Jump to content
SAU Community

M35 Banjo Bolt Drilling For Highflows

scotty nm35
 Share

Recommended Posts

scotty nm35 Grand Master

scotty nm35

Posted
Posted

I have always suggested to drill out the banjo bolt in the block (that supplies the turbo with oil) to around 2.5mm once a highflow bush core turbo is installed. After the recent failure of a highflow due to oil starvation I did a flow test of the line at idle and found there wasn't enough oil flowing, even with the line/banjo disconnected. Suspecting a blockage in the block feed I checked another car and surprisingly found the same thing, the oil was only dribbling out. I checked on my spare engine and found in the sump another oil feed line, with two more 1mm restricted banjo bolts that feed oil to the external line. So it seems there are actually 3 x 1mm restricted banjo bolts as stock. Nissan definitely thought the oil pressure was way too high for the standard ball bearing turbo...

It also explains why the oil feed is so commonly blocked. On this car I have opened up the two sump banjo bolts to 2.5mm and approximately tripled the oil flow to the turbo, hopefully enough to supply the bush core with surplus. It was a bit wet today to take pictures but I will organise some next week, it's not a difficult job other than taking the pan off.

I am not suggesting everyone should rush out and drill these two extra banjo bolts out as I have, but Hypergear and I have agreed I should do this mod to all further turbo installs, to make sure not only the holes aren't blocked, and won't easily block again, but that there is sufficient oil flow to his turbos. I am also thinking about running braided lines and a filter inside the sump to replace the hard line, as it's easier to get to than the block mounted line, and would make sure no further blockages would occur. Not sure if it's warranted yet.

scotty nm35 Grand Master

scotty nm35

Posted
  • Author
Posted

Yep, Stao ships his turbo's out with a new banjo to suit the smaller thread in the CHRA. No idea why he doesn't simply tap it out, surely it's easier than cutting a banjo on the lathe... Anyway, what you did is fine Chris, just pointless if there are still two more restrictors. I would definitely suggest drilling them next service. ;)

scotty nm35 Grand Master

scotty nm35

Posted
  • Author
Posted

No worries guys.

I have had a few questions on this, one being can there be drawbacks. I personally don't think it will affect oil pressure to the engine, as only a small amount still flows to the turbos, even after drilling the banjos. I would definitely like to check the difference in oil pressure between my engine and this one but I have no gauge at the moment, and it is quite hard to read pressure without the adapter plate under the oil filter. I will check it at a later date.

Another question was, why aren't other turbo's blowing up. I believe there is JUST enough oil flow to keep the turbo's spinning, any partial blockage may be enough to do damage imo. Drilling the banjos out will give the turbo some leeway with oil requirements.

Here is the oil line we are discussing...

post-63525-0-89135900-1375444037_thumb.jpg

post-63525-0-28664500-1375444051_thumb.jpg

gleeson Community Regular

gleeson

Posted
Posted (edited)

No worries guys.

I have had a few questions on this, one being can there be drawbacks. I personally don't think it will affect oil pressure to the engine, as only a small amount still flows to the turbos, even after drilling the banjos. I would definitely like to check the difference in oil pressure between my engine and this one but I have no gauge at the moment, and it is quite hard to read pressure without the adapter plate under the oil filter. I will check it at a later date.

Another question was, why aren't other turbo's blowing up. I believe there is JUST enough oil flow to keep the turbo's spinning, any partial blockage may be enough to do damage imo. Drilling the banjos out will give the turbo some leeway with oil requirements.

Here is the oil line we are discussing...

Edited by gleeson

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

    • zillah
      Recommendation for engine oil funnel spill free

      By zillah · Posted

      Dear folks My family members have 4 different cars : Triton 2015 and Corolla 2011 and Mazda3 2012 and Hyundai Elantra 2014 Looking to buy engine oil funnel spill free What I found are are below  https://www.amazon.com/gp/aw/d/B0BBTTJNKX?ref=ppx_pt2_mob_b_prod_image&th=1 https://www.ebay.com.au/itm/145553221359?srsltid=AfmBOoqYBU6Ptw0LU_bAp_k67U3qkF97HHvePkA7iHZw8vUmiwoIRaRr https://www.amazon.com/gp/product/B09X23TCS5?th=1 Is there a funnel with attachment that fits most cars ? Don't mind to spend for a decent quality  Thx  
    • Kinkstaah
      Boost cut after swap(RB25DET NEO) R34

      By Kinkstaah · Posted

      Stock ECU (or more accurately stock tune) absolutely refuses to go over 10psi and behaves like you have seen. The Nistune is the same if it is the stock tune. If the Nistune chip has been tuned, the resulting tune could be literally anything for any combination of parts. The Nistune just makes the stock ECU Tunable.
    • Kapr
      Boost cut after swap(RB25DET NEO) R34

      By Kapr · Posted

      So stock ECU does not like anything above 10 psi?  That Nistune one is just for "try" if it will be any different, I know it need to be tune for that. I know but YOU may know about these problem but i/we dont. They few little Skylines here let alone people who know anything about tham so that is why iam asking here  
    • Duncan
      V37 Radiator removal

      By Duncan · Posted

      So now we have a radiator with no attachments whatsoever. It lifts up with a particularly tight spot between the drivers side air box mount and the lower radiator outlet, but if you've got this far you will sort that too. This is the lower mounts with the rad out so you can see where the rubber bushes go, it is a straight shot upwards Done! Assembly is the reverse of disassembly, with blood less likely to be shed.
    • Duncan
      V37 Radiator removal

      By Duncan · Posted

      Right, onto the second last trick. The Air Con condenser is mounted to the front of the radiator and stays in the car when the radiator is removed. There are 2x 10mm headed self tappers holding the top of the condenser to the radiator, remove those The bottom of the condenser is attached to the radiator with clips. You need to lift the condenser out of those clips and clear (up, then forward). f**ked if  could work out how to do that last bit with the front bumper on. I hope you can, and you share the trick.  Bumper removal probably deserves its own thread one day once I've recovered the will to live, but basically you need to remove the wheels, front inner guard liners (clips and 10mm headed bolts), the self tapper between the guard and the bumper at the rearmost point of the bumper (same as an R32 that bit), any remaining clips at the top/front of the grill, an absolute bastard design with a plate that holds the top of the bumper above the headlight each side (only 1 bolt which is tricky to get to, but the plate catches 2 places on the bumper and must be removed....carefully!) and push clips between the bumper and guard under the headlight. If you've done all that you will be faced with wiring for the fog lights on both sides and in ADM Q50 RS at least, 4 nasty tight plugs on the driver's side for the ADAS stuff. So, the clips at the bottom look like this on drivers side (looking from the front) And on the passenger side (also from the front), you can see this one is already out Clearance on both of these are super tight; the condenser needs to move up but the upper rad support mount prevents that, and the radiator can't move down far because it is (rubber) mounted. Once you achieve the impossible and drop the condenser off those mounts so it does not stop the rad moving, you are good to go
×
×
  • Create New...