Jump to content
SAU Community

Recommended Posts

Hey everyone,

Got an issue with the GTR, curious if anyone else has had the same...

On low boost I was loosing oil pressure..... it would drop from 5-4 bar when giving it hard on gate pressure.... now I took to a shop and I got a Mechanical gauge on it..... we topped up the oil as it was low.. and now it only looses pressure on high boost where it drops about 20 psi... I am hoping this is not a engine out job, but assuming pump, or engine damage the engine runs fine as it is... So I dunno seeing as its only on boost I am hoping its just a turbo issue....

It is fine Free revving, No engine noise, oil pressure is fine, no smoke... the night before I had 2 intercooler pipe blow offs when I was on the 2 step at willowbank.... assuming this caused it.

There was a fair bit of oil in the cooler pipe not sure if turbo is ok, checking it tomorrow.

Has anyone had it where the oil pressure has dropped on boost?

Link to comment
https://www.sau.com.au/forums/topic/378802-oil-pressure-drop-on-boost/
Share on other sites

  • Replies 69
  • Created
  • Last Reply

Top Posters In This Topic

You got an aftermarket sump baffle, not the stocker...

My old car would drop off when accelerating in the first 3 gears. Only had a stock sump baffle.

My aftermarket oil pressure gauge showed the drop, and that was with 5l of oil in the sump.

After that I always put 6litres in every oil change in GTR's and that seems to stop the problem, before it's too late.

When I had the 26 apart, I measured how much oil you could put in the sump without it getting whipped up by the crank.

6litres fills the sump to the brim. When the engine is running a certain amount is in circulation (in the oil galleries, oil pickup, head, turbo's etc) and it ran with no dramas. I had done that for years, and also do it to my 34. Never killed an engine, just gearboxes!

The oil I use comes in a 6 litre container so no problems for me :)

Another point, the stock oil pressure gauge is not quick enough to tell you that you are losing oil pressure for those few brief seconds, when it does it's definately too late! spin a bearing anyone??

Cool stuff.... cheers for the info

Just found a massive thread on the forum where the general concensous is to over fill by a litre which would take it to just under 6L...

what oil do u buy that comes in 6L btw?

How much power do ur 26 have and how often did u give it some stick?

Edited by GTR_JOEY

No worries!!. I just run nulon 10W40 and change it every 5000km or less. Also run a relocation kit and oil cooler.

See my sig for the 32.

34 is currently on 294 all wheel kw, with more soon...

It's mostly cruising, with the odd twisties thrown in with 7000RPM plus sometimes.

Big thing is servicing and keeping the little things in check with these cars.

No worries!!. I just run nulon 10W40 and change it every 5000km or less. Also run a relocation kit and oil cooler.

See my sig for the 32.

34 is currently on 294 all wheel kw, with more soon...

It's mostly cruising, with the odd twisties thrown in with 7000RPM plus sometimes.

Big thing is servicing and keeping the little things in check with these cars.

Do you drop the oil in the oil cooler as well, when you do your oil changes?

Yes I have....although I think it was load, not boost. I spun a big end bearing shortly after. seriously.

I dont like that idea :( lol.

You got an aftermarket sump baffle, not the stocker...

My old car would drop off when accelerating in the first 3 gears. Only had a stock sump baffle.

My aftermarket oil pressure gauge showed the drop, and that was with 5l of oil in the sump.

After that I always put 6litres in every oil change in GTR's and that seems to stop the problem, before it's too late.

Stock baffle. I am going to try the overfill idea, hopefully that solves the problem but yeah... do you know what causes it?

You got an aftermarket sump baffle, not the stocker...

My old car would drop off when accelerating in the first 3 gears. Only had a stock sump baffle.

My aftermarket oil pressure gauge showed the drop, and that was with 5l of oil in the sump.

After that I always put 6litres in every oil change in GTR's and that seems to stop the problem, before it's too late.

My Rb26 is rwd and it surges like a bitch if you fill it to the normal H mark on the dip stick, so I for you guys with a little more grip of the awd, it would obviously be worse.

When I fill it with 5.5L it sits just above the H itself on the stick, but it still surges a bit, but I think it should be ok for normal street duties....Track will definately use 6L.

EAT26...Does it drop only on hard accel.? Or does it do it too when already in motion and bringing up the revs?

