just got FI metallic HFC, odd noise, suggestions please
 

Just put on FI metallic HFC's, there is an odd noise which only occurs between 2600-2800 rpm only on deceleration. it also occurs when in neutral just revving it up. as the rpms come down it makes a noise I can only decribe as a rattle snake Zzzzzzz. I put it on the lift at work everything is tight, and its only coming from the drivers side. Any suggestions on what it could be?? :confused:

by the way fellas, so far I put about 350 miles on them

I've never had good luck with HFC, they maybe taking a **** already man, mine only lasted a few k miles.

i have that too. i just ignore it (never really gave much thought about it)...mainly cause i'm too busy to worry about it at the moment. things have been kinda hectic lately.

give rick a call to see what's up and lmk too! doesn't seem like it's hurting my car or anything, which is why i just kinda brushed it off. i figured it was normal for HFCs. we'll see...

any updates on this?

i'm hoping mine will go away after the HKS install

Im just waiting for rick to get back with me...

You probably have a leak. Did you replace the gaskets?

yea.. I replaced them with the gaskets FI provided.

Is it the rasp that comes from HFC, i thought that was around 3500 though...

well....see the thing is that is doesnt occur during acceleration. It only occurs on decel at around 2600-2800 rpm. like I mentioned before you can be just sitting in the car revving it up & it makes that ZZZzzzzz noise.
its actually quite annoying.

that does sound annoying

i installed the same cats on my car two days ago. i know what noise your talking about. i was a little concerned at first when i heard it but i figured its just normal for a metalic cat to do that so i havent payed any attention to it.

geeeeeeez man :mad: , if thats normal for metallic cat, how are you supposed to profile riding around. its embarrassing really. dont get me wrong, I love em' but I dont know if I can be riding around like that.

mine goes away after a couple minutes of driving i think

either that or i just forget about it :p

Now I feel extra stupid. I have this noise too with the FI HFC. I thought it was my new engine rattling already, must just be the cats. Ill have to ask Tony or Rick about this.

well....I'm still waiting for rick to get back with me.......waiting....waiting..

you know come to think of it. mine goes away after a few minutes of driving once the cats get heated up. the colder it is the longer it lasts. kinda odd lol. its not really that loud of a sound though so half the time i even forget its there

for the record, this isnt only on the metallic cats. andrew has ceramic cats from fast intentions and it does this as well.

*subscribed* :D

was planning on getting these also, want to see outcome

Anything from Rick or Tony ??

Sounds like bad cats....seriously.

I smashed a ceramic cat on another car a while ago and it made that ZZZZZ rattle noise.

But why would it make that sound for the metallic cats too?

Very weird.

zzzzzz rattling noise = rasp?


or am I out of the picture here..

still waiting on rick to get back with me. Hopefully he can jump in and enlighten all of us here. interms of the temp relation of the cats to the noise, yes, it does go away a little, BUT overall the noise is still present.

No, the ZZZZZZzzzz/ rattle noise is not a rasp. Its completely different.

Rasp is really common on all HFC..
while Rattling is another story

Ill call Tony on Monday and talk to him about this. He and I are in close contact. Ill ask him whats up and see what he has to offer and post here with an update.

^ sounds good.

Hey all -

You guys still have flex joints on your cars???? They get loose after a bit from the expansion and contraction. The increased heat and velocity and new pulse arrangement cause them to make noise sometimes. After they warm up and get tight again...noise goes away. If they are older or many miles on the car - they can make more noise or it wont go away.

Let me know if this helps ya!!

Rick

so will it go away when i get my HKS exhaust next week?

It should - but the HKS rasps a little and with your CATS you may get even more...rasp that is.

Rick

how come andrew's car gets this ZZZzzzz noise with his injen exhaust which is less that 6 months old?

actually, i'm getting a little rasp right now with my stock exhaust...but only when it's cold. after 2 mins of driving it's gone.

Could also be a heat shield or underbody heat deflector that is buzzing...

any ideas as to what heat shields/deflectors would be buzzing? why only when decelerating and during certain RPMs?

Not without being under the car....sorry. There are many areas that could buzz. The car vibrates and acts differently with the TP's and CATS. Sometimes cars do this, and sometimes not. We have seen VERY few do this thus far, but it does happen.

Rick

okay. it doesn't worry me that much...i'm just curious about it...

so why does it only happen when decelerating and during certain RPMs?

Coinsider it like drone - the pulses are low, and will buzz things at certain RPMS...they just do.

Rick

but why not when accelerating at those same RPMs? sorry for the questions...just confused/curious

It's a good question - and I don't have much of an asnwer than I have a feeling ;)

To me, there is more stress on the car, transmission, engine torque on deceleration or downshifting, so the effect is more promenant.

I thing you can hear it when accelerating too, it just blends better with the engine sound at that time.

Not a great answer....but like I said, I really don't have one either in this case.

interesting...hm...so would you expect this same noise from other brand HFCs and test pipes as well?

ya i am having this same problem acctually with the test pipes i just bought from drunkenmaster aluminized from F.I. also. does the buzz sort of sound like an air leak when decelerating because my car does exactly how they described there noise and honestly it has been extremely annoying me and it is embaresing just wondering what i can do if anyone figures this out

i thought it was my borla at first with a leak but i put the factory exhaust back on and the sound is still there. i was also thinking of putting on the HKS or INJEN track edition soon and that noise will get louder and i dont honestly this i can deal with it louder

test pipes too, eh?

i've never heard of this problem from crawford owners or other HFC and test pipe brand owners =/

and i've rolled my windows down and literally stuck my head out the window while accelertaing a few times...and i didnt hear anything while accelerating

weird.

ya it really is strange but annoying im not sure why Fast Intentions Pipes would work fine on one car then sound wierd when put on mine. but one thing i do know is that when you put a aftermarket exhuast on from my expirience at least the sound will only get louder thats why i took mine off and am looking for a solution. also i dont want it to sound wrong as in im trying to put down F.I. or Rick just saying wat has happend i know they are good people who do good work this is just strange

Well guys - this is most action on this topic I have ever had.

We have made it go away with factory Y-pipe removal, flex joint removal, etc...but have not had it come into play with those items gone out of the equation.

the increased flow and pulse characteristics must be making this happen - it's the only thing I can think of. When I tested the Crawford's, on a stock system, we had the issue too, but when the y-pipe went..so did the issue.

hmmmmm...again....

Your cool man...it's an issue that should be discussed - if a few are having it. Also, we have noticed VERY well that there are virtually no 2 G's or Z's that are alike. They sound a little different from each other, the systems all fit a little different too...

Rick

if it werent for andrew's case, since he has a fairly new injen td exhaust, i would agree with this...

it makes sense what youre saying...but i dont understand why it's happening to him?

as for the borla exhaust...i know nothing about it so i cant say anything about it. is it true dual? or a ypipe back (do you still have the stock ypipe?)

++1

well i've heard mine..obviously..and i heard andrews the other night..they both sound the same O.o

its the true dual on my 04 coupe cat-back and when i put the tp on the sounds made me go ahhh. i just went out side and reved it a little and stuck my head under the car and its a wierd sound. like air with a little squeek at the end when the rpms are falling. but right now im running the factory system with factory Y pipe. but with the borla there was still a wierd noise