FFM

Seemed reasonable to me. That's about what a pair of polished magnaflows cost which are universal and you would need to add tips. These at least bolt to the factory Y pipe, and would just need to be adapted to whichever aftermarket exhaust you had. Sounded mean too.

Diesel350

Yeah I can see how the muffler with custom tips and ready to bolt on makes it more costly. I was looking at just mufflers only and came across some chambered mufflers as an option to get rid of the drone but the problem with reactive type mufflers is that they are more restrictive. Seems like the Borla and Joe'z mufflers are absorption type mufflers where they have very good flow but they do little to silence unwanted drone. I've been looking for a muffler that provides the combination of an absorption and reactive type properties but I can't seem to find a muffler that would fit our application. Obviously this would be a custom welded job to whatever exhaust system you have already on your car. I guess what I'm trying to figure out is a chambered muffler design any less restrictive than the stock muffler design?

Reactive type mufflers:
https://www.holley.com/products/exha...parts/21505HKR

And here is Flowmasters chambered muffler design:
http://www.flowmastermufflers.com/super-50-delta/

Edit,
I did find a combination absorption/reactive type muffler that would fit the IS-F. http://www.flowmastermufflers.com/dbx-series/
I measured the length of the stock exhaust from the tip to the inlet and it's 15 inches so anything below that would fit. These mufflers would run about $360.

msgs350

iTrader: (2)

Do you guys know what is a reasonable price including installation should be for these resonators?

Tom2769

iTrader: (3)

Msgs, interesting video, thanks for posting that. I don't know if it's accurate or not, but the concept makes sense. I think that even if getting the resonators closer to the cabin is most effective, it seems that there are many examples (including the HKS SSM) that are behind the axle and are at least effective enough to make a significant difference. At least that's what I'm really hoping... As far as price, PPE quoted me around $400ish depending on how much snaking of the piping has to be done. They thought it would take about 5 hours. I don't doubt that you could find a shop to do it cheaper, PPE seems to do high quality work and they charge for it. I really went over their headers closely before installing them and the workmanship was exceptional. I also had a hole-in-the-wall shop add a 31" long 3" diameter quarter wave resonator to my Tacoma for about $140ish (don't recall exact #s), but there were oceans of room under that truck compared to the F, and it was almost a straight resonator run. BTW, that resonator was installed just behind the cab in front of the muffler, and it was very effective.

Diesel, are you considering trying a chambered/reactive type muffler? That Flowmaster 50 looks like it may have an internal helmholtz-type chamber. Would love to see how that would work on the F...

Diesel350

I think I'm going to go for the absorption/reactive type muffler like the Flowmaster dbX. A chambered/reactive type muffler would be too restrictive. I might as well stay with the stock mufflers if I was going to a chambered muffler. A absorption/reactive muffler is like a combo of both worlds. Low on sound and free flowing without being too restrictive.

msgs350

iTrader: (2)

Diesel- what are exhaust and header are you running now? How is the drone?

Diesel350

I'm stock right now. Just looking at different options. I've been through a lot of different exhaust set ups on previous Lexus's so I know what I'm after. Muffler design makes a big difference in whether or not you will get a lot of interior resonance.

Tom2769

iTrader: (3)

Just yesterday I read through the long CL thread on the new x-force exhaust, including the varex muffler option. I'm quite intrigued by the varex option, it seems to give the best of both worlds - chambered or flow-thru on demand (and variable between the 2). But I am still not clear on the internals of the varex muffler when the flap is closed (reflective? absorption?). Their website is vague on the interior design, but the user feedback on this forum is pretty positive, especially as it relates to drone. This is a tempting option - more of a known than installing quarter wave resonators, which may involve some trial and error. Any experience with these?

Diesel350

Someone just posted on that thread that the exhaust is actually 2.36 and not 2.5. That alone I would not consider that option and also the fact that the workmanship seems to be less than desirable. Some people have mentioned drone with that exhaust which leads me to believe it's an absorption type muffler. I don't know what it would be like with the Varex option. I'm assuming with that option it would make it pretty quiet.

Tom2769

iTrader: (3)

Yeah, saw that - the size discrepancy doesn't bother me too much (except for the principle of it - it's falsely advertised), and the workmanship for the price seems acceptable to me. Re those few references to drone - hard to tell from the posts if that's for non-varex/varex open/varex closed - but that alone makes me hesitate. Check out this video - skip to 2:49 - looks like x-force at least used to (early 2015) offer a non-varex muffler with an integrated helmholtz resonator. I don't see it on their website, though - sent them an email inquiry about it...

​​​​​​http://xforce.com.au/tv?view=showcli...eo=kdplP72DOZ0

Tom2769

iTrader: (3)

Just to bring this full circle for anyone who is still following this thread: X-force confirmed that they no longer make a muffler with a built-in helmholtz resonator. But I did just have side branch resonators added to my F. Here's a thread I started with results:

https://www.clublexus.com/forums/is-...s-results.html