electronic boost control. Are you suggesting the only way to control boost is with a spring connected to a wastegate? I guess the spring is one of the original regulation systems but its a bit 1800s don't you think? Or was this what you had in mind? Click here to enlarge

    Click here to enlarge
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  11. #11
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
    We need it because when you input x amount of current/voltage to some kind of device to make it work, it cannot automatically go to Y result. It has to start moving. Think of a motor that is at a stand still. You want it to go to Y rpm, so you turn a knob that calls for it to go Y rpm. The motor has to start turning to get up there, then has to slow down to Y speed. This cannot be done instantly, but takes a finite amount of time (this is called the transient state). Well, if the motor could take 10 hours to get to Y rpm, then it probably would easily be able to stop when it gets to Y rpm. The problem is we want that rpm and we want it NOW! So the motor ramps up at a very high rate. Well the problem with this is that once we get close to Y rpm, we want it to stop on a dime. Not happening with all that created momentum. So the rpm overshoots Y a little and now we need to bring it back down. Then we have to figure out how quickly do we want to speed him down? IF its too slow then it takes forever, if its too fast then we go under Y rpm. All this crap is controlled by corrections of the PID controller. The bottom line is to blame it on physics. But we love physics, so we will forgive her.

    OOh, trust me, I understand physics and I understand how this works. I am just not too fond of how things are working at the moment... ...and stepper motors would be prohibitively expensive to use for something like this.

    Anyway, do we know at what frequency does this PID system work?
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  12. #12
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    OOh, trust me, I understand physics and I understand how this works. I am just not too fond of how things are working at the moment... ...and stepper motors would be prohibitively expensive to use for something like this.

    Anyway, do we know at what frequency does this PID system work?
    The motor was purely a random example to illustrate how/why we need PIDs.

    I do not know any of the specifics of any tuners' PID systems. They are all setup differently with different values. It's been a while since I was involved in controls design so getting into the specifics of this particular system may require me to brush up on my knowledge. If I get a minute I'll try and get back to you with more thoughts.

  13. #13
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,219
    Rep Points
    9,374.4
    Mentioned
    655 Post(s)
    Rep Power
    94


    Yes Reputation No
    Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
    Electronically controlled wastegates provide much more control and fluidity. A good PID system will never be felt. It's all in the genious of the design(er). There are lots of forms of controls in all different things that you use. Your electric oven has a form of control to get to its called operating temperature, although much more basic than what we are talking about here.
    Interesting move on BMWs part coming down the pipeline... Click here to enlarge
    Attached Images Attached Images  
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  14. #14
    Join Date
    Mar 2012
    Posts
    308
    Rep Points
    310.7
    Mentioned
    9 Post(s)
    Rep Power
    4


    Yes Reputation No
    I've only had limited experience with Cobb. Can you log throttle plate and/or Wastegate with Cobb? Would be interesting to see. What happens when you use a different map?
    Loe P.
    B8.5 Audi S5 3.0"T" - GIAC stage II ECU / GIAC DSG TCU / AWE-tuning Pulley / AFe filter / 034 TBB / mod airbox / X-pipe
    - 09' E90 M3 7-DCT Interlagos Blue / Novillo Silver - gone Click here to enlarge
    [K&N filter|MS pullies|test pipes|Evolve Stg II tune/Servotronic/GTS-DCT Tune|Euro MDM]


  15. #15
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    @Terry@BMS,

    What are we looking at here? Cable operated wastegate? I can't tell from the picture...

    @Spooled twice, yes, you can pretty much log anything you want with Cobb. As a matter of fact, there is no other tune that offers such an extensive logging capability.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  16. #16
    Join Date
    Aug 2010
    Location
    Valley Stream NY
    Posts
    3,327
    Rep Points
    2,780.2
    Mentioned
    85 Post(s)
    Rep Power
    28


    Yes Reputation No
    You are looking at an electronically controlled wastegate from what I see. No more vacuum control

  17. #17
    Join Date
    Nov 2009
    Location
    Simi Valley, CA
    Posts
    8,219
    Rep Points
    9,374.4
    Mentioned
    655 Post(s)
    Rep Power
    94


    Yes Reputation No
    Click here to enlarge Originally Posted by Matt@AUTOCouture Click here to enlarge
    You are looking at an electronically controlled wastegate from what I see. No more vacuum control
    +1
    Burger Motorsports
    Home of the Worlds fastest N20s, N54s, N55s, N63s, S55s, and S63s!

    It is the sole responsibility of the purchaser and installer of any BMS part to employ the correct installation techniques required to ensure the proper operation of BMS parts, and BMS disclaims any and all liability for any part failure due to improper installation or use. It is the sole responsibility of the customer to verify that the use of their vehicle and items purchased comply with federal, state and local regulations. BMS claims no legal federal, state or local certification concerning pollution controlled motor vehicles or mandated emissions requirements. BMS products labeled for use only in competition racing vehicles may only be used on competition racing vehicles operated exclusively on a closed course in conjunction with a sanctioned racing event, in accordance with all federal and state laws, and may never be operated on public roads/highways. Please see http://www.burgertuning.com/emissions_info.html for more information on legal requirements related to use of BMS parts.

