GT2359V safe/sensible boost

[Dum-Dum]

Just wondering if anyone had any ideas on what the safe / sensible boost limit is for the GT2359V

[Ruan]

Wouldn't be so concerned about boost limit, it's probably about 26psi according to the compressor map,but will go to 28 without too much of an issue, it's whether you're pushing into surge before then which I suspect you are...

This is why you need to be so careful with the stop screw, which since yours was a VK you didn't have, if they close up too much, you will strangle the engine, cause massive EMPs and it'll surge like a fucker, that's what absolutely destroys turbos.

The later GTBs really improve on the surge resistance, also yours being off a fairly large engine, I suspect there will be more of a bias towards air movement efficiently rather than higher pressure ratios - but it's a typical Garrett unit which no one has the compressor map for, so you can't tell.

[Dum-Dum]

I have worked out the stop today. I had it too far out when I first fitted the turbo and it struggled to start and wouldn't make more than 5 psi. It's now in very close to where it was standard with the merc, maybe half a turn out.

[zx_volcane]

might be worth chucking an emp gauge on - won't be too much trouble now you're handy with a welder

then you can keep an eye on the ratios during spool, and see if you're raping the turbo or not

[Dum-Dum]

Yeah I defo need an EMP gauge I think as I'm entirely confident it's surging. On a long pull at full throttle in 4th or 5th its making a noise that most people would call wastegate chatter every few seconds with a huge flutter of the boost gauge.

It also makes epic turbo noises if you let off the throttle from full throttle at higher RPMs. I know I shouldn't but I had a great laugh this afternoon startling everyone in town by boosting about in 2nd and then snapping the throttle shut with the associated noise. Such a hooligan.

[Ruan]

And you wonder why you destroyed a turbo... Dear god...

Have you read anything I've posted about vnts and the problems with them!!!!!

[Piggy]

Need to learn to double clutch n keep throttle fluttering between shifts to avoid this.... Or run arduino control.

Its noise addiction that made me ruin the GTS

[Dum-Dum]

And you wonder why you destroyed a turbo... Dear god...

Have you read anything I've posted about vnts and the problems with them!!!!!

Actually in fairness the last one probably died from a kinked oil line.
And I have read one or 2 things you posted, I am aware it kills the turbo but f*ck it sounds awesome. I'm actually considering finding a different actuator and trying to run the vane control off the EMP.

Need to learn to double clutch n keep throttle fluttering between shifts to avoid this.... Or run arduino control.

Its noise addiction that made me ruin the GTS

I just need to lift every couple of seconds on a long pull and not just dump the throttle. The noise is properly addictive though.

[zx_volcane]

Kinked return? You'd know about it, oil backs up, through oil seals and you get a tone if constant blue smoke out back

[Piggy]

Kinked return? You'd know about it, oil backs up, through oil seals and you get a tone if constant blue smoke out back

He did I believe

[pugmanxud]

Not that clued up on vnts but is it worth fitting a dump or recirc valve. Can plumb it in to vac pump microswitch on throttle idle stop and a 12v solenoid valve wouldn't be to much hassle. What sort of noise is it being a vnt Virgin I wouldn't know haha

[Ruan]

This is surge ON the throttle... Nothing to do with lifting off the throttle - that's why it's damaging.

This is happening due to the fact that the turbo is moving too much air at too lower shaft speed - the air pressure is going up due to increased airflow rates, but the flow becomes unstable in the compressor - the turbo eventually gets to the point where the air starts tumbling on the tips of the compressor blades and starts effectively returning back through the housing, causing that massive chirp...

I've seen compressors do this ONCE and snap the shaft clean in half...

https://www.youtube.com/watch?v=nCj6Spwl1CU

Notice it's ON the throttle making those horrific noises. This is generally due to poorly sized or older turbochargers, older generation turbos that are used in larger applications that generally aren't designed for high pressure ratios, rather higher airflow rates... This is why I've harped on so many times about the GTB2056VK on the basis it's compressor geometry is designed for high pressure ratios, making it very resistant to surge. Same goes for the new GTX2860RS Rally turbo:



Notice the pressure ratio goes to PR4.5!!!



Versus the older GT2860RS - only goes to 2.5 before it runs out of puff...

But all of this bollocks is irrelevant because apparently it sounds awesome.

[Piggy]

[bashbarnard]

Yeah but turbo noise is bangin init

On the more serious note we had a pd engine golf in the other day that shat its hot side down the exhaust. Customer was lack of power and rattle.