RB sound differences

[TTT]

All RB's sound slightly different to one another yet still sound similar.

Like most of the time, you can tell the sound of an RB25 exhaust note to an RB20.

however, the RB26 sounds different to all of them.

my question is what is it that makes it different?

It just sounds alot tougher than the other RB's.

so what is the reason for this?

At idle, or cruising on WOT.

they just sound ALOT tougher than the other RB's.

is it the fact that there are 2 turbos?

is it the individual throttle?

is it cams?

I understand that the exhaust system has a lot to do with it, but no other RB sounds quite like an RB26.

I don't want replies like "because teh GTR can neva lose" or something equally stupid.

This is a serious question on what gives the RB26 an angrier note.

[WazR32GTSt]

i would have thought it would have been mainly due to the fact that there are 2 turbo's and thus two turbines in the exhaust system.

plus the exhust design varies because of this.

but, this is just a thought and nothing more...

[Abo Bob]

I think also the solid lifters have something to do with it and displacement will usually give a deeper note too.

[Beer Baron]

i'd say the twin turbos would have fark all to do with it. like abo said a big part could be the solid lifters, multi throttles would also change the note. plus head design inlet and exhaust ports shape would have an effect.

[Ronin 09]

It does have 2x the exhaust discharge area, plus cams are more agressive, multi throttles.

predominately the exhaust discharge area and cams AFAIK

[TTT]

if capacity had anything to do with it, RB30's would sound tougher..

but they don't.

but the lifters, throttles and port shape...

not too informed on these..

anyone care to go into more detail?

SK?

mmmmgtir?

[TTT]

what do you mean by 2 x the exhaust disharge area?

2 turbos?

[Scooby]

All these differences contribute. That's why a Ducati sounds different to a VTR Honda, which is different to an RSV Aprilia. They are all twins and - different cans aside - the Ducati still has a distinct exhaust note primarily due to the valve train design. Hence the Desmosedici head engines sound different again to their predecessors.

[Ronin 09]

what do you mean by 2 x the exhaust disharge area?

2 turbos?

yup

[SLY33]

they (RB26's) just sound ALOT tougher than the other RB's.

sorry but ill have to flat out disagree with that!

i do definitly agree they sound different, and from my own description id tend to say they sound more "mechanical" in their note. I think you need to hear my 25 at full noise

From the 26's ive heard, i reckon the 25's have a "sweeter" and more "howling" note, and not as harsh sounding as 26's. As for reasons why, i think theyve all been covered. Of course exhaust systems are going to make each and every one sound different so i guess it comes down to personal preference.

its also very possible that i just havent heard a really nice sounding 26!

cheers.

[Cubes]

Any one who has changed thier turbo to a larger item will know how the exhaust becomes louder and more angry sounding.

I've heard RB25's that sound mighty tough. It simply comes down to the exhaust.

The RB30 sounds a little deeper than the rb20, it does sound nicer, especially if I jam the wastegate open it becomes much louder and brup brup sounding.

[SLY33]

spot on cubes!

[GTRgeoff]

Since converting the RB25 to a GTR34 twin turbo setup, the difference is in the fact that the 2 turbos separate the pulse of the front and rear 3 cylinders. They don't merge until after the firewall. It was very noticeable, especially with another 25 to compare to in the garage.

I have the HKS style split pipes as well so it is a bit louder, but it all bolted straight up to the single cat location

So while some of these other points are slight contributors, it's mainly the turbo configuration. And, It sounds PHAT as hell

[TTT]

they do sound more mechanical and that is what I would say is tough.

get a stock rb26 with an exhaust and any other stock RB with an exhaust, and the rb26 sounds a lot more angry, mechanical, harsh, tough.... what ever you want to call it.

I just like it and wanted to know what caused it.

I don't agree that it's the turbo's.

if that were the case, then an rb26 with a large single would sound like an rb25 with a large single..

but it doesn't.

still sounds more mechanical.

I'm going to go with the thought that it is the combination of cams, exhausts ports (if they are infact different), throttles...

[Ronin 09]

Since converting the RB25 to a GTR34 twin turbo setup, the difference is in the fact that the 2 turbos separate the pulse of the front and rear 3 cylinders. They don't merge until after the firewall.  It was very noticeable, especially with another 25 to compare to in the garage.

