Jump to content
SAU Community

25det Wastegate Issues

chur

By chur,
in Engines & Forced Induction

 Share

Recommended Posts

chur Rookie

chur

Posted
  • Author
Posted
how odd..

So, just to get this right, the waste gate is wired so the flapper is in the open postition..

Then there should be no way that thing should be climbing in boost pressure reguardless of where u get the signal from.

arrghh.. question,

can the wastegate actually 'open' all the way? I mean is it only opening say half way or two thirds?

Are you sure there is nothing in the wastegate dump pipe that is blocking gas flow?

well thats all i got! not much help huh?

Yup I know what your saying, the flapper was definetily wired fully open, infact further than the actuator would normally throw it.

Hmm I had the dump pipe completely out of the car the other day all seemed to be in order, maybe I will need to dig deeper.

I know it sounds impossible, seems impossible to me too :worship:

chur Rookie

chur

Posted
  • Author
Posted
if the wastegate and actuator are working fine, why not look at other possibilities?

haha i was about to suggest boost controller but u said u dont have one.

i would check vacuum lines and pretty much anything looking for any leaks splits or anything like that.

but hey im no expert.

Cheers lineskee

Na your right, I need to start again at the basics, thanks for your input

Cubes Grand Master

Cubes

Posted
Posted

Its quite possible the motor is breathing a little better due to the recent inlet mods. That paired with the stock dump that definitely favours turbine flow rather than wastegate flow 'could' tip it over the edge of boost creep.

I'd almost be inclined to again flick that circlip from the wastegate/actuator arm, disconnect it and wire the flap open again.

It just can't/shouldn't over boost with the wastegate wired open.

All bets are still on the stock dump and combination of inlet/breathing mods. :worship:

The problem I have though is a cat back with stock dump/front and fmic is quite a common mod, others don't see boost creep problems, so why do you? :S

chur Rookie

chur

Posted
  • Author
Posted
Its quite possible the motor is breathing a little better due to the recent inlet mods. That paired with the stock dump that definitely favours turbine flow rather than wastegate flow 'could' tip it over the edge of boost creep.

I'd almost be inclined to again flick that circlip from the wastegate/actuator arm, disconnect it and wire the flap open again.

It just can't/shouldn't over boost with the wastegate wired open.

All bets are still on the stock dump and combination of inlet/breathing mods. :mellow:

The problem I have though is a cat back with stock dump/front and fmic is quite a common mod, others don't see boost creep problems, so why do you? :S

Its cause I'm special :worship:

I'll take it for a longer squirt with the wastegate wired open tomorrow, I agree it should be impossible!

thanks

13thracer Rising Star

13thracer

Posted
Posted

my old post for your same issue may help, the problem would come and go for me but in the end with the stock 25 in it, it was the intercooler piping causing my issue.

maybe you are special like i was, the previous motor in it was meant to be a 25 until it went bang and when i pulled it down found it had 26 internals with massive cams hence the too munch exhaust flow out of a stock 25 turbo. id be hoping to be special :)

http://www.skylinesaustralia.com/forums/in...=133869&hl=

zebra Grand Master

zebra

Posted
Posted

no dramas mate....

where abouts are you getting the reading for the boost gauge?

is it off the IC piping or the manifold?

was thinking along the lines of what has been said previously about the tight bends in the piping, so if your are getting your Gauge feed from the IC piping maybe its blocked and backing up before it gets to the manifold.

Does the car go like shit off a slippery shovel when on boost or is it unresponsive and....well...slow?

GT

chur Rookie

chur

Posted
  • Author
Posted
my old post for your same issue may help, the problem would come and go for me but in the end with the stock 25 in it, it was the intercooler piping causing my issue.

maybe you are special like i was, the previous motor in it was meant to be a 25 until it went bang and when i pulled it down found it had 26 internals with massive cams hence the too munch exhaust flow out of a stock 25 turbo. id be hoping to be special :cool:

http://www.skylinesaustralia.com/forums/in...=133869&hl=

13thracer thanks for the link it got me thinking, went to the garage in anger determend not to sleep till I found the problem coz it just didn't add up.

