Jump to content
SAU Community

R33 boost spike issue

Custard

By Custard,
in R Series (R30, R31, R32, R33, R34)

 Share

Recommended Posts

Custard Contributor

Custard

Posted
Posted
R33 boost spike issue

Hi all, I need to find a solution to fix a boost spike issue that my car has. It's a 1997 manual GTST, only mods are YJ coils, return flow FMIC, MBC and 3 inch turbo back exhaust.

Since I installed my front mount and dialled my boost up to 10/11 PSI I have noticed that when I punch it from 3.5 grand upwards the boost will spike to 12 or 13 PSI for a moment and then taper back to my set pressure. Just last night I installed a JJR bellmouth 3 inch dump pipe and now when I punch it, it will spike to 15 PSI! Would prefer not to launch my exhaust wheel out my exhaust, so I need to get this under control. Do I need an electronic boost controller or what?

 

Link to comment
https://www.sau.com.au/forums/topic/467794-r33-boost-spike-issue/
Share on other sites
Custard Contributor

Custard

Posted
  • Author
Posted

I have a cheap 'Drift' brand MBC - would be I correct in believing that this is a bleed type MBC? Would I benefit from changing to a ball type MBC such as this? http://www.ebay.com.au/itm/Turbotech-manual-turbo-boost-controller-THE-ORIGINAL-and-still-the-BEST-/321155544509?hash=item4ac65cb5bd:m:mJ5Yk12EnMVqXBuR8UxKxhQ

Custard Contributor

Custard

Posted
  • Author
Posted
1 hour ago, jhjones said:

connect the wastegate actuator hose directly to the intercooler pipe and see what happens

Okay, I did this. I saw 5 PSI when easing into boost and around 6-7 when stomping it from higher revs. I had a thought: perhaps with the addition of my front mount intercooler, the extra volume that has to be pressurised before results in the opening of the wastegate being delayed? If this was the case, would relocating the barb from the cold side to the hot side fix this?

13 minutes ago, djvoodoo said:

Why don't you just turn the boost down via the MBC??

Probably would have achieved the same result what as post above suggested, but it's done now. :P

Sklyn Grand Master

Sklyn

Posted
Posted

Just to be sure, the stock solenoid has been disconnected and the other hose blocked properly right? Getting 5 and 7 suggests the stock solenoid is still in use. Are your psi readings from an aftermarket gauge? Stock one is not psi.

Custard Contributor

Custard

Posted
  • Author
Posted (edited)
35 minutes ago, Sklyn said:

Just to be sure, the stock solenoid has been disconnected and the other hose blocked properly right? Getting 5 and 7 suggests the stock solenoid is still in use. Are your psi readings from an aftermarket gauge? Stock one is not psi.

Yes, actuator is connected straight to the nipple on the cold side of the intercooler piping, no stock solenoid. Readings are taken from an aftermarket boost gauge in PSI. The higher boost level that I'm getting isn't dependant on my RPM but rather how hard and fast the boost is coming on. 

Edited by Custard

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
 Share
Go to topic listing


  • Similar Content

  • Latest Posts

    • Kapr
      What brakes on R34 GTT(Europe)

      By Kapr · Posted

      Ok i will get those 310mm. I found one but on a different site. This is the description on those...is it ok? Technical parameters: - Axle: front. - Disc type: ventilated. - Number of holes: 5. - Disc diameter: 310mm. - Total height with center: 54mm. - Thickness (new/min.): 30/28mm. - Designed for brake calipers manufacturer: Sumitomo.
    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      You Gregged a whole racetrack!?
    • GTSBoy
      R32 GT-R: 4WD Light Turns On After Bumps – Code 19 (ETS Motor) But No Issues Found

      By GTSBoy · Posted

      Look for broken wire or bad connector at the motor. Might not be it, but is worth starting there, as it is easy.
    • Bireley_32
      R32 GT-R: 4WD Light Turns On After Bumps – Code 19 (ETS Motor) But No Issues Found

      By Bireley_32 · Posted

      Hi everyone, I’m having an issue with my R32 GT-R. Sometimes, when the car goes over a bump or experiences some vibration, the 4WD warning light comes on the dashboard. When I check the code from the control unit in the trunk, it shows Code 19 – ETS Motor. However, everything seems to be working fine — if I turn off the engine and restart the car, the light goes away and everything functions normally. Has anyone experienced this before? Where should I start troubleshooting this issue? Thanks in advance!
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      I'm back from the dyno - again! I went looking for someone who knew LS's and had a roller dyno, to see how it shaped up compared to everything else and confirm the powerband really is peaking where Mr Mamo says it should. TLDR: The dyno result I got this time definitely had the shape of how it feels on the road and finally 'makes sense'. Also we had a bit more time to play with timing on the dyno, it turns out the common practice in LS is to lower the timing around peak torque and restore it to max after. So given a car was on the dyno and mostly dialled in already, it was time for tweaking. Luis at APS is definitely knowledgable when it came to this and had overlays ready to go and was happy to share. If you map out your cylinder airmass you start seeing graphs that look a LOT like the engine's torque curve. The good thing also is if you map out your timing curve when you're avoiding knock... this curve very much looks like the inverse of the airmass curve. The result? Well it's another 10.7kw/14hp kw from where I drove it in at. Pretty much everywhere, too. As to how much this car actually makes in Hub Dyno numbers, American Dyno numbers, or Mainline dyno numbers, I say I don't know and it's gone up ~25kw since I started tinkering lol. It IS interesting how the shorter ratio gears I have aren't scaled right on this dyno - 6840RPM is 199KMH, not 175KMH. I have also seen other printouts here with cars with less mods at much higher "kmh" for their RPM due Commodores having 3.45's or longer (!) rear diff ratios maxing out 4th gear which is the 1:1 gear on the T56. Does this matter? No, not really. The real answer is go to the strip and see what it traps, but: I guess I should have gone last Sunday...
×
×
  • Create New...