perfectly normal. i have it on my car too. you'll be hearing many new/strange noises because of the boxer engine as well.

 

I've heard this exact description before, and that's not how I'd describe what goes on in my car.

- Is it at all like a ding/ping/knock sound? Or is it really like a flutterig air/leaves sounds?

- After the first time this happened (or anytime) did you feel that the car started to feel sluggish, or sort of unresponsive when mashing the pedal?

jason

 

Just making sure. I've heard the leaves-crunching story before and the guy said it turned out to be detonation. It also turned out he wasn't really describing the problem/sound very well.

For what its worth, I do not hear a leaves crunching sound. BUt then, I might perceive and anologize the sound differently than you. I'd say though, if you are very keen to how your car drives and pulls, and you feel no difference then computer doesn't seem all that concerned. Even so, its a seat of the pants things. You should get someone local and experienced to take a listen if you really want to calm your fears.

Good luck!

jason

 

Hmmm, that would certainly seem like a telltale sign to me. Which year is your car? '02? '03? It seems that in some of the middle-aged ECUs (like around the turn from' 02 to '03) I've heard more of this behavior. There are other factors too, like you've pointed out. I've always thought Sunoco was pretty good gas, but then I've never used it . I almost always run Unocal/76 91 octane or Chevron 91 octane. (Unfortunately 91 is the best I can get, unless I throw in a gallon of Toluene or Xylene once in a while... yummy!)

Were you able to feel a marked difference in how smooth the engine ran and better throttle response and better consistency at the top end after putting in the 93? When I mix in the race gas ingredients my car feels like a dream! Going back to regular pump is always like a bad hangover .

Also, when I go back to regular gas I try to be gentle on the throttle or mix the regular stuff back in slowly. This way I can let the computer adjust on its own instead of having to baby it for a 1/4 tank so the ECU can realize its getting the crappy stuff again

jason

 

10 bucks says the sound is still there and you didnt have detonation. Thats exactly what the wastegate sounds like on any electronicly modulated boost controller (they open/close wastegate rapidly to control boost) and if you uncork the exhaust and run a bellmouth/divorced downpipe you'll really here it. Detonation sounds metallic (because it is the sound of you're cylinder sleeves being struck like a tuning fork by uneven ignition), not like fluttering. If it has a metallic quality to it then it might be detonation, otherwise it's the wastegate.

 

i'm not able to describe the noise exactly, but i get a wierd noise when i give it a good amount of throttle before the car is fully warmed up, once the car is warmed up, it doesn't do it anymore. but if i let it set idle and let it cool down a bit, it will do it again until it's warmed up again. it started doing it about 8 months ago when i got an uppipe, but it's not a leaking/whistling noise, it more like a louder "leaf noise" . but i've just learned to deal with it, becuase the car still runs very strong and there hasn't been any noticable powerloss. as i said before, it only does it the first couple of minutes i start driving. heat shield on the downpipe feels tight....maybe inside of it???

i have TXS stage 2 plus uppipe, UR pulley, intake, BOV

 

OOOOOOOH! You didn't that before! If this doesn't happen once its warmed up then I am certain its not detonation.

Br1t1shguy's right. But people describe different sounds differenly, and some don't notice certain sounds at all but subconsiously write them off as normal engine noise.

Play with pieces-parts around the turbo and shield when its cold sometimes. The shield is awfully close to the transmission case. Shrug. At any rate, I think you're fine.

As far as what else Br1t1shguy's saying, I have an EBC and I don't get this sound *shrug*. And I'm not sure I follow you. On a stock turbo an EBC is not controlling the wastgate (or actuator) directly. Its controlling the pressure going to the actuator and basically fooling it. The behavior of the EBC doesn't make intake pressure seem irratic to the actuator. The fast solenoid is just a more accurate way of regulating than a slow moving or static valve. To the actuator, things seem (relatively) gradual. If this is true then its the solenoid that's flipping quickly and not the wastegate. Right?

jason

 

All I was saying was that any kind of system, stock or aftermarket, that regulates boost electronicly rather than with a spring/diaphram system etc, opens/closes the wastegate rather than partially opening it etc.