Then it dawned on me that the idiot who assured me that the pod filter would flow more than enough air for my application may have been talking out of the wrong hole. Set the wastegate up as it should be,Yanked the poddy off and in a fit of foot stomping anger wheeled out of the garage, freaken thing is holding boost perfectly!!!

Somehow I new this problem was going to end up making me look like a total tool :( my experience with cars is that 90% of the time it's something simple.

Bad news is it probably doesnt have super awsome internals, damn it!

Thanks for all the advice guys

WogsRus Veteran

WogsRus

Posted
Posted

OK so i can't be bothered reading the post, drunk an all, but i had a problem with my stock turbo, in that it would bost creep, no matter what, so i took it off, and bored the gate out and the surrounding inlet, no more issues now. LOVE IT.

chur Rookie

chur

Posted
  • Author
Posted
no dramas mate....

where abouts are you getting the reading for the boost gauge?

is it off the IC piping or the manifold?

was thinking along the lines of what has been said previously about the tight bends in the piping, so if your are getting your Gauge feed from the IC piping maybe its blocked and backing up before it gets to the manifold.

Does the car go like shit off a slippery shovel when on boost or is it unresponsive and....well...slow?

GT

Thanks brother it turned out to be the pod filter without it, it holds boost perfectly... I still would have expected different symptoms but I guess if your not learning then your probably dead!

The guy that sold me the filter(and specifically assured me it would flow enough) is going to get a kick in the nads. :(

Cheers for your time

MANWHORE Grand Master

MANWHORE

Posted
Posted

The pod filter wouldn't cause your boost to go up to infiniti. Something is at play here.

With my stock turbo, it held boost perfectly. I had all of the usual gay stuff like ic, exhaust, pod, blah blah blah.

With just the actuator connected, it would hold 5 psi. with the normal dual boost thing, it woudl do about 9 psi after all those other mods. never higher.

Somethign is definitely at play there. It's impossible if the flapper is wired open for it to still go to crazy boost. If you knwo someone that knows a bit about turbos, get them to take a look at it.

A pod won't do shit in terms of affecting boost.

13thracer Rising Star

13thracer

Posted
Posted

out of interest does the pod have the top of it sort of blanked off (no air goes in the top just the sides) like you i had pod issues too with the crapy K&N have a look at the apexi power intake take a good look at the diagram on the box or on the web, of how the air enters the pod and how it goes into the AFM it creats less turbulance with air flow. i noticed it drove and went smoother after fitting a apexi than the K&N which when in comparison was just nasty, try a power intake and you will be pleasatly suprised.

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

    • GTSBoy
      Mistakes were made, my R34 Story

      By GTSBoy · Posted

      Nah, that is hella wrong. If I do a simple linear between 150°C (0.407v) and 50°C (2.98v) I get the formula Temperature = -38.8651*voltage + 165.8181 It is perfectly correct at 50 and 150, but it is as much as 20° out in the region of 110°C, because the actual data is significantly non-linear there. It is no more than 4° out down at the lowest temperatures, but is is seriously shit almost everywhere. I cannot believe that the instruction is to do a 2 point linear fit. I would say the method I used previously would have to be better.
    • GTSBoy
      DeAgostini 1/8 scale BNR32 Nissan Skyline GT-R Nismo

      By GTSBoy · Posted

      That's hilariously putrid!
    • GTSBoy
      R33 Fuel Pump & Brakes after alarm swap

