Rb26 Twin Turbo Shuffle/surge

[tommis85]

Just out of interest - found a video with some very intense shuffling...R33 on dynopack....skip to about 40 seconds into video..

[maclarenf1]

Just out of interest - found a video with some very intense shuffling...R33 on dynopack....skip to about 40 seconds into video..

so that's what shuffling sounds like .... F**** was thinking what the hell these guys are on about.... .going back to reading mode

[tommis85]

Yeh i reckon that could be quite annoying and other peeps would ask you every time what's wrong with your car lol!

I've never had it but I'm assuming it doesn't do much harm to anything...although I think someone on here said that it did make their car shudder a bit?

[Nee-san]

It's not good for the turbocharger.

[tommis85]

Yeh it would be like an most epic flutter of all time

[iplen]

Running-7s, had shocking shuffle, car is otherwise pretty much bog stock. The problem ended up being damage to the front of the exhaust cam, which was resulting in the ignition timing moving possibly 15 degrees. The other issue we found after replacing the cam was that the timing has to be set using a plug lead between the coil and plug on 1, not the loop at the back of the head.

Since fixing these 2 things I have only had it shuffle once, and was testing to see if I could get it, very gently lifting off on small throttle opening. Anyone getting shuffle I can not recomend strongly enough checking basics, like timing..

[tommis85]

Running-7s, had shocking shuffle, car is otherwise pretty much bog stock. The problem ended up being damage to the front of the exhaust cam, which was resulting in the ignition timing moving possibly 15 degrees. The other issue we found after replacing the cam was that the timing has to be set using a plug lead between the coil and plug on 1, not the loop at the back of the head.

Since fixing these 2 things I have only had it shuffle once, and was testing to see if I could get it, very gently lifting off on small throttle opening. Anyone getting shuffle I can not recomend strongly enough checking basics, like timing..

Wow that sounded pretty nasty what you had there! Well I'll be taking it down to one of the tuners at the coast like Mercury or Godzilla for a decent tune - the people round where I live have no idea on tuning imports, let alone 26's.

[DVS JEZ]

Iplen are u running the stock intake pipes?

[iplen]

Iplen are u running the stock intake pipes?

I am now, I had an aftermarket one but it was leaking, and didn't offer any obvious benefit until I read above about the mods to the turbo pipe, which a/m one had done. Does have an Apexi suction kit and HKS hard piping.

[tommis85]

Yeh I read that the stock intake pipework along with the AFM's etc creates enough drag to slow down the turbos down low thus reducing the shuffle affect. If you totally streamline the intake side and the exhaust side you give those buggers free reign down low - spin up way too fast! I think it's the sharp bends and the corrugations in the rubber intake pipes that do the trick....drag and turbulence galore lol

[DVS JEZ]

Ok the -7's i just installed and tune have slight shuffle on low throttle loads like slight incline etc has a restrictive 2.5inch cat and made 277kw on 18psi which then led to coilpacks dying on high boost. On 14psi it made 255kw

[tommis85]

Ok the -7's i just installed and tune have slight shuffle on low throttle loads like slight incline etc has a restrictive 2.5inch cat and made 277kw on 18psi which then led to coilpacks dying on high boost. On 14psi it made 255kw

Nice work! Yeh I ordered my -9's a couple days ago so might be fitting them on the weekend. So what sort of plumbing are you running - you got all your stock stuff still on there including factory BOV's?

[Hadouken]

That would be my mates car. He's got a intercooler hard pipe kit and other than turbos and dumps its stock.

I told him about that shitty cat. Haha.

[DVS JEZ]

We fitted (with alot of modifications) the NPower dumps from ebay.

Has atmo BOV's ad as hadouken said has a hard cooler pipe kit with stock intakes

[Hadouken]

Are those npower dumps heaps dodgy?

Lol his car must be much better than the 211kw lolz.

What do you reckon the end result would be with a new cat and coil packs?

[Deano 1]

the atmo bov's dont contribute to this???

[tommis85]

Are those npower dumps heaps dodgy?

Lol his car must be much better than the 211kw lolz.

What do you reckon the end result would be with a new cat and coil packs?

Hey just read your sig - I didn't know you have -9's 400 horsies at 18 pounds is quite a nice figure.

[tommis85]

That would be my mates car. He's got a intercooler hard pipe kit and other than turbos and dumps its stock.

I told him about that shitty cat. Haha.

Yeh I read on some other forums that it's the removal of the stock bov's and putting in a hard piping kit that does it. The BOV's do some interesting stuff....they actually open to almost half way when you blip the throttle to get some air into the engine quicker by bypassing the turbos. All this gear apparently also stops or minimises shuffle.

But I will know for sure soon as I'll be putting my -9's on with FULL factory intake and compressor to cooler plumbing.

[Hadouken]

Lol, hi mate. Yes I have them -9's, unfortunately shot to 320kw but afms couldn't keep up, so had to drop it back a peg.

Anywho.

Don't the Atmo bovs just screw around with idle and stalling? Not so

Much shuffle.

[tommis85]

Well, I've observed the bov's doing this myself...not exactly sure how much they influence shuffle down low...they do open down low so they would take some of the air away from the turbos (sucking it back thru the recirc pipe and stealing it before it its the compressor....but after running thru afm offcourse)

The reason why the stock intake piping reduces shuffle is because it generates so much drag inside it's piping (corrugations in the rubber piping, afm mesh etc etc) that it effectively throttles the turbos by just enough to stop them getting too far ahead of themselves which would cause shuffle (too much air for engine to ingest etc)