buch

Hey what about us conservative types that like what a sleeper this machine is (at least until it gets above 4000rpm) :-) What are our options:

Exhaust systems which improve 'flow' without getting a whole bunch louder
Headers alone (no exhaust)
Remaps (seems unlikely with this system plus the warranty implications)
etc.

???

Thanks, Doug

JCtx

May I ask you if it's too loud in stock form? I'm considering jumping from a 2015 GTR to this, especially because it's too noisy inside the cabin. I don't care if it's loud outside, but I want a quiet interior while traveling. I think this car has a 'valved' exhaust, right? But does it have a button that you can control that, or is it like Corvettes, that it's going to open at 'x' rpm no matter what?

buch

Overall the car is fairly quiet for it's output. There's no real valve for increased flow/noise, but Sport+ mode pumps some simulated growl into the cabin (nothing outside) which I like in spirited driving situations as it better 'connects' the driver to engine speed without needing to look down at the tach.

I've eventually regretted aftermarket exhausts in the past, and found the stock exhausts open up somewhat over time. My post is to find out what's coming at us from the aftermarket to add power (actually preferably low-end grunt) that is not coupled to exhaust mods. Having said that I might consider an exhaust that brought a nominal amount of growl and dropped a significant amount of weight.

JCtx

Thank you very much for your reply. Shame no valves on such expensive sports coupe, but not the end of the world. I'm like you, but will probably leave this car alone if it's quiet enough inside. Wish it was like the GTR, which had restrictive CA secondary cats, and just a midpipe change significantly increased outside noise without increasing cabin one.

Hey, what did you mean by 'simulated growl'? Please don't tell me it's the same BMW crap that it's thru the stereo/speakers. I was under the understanding that ACTUAL engine noise was let into the cabin via a vacuum valve that can be disconnected (inquiried how to do that on another thread). And finally, if it's speaker activated, does it only happen in sport+? How about rev-matched downshifts: Is there just one setting, like starting in sport? Or do they start in sport, but are more aggressive in sport+? There're other 2 settings that I saw on a video: expert, and all nannies off. Wonder if there're any changes to that. ALso read this car supposedly has 'adaptive suspension', but that doesn't seem to be accurate. Thank you for your help again, and sorry for all the questions. If you don't have them, hopefully somebody else.

buch

I actually think it might be similar to what BMW does with noise simulation but I'm not sure it's through the stereo - others may know for sure? I was told by the dealer that some changes occur in the suspension system in the two Sport modes but I don't see anything about that in the manual - again others may know more? I'll add that other than some minor idiosyncrasies with the transmission programming and torque converter settings, this is a brilliant car with a great balance of performance, luxury and sophistication (if that's what you're looking for?).

JCtx

That's exactly what I'm looking for. And as a previous owner of 5 new Lexus V8 vehicles, I personally know Lexus can deliver . Thx.

Fysisist

For my taste, the OEM exhaust was just too tame and then the ASC (active sound control) just struck me as too artificial. I poked around on the forum and PM'ed different people for more info on the after-market exhaust they chose for the RCF and the list was short: Meistershaft, Apex-i, PTS/JoeZ, and maybe a couple others. I chose JoeZ for value and quality and haven't been disappointed. Power gains? Not too sure - didn't have the car dyno'ed or anything like that. It's a cat-back system and loses one cat, so might not fly in CA or possibly other states, not sure. I am very pleased with the much more aggressive sound, especially at lower RPMs, and it does howl at full open throttle, but maintains a very civilized yet muscular sound otherwise. It does make the ASC redundant which is a good thing in my book. The butt dyno indicates a modest kick but I think to realize the full potential of after-market exhause, intakes, etc would require and after-market or custom tune, and apparently that is not going to happen.

buch

Thanks and fair comment. There are a lot of good report-outs on the JoeZ. Do you happen to know if the ASC can be disabled, possibly by something simple like pulling a fuse?

If you're getting a bit more hp in your setup, is any of it showing up at lower rpms where it's needed?

Fysisist

I would be speculating on the low end gain since I don't have any numbers, but it feels a bit quicker. But that could be due to the fact that it sounds quicker...

When I first got the car I was intent on disabling the ASC but two things happened - first I got used to it and then secondly it is much less conspicuous with the new exhaust. I did search around on the forum and posted a thread here on disabling it - "Not a Fan of Active Sound Control" I think it was.

JCtx

I knew it could be disabled because one magazine tester (Carlos Lago) said he did that in a minute, and the cabin was quieter, plus the engine sounded much nicer and refined. After test-driving an RC-F yesterday, that POS would be a deal-breaker to me if it couldn't be disabled. Couldn't find out how, but should be real easy. Maybe you can do it for all of us . Remove the engine cover, and look for a 'trumpet' pointing to the firewall, coming out of the intake tube somewhere. Then find the vacuum actuator, and just disconnect the vacuum hose attached to it. Then plug the vacuum line with a golf tee (or similar), ziptied it somewhere out of sight, and you're done. It can be reversed just as easily.

My question is if there's extra noise coming out of the car speakers, a la BMW. Hope not, or this car would be scratched off my list. If you can do this, please report to us if the louder noise starting at 4K rpm is gone. THAT's the one I'm afraid could be noise coming out of the speakers. But hopefully that valve is a 2-stage one, but if there's only 1 vacuum hose, then my suspicions could be true. That vacuum trumpet could be the droning noise starting close to 3K rpm, which is annoying. But not nearly like the awfully artificial one starting all of a sudden at 4K rpm. Will try to persuade a friend I have at the local Lexus to let me disable that thing on a used RC-F they have, before doing any deals. But hopefully somebody here can try it on his car and report back to us. Thank you.