Jump to content
SAU Community

Recommended Posts

when you change gears quickly the bov doesn't have much time to dump air, so there isn't much of a pressure loss in the piping.

i'd possible point the finger at the boost controller. the air between the controller and the wastegate isn't able to escape fast enough, so the wastegate is still partly open when you get on the gas again, so you have less boost until the wastegate is fully shut.

My thoughts also.

When I was fiddling around making my own bleeders a few years back I came across this issue, but boost didn't come on with a jolt it was a smooth slow spooling laggy gutless feel.

IF the bov is venting to atmosphere you can experience a 'lag' of sorts between gear changes that feels like a jolt as the motor floods. The reason for this is between gear changes the ecu has metered an amount of air that has entered the ic and its piping, when shutting the throttle partially for a gear change the bov opens and dumps this air. So the mixture is going to be pig rich.

There's a couple of ways around this... Recirc bov or no bov at all.

For almost none of that slight 'lag' when you jump back on the throttle after a slow/mediocre speed gear change run no bov as the turbo doesn't have to do any work to 're pressurise' the ic and its piping. You get back on the throttle and the turbo torque is just simply there. ;) The total opposite of what many believe. The bov in fact increases slow/mediocre gear change lag.

A fast slapping change.. well bov or no bov there's no real difference.

In your case... I would start by blocking the bov off. See if it makes a difference. If there's no difference you know the issue is some where else.

  • 3 weeks later...

Oh by the way i finally got around to blocking my bov off and it's fixed the surging problem on gear changes, and seems to have more go after changes as well (+ i just got hi flo panel so i dont get any flutterz) so give it a shot and post results here if any one can be bothered

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • HFM BM57 has a "bad" knee point, IIRC. It's not the same thing as the later R chassis MC.
    • The ATTESSA is functionally identical to R34; there were a bunch of JDM models that continued ATTESSA including Fuga/Q70, Skyline/Q50, Cima etc as an option. All with Auto only and I think mostly for snow regions. AFAIK there were no AWD VR30DDTT sold in Australia - it is on my to do list to check regs for racing a LHD car in Targa/ATR/AASA/CAMS events because if I can get the auto to work it would be interesting to run a 4wd car The Ecuteck TCM tuning is the same model as their ECU tuning, they already have it for R35 and Dose's favourite, BMW. You buy "points" to allow your computer to be tuned, buy either a bluetooth (phone app) or bluetooth+USB+Key (phone and PC) dongle, and pay for a tune that will be locked to your tuner ( ). You can also access the tuning software yourself but 1. it is mega expensive and 2. these computers have a billion parameters that intersect, so how could you ever spend enough time on it to get a decent result.
    • Or, is it a case of what it is like owning an R series Skyline? NFI what the previous owner has done or fiddled with... Ha ha ha After reading through this thread, I went on a bit of a research about the Q50/Q60. Now I'm quite intrigued by them! Is the AWD in them more like a WRX where it's always AWD, or is it more like the ATTESSA in the GTRs? By the sound of this TCU tuning, this sounds like a case of someone has made some real software for it, and you just need the right piece of hardware, and then you license that specific vehicle/TCU. Or is this a case of the software will be really expensive so only a few tuners have it, and you still have to pay a license per vehicle?
    • By popular demand.. it was a coil. Got my hands on 1 new OEM coil, replaced with the one that made the less noise difference when I unplugged it while the car was running and started the car up. No stutter and the engine light was gone. I guess I’ll buy the other 5 they have lol
    • No, code 21 is very straightforward. It can only be the things described in that diagnostic flow. In fact it has no way of knowing that the spark plug resistance is out of spec.
×
×
  • Create New...