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Engine Specific Info and Questions => IDI Engine => Topic started by: R.O.R-2.0 on February 15, 2012, 12:06:40 pm
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so, my turbo barks every time i shift and i have ANY sort of boost..
ive been under the impression that turbo bark is bad?
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CRSMP5 turbo is living and IIRC his barks every shift.
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Not an expert on this by any means, but from the reading I've done that barking sound is actually the compressed air in the intake manifold / IC following the path of least resistance--which happens to be back through compressor wheel at that particular moment, traveling BACKWARDS through the turbo. It happens when you let off the throttle to shift, which means that the motor isn't providing the turbo with enough exhaust pressure to continue to compress the intake air; this means that you've got 20psi of pressure in the intake that the engine can't use b/c the rpms are too low, and the path of least resistance for that pressurized air is simply to go back through the turbo.
From what I've read it isn't such a huge problem if it only does it once in a while, but supposedly continuous barking spells a guaranteed turbo failure; only a question of time.
Having said that, the only thing I can think of to alleviate the problem would be some sort of one-way check valve right after the turbo, and I've never heard of anyone doing that.
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How many rpm's are you dropping on a shift? Are you granny shifting so that you return to idle every time? ;) kidding.
That seems weird that least resistance would be to fight the already turning compressor wheel.. And not jsut continue its path through the motor and through the exhaust turbine, considering even when you take your foot off the pedal to shift the engine is still processing air.
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How many rpm's are you dropping on a shift? Are you granny shifting so that you return to idle every time? ;) kidding.
That seems weird that least resistance would be to fight the already turning compressor wheel.. And not jsut continue its path through the motor and through the exhaust turbine, considering even when you take your foot off the pedal to shift the engine is still processing air.
yea, its not like the throttle plates close when you shift on a diesel..
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not this again...get off the internet
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not this again...get off the internet
what are you talking about? i just want to be sure that im not gonna kill my turbo before i get a proper downpipe and exhaust fabbed up..
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not this again...get off the internet
Are you drunk again..
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ok ill ask.. wtf is bark?? i get a pm asking.. theman says i have it.. but not a clue to what you speak..
when i say bark.. which i cannot say i have.. its the tires with not enough traction.. :D
i also do not granny shift.. my rpm drops very little between shifts..
my boost is set to 18-21psi
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i feel stupid now >:(
the K24 performs better than the VNT.
i think it even spools as quick, or maybe even quicker..
wastegate unhooked, and i peak 20psi in every gear..
its got compressor surge like a mofo tho.. like every time you shift, the turbo barks.. what gives?
Do you think it would still bark if the wastegate was hooked up?
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My k24 barks, but I only hear the bark after 13-14 psi shifts. Nothing abnormal when shifting down low.
If I stay in to boost longer the bark gets louder. With wastegate hooked up (no MBC) 8-9 psi no bark.
Currently I have no exhaust, just a 2.5" downpipe that just enters the shift rod tunnel.
The GT15 I took off about 2 months ago did not do this when ran with a 2" downpipe only.
The bark occurs about the same time a blow off valve would open on a gasser.
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My k24 barks, but I only hear the bark after 13-14 psi shifts. Nothing abnormal when shifting down low.
If I stay in to boost longer the bark gets louder. With wastegate hooked up (no MBC) 8-9 psi no bark.
Currently I have no exhaust, just a 2.5" downpipe that just enters the shift rod tunnel.
The GT15 I took off about 2 months ago did not do this when ran with a 2" downpipe only.
The bark occurs about the same time a blow off valve would open on a gasser.
what intake setup do you have?
i know ror has an intercooler and a gas intake which would both add volume, so when you let off the the gas and stop giving it fuel, the exhaust side loses the driving pressure so nothing is keeping the pressurized air in the intake/intercooler piping so it can easily revert out the same way it came in, if the engine does not consume that pressurized air fast enough.
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what intake setup do you have?
i know ror has an intercooler and a gas intake which would both add volume, so when you let off the the gas and stop giving it fuel, the exhaust side loses the driving pressure so nothing is keeping the pressurized air in the intake/intercooler piping so it can easily revert out the same way it came in, if the engine does not consume that pressurized air fast enough.
Nicely put; you said what I was trying to say, only much more concisely.
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what intake setup do you have?
i know ror has an intercooler and a gas intake which would both add volume, so when you let off the the gas and stop giving it fuel, the exhaust side loses the driving pressure so nothing is keeping the pressurized air in the intake/intercooler piping so it can easily revert out the same way it came in, if the engine does not consume that pressurized air fast enough.
Just as it reads in my sig. 1.6td intake and intercooled as well.
Kinda sound like ROR and I need a gasser BOV???
Any input on long term effects of running it like this?
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what intake setup do you have?
i know ror has an intercooler and a gas intake which would both add volume, so when you let off the the gas and stop giving it fuel, the exhaust side loses the driving pressure so nothing is keeping the pressurized air in the intake/intercooler piping so it can easily revert out the same way it came in, if the engine does not consume that pressurized air fast enough.
Just as it reads in my sig. 1.6td intake and intercooled as well.
Kinda sound like ROR and I need a gasser BOV???
Any input on long term effects of running it like this?
but, how to operate it?!
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yeah itd be tough unless you let off the gas completely every time u shifted, then it'd be easy you could just have a microswitch that operates a valve that sends the proper signal to the bov. i wonder if it could operated using emps some how like when the difference is above 10psi or something the bov opens
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mine does it to i wouldnt call it a bark tho but i also dont have any really restrictive flow. if i redo my piping ill probably put a bov in my piping and use the vuccume pump as a vac source and a micro switch on the throttle lever of the injection pump. pending it getting sold anyways haha
I don't think that this is as big of an issue as people make it out to be. Especially since u have no throttle body to slam closed. Look at cars like the grand national and others who came without blow off valves and such and still work plenty good. A bov wouldn't hurt tho
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who ever says i do is wrong.. me has no bark at all from teh turbo.. and i have straight pipe off mine.... 2" ic pipes into my big honkin ic..
