FI Interior Drone
#1
FI Interior Drone
Hey everyone! I installed FI HFCs 2 summers ago, unresonated, as i thought that is all i was going to do. They sounded great.
THis summer, i bought the full cat back with 18 inch resonators, hoping it would be a good combo sound wise
So, it sounds amazing when accelerating and at idle, but the interior drone is becoming a little intolerable/embarrasing when i'm holding speeds at 80 km/h and above (especially on the highway). I'm not sure what to do, but I'm thinking to switch back to my stock cats, and keep the catback (with 18 inch resonators), do you think that may solve my problem?
My suspicion is the drone is being caused by the un-resonated HFCs in conjunction with the cat back. Reason I think my HFCs are the culprit in this set up is that I can't find many people complaining of drone or too loud of an exhaust noise with a catback alone (with 18 inch res), and I've also read that RHFC + CBE w/ 18 res has 'zero drone' by some reviewers here.
Hopefully someone here has some insight or experience with this before I decide to go back to stock cats, or if you can think of any alternative solutions I can pursue, like can I still add a resonator to the cats, or swap my cat back resonators with larger ones. Is this still possible after the fact?
PS: I realize they will 'break in' after around 1000 miles and the sound may become softer. But I'm prob just at around 1000 miles since installation, and nothing has changed much
THis summer, i bought the full cat back with 18 inch resonators, hoping it would be a good combo sound wise
So, it sounds amazing when accelerating and at idle, but the interior drone is becoming a little intolerable/embarrasing when i'm holding speeds at 80 km/h and above (especially on the highway). I'm not sure what to do, but I'm thinking to switch back to my stock cats, and keep the catback (with 18 inch resonators), do you think that may solve my problem?
My suspicion is the drone is being caused by the un-resonated HFCs in conjunction with the cat back. Reason I think my HFCs are the culprit in this set up is that I can't find many people complaining of drone or too loud of an exhaust noise with a catback alone (with 18 inch res), and I've also read that RHFC + CBE w/ 18 res has 'zero drone' by some reviewers here.
Hopefully someone here has some insight or experience with this before I decide to go back to stock cats, or if you can think of any alternative solutions I can pursue, like can I still add a resonator to the cats, or swap my cat back resonators with larger ones. Is this still possible after the fact?
PS: I realize they will 'break in' after around 1000 miles and the sound may become softer. But I'm prob just at around 1000 miles since installation, and nothing has changed much
Last edited by SS2006; 08-10-2015 at 01:50 AM.
#2
Registered Member
iTrader: (1)
From what I have read only way people have not complained about drone is with resonated HFC. Everyone who has installed non resonated HFC said they have drone.
Heres a thread-https://www.myg37.com/forums/g37-sedan/268609-question-about-hfc-s-rhfc-s-and-rasp.html
Heres a thread-https://www.myg37.com/forums/g37-sedan/268609-question-about-hfc-s-rhfc-s-and-rasp.html
Last edited by xpcgamer; 08-10-2015 at 06:28 AM.
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SS2006 (08-11-2015)
#3
Administrator
iTrader: (9)
Good luck, OP. A set of resonated cats is a reasonable expense considering what you spent on your catback. And you can easily sell your old cats for a couple of bills, im guessing, to offset things a little. You dont really want tp go back to OEM cats... Thats where most of your exhaust power gains come from.
#5
Administrator
iTrader: (9)
Well hey... Then consider something a little more creative, and look into ARK resonated cats. That Helmholtz design sounds amazing.
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SS2006 (08-11-2015)
#6
what do you guys think a fair price for my used FI HFCs is? They are 1 year old. Pulled from a 2010 G37x Sedan
and technically would they fit a 350z or a G37 coupe? Someone is asking me
and technically would they fit a 350z or a G37 coupe? Someone is asking me
Last edited by SS2006; 08-11-2015 at 07:07 PM.
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#9
Premier Member
iTrader: (5)
Definitely consider the Z1 HFC. Much more affordable option and they are readily available.
I enjoyed the tone of the Z1 plus the resonated FI system. Albeit I had a 12" resonated system and it still sounded great. No rasp, no drone - perfect in that regard.
Because I was looking for a deeper tone, more burble and a bit louder, I swapped the resonated X-pipe for a non-resonated X-pipe. Great sound combo with the Z1 HFCs, still.
I enjoyed the tone of the Z1 plus the resonated FI system. Albeit I had a 12" resonated system and it still sounded great. No rasp, no drone - perfect in that regard.
Because I was looking for a deeper tone, more burble and a bit louder, I swapped the resonated X-pipe for a non-resonated X-pipe. Great sound combo with the Z1 HFCs, still.
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SS2006 (08-11-2015)
#10
Interesting. This reviewer says they are very raspy (is that different than drone?)
https://www.myg37.com/forums/engine-...fc-review.html
Tho elsewhere they seem to get good reviews
I know the cats are the choke point of our ehxaust, so I do want something over stock, I just wish there was an option that provided performance with no extra (or little) sound
https://www.myg37.com/forums/engine-...fc-review.html
Tho elsewhere they seem to get good reviews
I know the cats are the choke point of our ehxaust, so I do want something over stock, I just wish there was an option that provided performance with no extra (or little) sound
Last edited by SS2006; 08-11-2015 at 09:51 PM.
#11
Registered Member
iTrader: (1)
Interesting. This reviewer says they are very raspy (is that different than drone?)
https://www.myg37.com/forums/engine-...fc-review.html
Tho elsewhere they seem to get good reviews
I know the cats are the choke point of our ehxaust, so I do want something over stock, I just wish there was an option that provided performance with no extra (or little) sound
https://www.myg37.com/forums/engine-...fc-review.html
Tho elsewhere they seem to get good reviews
I know the cats are the choke point of our ehxaust, so I do want something over stock, I just wish there was an option that provided performance with no extra (or little) sound
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