Hey all, have done a search, but have not found anything helpfull.

Some of you guys might remember a post of mine : S5 'bunny hops', i had two questions in there but 1 of them would of been hard to answer, and i stated that i would have to get under the car to see where this mystery noise was coming from. well...................track forward to today and i now know. This is how it goes, but i still need some advice please.

The car had a funny whining sort of noise comming from under the car. I assumed it might have been the gearbox, but i've finally found time to get under the car and check it out, and im 100% certain that its coming from the RB pre-silencer. Now also i've noticed a loss of pickup (boost) as well, car doesnt rev out like it used to, the car is lucky if i take it above 5krpm (does get a good going over every now and again tho ), used to get there nice and quick, but now it struggles (sort of).

So i've come to the conclusion that thje pre-silencer is really really clogged, and not free flowing the spent gases enough for the car to rev nice and easy (and quickly to 5k +)? sounds right?

Bar the whining noise and the sluggish booosting and pickup, the car drives bloody well, and idles well, and etc etc etc. I think you get the point. I know this is liong and winded, but i like to put as much info in posts as poss

I think i'll just take the pre-silencer out and get a shop to fabricate abit of piping there instead. Being in new zealand, we dont have any emission tests, so i dont have anything to worry about in that sense. I just want to know how many guys have gone with out the pre-silencer and there effects, or when i take the pre-silencer of, is it cleanable (sp?) i.e is it as simply as tipping it upside and de-clogging it and putting back on?

Cheers Guys
G

 

RB sells same exhaust without presilencer so you will be fine without it and I dont think you can clean it with anything other than a broom handle or other long thin blunt object and a few swift jabbing motions.

 

How old is it? I don't know how it would get clogged as it's a straight through design as far as I know.Mine is at least. I'd say pull it off and verify if it is clogged and go from there. I think a staight pipe would work fine ,it'll just be louder.

 

Will you send me the old presilencer? BTW get ready for the car to be bloody freakin loud. It must be nice to live in a place as beautiful as new zealand and not even have t worry about emissions equip that will rob your FC's wonderful power.

 

If you think it's clogged then take it out and have a look, it's just a straight through muffler. You should be able to easily remove any buildup of anything in there.

 

hi Dak -

i just brought the car, the old owner said it got put on about 5 years ago, not sure if it was new then or 2nd hand, will ask him. he replaced the 2 rear mufflers because they were rusted or something. I will take it of, tried to yesterday, but need to get some penetrating oil.

1990RXHeaven -

yeah i can, dnt know how much shipping would be. And i guess its nice to live in a country with no emission laws. Though i think they are trying to bring in legislation for testing, but im not to sure how that would work for older cars etc. We have just had a law passed re: exhaust loudness - we have always had a db restriction, but never really enforced, but now police officers can fine you 150$ or 250$ plus demerit points but its pretty bs, as harley davidsons from factory are as loud as f**k, and so are brand new holden v8's and ford v8s. I think its more to do with boy racers in (not being biased) hondas with that horrible vtec bark that just goes on and on. Rotarys have always been alittle loud, but i think vtecs aree the most horrible sounding cars. its sounding like i hate hondas lol, i dont, i like most cars - be it a v8, mini, etc etc.

Black91n/a -

as above will take of and have a look. But if its not clogged, does anyone know why its emitting a whining sound?

Cheers all.

p.s, never mentioned this, but i assume since i live in nz and its a s5, you guys prob knw its a turbo, and the rb is from turbo back

Cheers
G

 

My RB presilencer is also around 5-6 years old, and it's a straight thru design, I can't imagine how that would be clogged.

 

No idea why it would be making a whirring sound unless the internals are coming apart and vibrating or something. Once you get it off the car and can have a look inside it maybe you'll be able to see if there is a problem with it.

 

what would clog it? does anything solid even come through that pipe? I'm not too technical.

 

Yea im not to sure what would clog it. I thought the silencer also had a cat in it? abviously not, i only assumed this because from what i can gather from the info i've been reading, you guys wont pass your smog test etc? yeah i'll take it of this weekend and have a good look at it. If i cant find anything wrong, ill just get a pipe made up for that section instead, and not worry about the silencer.

Cheers for the info guys, great help

G

 

I passed smog just fine, but I had to re-install my stock cats and remove the RB downpipe and presilencer.