i lowered the rear of my car today ( i previously just had the front lowered until autozone ordered an arm puller for me to rent ) and after finishing, setting the car back down, i took it for a test drive.

for some reason unbeknownst to me, i have a weird rattling sound now. but it doesn't come from either rear shocks. it sounds like it's coming from the exhaust, like when the exhaust rattles and hits the heat shield. but i don't have a heat shield. anyway, it rattles if i blip the throttle in neutral and at low rpms in first gear. by the middle of any gear, it stops.

it didn't rattle before i lowered the car, which was the only modification i did to the car today. the car itself has many mods, i guess the pertaining mod being an apex'i catback system. i checked the pipes and everything; they seem firmly bolted on there. no shaking of them. any ideas from the prelude guru's that lurk this forum?

 

do you have a dc header? Check your header flange the connect to the back side of the block.....most peoples break....mine did. Before i took it off, it sounded exactly like you are sayin

 

get someone to hang on underneath the car while your driving and see if they can figure out where the noise is coming from...........oh, be careful for those speedbumps too. j/k man.......jack the car up and look all around underneath the car to see if you can see anything loose or if the exhaust is up against something.

 

funny, chris now about the dc header-yeah, i DO have dc headers. is it b/c of something done while the car was jacked up to lower it, or was it just coincidence that it broke when it did? i'm gonna check that bitch out tomorrow. if not, i'm just strapped for ideas for the moment.

 

Mine did this too, but before I lowered it. It only rattled at like ~1600 RPMS- it was my catback rattling, it was firm in place, but the bolts were rattling.

 

maybe the stiffer springs cause a little more vibration.

 

did ur dc headers give u any of a hp gain. jus curious cuz im planning on getting stainless steel dc's for my h23.

 

my dc header did the same ... i was only able to get one bolt to line up ... the bracket around that bolt broke in less than a freakin month !! the rattling was awful. idle to mid gear just like you said. i took it to a shop and the mechanic was able to get the other hole to line up and he stuck a bolt in it ... that was about 2 monthes ago ... TODAY ... i started to get that same damn rattling sound ... so i am imagining that the other side of the bracket broke too ... i knew it was only a matter of time ... lol

do you guys think it is too lose to leave the bracket off completely ( cut it off ) or to have a new bracket welded on and bolted up ??

DC SUCKS

 

hey i did notice some gains when i put the dc header on ... but i also yanked out the cat and bolted up a test pipe and brand new apexi WS catback ... so i am sure it was the combination of the 3

good luck with your DC ... before you put it on get a torch and cut that worthless headache causing bracket and weld up a good one

 

kewl. i was hopin to gain 5 or 6 hp ..at least. dc website claims 10-12 but i dont buy that lol. also does it give the engine a different sound??

 

bullshit.....DC gains are like 4 hp......if you acutally compare them to stock, they are nearly identical.

The OEM downpipe is actually bigger than DC.


And yes it is ok to completely remove the bracket.

 

i couldnt really say about the sound ... obviously it sounded different because of the open cat and apexi WS catback ...

at first idle was quiter than it was before i put it on and you really only heard it with vtec engaged ...

however progressively it got alittle bit louder month by month...

all these parts have been on my ride for about 5 - 6 monthes and it's just now hitting the tone and volume that i like ...

most of this is due to the WS catback i imagine ... it has a huge resonator plus a cambered muffler, i kinda didnt like it at first but like it already said the tone and sound got better with time...

the WS does really well at low to mid gains

 

sorry to bump this old thread, but i have an update on my rattling; it appears as if my apex'i cat is going out.

it's been on there for a while and my mechanic said the rattling is coming from inside it (i was up on the lift blipping the throttle, so i couldn't get to hear where it was from).

so i'm going to run an open cat. the dc headers were tight and it was just a coincidence that the same day i lowered the car, the cat went bad. just an update, thanks for the helps!

 

Thank goodness for this site! I have had that same rattle for months now and was unable to get to the bottom of it. It occured around 1800 rpm. Turns out to be that damn bracket mounting the dc headers to the back of the engine block. I went under and the thing had completly cracked apart so I just removed it and everything is still solid and that noise is finally gone!