Jump to content
SAU Community

Recommended Posts

hey, just put splitfires and NGK iridium plugs into my skyline r32 gtst which has solved my missfire problems instantly :laugh:

but my next question is about the boost the car is running.

there is an aftermarket boost gauge installed on my car (previous owner) and when im flat chat accelerating in 5th the needle goes up to about 17psi.... could this be misreading?

i havent got an aftermarket boost controller so im interested to know how the car limits its boost levels?

not real cluey on this sorta detail unfortunately, any help appreciated!

mods include: FMIC, Cat Back 3" exhaust, otherwise stock

Link to comment
https://www.sau.com.au/forums/topic/147229-standard-r32-boost/
Share on other sites

Boost is regulated via the spring in the wastegate actuator. R32 GTSt's run 10psi normally but by freeing up flow in other areas (exhaust) you can gain small increases in boost.

Does it level out at 17psi? or is that all you let it get to before you freak out and shut it down?

i will check it again 2day, but off the top of my head the VAC is at about 20 on idle....

its only got the stock BOV on it (no aftermarket bleed valve), i will check bout the levelling out but yes it is a bit scary watchin the needle just keep rising.....wood be fine if i knew that the components could handle it, but like u sed it isnt exactly safe

will check back soon after lookin at a few more things 2day

Maybe check the wastegate vacuum hoses before you drive it again.. if it is rising past 17psi I don't think you actually wan't to let it do that to confirm it is a wastegate hose fallen off.. much healthier for your engine to check it first :dry:

i will check it again 2day, but off the top of my head the VAC is at about 20 on idle....

its only got the stock BOV on it (no aftermarket bleed valve), i will check bout the levelling out but yes it is a bit scary watchin the needle just keep rising.....wood be fine if i knew that the components could handle it, but like u sed it isnt exactly safe

will check back soon after lookin at a few more things 2day

By bleed valve I meant boost controller not BOV.

lol, well i drove it round today and tried not to push it, but i did give it a boot to check and it only goes as high as 17psi n peaks, VAC is 20 at idle....

will check the vacuum hoses n that 2moro but other than that what else could i check?

it doesnt have an aftermarket boost controller, should i maybe invest in one of these to limit the boost level?

thanx for all ur help so far guys

Bleed valve can only increase boost, can't decrease it. Sounds like you have a crack/split in your waste gate vac line acting the same way a bleed valve does. If its even remotely perished replaced it, if it gets any bigger itll boost infinitely and POP goes your motor.

What is odd though is normally the ECU will just fuel cut or the car would start misfiring badly at that sort of pressure, I really would not drive it until you have sorted the issue.

Pretty sure standard boost on an RB20DET is 10psi. Anyone want to back me up?:)

i will back you up. people look at the stock boost gauge and this yeah 7psi. the rb20 actuator doesnt open below 10psi. if you look at the gauge closely the gauge isnt measured in PSI. the gauge is in bar. 0.7bar =10.152642psi

fin... :)

Well on my aftermarket guage I get 9-10psi with only a cat back exhaust and a split dump (for some stupid reason it still has a stock front pipe and stock cat) so I would imagine it not being much more freed up than it was standard.

Have since put a Turbotech manual boost controller in and think I was hitting R&R around 14psi. I've dropped it back to 11.5-12psi and it seems to go better in the top end, doesn't come on boost as harsh though which was fun but then it didn't really go anywhere.

stock boost on a rb20 is def 10 psi!!! that is why when people buy rb25 turbos they put the actulator off the rb20 turbo to run 10 psi... def sounds like u have a split in the hose or something like that... or a faulty guage.

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

    • I refreshed the OEM injectors with the kit and connected it up. It now ideals okay even with the IACV removed. Driving still has the same cutoff issue like the 550cc injectors so the issue is somewhere else. I bought FPG's Fuel Pump Hanger. I will be installing it next, but it is not as straightforward as I thought it was with my limited wiring knowledge and no instruction on the specific model I purchased (FPG-089). I also got the incorrect billet clamp as I could not find info on the OEM sizing.
    • Stop looking at the garage floor, and turn the radio up a bit louder if there's any strange noises...
    • No. Turbo shuffle and surge/flutter are not the same thing. Specifically, on a GTR, turbo shuffle has a definite meaning. On a GTR, the twin turbos are assumed to be the same thing and to operate the same way, exactly. In reality, they do not. Their exhaust sides are fed and exhaust a little differently, to each other. Their inlet sides are fed and exhausted a little differently, to each other. Consequently, when they are "working" they are often at slightly different points on the compressor map compared to each other. What this means, particularly when coming on boost, is that one of them will spool up and start producing extra flow compared to the other, which will put back pressure on that other compressor, which will push the operating point on that other compressor up (vertically). This will generally result in it bumping up against the surge line on the map, but even if it doesn't, it upsets the compressor and you get this surging shuffle back and forth between them That is "turbo shuffle" on a GTR. It is related to other flutter effects heard on other turbo systems, but it is a particular feature of the somewhat crappy outlet piping arrangement on RB26s. There are plenty of mods that have been attempted with varying levels of success. People have ground out and/or welded more material into the twin turbo pipe to try to prevent it. Extending the divider inside it works, removing material doesn't. There are aftermarket replacement twin turbo pipes available, and these exist pretty mush purely because of this shuffle problem.
    • You can temporarily* use lock collars to keep it in place until you can do the bushes, back the nuts off, slide them in, snug back up. *temporarily is often for ever
    • Thanks for the quick reply. To be clear, when you say turbo shuffle do you mean turbo flutter "stustustu" or referring to something else? I had thought they were the same thing. When I wrote the post my intention was to say it wasn't a flutter/compression surge sound. My understanding was that a flutter sound would be occurring when throttle is released, whereas I can keep the throttle in the same position for this noise
×
×
  • Create New...