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Im guessing that the 26 and 25 have the same firing order?#

Other wise, cams, 6 throttle bodies would have a big impact, and exhaust manifold design... Are the valve sizes the same on the 25 & 26? I dont think solid lifters would have an effect on exhaust sound, apart from the cam differences. I had an SR with different turbo/exhaust manifold and sounded much different from any sr i heard before, very raspy and much tougher....

I think that the only way a 25 or an rb for that matter could sound like a commodore would be if it was non-turbo... But ive never heard a turbo rb make the fart like sound of the old 202, or any of the v6's.

i reckon the rb20 sounds better than the rb25, sr20 or CA18 - I havent heard the RB26 enough times to know but I expect it would sound different and better

Think so? The RB20 sounds like a tinny version of the 25. (I used to own a 32 GTS-T)

the rb30e may sound shitter, but the rb25/30 hybrid has got its own sound. Id say the rb20 sounds like a car with a fat exhaust note - more noise than HP, then the rb25 sounds a bit gutsier, rb26 sounds different again (id say due to all previos things mentioned).

The rb30 has a very deep rumble note. I dropped it in my car changing nothing else but the engine, and it sounds like the rb20 did, but with a better rumble...like its talking the talk now its walking the walk ;)

if you put a rb26 head on a rb30 and leave all the support gear ie turbo, manifolds, exhaust and inlet they sound the same.... the acoustics of the engine come from the valvetrain and head design as mentioned in the ducatti analogy, its all to do with the head design.... rb30 single cam engines sound crap cause of the shit head they are running!!!! The rb20 and 26 use the same head casting but very different set ups and the reasone an rb20 sounds different to a rb25 that has the same valve train set up is the camber circumferance is only 77mm not 86 thus the rb25 has a deeper note.....

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 :rofl:

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

I also have a RB25DETT but in a RS13 and it doesn't sound quite the same as an RB26DETT to me. I suspect the RB26's throttlebodies are the main reason.

A RB25DETT does sound gorgeous though, a bit higher pitched than the GTR's I've been in.

  • 6 years later...

Bit of an oldie but i have a question!!!!!!! - My s14 (rb25det) seems to sound like some sort of angry whippersnipper ?!

6boost mani, 3 inch dump/front into cat, then 3 inch all the way to some weird twin pipe muffler thing(xforce? - its sh^t) ive dropped it at the diff before (removing the last muffler) and the whippersnipper just gets angrier and begins to sound like a rally car.....has anyone else experienced this lol?

Aiden

no one has mentioned the difference in stroke with each rb, the rb26 to me sounds more like a motor bike with its shorter stroke, the rb25 is shorter and the rb30 shorter again, so maybe its the stroke that play a big role as well as the compression ratio's of each rb.

Ive noticed the turbo makes a big difference as in how well it flows and spools makes the sound of the gases both intake and exhaust rush in and out faster making it sound really angry or a bit soft..

no one has mentioned the difference in stroke with each rb, the rb26 to me sounds more like a motor bike with its shorter stroke, the rb25 is shorter and the rb30 shorter again, so maybe its the stroke that play a big role as well as the compression ratio's of each rb.

Ive noticed the turbo makes a big difference as in how well it flows and spools makes the sound of the gases both intake and exhaust rush in and out faster making it sound really angry or a bit soft..

:huh:

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