      By GTSBoy · Posted

      When I said "wiring diagram", I meant the car's wiring diagram. You need to understand how and when 12V appears on certain wires/terminals, when 0V is allowed to appear on certain wires/terminals (which is the difference between supply side switching, and earth side switching), for the way that the car is supposed to work without the immobiliser. Then you start looking for those voltages in the appropriate places at the appropriate times (ie, relay terminals, ECU terminals, fuel pump terminals, at different ignition switch positions, and at times such as "immediately after switching to ON" and "say, 5-10s after switching to ON". You will find that you are not getting what you need when and where you need it, and because you understand what you need and when, from working through the wiring diagram, you can then likely work out why you're not getting it. And that will lead you to the mess that has been made of the associated wires around the immobiliser. But seriously, there is no way that we will be able to find or lead you to the fault from here. You will have to do it at the car, because it will be something f**ked up, and there are a near infinite number of ways for it to be f**ked up. The wiring diagram will give you wire colours and pin numbers and so you can do continuity testing and voltage/time probing and start to work out what is right and what is wrong. I can only close my eyes and imagine a rat's nest of wiring under the dash. You can actually see and touch it.
    • Kinkstaah
      Mistakes were made, my R34 Story

      By Kinkstaah · Posted

      So I found this: https://www.efihardware.com/temperature-sensor-voltage-calculator I didn't know what the pullup resistor is. So I thought if I used my table of known values I could estimate it by putting a value into the pullup resistor, and this should line up with the voltages I had measured. Eventually I got this table out of it by using 210ohms as the pullup resistor. 180C 0.232V - Predicted 175C 0.254V - Predicted 170C 0.278V - Predicted 165C 0.305V - Predicted 160C 0.336V - Predicted 155C 0.369V - Predicted 150C 0.407V - Predicted 145C 0.448V - Predicted 140C 0.494V - Predicted 135C 0.545V - Predicted 130C 0.603V - Predicted 125C 0.668V - Predicted 120C 0.740V - Predicted 115C 0.817V - Predicted 110C 0.914V - Predicted 105C 1.023V - Predicted 100C 1.15V 90C 1.42V - Predicted 85C 1.59V 80C 1.74V 75C 1.94V 70C 2.10V 65C 2.33V 60C 2.56V 58C 2.68V 57C 2.70V 56C 2.74V 55C 2.78V 54C 2.80V 50C 2.98V 49C 3.06V 47C 3.18V 45C 3.23V 43C 3.36V 40C 3.51V 37C 3.67V 35C 3.75V 30C 4.00V As before, the formula in HPTuners is here: https://www.hptuners.com/documentation/files/VCM-Scanner/Content/vcm_scanner/defining_a_transform.htm?Highlight=defining a transform Specifically: In my case I used 50C and 150C, given the sensor is supposedly for that. Input 1 = 2.98V Output 1 = 50C Input 2 = 0.407V Output 2 = 150C (0.407-2.98) / (150-50) -2.573/100 = -0.02573 2.98/-0.02573 + 47.045 = 50 So the corresponding formula should be: (Input / -0.02573) + 47.045 = Output.   If someone can confirm my math it'd be great. Supposedly you can pick any two pairs of the data to make this formula.
    • Jarsky
      R33 Fuel Pump & Brakes after alarm swap

      By Jarsky · Posted

      Well this shows me the fuel pump relay is inside the base of the drivers A Pillar, and goes into the main power wire, and it connects to the ignition. The alarm is.... in the base of the drivers A Pillar. The issue is that I'm not getting 12v to the pump at ignition which tells me that relay isn't being triggered. AVS told me the immobiliser should be open until the ignition is active. So once ignition is active, the immobiliser relay should be telling that fuel pump relay to close which completes the circuit. But I'm not getting voltage at the relay in the rear triggered by the ECU, which leaves me back at the same assumption that that relay was never connected into the immobiliser. This is what I'm trying to verify, that my assumption is the most likely scenario and I'll go back to the alarm tech yet again that he needs to fix his work.      Here is the alarms wiring diagram, so my assumption is IM3A, IM3B, or both, aren't connected or improper. But this is all sealed up, with black wiring, and loomed  
×
×
  • Create New...