Compressor Surge GOOD or BAD?

[enjoitharex]

Originally Posted by Roto

How about five weeks? That is how long it took my freshly rebuilt TD04 to start pouring oil from thrust bearing wear when the spring in my BOV failed and I was too busy listening to music than to what was going on under the hood.

P.S. That is not my diagnosis, that is the diagnosis of a reputable turbo rebuilder.

quality of parts maybe?..Was the CHRA balanced in the first place??

So for 5weeks you went driving around with a "NO BOV and you never heard the compressor. Or you did but failed to do anything about it..

[redtoprps13]

Originally Posted by Roto

How about five weeks? That is how long it took my freshly rebuilt TD04 to start pouring oil from thrust bearing wear when the spring in my BOV failed and I was too busy listening to music than to what was going on under the hood.

P.S. That is not my diagnosis, that is the diagnosis of a reputable turbo rebuilder.

did you break the turbo in before beating on it...that is the common early death cause for most turbos.....

[Roto]

Originally Posted by enjoitharex

quality of parts maybe?..Was the CHRA balanced in the first place??

So for 5weeks you went driving around with a "NO BOV and you never heard the compressor. Or you did but failed to do anything about it..

Yes, it was balanced. I kept hearing flutter, but kept thinking it was normal as long as I hear what I thought was my BOV until one day I start smoking like a diesel Jetta and than send the turbo back under warranty only to have them tell me that thrust bearings don't wear like that in 5 weeks when you have a properly functioning car. Took me a couple of days to finally figure out my bov wasn't working at all, taking it apart and finding this:



Basically I was running no BOV all this time and turns out this damn thing was the reason I had to rebuild it in the first place. Same exact thing both times - worn to hell thrust bearing.

[Roto]

Originally Posted by redtoprps13

did you break the turbo in before beating on it...that is the common early death cause for most turbos.....

Not only did I take it easy on it for 500 miles I also pre-oiled it.

[redtoprps13]

Originally Posted by Roto

Not only did I take it easy on it for 500 miles I also pre-oiled it.

how long did you let the car idle before driving it with new turbo?

and how much boost were you running on it?

[TunedIS300]

Originally Posted by Roto

How about five weeks? That is how long it took my freshly rebuilt TD04 to start pouring oil from thrust bearing wear when the spring in my BOV failed and I was too busy listening to music than to what was going on under the hood.

P.S. That is not my diagnosis, that is the diagnosis of a reputable turbo rebuilder.

damnnn

[TunedIS300]

how bad would compressor surge me for a turbo running say 10-12 psi daily wiuth no BOV?

[Roto]

Originally Posted by redtoprps13

how long did you let the car idle before driving it with new turbo?

and how much boost were you running on it?

it idled for about 40 minutes. I ran for 500 miles on base boost which is 5psi and than went right up to 20 as that's where I daily drive it at.

[redtoprps13]

Originally Posted by TunedIS300

how bad would compressor surge me for a turbo running say 10-12 psi daily wiuth no BOV?

psi means nothing...10 psi on t25g is different than a gt30r.......and then you have to consider what type of turbo...jounal or bb turbo etc....and it's really hit or miss to begin with...some turbos are fine others just go to go

[Roto]

Originally Posted by TunedIS300

how bad would compressor surge me for a turbo running say 10-12 psi daily wiuth no BOV?

That will depend on the motor/turbocharger combination. I bet you know what my position is on running with no BOV, but than again I was overboosting. Who knows how long it would have lasted at 10 or even 15 psi which is the factory limit.

