Jump to content
SAU Community

Recommended Posts

Hey all ! I'm new on here and to my to my nearly stock R33 gtst S2. I got an issue with it, when I put my foot down and give it some, the stock boost gauge on the dash never goes to the max of 7 psi, more like a steady 3- 3.5psi. The turbo is leaking a bit of oil and I had the car serviced and checked for vacum, intercooler leaks etc. Is it the turbo thats gone? any ideas? Thanks heaps.

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/
Share on other sites

Hey all ! I'm new on here and to my to my nearly stock R33 gtst S2. I got an issue with it, when I put my foot down and give it some, the stock boost gauge on the dash never goes to the max of 7 psi, more like a steady 3- 3.5psi. The turbo is leaking a bit of oil and I had the car serviced and checked for vacum, intercooler leaks etc. Is it the turbo thats gone? any ideas? Thanks heaps.

Have a look at the factory boost gauge, notice how it says "x100 mmHG". That stands for "millimeters of mercury" ... IE, it's not measuring boost in PSI.

The 7 on the gauge is actually about 14 PSI, therefore in stock form it should go about half way to 3.5, so everything it hunky dori!

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1498160
Share on other sites

Thanks for that Ionos! ;) Another great thing i found out yesterday when my car got serviced, I had no air filter in it at for days since i bought it, and I've been driving it :( any possible issues or damage it could have caused ?eg. air flow meter? What should I do now ? Thanks heaps.

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1498635
Share on other sites

Thanks for that Ionos! ;) Another great thing i found out yesterday when my car got serviced, I had no air filter in it at for days since i bought it, and I've been driving it :( any possible issues or damage it could have caused ?eg. air flow meter? What should I do now ? Thanks heaps.

I wouldn't worry about it, unless you've driven through a lot of dust, dirt roads etc. If it was just normal road driving I'd say you'll be fine.

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1498801
Share on other sites

Yea i hope its all ok. What ill do is clean the whole airbox and get a soft brush and clean the air flow meter from the outside. I guess if dust and dirt got in the engine it will make my new oil black very quickly right ? So i guess i would up for another oil change.

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1498827
Share on other sites

Yea i hope its all ok. What ill do is clean the whole airbox and get a soft brush and clean the air flow meter from the outside. I guess if dust and dirt got in the engine it will make my new oil black very quickly right ? So i guess i would up for another oil change.

Use electrical contact cleaner to clean the AFM, comes in at blue and white spray can.

Not sure about the oil thing ...

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1499466
Share on other sites

I doubt it'd make a huge difference - unless you've been driving through a dust storm - or on country roads..

As for the boost gauge - yeah should sit at about unde 1/2 when <4,500 - than @ 4,500 it'll go to about 2/3's..

did you know the car goes from 5psi to 8psi from 4,500 rpm onwards?

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1499495
Share on other sites

I doubt it'd make a huge difference - unless you've been driving through a dust storm - or on country roads..

As for the boost gauge - yeah should sit at about unde 1/2 when <4,500 - than @ 4,500 it'll go to about 2/3's..

did you know the car goes from 5psi to 8psi from 4,500 rpm onwards?

And that you can make it go in high boost mode at all RPM's by doing the following:

http://www.skylinesaustralia.com/forums/in...showtopic=42895

:rofl:

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1499537
Share on other sites

Yeah i heard that boost change as rpm rises. Everyone keeps telling me that since i bought the car and drove it around with no filter i could have picked up a rock or some other crap which went straight into the turbo and stuffed up the blades or it could be the coil packs thats causing low boost.

Should get a workshop to take off the turbo, get it checked and if it is damaged go back to the guy who issues the RWC or the seller? :(

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1500431
Share on other sites

If you say your turbo is shot (like you did in the 1st post :() then you'd need a new turbo, but from sounds of things the other guys answers have helped. But if oil is leaking from the turbo... that isn't a good thing!!! should get it checked out and fixed!!!

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1501731
Share on other sites

Well thanks for your help guys. I got a workshop to look at the car next week and dyno tune it for me, it looks like the stock boost controler isnt connected properly, im hoping that fixing that will end the issue.

BTW i still hear different stories about the stock factory boost guage on the dash board, is it in PSI or BAR, as in max on it is 7 PSI or 0.7 BAR ?

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1502999
Share on other sites

Ionos already posted the right story it is mm of mercury not PSI or BAR. The boost you are describing is the standard factory boost.