Ccome sunday we will sort it out my mang

:thanks::3some::wub:

My Rb26 is rwd and it surges like a bitch if you fill it to the normal H mark on the dip stick, so I for you guys with a little more grip of the awd, it would obviously be worse.

When I fill it with 5.5L it sits just above the H itself on the stick, but it still surges a bit, but I think it should be ok for normal street duties....Track will definately use 6L.

EAT26...Does it drop only on hard accel.? Or does it do it too when already in motion and bringing up the revs?

Its dropped only when Highboost at 21psi is introduced and drops 1 bar on the internal gauge.

Your not flooding the head are you? This would lower the sump level and could cause issues with surge? More oil may not help if its all being pumped up.

Just a thought?

Honestly do not know lol.

You seem to be pulling lots of G's!!! in acceleration.

About the only way to fix would be:

In order of cost:

Turn the boost down :no:

Trapdoor sump baffle, eg tomei,(stops some of the oil from going to the back of the sump, away from the oil pickup), stock baffle is not that effective, except for stock vehicle...

sump extension with sump baffle (deeper sump to keep oil pickup sucking oil, not air and also holds more oil)

dry sump set up, now we are talking $$$$ (race car stuff, running semi's, slicks, high HP, G's).

Feel free to add any other ideas.

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

    • GCG is a good company, they're a major distributor for Garrett in Japan as well.
    • Nah, OEM washer bottle and brake fluid reservoirs are fine I don't know what it is with the plastic that Mazda used, some plastics, like the washer bottle and brake fluid res are fine, and still look new after 20 years use, where as the coolant expansion tank, and PS reservoir, that I replaced with new OEM items when I first got the car, turned yellow and started getting brittle a few years later If the dirty yellow stained plastics didn't trigger me there wouldn't be an issue, but they did, much like the battery bracket....... Meh As for going back to work full time to support car stuff, nope, why, because I own a Mazda NC MX5, not a Nissan R series Skyline 🤣
    • I've never heard of CJ-motor, so can't advise you on them. I'd just go straight to GCG for a GCG highflow though. Seems no point to use a middleman. I'm somewhat surprised that the price on the CJ site is lower than the GCG retail price. Even though CJ would get a discount of some sort, you would hardly expect them to give up so much margin. Maybe the price is out of date? Having said that "I'd go to GCG"...when I did my highflow, I went to Hypergear. I did this https://hypergearturbos.com/product/rb25dethighflow/#tab-dyno-results with the R34 OP6 450HP profile. With the BB centre (extra $400) and intially with the standard boost actuator, but I eventually got him to send me the high pressure one when I got to the point of being able to actually use it. Ends up costing the same sort of money as the GCG highflow, but this is, of course, the turbo that I KNOW has a shorter length core and so moves the comp cover rearwards. The GCG apparently doesn't do that. My mechanic also swears by the GCG highflow, given that we have another turbo rebuilder who does something essentialy the same as theirs, using Garrett wheels. He says it stands up at really low revs and makes good power. I haven't pushed my HG highflow past ~240-250rwkW yet (should have a little more in it, but unclear how much) and it does have a fairly gentle boost ramp. OK, it's much better now that I have gotten my boost controller tuned up on it.  A lot of my earlier unhappiness was because I couldn't keep the wastegate flap as closed as it needed to be (including some mechanical issues). I'd still prefer it to boost up nearly as quickly as the stocker, and it certainly a bit slower than that. So maybe the GCG one is worth the first look (for you).
    • Ok thanks 🙂 I will higly consider this. Any "known" company for a good reviews and experience to send that off? Is that CJ-motor good one? Or go straight to GCG site? I need to use VPN to even find some of those "shops" let alone access them 🙂 
    • You can literally put in as much WMI as it takes to quench the combustion totally (and then back it off a little, obviously), and it will keep making more and more power. The power comes from the cooling effect of the water (and the meth) and the extra fuel (the meth, which also has massive octane). It is effectively exactly like running E85. One might be slightly better than the other, but they are damn close. But with either you can lean on the boost or the timing (or both) waaaay more than with just petrol and the results are similar. Here's the first thing I googled for an anecdotal bit of evidence. Can't access the attachment without being a gold member, but it is there for the getting if able to, or searched up elsewise perhaps. https://www.hpacademy.com/forum/general-tuning-discussion/show/wmi-vs-e85/
×
×
  • Create New...