Turbo Snort?

[Glenn_A]

I'm wondering what I'm dealing with here and any help is great. I have the famous turbo snort when under throttle and then let off the gas, but what I don't understand is that it happens all the time, even under normal driving conditons (or those where the turbo kicks in a little bit...and I mean just a little bit) that I get the back snorting or back pressure. I know it's the turbo back pressure of exhaust gas and that it can be real detrimental to the turbo's bearings, but I barely get into it such as passing on the road and it does this. Do I need some sort of pressure relief valve like ATR used to sell or what. My mods are the usual street items like adj fuel, 204/214 flat, RJC, 340 Wal, Hot Wire, ported heads, 65mm TB/plenum, 100 lb springs, 36 lb'ers....but to be honest with you, I'm not sure what turbo I have. It could still be the factory Garrett, but the 49's have Garrett stamped on the housing also :redface: I'm reading 0 knock all the time and have plenty of power...I just don't wanna bust something up on my very menial budget....thanks fellas!....Glenn

 

[turbo nasty]

I'm running a smaller GT3255E on the 87 and it spools quick and compressor surges easily.

 

[scottyb]

FWIW, mine also makes the snort sound under normal driving conditions. The sound is there on all cars, but you don't hear it until you install a free flowing air filter setup. The stock setup muffles it. If I get the vacuum anywhere less than 5in and let off, it makes the noise. I can't comment on how "damaging" this is. My turbo is a stocker with unknown age (could be original for all I know), car has 200k miles, and I've put the last 50k miles on it. Frankly, I wish the turbo would take a dump so I can more easily justify an upgrade, but my antics haven't killed it yet!

 

[Glenn_A]

Turbo snort

Yea, thats for sure about where it's coming from because I hear it coming from the K&N behind the drivers air dam....well, maybe nothings wrong then

 

[Ormand]

Mine has almost 200,000 miles on the original turbo, and the "noise" hasn't hurt it yet. The ricers have a blowoff valve, which substitutes a different noise, and takes the load off the thrust bearing, but it doesn't seem to be needed on the Buicks, unless maybe the ones with the big turbo/small shaft combo. Not on the OEM turbo, anyway.

 

[turbopete]

Turbine flutter

Do a search for that. There was a long post about it a few months ago. For part throttle, it has something to do with the exhaust side not moving as much air out as is coming in. When you let off, I think it is the air not moving out the exhaust going out the path of least resistance (K&N).
I have the "flutter" at part throttle, but less at WOT.
I think the majority opinion was that it was not damaging, all else being in good shape.
Don't quote me on this. It is what I remember...

 

[Glenn_A]

Snort

Thanks for the help fellas, I've always known about the snort with our cars, but it's more noticeable on my T and sounds like crappola to me. Again I don't seem to suffer any power loss of any kind and the wheels really break loose on the street. I'm still in my break-in period with the motor and never really looked at the turbo, but I did figure it out to be a 49.....any other opinions or ideas are appreciated