[redtoprps13]

Originally Posted by Roto

it idled for about 40 minutes. I ran for 500 miles on base boost which is 5psi and than went right up to 20 as that's where I daily drive it at.

that's probably what did it

[redtoprps13]

http://www.turbobygarrett.com/turbob...nter/faqs.html

What is compressor surge?
The surge region, located on the left-hand side of the compressor map (known as the surge line), is an area of flow instability typically caused by compressor inducer stall. The turbo should be sized so that the engine does not operate in the surge range. When turbochargers operate in surge for long periods of time, bearing failures may occur. When referencing a compressor map, the surge line is the line bordering the islands on their far left side.
Compressor surge is when the air pressure after the compressor is actually higher than what the compressor itself can physically maintain. This condition causes the airflow in the compressor wheel to back up, build pressure, and sometimes stall. In cases of extreme surge, the thrust bearings of the turbo can be destroyed, and will sometimes even lead to mechanical failure of the compressor wheel itself.
Common conditions that result in compressor surge on turbocharger gasoline engines are:

* A compressor bypass valve is not integrated into the intake plumbing between the compressor outlet and throttle body
* The outlet plumbing for the bypass valve is too small or restrictive
* The turbo is too big for the application

there you go

[Roto]

Originally Posted by redtoprps13

that's probably what did it

Not really a valid argument. I drive it that way now and it's been 8 months since the rebuild after that one. There's also countless others who drive the same engine/turbo with even more boost (which over 20psi starts making no sense with this turbo) daily and have no failures.

[TunedIS300]

i was "told"/"heard" that journal bearing turbo are some what "ok" with surge is there any truth to this...i kinda feel its either ur lucky or unlucky with surge.

[redtoprps13]

Originally Posted by Roto

Not really a valid argument. I drive it that way now and it's been 8 months since the rebuild after that one. There's also countless others who drive the same engine/turbo with even more boost (which over 20psi starts making no sense with this turbo) daily and have no failures.

i was talking about without a BOV. and in my other statement i said it's really hit or miss...some turbo die others are fine.

[Roto]

Originally Posted by redtoprps13

i was talking about without a BOV. and in my other statement i said it's really hit or miss...some turbo die others are fine.

Yeah... without a BOV a TD04HL-18T at 20psi eats itself up... I learned the hard way and I dare anyone to try this again and prove me wrong Than again I don't know how it'd do on 10psi without a BOV on something with a much bigger intake tract volume.

[enjoitharex]

Originally Posted by Roto

Yeah... without a BOV a TD04HL-18T at 20psi eats itself up... I learned the hard way and I dare anyone to try this again and prove me wrong Than again I don't know how it'd do on 10psi without a BOV on something with a much bigger intake tract volume.

We all know PSI means nothing..in respect of comparing turbo to turbo.

But if a turbo thats can handle 1bar+ shuts down after split second blips of compressor surge mgiht have me wondering. IDK what PR it would quickly shoot to, but compressor surge is a bit like grinding gears, it happens for a second and its gone, but rather than metal and metal...its "air" and metal....

Basically what i am saying is it should be built to handle the abuse...unless your already amxing it out which i highly doub you are.

[redtoprps13]

don't race cars run like 30+psi with no bov on much more expensive setups with issue?.....my bov is set to maximum stiffness granted i've never run more than 15 psi off of a t25g....and the gt28rs is set to 8 psi since i only have 370cc injectors...but i never had issue with my car...in fact i only got an issue after boosting my turbo near effciency limit for prolonged periods of time

[TunedIS300]

Originally Posted by enjoitharex

We all know PSI means nothing..in respect of comparing turbo to turbo.

But if a turbo thats can handle 1bar+ shuts down after split second blips of compressor surge mgiht have me wondering. IDK what PR it would quickly shoot to, but compressor surge is a bit like grinding gears, it happens for a second and its gone, but rather than metal and metal...its "air" and metal....

Basically what i am saying is it should be built to handle the abuse...unless your already amxing it out which i highly doub you are.

so ur saying the turbos should be built to handle the abuse of compressor surge..i mean it sounds right.

[Roto]

Originally Posted by enjoitharex

We all know PSI means nothing..in respect of comparing turbo to turbo.

But if a turbo thats can handle 1bar+ shuts down after split second blips of compressor surge mgiht have me wondering. IDK what PR it would quickly shoot to, but compressor surge is a bit like grinding gears, it happens for a second and its gone, but rather than metal and metal...its "air" and metal....

Basically what i am saying is it should be built to handle the abuse...unless your already amxing it out which i highly doub you are.

Oh I am actually maxing it out. Anything more and it's just more hot air, more psi on the gauge, and no performance benefit. These were designed with half the pressure in mind with short spikes to what I'm running daily.