Wastegate question...

I understand what they are and how they work, but other than watching rally, I've never actually heard one on a street vehicle. How often would you actually hear it, and I mean the full blown "psshh" sound? I'm asking because there's a guy who drives by a few times a night, and every gear I'm hearing it over the fart can. And I live in a 40km/hr zone (and he's not getting much higher than that, if at all). My suspicion is his Neon (might be an SRT/4) has the fake one with the speaker on it. Especially if he is only doing 40km (25 mph). I'd think for him to get the gate going, he'd be spinning his tires if he's stomping it, and he's going 1-2-3, and certainly wasn't blowing away the speed limit.

 

The Psssht sound is from the blow off valve and not the waste gate. You will hear it each time he shifts or completely lets off the gas. The blow off valve vents pressure from the intake between the turbo and manifold when the throttle completely closes to prevent excess pressure build up in the intake. The reason you don't hear it on factory turbo cars is because it is vented back into the intake before the turbo and not to the atmosphere.

 

Whattaya know...apparently I wasn't as smart about wastegates as I thought. I always thought the BOV was part and parcel of the wastegate. I've seen a couple of fake ones on the internet for just the reason you mention, Whipper. Any chance this thing is legit, or is it purely so it can sound like a fat gay man after too many beans? Seems odd that I guy would go through three gears before 40km/hr and sound like he's rallying.

 

Okay, but the important thing is...it's still correct for me to point and laugh at 1 am when he goes by my house and not breaking 25 mph?

 

that's why you adjust the spring. or use a SSQV or a Synapse that don't need adjustment.

yes BOV's aren't completely necessary but they do aid in alleviating whatever little compresser surge builds up during the shift.

the loss of pressure and subsequent need to build boost up can be seen by some as a drawback; although some people i know prefer this as it suits their driving style better.