Mazda Rotary Club

General => General Technical => Anything Engine/Performance/Tuning related => Topic started by: gear1275 on March 02, 2010, 10:26:05 PM

Title: whooshing noise
Post by: gear1275 on March 02, 2010, 10:26:05 PM
hey guys,
bought a new fd yesterday.
the bov was stuck so i freed the piston and cleaned the bore.
since i have refitted the bov i have been having a whooshing noise whilst the car is boosting.
it sounds almost like the bov is opening under boost?
the car still boosts fine when it does it.
the bov still dumps properly when you lift off.
it has only done it since free-ing the bov and seems to do it more under load in higher gears
any help would be great
james
Title: whooshing noise
Post by: m1tch on March 02, 2010, 10:32:43 PM
The whooshing noise is most probably the wastegate in the turbo opening causing a change in the exhaust note, what BOV is it? is it the normal recirc sort? What mods does the car have?
Title: whooshing noise
Post by: Lil-Steve on March 02, 2010, 10:50:50 PM
I\'ve had a BOV pack up on me turned out the spring was too weak for the boost I was running, sounds like a very sharp high pitches hiss (very loud, as loud as the engine at least) the open wastegate changes the exhaust note a lot on the other hand as Mitch said.
 
Do you have a boost gauge at all if the BOV is leaking you should see a drop in boost pressure as it\'s being spat out to atmosphere (drop in pressure depends on how big the outlet for the BOV is) if the valave is playing up.
Title: whooshing noise
Post by: m1tch on March 02, 2010, 10:57:04 PM
Good point regarding the spring setting! What BOV do you have installed?
Title: whooshing noise
Post by: gear1275 on March 02, 2010, 11:01:47 PM
hey guys,
its a blitz bov with adjustable spring.
it vents to atmosphere so i dont think its a re-circ?
im running stock twins on stock ports with pfc.
would it be worth adjusting the spring down atall?
james
Title: whooshing noise
Post by: m1tch on March 02, 2010, 11:06:10 PM
Is it a blitz duel drive? I have one of those :) its an atmos. bov, think all you need to do is losen the lock nut and then turn the rod in the centre to adjust the spring firmness, might be an idea to try and find a manual on how to adjust :)
Title: whooshing noise
Post by: gear1275 on March 02, 2010, 11:52:53 PM
okay then,
i adjusted it back to where it originally was before i stripped it, and it only seemed to be taking up the spring pressure a little bit
dont suppose you have any literature on it mitch??
james
Title: whooshing noise
Post by: trotter on March 03, 2010, 08:52:04 AM
Just as an aside, could it be a boost leak from somewhere? I had a hose come off and you could hear it boosting.

Also, I tend to hear air getting sucked IN through the filters when really going for it!! But that\'s not really a wooshy type noise :p
Title: whooshing noise
Post by: gear1275 on March 04, 2010, 10:50:19 AM
problem now solved guys, hose off thre back of the air pump was split badly
james
Title: whooshing noise
Post by: gear1275 on April 05, 2010, 08:31:07 PM
guys, thread re-opened!!
im still getting the whooshing noise, same thing, more under load in higher gears from as little as 1500rpm.
i have removed and blanked off the blitz ss bov and today took the cross over pipe off to find that both the jubilee clips on the silicone coupler between y-pipe and cross over pipe were loose, so i tightened them.
i also checked the crossover pipe and the stock ic pipes and all seem good.
but i still have the noise!!
also, when i get the whooshing noise, i also get a fuelly smell afterwards??
help please!
james
Title: whooshing noise
Post by: trotter on April 05, 2010, 09:51:11 PM
fuel smell (if not just coincidence) points towards a leak somewhere AFTER the engine on the exhaust side. Have you had a look at the turbos themselves for signs of leakage?

Also, now I come to think about it. A faulty external wastegate would cause whooshing AND fuel smells, but also a loss of boost (may or may not be noticable depending upon how open it was). But IIRC, the stock wastegate is a recirculating type??
Title: whooshing noise
Post by: davehg on April 06, 2010, 12:57:32 PM
im happy to take a quick look for you chap if you want?
Title: whooshing noise
Post by: gear1275 on April 07, 2010, 02:35:27 PM
yes please dave! ill ring you this afternoon, cheers mate
Title: whooshing noise
Post by: BenLewisMav on April 08, 2010, 01:53:34 AM
I have a similiar issue with a basically standard setup, I\'m loosing not boost (Power fc reads 0.8bar both turbos) and there are no visible leaks/cracks/splits so I\'m not massively concerned. I just presumed it was to do with the aftermarket air filters, as it only does it under partial load/as the turbos are starting to work.
Title: whooshing noise
Post by: trotter on April 08, 2010, 08:29:56 AM
Quote from: BenLewisMav;685613I have a similiar issue with a basically standard setup, I\'m loosing not boost (Power fc reads 0.8bar both turbos) and there are no visible leaks/cracks/splits so I\'m not massively concerned. I just presumed it was to do with the aftermarket air filters, as it only does it under partial load/as the turbos are starting to work.

yep, my apexi\'s do this ;)
Title: whooshing noise
Post by: gear1275 on April 16, 2010, 10:17:48 AM
Mine does it all the way through the rev range and I\'m on a stock air box, I have been told to try blanking off the crv and checking the three vacuum hoses coming from the lim to the y pipe and crv, I will know soon if that does any good.