Jump to content
SAU Community

Rb26 Twin Turbo Shuffle/surge

tommis85

By tommis85,
in Engines & Forced Induction

 Share

Recommended Posts

  • Replies 126
  • Created
  • Last Reply

Top Posters In This Topic

Popular Days

Top Posters In This Topic

Popular Days

tommis85 Mentor

tommis85

Posted
  • Author
Posted

I've done heaps of divided turbo pipes, they do work but having done so many I also found a trick with the divider plate.

I leave a small section of the front turbos air path in plated, it allows some of the front turbos air to swirl around into the rear turbos path.

A customer of mine who is a fluid scientist type guy explained how making the front turbo swirl around the inside of the pipe before merging with the rear turbo helps promote a lamina flow and draw the air away from the compressor housing thus reducing the shuffle.

The mod does seem to improve the issue on all the cars I've ever done one for.

Can't hurt to give it a go.

Risking,

So if mine was to shuffle for some strange reason (people say it should be OK)....then to what level would the TT pipe mod cure the shuffling? Would it still be there a little bit or would it completely disappear?

tommis85 Mentor

tommis85

Posted
  • Author
Posted

Everyday I'm shuffling :D lol sorry had to throw that one in...

I've currently got t517z turbos and no TT pipe mod, no shuffle

I had the impression shuffling comes from bigger turbos (gtr-s, -10 etc)

LOL I've been waiting for that :D

Yeh same here. It's meant to happen with big efficient BB turbos that spool up a bit too much air down low and cause surging and stalling out of each other in a seesaw/back and forth fashion. That's how I understand it anyway :P Sort of similar to that shhh-shhh-shhh-shhh that it does when you back off the throttle very slowly at lowish RPM and on boost. ....i think.

I'm thinking I'll be fine.

Piggaz Grand Master

Piggaz

Posted
Posted

Everyday I'm shuffling :D lol sorry had to throw that one in...

I've currently got t517z turbos and no TT pipe mod, no shuffle

I had the impression shuffling comes from bigger turbos (gtr-s, -10 etc)

What ECU do you have?

R31Nismoid Grand Master

R31Nismoid

Posted
Posted

Ah damn, so there's probably a 50-50 split of people who've experienced shuffling and those who haven't with -9's

Ah there is one person in the thread, everyone else hasn't had an issue.

Not sure how that is a even split.

tommis85 Mentor

tommis85

Posted
  • Author
Posted

newb time... what exactly is shuffling and i'm assuming it's a bad thing from how this thread is referring to it?

As far as I know, shuffling is a thing where the two turbos will try to stall each other out down in low rpm ranges because they're creating too much air than what the engine can swallow. Both turbos are trying to force more air into the one overhead collecting pipe and that pressure will not always go to the intake mani but back down the other turbos xompress

tommis85 Mentor

tommis85

Posted
  • Author
Posted

Ah damn iPhone!

....was say that it will instead go back down the othe turbos compressor out let thus causing it to momentarily stall out. It's meant to happen with bigger, efficient bb turbos where the two turbs create too much boost down low...similar to surge. It's meant to give off a shoo shoo shoo sound when it happens...hope that helps ;)

Don Dada Mentor

Don Dada

Posted
Posted

I was thinking shuffle would happen easier with the smaller BB type turbs like the -7,-9 where they make boost very early in the rev range, say 2k-2.5k and the engine just simply cannot ingest that amount of air, and with the oem journals and the -5,-10 that do not start to make positive pressure so early it would not really be a problem.

With the -9s crusing along on 5th flat roads, just easing on the throttle at 2k ish is enough to make +ve pressure and you get shuffle. Ive never driven a car with -5s, but under the same conditions, does it make +ve pressure to induce shuffle?

tommis85 Mentor

tommis85

Posted
  • Author
Posted

I was thinking shuffle would happen easier with the smaller BB type turbs like the -7,-9 where they make boost very early in the rev range, say 2k-2.5k and the engine just simply cannot ingest that amount of air, and with the oem journals and the -5,-10 that do not start to make positive pressure so early it would not really be a problem.

With the -9s crusing along on 5th flat roads, just easing on the throttle at 2k ish is enough to make +ve pressure and you get shuffle. Ive never driven a car with -5s, but under the same conditions, does it make +ve pressure to induce shuffle?

That's all very true, just curious why in this particular thread you're the only one experiencing these problems? The majority seem to say that there're no issues with the smaller turbos in the GT2860 range.

Don Dada Mentor

Don Dada

Posted
Posted

Bearing in mind every set up is different and there are many factors that have to be considered eg. actuator preload(mine are f*ck tight) boost controller settings and as some have said tuning.....and hell, diff ratios for all I know

Also mine is not in a gtr, but everything is set up as normal beside for a 2.5" hot pipe from TT pipe to intercooler which I guess could be contributing.

Either way no biggie. There are some here who get it with oem turbs....

luke gtr Grand Master

luke gtr

Posted
Posted

I've got gtrs, shuffle under higher load.

Went to a bigger exhaust, problems better.

Getting a modded TT pipe from risking soon, will report how that goes.

