Jump to content
SAU Community

Recommended Posts

Just want to know if anyone has done this and how effective it was

I have a problem at the moment where when I run highish boost i can hear the rubber pipe between the AFM and the turbo sucking shut, and the car drops massively in performance. When running normal boost - 1bar, its fine but when I wind it up a bit further to 1.2bar I can hear it really sucking the intake and restricting the inlet air - really frustrating as the little HKS turbo really want to go, but it is being choked!

So I want to change the pipework to metal to stop this from happening, but want to know if anyone has had any troubles, especially with the AFM playing up due to the pipework being changed?

Thanks for any info

Chris

Link to comment
https://www.sau.com.au/forums/topic/30014-afm-to-turbo-pipe-rb20-upgrade/
Share on other sites

nah, its been re-programmed so the boost cut is about 22 or 24 psi from memory, definatley pipe sucking shut

When its cold (weather wise) the rubber hose stays quite hard and isn't a problem, I have seen 1.3bar on the gauge in 3rd when it was cold, so its no boost/airflow cut, as they have all been lifted quite high to stop this

This rubber pipe shouldn't close over at those boost levels but installing a nice smooth metal pipe will improve flow. One thing to note is that the original pipe has a section in front of the turbos inlet designed to reduce turbulance in the pipe caused by the turbo. Not having this in place can cause minor airflow meter inaccuracy but will not do any damage.

Interesting, as I am 100% positive that its causing the problem, to what degree I am unsure but high boost is pretty well useless at the moment

What about using some coiled wire to wind inside the pipe? Has anyone tried this?

Yeah this is a sort of common problem. I know (personally) that the RB20 pipe won't support anymore that about 200rwkw, although they can fail at a fair bit less that this. Mine was replaced with a 3 inch mild steel pipe. It works really well, heaps of flow awersome unrestricted flow capabilities. It should definately be upgraded even if you are not having problems with the stock pipe yet.

Ok sounds like it would be best to replace it, as at the moment with 1bar its making 200rwkw, so I am guessing with 1.2bar its just to much vacum for the poor old rubber pipe to handle! Should be a good upgrade either way, I'll keep everyone posted of the results

Can anything be put in the new pipe to replace whatever it is in the standard pipe to reduce the turbulence or is it not worth the hassle....

After reading this i am considering doing the same to my car... 3" mild steel from air-filter to turbo... does it require any other modification....???...

Just want to know if anyone has done this and how effective it was

especially with the AFM playing up due to the pipework being changed?

Well if your pipe is getting sucked shut, then it would be very effective to put in a pipe that doesnt get sucked shut.

And as for AFM, no worries, the AFM would be before your pipe starts anyhow :(

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

    • Old Son, did you re-use the Holden ABS in the new shell or try a different module?
    • Yeah, nah. I had the actuator rod off it today. The arm will not move at all. Neither out, nor in. Yeah, you'd think so, but I've been thinking about that. Even when the actuator rod fell all the way off at the beginning of this saga, it would build more boost and faster in lower gears than it would in higher gears, and you'd think that that was the opposite of what should happen. But I strongly suspect that there is a thing with the gearing getting the revs to rise faster, that there must be some transient effect with the gas flow rate rising quickly, that you don't get with the more steady state case of the higher gears. Keep in mind - the gate is not shut in either of my weirdnesses. So things are not "normal". We normally think about a turbo spooling up (below the wastegate target) with the gate shut. I have all sorts of mental models running now where the gate is a little bit open, and having it stuck open allowing gas out while it should be going through the turbine has all sorts of weird effects (in these mental models). I'm thinking in the higher gears, the ex mani pressure builds to the point where enough gases spill out the wastegate to just prevent the pressure rising much more at all, or just creeping up, all the whole the revs are increasing and getting closer to the point where a gear shift becomes necessary.
    • Is it possibly wastegate actuator itself is sticking, or even the rod to flapper? Otherwise I reckon things are getting a bit rusty/worn   Also odd it won't boost in 3rd to 5th, but will in 1st, I'd expect the other way around with it slightly open as there's more time on your way to redline for it to spin up
    • Does anyone know ow what these two plugs are for and if they should be unplugged? Just put the dash back together and can't remember if these were plugged in before or unplugged! (Blue and white plugs) 🤦🏽‍♂️
    • Did some FASTing ...got the impression that the actual part# was a moot point ; seems all of these hardlines for coolant are discontinued/NLA... like, I take it you're after the hardline that bolts onto to the manifold...that's NLA according to amayama & nengun .... ...just to clear up some confusion, they typically mounted the AAC valve to the intake manifold somewhere near a coolant passage, so the body of the valve heats up & holds it open when engine's up to temp - no coolant flows through the valve, it's a mechanical, thermal connection.
×
×
  • Create New...