msgs350

iTrader: (2)

For me, it lowered it 5 decibels.

FWizard

I felt the entire silencer was too quiet for my liking, but it felt like it pulled stronger off the line. I then removed the two end caps of the silencer and tried that out. It increased the noise slightly but not as aggressive without them. I didn't think there was too much difference with and without the end caps of the silencer.

Like OP mentioned, i think i will use them for winter and remove it all together for summer

Leander311

iTrader: (2)

Anyone with any dyno feedback?

I got my silencers in last night and boy what a difference in drone! Almost too quiet, but the girlfriend definitely approves.

Butt dyno isn't telling me much, but I've wanted to get a dyno anyway when the weather cools off in a few months.

Edit: I pulled the center pieces out as I think someone else had done - one less thing to loosen up and lose over time, right? - and remarkably could not perceive a difference in volume/drone... I imagine having this opening would help close any gap in power though vs. completely open setup. I also found a tuner near me and plan on doing a few pulls with/without insert as soon as the weather cools off from the 103-105 highs we've had all week, as I know successful pulls in the IS-F are sensitive to heat soak.

Eedo123

Can you hear the intake noise again? I really want to have that back, it's a very nice feature of the IS-F

mahcah

iTrader: (3)

Yes you'll hear it again with the exhaust silencers in.

Eedo123

Perfect, thank you. I ordered mine a while ago, really hoping to get them soon, it really seems to be a great mod for people who want to adjust between loud and normal exhaust sounds.

yardie876

Ordered these over the weekend and installed them this evening (gotta love Prime lol). Don’t judge me but my lowly 3.5L with JoeZ catback gets raucous between 1200 and 1800 rpm and these really calmed them down. According to my super (duper) accurate phone dB app, I dropped 4.7 dB but the difference is amazing in terms of lower frequencies vibrating through into the cabin. Merely a hum!

BUT there’s the power loss. It’s noticeable.
The (tiny) torque gained from the catback is lost with these restricting exhaust flow again. I think it’s worth it though. The cabin is quiet again. And the girl approves so all is well lol.

Time will tell if they’re too restrictive to cause an issue I guess...

Leander311

iTrader: (2)

Almost forgot to give some feedback. After dyno'ing my car with and without the db inserts, they made a ~8hp difference, and this is without the small center pieces installed, which had negligible impact on sound, but I assumed would help with flow/hp with them removed.

I will say, taking them in and out is only about a 5 minute procedure now that I've done it a few times. Will definitely have them out when I'm tracking her for the first time at CoTA on 8/30.

Cheers,
Nick

MileHIFcar

Wow, thanks Nick for doing this!

I've had mine in for a while now and was always curious as to how much power I'm actually losing in the top end at WOT..........I didn't think it was much considering the cars I've beaten in my weekly drives to Mexico

I wonder if you can even feel 8hp @ wot and if it's noticeable at the 1/4 in trap speed?

msgs350

iTrader: (2)

Thanks for doing this. I had mine in for a while and decided to take them out a couple weeks ago when I got the RR Tuned intake.

5280ISF

^^^^^ Yes, thanks Nick for the dyno input. I have left my silencers off since the header install. Have been enjoying the sound of the PPE/Borla combo. Easy enough to put them back in for long road trips if needed.

Leander311

iTrader: (2)

^^^^How do you like your Penskes? Been debating getting those and also trying to figure out why FIGS commands $1500 more for a product based on the same 7500 series damper. I waited on getting a '11 just so I had the "better suspension", so dropping another $3-4K is a tough pill to swallow.

mikersoft

iTrader: (1)

I had similar results over the weekend.. I did two pulls with the inserts, then two without... Second two were both ~8hp higher. I'm fine with that on the street, and it's very easy to remove them for track days...

-Mike

MileHIFcar

Do you mean that you left the silencers in and just pulled out the center insert? ..........just clarifying when you guys are saying inserts or the whole unit itself?

mahcah

iTrader: (3)

I think Mike is talking about the entire assembly of the silencers.