  18. #18
    Join Date
    Apr 2011
    Location
    Jersey City
    Posts
    3,852
    Rep Points
    3,647.6
    Mentioned
    74 Post(s)
    Rep Power
    37


    Yes Reputation No
    Just change back to v 3 maps until Cobb releases the v 4 non beta if ur having trouble. My car is running great, better/smoother than it ever has on my Cobb tune. I have the ver 3 map, stg 2, or go get the car pro tuned and really unlock the power.

    I would never get a m3 unless u plan on supercharging it, you may as well wait for the next turbo m3 :-)
    Click here to enlarge
    ESS 6XX kit

  19. #19
    Join Date
    Jul 2011
    Posts
    42
    Rep Points
    40.2
    Mentioned
    1 Post(s)
    Rep Power
    0


    Yes Reputation No
    Vasillalov, I'm very interested in what you find out this weekend as you and I seem to be having the EXACT same issues and are running very similar mods. I'm wondering whether or not my actuators are acting up and if that's the case, I'll probably stop tracking the car as I can't seem to justify spending the money on upgraded turbos if I can't replicate the problems on the street. The other thing I'm wondering is if GIAC, JB4, or PROceed would give me a remedy.

  20. #20
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    @Skyhart

    Yeah, this Saturday will be very interesting for me as well. I'll be bringing a laptop and all of the 3.02 maps and 4.01 maps. I'll log the living hell out of it. Hopefully something good will come out of this. Last time, on the same track I was also hitting overboost condition (22 psi) with Cobb on any map possible including Stage 0. All this while the oil temps were below 250F and coolant temps were at 210F
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  21. #21
    Join Date
    Jul 2010
    Location
    Stockholm, Sweden
    Posts
    1,104
    Rep Points
    1,398.3
    Mentioned
    16 Post(s)
    Rep Power
    14


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    @Skyhart

    Yeah, this Saturday will be very interesting for me as well. I'll be bringing a laptop and all of the 3.02 maps and 4.01 maps. I'll log the living hell out of it. Hopefully something good will come out of this. Last time, on the same track I was also hitting overboost condition (22 psi) with Cobb on any map possible including Stage 0. All this while the oil temps were below 250F and coolant temps were at 210F
    Have you tried a procede or jb4 to rule out hw issues with your car?
    Click here to enlarge
    997.1 tt
    Kline 200cell exhaust
    997.2/GT2RS IC's
    Cobb E85 custom stage3 tune by Mitch
    ID1000 injectors
    Sachs stage 2.5 clutch

  22. #22
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    Click here to enlarge Originally Posted by xbox_fan Click here to enlarge
    Have you tried a procede or jb4 to rule out hw issues with your car?
    No, I have not. I choose to be stubborn about this as I am very much against any piggie-backs. In my book those are just parasites.
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  23. #23
    Join Date
    Apr 2010
    Location
    espaņa
    Posts
    754
    Rep Points
    804.2
    Mentioned
    19 Post(s)
    Rep Power
    9


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    No, I have not. I choose to be stubborn about this as I am very much against any piggie-backs. In my book those are just parasites.
    you speak like a German or Spanish tuner but are not as currentECU in the decade of the 90's or early 2000

    I have always used dial up I use bms for 4 years and the reality is that it was a great find and change my thinking in piggien-backs and changing habits many Spanish boys
    [SIGPIC][/SIGPIC]

  24. #24
    Join Date
    Jun 2010
    Location
    Chicago, IL
    Posts
    919
    Rep Points
    780.4
    Mentioned
    42 Post(s)
    Rep Power
    8



    Yes Reputation No
    Well, I don't want to get into this tune vs tune discussion here. This was not the intent of this thread. I am glad that you are happy with your tuning solution. Click here to enlarge
    From all the things I've lost,
    I miss my mind the most!
    Click here to enlarge

  25. #25
    Join Date
    Mar 2012
    Posts
    330
    Rep Points
    353.4
    Mentioned
    10 Post(s)
    Rep Power
    4


    Yes Reputation No
    Click here to enlarge Originally Posted by vasillalov Click here to enlarge
    Well, I don't want to get into this tune vs tune discussion here. This was not the intent of this thread. I am glad that you are happy with your tuning solution. Click here to enlarge
    Back to your original post - are you still on stock DVs or do you have Forged DVs with different spring? (I think I'm running yellow, don't remember exactly though).

Page 1 of 2 12 LastLast

Tags for this Thread

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may post replies
  • You may not post attachments
  • You may not edit your posts
  •