Is this compressor surge?

[cat007]

Take a look at this video.
Ignore the text in the video and the miss etc - its an oldish video but the sound at the end of each pull is the same as now - is it compressor surge?
Its NOT coming from the BOV - it's coming from the turbo.
The BOV is opening - but it would seem too slow?
What are your thoughts?

http://youtube.com/watch?v=EFt05ck2iYg

[IH8TEC]

same dyno as i used as for an answer, hmmm, is it worse than in the movie now?

is the bov actually letting out much air?

[Caveman]

hard to tell from the video...

did the tuner say the surge is coming from spooling too fast or if its coming from the BOV not working properly. Both are just a case of the pressure ratio too high for mass flow rate. Im assuming from the nature of your questions is the BOV not working correctly.

Best to try a different BOV off a mate, run a dedicated vacum line off a reliable source with no tees etc.

compressor stall sounds like a chatter noise from the turbo.

[cat007]

Hey all
Yeah that dyno tune was crap. Had a bad miss and the tuner didnt know about the ECU. The new tuner (Kent at Speed Source) didn't say anything about it. I didnt think to ask him - was a bit to excited about getting my car dyno'd and not have it blow up haha. There is no surging or "chattering" from the turbo while on boost - its just as soon as he backs off.....

The noise isn't really any worse/louder than in that video - but it is LOUD.

The BOV is Venting a lot of air - but its almost like its opening too slowly so there's compressor surge THEN the BOV vents...

It sounds almost exactly like this:
http://youtube.com/watch?v=TWTuu1NMWwY

[AE25]

this is what a 1ggte, t04e with no BOV sounds like.. aka the turkey chaser

http://www.youtube.com/watch?v=C9IgBF_TNhQ

[cat007]

Ok well it makes that sound - but only for 1/10th of a second then the BOV vents.....

bah I dont know.

[AE25]

id try a bigger bov and see if that helps

[Crucible]

There has been quite a bit of discussion about what is true compressor surge in this thread..

viewtopic.php?t=61544&highlight=sick

To cut a long story short, The surge you get back through the turbo is caused by the bov opening being too restrictive either by the opening too small or the BOV not responding quick enough. True compressor surge only happens at wide open throttle NOT off throttle and has a way louder aggressive note.

The surge you are experiancing is nothing to worry about and wont damage you're turbo, this is what people in the know have told me on this forum.

I too get surge back through the compressor until my bov responds and vents, thats with a 50mm bov and dedicated line aswell, but meh its been fine and ive had no trouble...

[touge rolla]

Try a softer setting on your blow off valve. If it's out by enough it MAY be the cause.

[cat007]

There has been quite a bit of discussion about what is true compressor surge in this thread..

viewtopic.php?t=61544&highlight=sick

To cut a long story short, The surge you get back through the turbo is caused by the bov opening being too restrictive either by the opening too small or the BOV not responding quick enough. True compressor surge only happens at wide open throttle NOT off throttle and has a way louder aggressive note.

The surge you are experiancing is nothing to worry about and wont damage you're turbo, this is what people in the know have told me on this forum.

I too get surge back through the compressor until my bov responds and vents, thats with a 50mm bov and dedicated line aswell, but meh its been fine and ive had no trouble...

Thank you for your reply.
I understand that comp surge can happen at WOT - but if the turbo is pumping out 15psi @ 8,000rpm into a 2Litre engine (which is a LOT of air) and the throttle is slammed shut - you get the same effect as a massive turbo on a small engine with high boost under WOT - the air has to go somewhere.....

The squeaky compressor surge type noise is LOUD - I am almost tempted to say its louder than my car at full noise on the dyno (240rwkw with wastegate venting externally). Of course its a different tone to the engine/exhaust - but still - VERY loud....

[cat007]

Try a softer setting on your blow off valve. If it's out by enough it MAY be the cause.

I have it wound out as far as it can

[touge rolla]

yeah i figured, but you'd surprised with some people lol.
And my mate actually got better response by HARDENING his HKS bov, weird.
Sounds like you have got a "Toyspeed Anomaly". Try a different bov, hard for anyone to recommend one as they all seem to work differently on different peoples cars

[cat007]

yeah i figured, but you'd surprised with some people lol.
And my mate actually got better response by HARDENING his HKS bov, weird.
Sounds like you have got a "Toyspeed Anomaly". Try a different bov, hard for anyone to recommend one as they all seem to work differently on different peoples cars

I haven't tried tightening the screw yet - too scared too hehe.
I'm almost thinking of putting another BOV just after the turbo (before intercooler) - first thought was the bosche replacement for the 7M-GTE - but I'm not sure what boost they can handle before the start to leak....

[Crucible]

Of course its a different tone to the engine/exhaust - but still - VERY loud....

When I had the faulty SSQ, it kinda sounded like a whip being cracked, with the chachacha after, and was very loud also!. With the 50mm one now, I only get a brief cha, then bov vents. Thats on 19psi aswell.

It sounds like your BOV is just rooted to me lol...

[cat007]

Of course its a different tone to the engine/exhaust - but still - VERY loud....

When I had the faulty SSQ, it kinda sounded like a whip being cracked, with the chachacha after, and was very loud also!. With the 50mm one now, I only get a brief cha, then bov vents. Thats on 19psi aswell.

It sounds like your BOV is just rooted to me lol...

How was yours faulty?
they are so simple I dont see how they can be faulty.
There are no vacuum leaks - maybe the diaphram has gone a bit hard so its slow to react?

[sk1dlet]

this is what a 1ggte, t04e with no BOV sounds like.. aka the turkey chaser

http://www.youtube.com/watch?v=C9IgBF_TNhQ

this is what the stupid aussies call dosing they're mad on it over ther
especally the wogs search VL turbo dosing you'll see what i mean

but yea i'd be looking at ur bov or where your vac feed to the bov is coming from

[Crucible]

How was yours faulty?
they are so simple I dont see how they can be faulty.

dunno, didnt bother stripping it, I just switched to a bigger one.

the diaphrams on the ssqs flex, but dont actually lift off the seat. hks ones use the same diaphram type. the video below shows what I mean about 2/3's through!.

Some people have had better luck with them, but Id never use another one.

http://www.youtube.com/watch?v=MU5Y6d9rh1k

.

[mjrstar]

Here's the video of my 1ggte on 13psi boost (190kw). about 1 minute before i burst the inlet manifold. have since put a larger turbo on and made a bit more power.
http://www.youtube.com/watch?v=QrM43jsoTS8

[cat007]

Nice - have you got any videos of your car on the dyno with 240rwkw?

Hearing Ron's car, he gets the "squeaking" noise as well..... hmmm

http://vids.myspace.com/index.cfm?fusea ... =212981461