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    • Trouble in paradise? Vishnu/FFtec N54 335ii Single Turbo kits experiencing issues as a BimmerBoost member runs 12.5@121 with misfires and having to short shift

      BimmerBoost would like to thank member GeorgiaTech335Coupe for his openness and honesty regarding his Vishnu/FFTEC single turbo setup. Recently, this member took his single turbo upgraded 6-speed manual 335i to the PBIR (Palm Beach International Raceway) dragstrip in Florida to do some testing. His best run was a 12.50@121.6 alongside a 12.8@117. Yes, these times are quite a ways away from the 10.8@131 glory pass from Vishnu demonstrating the kits capability.


      This is in no way the fault of GeorgiaTech335Coupe who experienced misfires on his car and had to short shift at 6300 rpm in order to avoid them. Now, Vishnu has basically portrayed this kit as perfect and ready for sale with nobody having any issues. The reason BimmerBoost is bringing this issue to the attention of the community is for potential buyers to understand what they are getting into.


      There is absolutely nothing wrong with having issues when modifying a car to this level and BimmerBoost is confident Vishnu will resolve them. There is something wrong with pretending nothing is wrong. A few cars with the single turbo kits have gone up for sale and apparently a total of three people, that are willing to open their mouths, are having misfire issues with these kits.

      These issues will no doubt get resolved but potential buyers and current customers needs to be aware of the process, effort, and that progress is being made. Pretending nothing is wrong and collecting money simply is the wrong way to go about this and once again (it's becoming a trend) BimmerBoost is the only site bringing these issues to the attention of the community.

      For the record, a member by the name of @tmo335tt says he has a hardware solution for the misfires that he will likely share with Vishnu (hopefully not for free). Interesting that it isn't Vishnu but the community solving this.

      Thanks again to @GeorgiaTech335Coupe for sharing his details, good or bad, as we all learn thanks to honesty and openness. There is more to tuning than just collecting money.

      This article was originally published in forum thread: Vishnu Single Turbo at PBIR - 12.50@121.6 having to shift all gears at 6300rpm started by Sticky View original post
      Comments 1090 Comments
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by DefactoM6 Click here to enlarge
        2 gear changes in an MT adds significant time compared to the 1 shift usually done in a 6MT stock turbo car. That said, I'd be very surprised if he didn't have full boost well before or at 3800 RPM if he brake boosted the car and started it in the 45-50mph range. Shiv showed a video of his car making 1 bar around 3100ish RPM, which is what I would expect given the engine in question and the turbo used, so I'd be surprised if he really needed to start the car in 2nd for a good time.
        yeah I probably need to brake-boost in 3rd to get any kind of respectable time.
      1. bigdnno98's Avatar
        bigdnno98 -
        That's what most people do but that's on stock turbos. Not sure if it'll get you in your powerband but it can only help. Brake boost around 45-50MPH, by the time you hit 60MPH hopefully you've hit full boost or close to it.

        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        yeah I probably need to brake-boost in 3rd to get any kind of respectable time.
      1. Sticky's Avatar
        Sticky -
        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        VBOX has been proven to be very accurate. It's just a very accurate GPS that constantly records position and calculates speed/acceleration.

        IHRA sanctioned track equipment still has to be placed correctly to work properly. They just use beams that are broken and record time between each beam break and calculate speed. Think of what would happen if those blocks were placed a couple feet short.
        It's not that the Vbox isn't accurate. It just does not equal a slip like how some people treat it.
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by Sticky Click here to enlarge
        It's not that the Vbox isn't accurate. It just does not equal a slip like how some people treat it.
        100% agree. Not a substitute. More for verification.
      1. lulz_m3's Avatar
        lulz_m3 -
        Whats interesting to me is that your 1/8th Mile trap speed is fairly stout - almost 97 mph. You are picking up just over 26 mph on the back half of the track. For comparison, i typically run 93 in the 1/8th, and trap 118, picking up 25mph on the back half. I would expect the ST to be a monster on the back half of the track, 1 mph difference seems like something is off.
      1. bigdnno98's Avatar
        bigdnno98 -
        Very good point, I also was picking up around 25MPH on the back half. I would think this is where the ST should shine.

        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        Whats interesting to me is that your 1/8th Mile trap speed is fairly stout - almost 97 mph. You are picking up just over 26 mph on the back half of the track. For comparison, i typically run 93 in the 1/8th, and trap 118, picking up 25mph on the back half. I would expect the ST to be a monster on the back half of the track, 1 mph difference seems like something is off.
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by lulz_m3 Click here to enlarge
        Whats interesting to me is that your 1/8th Mile trap speed is fairly stout - almost 97 mph. You are picking up just over 26 mph on the back half of the track. For comparison, i typically run 93 in the 1/8th, and trap 118, picking up 25mph on the back half. I would expect the ST to be a monster on the back half of the track, 1 mph difference seems like something is off.
        Yes, exactly...and I'd bet money (enough to buy a new rear diff) that it's my gearing. At 125mph, I'm only at 5950rpm in 4th. If I shift 3rd at 7000rpm (~111mph), then 4th gear starts at 5280rpm.
      1. bigdnno98's Avatar
        bigdnno98 -
        You think 1st and 2nd gear are bad now though. Wait till you put that 3.46 in there. You're going to need real hoosier slicks and some dedicated lightweight drag wheels like some Koesi K1 17" or something.
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by bigdnno98 Click here to enlarge
        You think 1st and 2nd gear are bad now though. Wait till you put that 3.46 in there. You're going to need real hoosier slicks and some dedicated lightweight drag wheels like some Koesi K1 17" or something.
        Yeah I know. It's unfortunate but overall I think it'll be better. 1st is almost useless now anyway. I will be getting dedicated lightweight 17s and slicks eventually.
      1. themyst's Avatar
        themyst -
        I guess we now know why Shiv went to a 3.46 rear now.
      1. BavarianBullet's Avatar
        BavarianBullet -
        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge

        Had no timing in 4th on this one. Think I shifted too quickly.

