Jump to content
SAU Community

What Would Happen If...

rbee25

By rbee25,
in Engines & Forced Induction

 Share

Recommended Posts

fLhayabusa Enthusiast

fLhayabusa

Posted
Posted

it would most likely wear a standard turbo out quicker due to backspin.. not straight away. the car would still be drivable though it'll wear quicker the harder you drive/boost it.

Im currently running an aftermarket turbo with no bov. And have not seen any signs of problems or wear to the turbo'.

gt-ahhh! Proficient

gt-ahhh!

Posted
Posted

no expert, but my hypothesis would be that you would suffer boost spikes everytime you changed gears, or got off the loud pedal after boost. invariably there is nowhere else for this air to go but your engine. and remember the throttle is never fully closed, it remains slightly ajar to allow idle. so the pressurised air would find its way into the chambers and create an extremely lean mixture, and possibly result in detonation.

thats just my theory. i want to see how close i am to the truth.

mitchy_ Grand Master

mitchy_

Posted
Posted

the butterfly does close, the idle control valve at the back of the plenum is used to idle the engine.

the air that is usually supposed to go out the bov is just sent back to the turbo and tries to spin it the opposite way.

MBS206 Grand Master

MBS206

Posted
Posted (edited)
the butterfly does close, the idle control valve at the back of the plenum is used to idle the engine.

the air that is usually supposed to go out the bov is just sent back to the turbo and tries to spin it the opposite way.

IT DOES NOT TRY AND SPIN IT THE OPPOSITE WAY!!!

Turbo fins are setup uni directional.

Spin the compressor one direction, air will move through it. Spin it the opposite, the air doesn't get moved through it.

The same applies if you blow air through it, it'll spin one way, blow it the opposite, it won't.

The issue of turbos slowing down, is you get a large pressure build up between the turbo and throttle, if your pressure source, for your wastegate, is pre-throttle body, the wastegate remains open, but your turbo has less gas flowing through it, and the majority of what exits the motor, is headed down the wastegate anyway, so the turbo slows down that way.

Take the pressure source post-throttle, and you're fine.

edit: On a motor running an AFM, you will get "double counts" of air as it reverts through the intake, and you'll get double the amount of fuel, On an aftermarket ECU, you can tune this issue out to a fair degree, on a factory car ecu car, you'll have stalling issues.

Throw an ECU on that makes the AFM just a piece of pipe (IE, convert to MAP) you won't have an issue.

Edited by MBS206
Guest
This topic is now closed to further replies.
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Duncan
      After market rear camber arm adjustment

      By Duncan · Posted

      Then, shorten them by 1cm, drop the car back down and have a visual look (or even better, use a spirit level across the wheel to see if you have less camber than before. You still want something like 1.5 for road use. Alternatively, if you have adjustable rear ride height (I assume you do if you have extreme camber wear), raise the suspension back to standard height until you can get it all aligned properly. Finally, keep in mind that wear on the inside of the tyre can be for incorrect toe, not just camber
    • V35Newbie
      After market rear camber arm adjustment

      By V35Newbie · Posted

      I know I have to get a wheel alignment but until then I just need to bring the rear tyres in a bit they're wearing to the belt on the inside and brand new on the outside edge. I did shorten the arms a bit but got it wrong now after a few klms the Slip and VDC lights come on. I'd just like to get it to a point where I can drive for another week or two before getting an alignment. I've had to pay a lot of other stuff recently so doing it myself is my only option 
    • Duncan
      After market rear camber arm adjustment

      By Duncan · Posted

      You just need a wheel alignment after, so just set them to the same as current and drive to the shop. As there are 2 upper links it may also be worth adding adjustable upper front links at the same time; these reduce bump steer when you move the camber (note that setting those correctly takes a lot longer as you have to recheck the camber at each length of the toe arm, through a range of movement, so you could just ignore that unless the handling becomes unpredictable)
    • V35Newbie
      After market rear camber arm adjustment

      By V35Newbie · Posted

      I got adjustable after market rear camber arm to replace the stock one's because got sick of having to buy new rear tyres every few months. Can anyone please let me know what the best adjustment length would be. I don't have the old ones anymore to get measurements. I'm guessing the stock measurement minus a few mm would do it. Please any help on replacing them would be fantastic I've watched the YouTube clips but no-one talks about how long to set the camber arm to.
    • GTSBoy
      Unpeeling the Orange

      By GTSBoy · Posted

      Heh. I copied the link to the video direct, instead of the thread I mentioned. But the video is the main value content anyway. Otherwise, yes, in Europe, surely you'd be expected to buy local. Being whichever flavour of Michelin, Continental or Pirelli suits your usage model.
×
×
  • Create New...