Jump to content
SAU Community

Help Help Help 48kw

shotter

By shotter,
in Engines & Forced Induction

 Share

Recommended Posts

shotter Rising Star

shotter

Posted
Posted

Ok i took my car in to get dynoed and tuned today and it was going fine and making about 180kw. Then during a run it made a loud popping noise and started backfiring. then it kept backfiring as you back off the throttle. and The car only made 48KW. Basically we tryed a lot of things to find the problem. the adj valve timing solinoid wasn't working for a little while, then it started working again. The AFM decided to go to 5.1V and the car wouldn't start. After some searching we found a cracked solder track. Fixed that and the car started but still no power. Tryed different AFM. Does anyone have any idea's or have been thought this problem before?

Link to comment
Share on other sites
  • Replies 124
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

Posted Images

shotter Rising Star

shotter

Posted
  • Author
Posted

The car makes boost. Sorry i should have said that. It makes and holds boost fine. And the fuel pressure raises and holds fine too. I checked all the intercooler pipes myself and they all were tight.

Link to comment
Share on other sites
Cjmartz2k Proficient

Cjmartz2k

Posted
Posted

Still sounds like a boost leak problem. Maybe split grommet or blown gasket somewhere. Do a boost leak check--quick, easy, and next to free, just to eliminate that as a potential problem. Maybe that's not it, but that's where I'd start.

Link to comment
Share on other sites
Kujotk Grand Master

Kujotk

Posted
Posted

could be a collapsed catalytic converter, saw similar thing happen to an evo on a dyno run, he hit 70kw though

Link to comment
Share on other sites
VB- Veteran

VB-

Posted
Posted
Still sounds like a boost leak problem. Maybe split grommet or blown gasket somewhere. Do a boost leak check--quick, easy, and next to free, just to eliminate that as a potential problem. Maybe that's not it, but that's where I'd start.

its making boost thought, even if there is a leak, its still getting 12psi or whatever hes running in the plenum, should be making more than 48kw.

the only powerloss from a boost leak should be the drop in effeciency as the turbos spinning hard to make the required boost at the plenum, due to the leaking air somewhere else. unless theres something im missing?

Link to comment
Share on other sites
shotter Rising Star

shotter

Posted
  • Author
Posted

The air ratio's are around a normal level. So nothing bad going on there. We thought it could be a timing problem when the adj valve timing stopped working. So we pulled the front cove off and pulled the trigger wheel off and noticed that the key that sits inside the cam and also the trigger wheel had snapped off. But we didn't think that was a huge problem because we checked the timing and it was ok. The one think that did pop out was the PCV hose and grommet. The grommet split. So we were able to put a bigger rubber hose in the hole and slide the PCV valve into it. It doesn't sound like it's leaking. But i dont know if it's venting pressure into the top of the crank case. And i guess it could even be the std ecu. it's not logging any fault codes but i dont know if that is causing it. Another idea i had and i really dont wanna think about this one is could i of melted a piston?

Link to comment
Share on other sites
Ultimategtr Proficient

Ultimategtr

Posted
Posted

It shouldnt be any internal damage i dont think.

I suppose it doesnt make any funny noises when you drive/boost?

Can you post up the last dyno run before it "blew"? It could still be a boost leak somewhere, but the turbo would be working harder to "make" 12 psi or whatever you boost. What was the peak boost you had?

Just a wild and noob suggestion - have you reset the ecu? since you said youre running the stock ecu, and if thats the case, able to swap ecu's or even the CAS with a working one off your mate?

You say that its boosting ok, does that mean you can "feel"the power as before? or you feel the turbo boosting but you dont go anywhere, is that the case?

Whats the timing set to?

Link to comment
Share on other sites
shotter Rising Star

shotter

Posted
  • Author
Posted

I dont have any dyno sheets. and it is still on the dyno. You can hear the exhaust note change at about 3000 rpm, it just goes really flat.

We have pulled the ecu out and tryed running the car with another r33 ECU but the car wouldn't turn off with that one connected. So we decided not to do a run with that connected. And it does make a ticking / rubbing noise at idle. which went away when we loosend off the bolts on the timing wheel /trigger wheel / destributor... whatever you call it.

Link to comment
Share on other sites

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

    • Lithium
      Boost level and torque curve

      By Lithium · Posted

      As someone who has been playing with turbo things for some time now, be prepared for this to not be the first time feeling this way    I'm busy as atm, but if no one else covers the things I'm realising are worth mentioning to you then I will when I have a chance as it seems like I overestimated your knowledge on how turbos and wastegates work.  Otherwise I recommend having a look around how wastegates and boost control work, really anything on understanding the general mechanism of boost control as it will help you find the answers to the questions you're looking for.  Your initial question jumps some fundamentals.
    • thx78
      Boost level and torque curve

      By thx78 · Posted

      I don't understand anything anymore.
    • thx78
      Boost level and torque curve

      By thx78 · Posted

      so this is an anomaly??? I thought it was a voluntary increase
    • Duncan
      Boost level and torque curve

      By Duncan · Posted

      we can only guess exactly what happened from our keyboards, but to me it looks like they were targeting 27 but the wastegate was too small or poorly controlled and the boost crept up, that is quite common
    • Lithium
      Boost level and torque curve

      By Lithium · Posted

      Good points!  Took those for granted - though I *did* actually give an example of winding boost up more than it had been before where I wasn't actually specifically looking for more peak power.  The Toyota Starlet dyno plot that I shared and mentioned showed an overlay from the previous tune it had and the one I'd redone, I left the boost targetting the same as the old tune but then after peak power I ramped boost up by a good 5psi or so over what the old tune had at the same rpm. The reason I felt comfortable with this (though the owner of the car had a "are you sure?" moment when I suggested it) is that the setup wasn't turbo limited, it was largely head sealing limited and the owner was a bit concerned as for the last few seasons he'd had issues with head lifting - sometimes not completing an event without having some headgasket issue, so he didn't want to run any more boost than it was. The reasons I was ok with raising the boost a good 5+psi MORE than that was that I left it where it was in the middle, and only increased it where VE (and therefore cylinder pressure vs psi) were dropping hard and I didn't stop the torque from dropping, just reduced the drop.  Well, there is that and the fact that the previous tuner had it overtimed by near 7degrees at peak torque - but that's another story haha.    I didn't really go into detail about that "turning it up more" thing but now you've mentioned the "not detuning", sometimes the boost *can* be turned up higher than you'd expect if the setup allows for it and you do it smartly.  I've tuned things to run 30psi on BP98 "safely" that a few years ago (or still?) people would cry that it was a stupid idea - but given they were well intercooled, low EMAP turbos and only doing that kind of boost where VE is dropping etc I was pretty confident it wasn't as cowboy as it sounded at face value and we never ended up with issues as a result of it.     
×
×
  • Create New...