Re the filter, pull the airbox and AFM off the car and clean them with Brake Cleaner, then reassemble with a filter this time. If you got it from a dealer without a filter it is time to go abuse them.

Dirt doesn't get in with the oil if you have no air filter, it goes straight into the combustion chambers where it can really mess up the bores of your engine. Its too late now any damage will be done so just put the filter back.

Link to comment
https://www.sau.com.au/forums/topic/82678-boosting-problem/#findComment-1503672
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


  • Similar Content

  • Latest Posts

    • This is awesome.     
    • Thanks for the quick replies guys its appreciated. A small extension was welded onto the standard 6boost external gate pipe which you can see where the pipe goes from black to stainless just below and to the right of the rear housing in the first picture. Overall I would say the flow is pretty good other than 6boosts choice to come straight off the collector at a decent angle.. Not sure why I went with two valves, I originally replaced the stock twin bovs with the GFB when I had the twins on. When I purchased the EFR it came with the Turbosmart Kompact BOV so I figured that would be a better option than the stock EFR Bov. I don't believe the Turbosmart BOV is adjustable? When I get the spike and then sudden dip in boost pressure, the turbo speed does drop as well. Stock head size wise however I believe it has Neo Turbo springs and a Neo Turbo intake camshaft and an aftermarket exhaust camshaft in the vicinity of 260 degrees. We didn't try a different MAC valve, we tried two different ways of plumbing it and we also tried removing the mac valve entirely and just having the boost source from the turbo directly connected to the wastegate and it still spiked / dropped and exhibited the same behaviour. Standard R33 GTR 5 speed tansmission. I'm running a Haltech Elite 2500 and can provide some logs if you. I understand what you're saying in that it looks like an auto plot however no, it's still a manual and it just has a lot of torque down low, for all intents and purposes it's a very impressive street car. I've attached a photo of the quickbitz dyno plot which was when the only difference is I was running -5 twin turbos with a mac valve. As you can see theres a decent dip in AFRs between 125kmh and 135kmh. Our problem now is not that the AFRs are dropping, just the boost pressure is dropping, however it is evident in the same RPM range of the map, coincidentally or not.
    • What transmission are you running?  It's a bit tricky with the scaling, but at face value the power "curve" looks more like a "line" which is a bit odd... basically a lot more like a dyno plot I'd expect with a highish (compared to a factory auto) stall torque converter type setup. If this is running an auto then this kind of boost control challenge is definitely a thing, the rpm scale on the dyno doesn't reflect what the engine is actually doing (unless the dyno has access to the engine's ACTUAL speed electronically) and what you'll get is a big rpm flare up as the engine torque launches past the converter pump's ability to resist torque at that rpm, then as the converter starts picking up rpm it will kinda even out again and the engine rpm will pick up more steadily. The trick with this "flare up" is if it's kinda near the boost threshold for the turbo then the engine's airflow requirements to maintain the previous boost level will outrun the turbo's ability to supply that boost - so you end up with a natural flattening off, if not dip when that happens.   If you are running closed loop, or even tune the "feed forward" wastegate duty cycle to deal with that rpm spike then when the engine starts settling to a more typical climb you'll actually have a situation where the gate is "too closed" and boost will run away for a bit, then have to pull down again.      It's not trivial to get this perfect as most boost control systems are generally expecting more predictable engine rpm rates of change, but if you *know* that's whats going on then you can at least "accept your fate" and realise getting that area perfect is kinda chasing your tail a bit, and assume that if the rest is working sensibly and the spike/dip isn't completely uncontrolled then you should be good. Sorry if I've gone off on a tangent, but the dyno plot and boost control behaviour look a LOT like what I've seen tuning autos in the past. What ECU are you running? Could possibly be convinced into looking at logs if I get too bored this weekend haha.
    • A few things that seem a bit off here. - why is there 2 BOV’s?  - the turbo smart BOV on the compressor housing, is it turned up ALL the way? I have seen this become an issue on old man Pete’s car. It would push open and recirc, turbo speed would rise and the boost pressure would do weird things. - stock head? Does that include springs? - tried a different MAC valve? Is it plumbed correctly?
    • Photo of manifold showing gate location? I mean, it's 6Boost, so we probably shouldn't be worrying, but always wroth knowing what the layout is. Plumbed back to atmosphere? Or into the dump?
×
×
  • Create New...