I have the HKS style split pipes as well so it is a bit louder, but it all bolted straight up to the single cat location

So while some of these other points are slight contributors, it's mainly the turbo configuration. And, It sounds PHAT as hell

It's ALIVE!! I want a spin in it

[GTRgeoff]

I don't agree that it's the turbo's.

if that were the case, then an rb26 with a large single would sound like an rb25 with a large single..

but it doesn't.

still sounds more mechanical.

I'm going to go with the thought that it is the combination of cams, exhausts ports (if they are infact different), throttles...

Sure mate, and you compared this to a handy RB25DETT just to tell me I'm wrong. Thought you'd appreciate an answer from someone who has done the conversion and speaks from experience, but obviously you didn't need help.

Yep, up close with the bonnet up the solid lifters cause a fair bit of mechanical rattling, but even after yesterdays cruise with variously configured GTR's to listen to from inside the nice quiet Soarer there is a distinct difference between singles and twins (and the luxobarge gave me plenty of chances to get passed )). A lot to do with the various exhaust systems as well with similar single or twin configurations.

As far as the cams go, I fitted a set of GTR cams and found the top had a bit more power at the expense of low rpm, but it wasn't a different note.

In fact, with a blind comparison I'd suggest none of us could tell the difference. Most well worked GTR's that stick in the mind with a great note are bolted together with good quality kit, including the exhaust. I'd suggest most are just a little too overawed by the whole GTR "thing". I'm no detractor of the GTR, in fact I expect to be buying a GTR33 next month to take the garage to 5 slots, but there is a lot of "it's a GTR so it's too cool".

Compare the Fujitsubo Jasma system on my track car to after the TT conversion and it changed dramatically, the only difference the TT setup I fabricated. Then I put a 3.25 Trust Jasma system on my auto 25t and it's a lot different again, but the NA 33 that it came off made it sound a bit coarse. Next I'll put the 3" front pipe on the auto and I bet it changes again.

Marcus,

it dropped compression on a couple of cylinders at 5psi boost in second after I installed some injectors that I stupidly didn't check for flow rate. Looks like another rebuild before that ride mate, but it was nice until it lost power.

[TTT]

geoff - please don't be offended.

I haven't heard a 25dett.

I have heard 26dett and 26deT and the exhaust note wasn't that different.

it was different... but not much. It still sounded much like a gtr then any rb25det with large turbo that I have been in or been behind to hear the exhaust.

I didn't mean to say that you were wrong..

I just assumed that the other things listed would give the car the rougher sound.

[inissane]

maybe useful to split sounds up into:

induction - filter/s, compressor/s, bov/s, throttle/s, plenum

exhaust - manifold design, turbine/s, wastegate/s, cat, muffler

engine - I am no expert but from above lifters, capacity???? RB20, RB25, RB26, RB30

induction/exhaust noises may more depend just on the turbo system bolt on design (ie single, twin, big, small) and the exhaust gas potential of the engine

what do the N/A versions of these engines sound like with an exhaust, say an rb25de - are they almost louder because the turbo doesnt 'muffle' the exhaust note??

[GTRgeoff]

GTST, none taken, and sorry to come across as if I was. I know what you are getting at though, but the TT really changed the entire sound from idle to further up the revs. It was already pretty good but after it just transformed and it confirmed the reason that particuler note comes from the 26. Plus mine also is a 2.6 in capacity now so that is not a huge factor in sound, but it has improved off boost torque due to increased compression.

The 25DE is a fair bit louder with the same exhaust as I had the opportunity to hear when I bought the Trust. I did the swap right away off the other car which got the stock cat back and it went from a sharp loud bark on the DE to a sweet deep rumble on the DET.

BTW the auto is stock except for the zorst and is an absolut POS power wise. Any boost over 10psi and it cuts hard. Any under 8 and it is a big doughy mess.

[SkyGTRline]

I agree the RB26 sounds tough.....

Personally dont know why..

Altho ive been told my gtst sounds similar to a GTR when in high revs..

So i dunno...

Just thought id share 26's do sound awesome..

The RB30 sounds a little deeper than the rb20, it does sound nicer, especially if I jam the wastegate open it becomes much louder and brup brup sounding.

The RB30 sounds like a commonwhore... in which it is.. Yes a bit deeper, but yucky.