I've got a set of hks gt-rs on my 2.6l. 441awkw @ 24psi no shuffle at all. :)

Have had hks 2530s and no shuffle either all of this with no modification to twin turbo pipe or any other..

How did you get it to stop?

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

    • Sean'O
      3D printing fun

      By Sean'O · Posted

      No worries at all 🫡 I think the most satisfying things to make are the little bits that are just impossible to find or they're no longer manufactured. Generally I always try to replace parts with OEM wherever possible. This little project is also great because it'll never see the light of day, but strengthen these brackets so it's not just relying on the little standard screws in the headlight plastic. As soon as I saw the standard brackets and screws I thought, "well I'm not going to install with just the screws, the plastic tabs will just snap off". It's crazy how expensive everything has become yeah. But I suppose that's supply and demand; granted it's a lot easier to get brand new genuine parts these days which is fantastic 😊, I don't have to get totally reamed at the local Nissan dealer ha ha We sure are lucky we have all these manufacturers making parts these days, a few really great Australian companies too like Platinum Racing Products and Fit Mint Automotive, what a time to be alive ❤️ . I've got my eye on the RB26 head by PRP as mine has a very fine hairline crack, so that'll need to be addressed some time in the future. If you have any requests or odd things to make feel free to let me know and I can have a crack at making replacement parts ✌️
    • Duncan
      3D printing fun

      By Duncan · Posted

      Thanks for sharing this, and BTW if your headlights are in good condition they are worth thousands....you might want to consider replacing them with brand new LED ones like this (https://www.nengun.com/78works/full-led-headlights-r32-skyline) and making enough profit to buy a house in Sydney
    • Duncan
      R32 GTS (RB20DE) clogged cat

      By Duncan · Posted

      I'm not sure what sort of shops are nearby, but I'd expect any reasonable exhaust shop could put a cat in it that will not restrict the power that engine makes. Otherwise, if you want to remove it, short lengths that replace the cat are readily available online, search for "de-cat pipes" or "test pipes"  
    • Sean'O
      3D printing fun

      By Sean'O · Posted

      Howdy friends, So another weird one today, I was looking into replacing some broken clips holding the front grille for the R32 GTR (part number 01553-03831), and noticed the brackets which are supposed to hold the grille in place were also missing 😑. I do recall seeing this issue many years ago, but didn't fix it at the time. A quick look on eBay and I was able to find the genuine brackets, along with all the screws which suited the headlights (part numbers 26042-08U05,26092-08U05). Happy days!....  Once they arrived however there was an extra nut in the packaging which implied that there should also be a bolt or a stud, and sure enough, after a bit of searching I found this thread from 2013, and @Ants clearly shows a stud should be present. Reading around a bit more, it's possible the headlights on my car are the "povo pack" headlights as mentioned by @funkymonkey in this thread way back in 2008. This could explain why the studs are missing on my set of headlights. Looking at the headlight diagram I wasn't able to see a suitable part number for the stud itself. The headlight did indeed have a recess that looked like it would accept a stud, but interestingly no thread or anything obvious how the stud would be affixed to the headlight, I suspect it may have been glued in, press fit, or melted into the plastic at the factory. Another member may be able to clarify if they happen to have a genuine set of N1 headlamps. The only thing we have to work with within the recess is a keyway which likely is there to prevent the stud from rotating within the recess. In any case, back to 3D printing, I put together a model which acts like a pug with a friction fit inside this recess, making use of the keyway so it doesn't rotate while tightening a bolt. Printing in TPU will allow it to slightly swell making a nice snug fit without cracking the part. I've designed the adaptor it to accept an 20 mm M6 bolt (stainless with a cap head in my case), as opposed to the standard M5 stud and I made use of the standard galvanised split washer that came with the genuine brackets from Nissan. Once the bolt and screws were all in place, giving the bracket a gentle shake gave the classic "shaking the car" feeling, very solid, which gives me confidence this is going to be able to hold on much better than the janky solution which seems to have been here for the past decade or so. Overall I'm really pleased with how this turned out and maybe there are more people out there running these headlights without a centre stud at all! Link to the freely available model on Printables: Click here Regards, Sean  
    • GabsReDeal
      R32 GTS (RB20DE) clogged cat

      By GabsReDeal · Posted

      Hey everyone, This is my first post apart of the introduction. I tried searching a bit on the forum but couldn't really get a straight answer. I got the car to my mechanic as I felt it being weak. It seems that it was missing on two cylinders due to the injectors. I had all my injectors clean and the car runs much better. The mechanic also confirmed my suspicions that the cat is clogged and needs to be tackled asap. The cat rattles a bit and the hot exhaust warning frequently lights up when driving after getting the injectors clean. In my introduction I was asked about what modification I might be interested in and mentioned a cat delete. From what I was told, this is not really beneficial on the RB20DE and there are more cons than pros.  Could perhaps anyone give some suggestions on what the best course of action would be since the current cat is toast and needs to be removed/replaced anyway? I can also sometimes smell a strong smell of fuel, but I'm not sure if this is related.
×
×
  • Create New...