Drone / Loud noise - Starup vs Warm

[Junkno's SS]

hey guys

i have a VZ Monaro and just have fitted the Sureflo 1 5/8 4>1 headers with the Sureflo dual 2.5 exhaust - with 3 inch mufflers in the back in MEDIUM(pipes that connect to the 3 inch mufflers are 2.5 inches which are expanded at the end which connects to the 3 inch piping of the 3 inch mufflers)


The exhaust sounds really great on idle, deep and not loud, and sounds amazing at HIGH RPM , which is a great Sureflo trait !!


But i am having a small dilemma, when the car is dead cold and just started, i have a kind of a loud boom noise ( as in no tone of the exhaust, just a loud irritating noise ) at 1000 RPM and 1500 RPM --- in between those rpm ranges i can hear the exhaust tone perfectly


When the car is warmed up , this annoying noise is lifted and is at 1250 RPM and at 1750 RPM - also i can hear the exhaust tone perfectly ( after warm up i can hear the exhaust tone at 1000 rpm and 1500 rpm normally and not a loud booming noise )


I searched alot but i cannot for the life of me figure out what the problem could be. It is very loud INSIDE and OUTSIDE the car.


Those rpm ranges are very important for me , because at night driving in suburban areas or parking lots , etcc, if am holding the rpm at 1250 or 1750 , all i get is a loud VOOOOOOOOOOO and not the sweet deep burble of the 3 inch mufflers


Sorry for the long thread, but i really need your help guys, i will post pix and videos of the system very soon :)


Cheers

[Junkno's SS]

forgot to mention that i am not running cat. convertors

[Junkno's SS]

i think i know where the drone is coming from

i think its coming from the middle resenators in the car

BTW, the guys who installed the exhaust installed the Sureflo Xpipe upside down, so i think that might have something to do with that, i will go and check tomorrow


i hope that fixes the drone ...

Video real soon..

[Junkno's SS]

Pictures are ready



The stickers on both the xpipe and the middle left resenator indicate " LHD DRIVE SIDE PIPE"


http://i106.photobucket.com/albums/m269/junkno/Image0109-1.jpg

http://i106.photobucket.com/albums/m269/junkno/Image0111-1.jpg

http://i106.photobucket.com/albums/m269/junkno/Image0112-1.jpg



Now check where the sticker location is, its installed upside down , and i think thats whats causing the exhaust to drone at 1250 and 1750 rpm

http://i106.photobucket.com/albums/m269/junkno/28032010135-1.jpg

http://i106.photobucket.com/albums/m269/junkno/28032010134-1.jpg

http://i106.photobucket.com/albums/m269/junkno/28032010133-1.jpg

http://i106.photobucket.com/albums/m269/junkno/Image0119-1.jpg


You will also notice that some pipes are heated just before the flanges, and thats because i was told there was a problem with the fitment, but turns out its because they are installed upside down that all the pipes were out of alignment



The drone is happening at the middle resenators, and i think it could be because of the error of fitting the x pipe upside down

What do you guys think ?

[ebbett21]

i run no cats and 100% sure thats cause of any drone ,

[Junkno's SS]

I had no cats before on the sureflo single 3.5 inch, and that didnt make a problem

if you have a good flowing headers and mid pipes then that shouldnt be the problem

it sometimes depend on the size of the muffleres or resenators

when i rev the car to 1250 and 1750 i feel the noise is coming from the middle mufflers

so my drone is coming from that area, check yours, let someone rev the car very slowly and just go around the whole car and check

[1BEAST2NV]

I think the x pipes being upside down will make no difference accept for clearence issues...

why not just put high flow cats in ???

any particular reason you deleted the cats??

[Junkno's SS]

deleted the cats for better flow :)

[1BEAST2NV]

deleted the cats for better flow :)

But surey if you put decent size cats in, the flow should'nt suffer next to none, and it will also help with drone....

maybe get some 5" body's with 3" in and 3" out, that way flow the same :) ???

[ebbett21]

But surey if you put decent size cats in, the flow should'nt suffer next to none, and it will also help with drone....

maybe get some 5" body's with 3" in and 3" out, that way flow the same :) ???

will cats enhance the note? or hotdogs instead of cats?

[1BEAST2NV]

I personally dont know....

IMO, I would say cats would make the sound clearer and help reduce drone, and have hotdogs further down the system, say just after the cats (that'll help make it bark).... then have the mufflers at the back.

But thats just me :)

every one prefers a different sound, but I hate drone :D

[Junkno's SS]

i had the car up the hoist yesterday, and was told having the X PIPE upside down doesnt really affect anythin ???


Also the drone that i felt from the middle resenators is not it


I was moving under the car and turning my head in all directions, and its coming only from the rear mufflers. I was told to let the exhaust carbon up for a while and you will notice less drone , So not sure what do do


A guy on the gto forum wrapped his exhaust with headers wrap and it decresed the drone and loudness of the exhaust, what do you guys think about doing this if all else fails?


Cheers

[1BEAST2NV]

maybe try a different rear muffler set up?? different brand or what ever, maybe one thats more like a silencer to help reduce the noise/drone

[Junkno's SS]

i wish it was that easy, i need to import everything from Australia as i live in the United Arab Emirates..

i can get mufflers and stuff like that here, but then the quality is a big issue =/


well see what we can do


Here is a video of the Exhaust finally hehe


the drone am taking about is at the end of the video, the quality of the video went bad after i edited it and uploaded it to youtube.. but i hope you guys can hear it


Also you will notice a sort of metallic rattle after Reving the engine, am still trying to find what that noise it


YouTube- SS Coupe exhaust 1 start idle rev

[Junkno's SS]

Video of the Exhaust


Sounds great at startup and while driving, has this scream in the upper rpm range when going WOT. What is also like about it is the idle, its very deep and not really loud, just a little louder than the stock exhaust. When at the lights you can feel and hear the idle burbling in the background quietly


the drone am taking about is at the end of the video, its where you dont really hear the tone of the exhaust, rather just a buzzing noise


the quality of the video went bad after i edited it and uploaded it to youtube.. but i hope you guys can hear it


Also you will notice a sort of metallic rattle after Reving the engine, am still trying to find what that noise it


CsNtBmCnZUk

[VZSSL986LTRUTE]

those dudes that fitted ur kit look straight outta the naughty house!!!! Im all for catless pipes but that system looks rough as.. Also im a big fan of drone.. my ute is a fugged full of drone goodness

[Junkno's SS]

hehe did get kind of ruffed up after installation

but am no fan of drone ... gets on my nerves really



another video just been uploaded for your enjoyment

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