Rb26 Twin Turbo Shuffle/surge

[SiR_RB]

Everyday I'm shuffling 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)

[tommis85]

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]

Everyday I'm shuffling 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

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 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]

Everyday I'm shuffling 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?

[DVS JEZ]

What ECU do you have?

He's running an FC. But has no cam gears so its a little laggy still. Wouldnt expect shuffling from it

[R31Nismoid]

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.

[SS8_Gohan]

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

[tommis85]

I just meant in general Nismoid Yeh this thread looks promising and I reckon all will be sweet.

[tommis85]

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]

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

[Piggaz]

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

You wouldn't know, you have a decent ECU

[Blitz]

Got a photo Brad?

I'd like to see this too

[Risking]

I've got a couple of pipes at work I'll take a photo of on Thursday when I go back.

[destrukshn]

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..

Edited April 24, 2012 by destrukshn

[Don Dada]

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?

[destrukshn]

I would assume that you would usually compressor surge if the turbo is too big for the motor.

[tommis85]

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]

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]

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?

[Piggaz]

How did you get it to stop?

Got rid of the rubbish RS's. Would not go back to them if they paid me!