        Also, notice there is a little bit of bog on 3-4 in both graphs. I could feel this at the track.

        I'm not using NLS on any of these runs (did it on my first run, but timing flatlined so I took it off - still seemed to happen on the above run).
        I marked up your log with my best guess at where the real-world 1/4mi numbers would fall so you can get a sense of how the engine was performing at each point.

        Let me know what you think.

        Attachment 24717
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by BavarianBullet Click here to enlarge
        I marked up your log with my best guess at where the real-world 1/4mi numbers would fall so you can get a sense of how the engine was performing at each point.

        Let me know what you think.
        Can you mark up the first log? That log is of a run where timing flatlined in 4th. Also, mark the rpm of each line, that would be helpful.
      1. LostMarine's Avatar
        LostMarine -
        Click here to enlarge Originally Posted by DefactoM6 Click here to enlarge
        2 gear changes in an MT adds significant time compared to the 1 shift usually done in a 6MT stock turbo car. That said, I'd be very surprised if he didn't have full boost well before or at 3800 RPM if he brake boosted the car and started it in the 45-50mph range. Shiv showed a video of his car making 1 bar around 3100ish RPM, which is what I would expect given the engine in question and the turbo used, so I'd be surprised if he really needed to start the car in 2nd for a good time.
        as i was reading your reply i was already contemplating brake boosting.





        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        Then I'd have to start in 2nd. That isn't good for 2 reasons: extra shift and 2nd gets very little traction.
        shifting is what it is, but traction is easily attended to. i feel your pain on that, nothing you can do but get better tires. shouldnt be an issue with DR's though
      1. TCW's Avatar
        TCW -
        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        Yeah I know. It's unfortunate but overall I think it'll be better. 1st is almost useless now anyway. I will be getting dedicated lightweight 17s and slicks eventually.
        I am curious as to what you're current setup is? I already purchased some Kosei K1's and Hoosier DOT Drag Radials 275/40/17 if you want to wait to see how they perform on my car at the end of march (installing ST this weekend.)
      1. themyst's Avatar
        themyst -
        Click here to enlarge Originally Posted by BavarianBullet Click here to enlarge
        I marked up your log with my best guess at where the real-world 1/4mi numbers would fall so you can get a sense of how the engine was performing at each point.

        Let me know what you think.

        Attachment 24717
        Your timing in 4th explains the mediocre trap on the back end. Are you using NLS?
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by themyst Click here to enlarge
        Your timing in 4th explains the mediocre trap on the back end. Are you using NLS?
        Yes for that particular run. If you look at the first datalog timing is where it is supposed to be in 4th (124.89mph trap).

        That second log had 0 timing in 4th, not sure why. Maybe shifted too quickly.

        I only used NLS for one run, but then turned it off becuase it almost always seems to make my timing flatline in 4th. That 2nd log was the only time 4th flatiline when not using NLS out of about 7 runs.
      1. GeorgiaTech335Coupe's Avatar
        GeorgiaTech335Coupe -
        Click here to enlarge Originally Posted by TCW Click here to enlarge
        I am curious as to what you're current setup is? I already purchased some Kosei K1's and Hoosier DOT Drag Radials 275/40/17 if you want to wait to see how they perform on my car at the end of march (installing ST this weekend.)
        I daily drive (and currently drag race) on 285/35-18s Nitto NT555R drag radials. The ones on my car now are very bald. I'm getting new ones in on Thursday so hopefully they offer more grip which I believe they will.
      1. BavarianBullet's Avatar
        BavarianBullet -
        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        Can you mark up the first log? That log is of a run where timing flatlined in 4th. Also, mark the rpm of each line, that would be helpful.
        Here ya go. Thanks for sharing your experiences btw. props!

        Attachment 24722
      1. JoshBoody's Avatar
        JoshBoody -
        The tuning just looks like it needs a little tweeking. I'd try to stable AFRs first... are they set in the flash or some bias by procede also?
      1. themyst's Avatar
        themyst -
        Click here to enlarge Originally Posted by GeorgiaTech335Coupe Click here to enlarge
        Yes for that particular run. If you look at the first datalog timing is where it is supposed to be in 4th (124.89mph trap).

        That second log had 0 timing in 4th, not sure why. Maybe shifted too quickly.

        I only used NLS for one run, but then turned it off becuase it almost always seems to make my timing flatline in 4th. That 2nd log was the only time 4th flatiline when not using NLS out of about 7 runs.
        I am guessing you trapped lower on the 0 timing log?