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It could easily be done. You have a constant vac source. You would need a switch of somekind on the throttle somewhere. A blow off valve and a vac solenoid off a regular car goin from the vac port of the bov to the vac pump which is switched on by the switch. I would think that the hks ssqv blow off valve would be the best seeing as it uses boost pressure to seat the seal and no springs to overcome in vac but I could be wrong.
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use a vacume pod from a distributer.... have boost move it.... and when no boost open up blow off.. way over thinking this...
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but, how to operate it?!
My bad forgot about the lack of vacumn.
What about one of those supercharger surge protectors/ bypass valves mounted in the charge piping.
Even cheaper, would a stock vw pressure relief valve hold up to higher boost (15-20 psi) with a stiffer/shimmed spring?
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Always have vac from the vac pump
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my boost never surges tho.. it drops when i shift, not rises. so i couldnt use the boost as a signal for a valve..
gotta remember, this is not a gasser engine, and it DOES NOT have any sort of vacuum suitable to operate a blow off valve..
you need a vac signal that comes on as the throttle closes..
on a vac pump, the signal rises as the RPM rises..
im just gonna build a downpipe, and see if the surging goes away..
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my boost never surges tho.. it drops when i shift, not rises. so i couldnt use the boost as a signal for a valve..
gotta remember, this is not a gasser engine, and it DOES NOT have any sort of vacuum suitable to operate a blow off valve..
you need a vac signal that comes on as the throttle closes..
on a vac pump, the signal rises as the RPM rises..
im just gonna build a downpipe, and see if the surging goes away..
If it pulls any vac it will be suitable for the hks bov. Did you not just read what I posted earlier about using a micro switch and a solenoid.
Also my boost drops off immediately also
Have a 2 1/4 inch exhaust biggest restriction is the muffler. It will still make that sound
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everyone is overthinking this.. there is an EASY solution somewhere..
and i ABSOLUTELY HATE the sound of blow off valves.. so im not running one..
and why am i the only one who this has ever happened to?
nobody else runs a BOV with a K24.. if i cant get rid of the turbo bark, im going to change the turbo..
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I really can't suggest adding a blow-off/diverter valve on a diesel. I've personally run 3k turbos VERY hard, 2.5bar with no bov or diverter valve in the system at all. Even with the CIS on my old 5ktq it sounded like a rally car, whoosh-whistle-scream-chatter - every gear. Although this was on a gasser, its the same thing happening. I only used one turbo throughout the time I ran the car, 2 engines, 100k miles of abuse. I used the turbo that I had put the abuse on because I had spares and figured I would save the "better" ones when it died, it didn't.
K26 turbo, I got the car with 224k miles with the odo broken. Was original engine, OG headgasket. Drove it for 3 years daily while upping the boost/tune progressively. I replaced the engine due to noise, put that turbo on a new lower end with a big valve/ported head and larger intercooler/exhaust. I even added EFI to it and pushed it HARD for a LONG time.
I found that when I added a diverter/bov it really softened the boost rise/response and promptly removed it.
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one other thing that i must say again, i still have NO DOWNPIPE, and someone else mentioned that K24s bark with no downpipe.. that may be the ONLY thing that i need to do, is finish building my downpipe..
ive driven my car less than 10 miles since installing the K24.. ive driven it enough to know that it barks.. thats all.
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everyone is overthinking this.. there is an EASY solution somewhere..
and i ABSOLUTELY HATE the sound of blow off valves.. so im not running one..
and why am i the only one who this has ever happened to?
nobody else runs a BOV with a K24.. if i cant get rid of the turbo bark, im going to get rid of the turbo..
haha...get rid of your turbo then and quit yelling at every other person on the site that uses one
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i don't know that it's such a big deal, so long as it's not surging while you're accelerating.
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ben, both of your responses to this thread have been somewhat irrelevant.. thats not like you
please quit cluttering my thread with your useless nonsense.. if it doesnt have something to do with your own problems and experiences, or my problem at hand, then please keep your comments to yourself..
both of your responses in this thread have made me think "man, wtf is this guy going on about?"
so, whats up with that? usually you atleast post about something pertaining to the thread at hand, but lately, you havent had anything worth while to say..
and who was i yelling at? what was i yelling about?
im baffled.. i really dont get it..
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i don't know that it's such a big deal, so long as it's not surging while you're accelerating.
only time it surges, is when i let off the throttle.. i can get it to surge in neutral.. but i can never get it to surge under power.. not yet atleast.
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Hey guys, lets be a little more calm. I think we are all trying to help here, so I think we are on the right track, just remember tact and that everyone can have a bad day.
ROR I think once you get a DP fabbed up you will not hear the bark. It will probably still go on, but you won't hear it like the rest of us don't. I could only hear my turbo at all when I was behind the car. That 3" that I ran was .190 wall and really deadens any higher pitched sounds.
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CRSMP5 turbo is living and IIRC his barks every shift.
and his turbo does not ever surge either..
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I don't know if CRMP5 has bark, I was talking to him on the phone one day and from what he described I thought he did. Sorry if I confused anyone. It gets to a point and our turbos or at least mine made a real big noise, I thought we were talking bark but maybe not.
I really think if you get a DP on there you will do well.
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CRSMP5 turbo is living and IIRC his barks every shift.
and his turbo does not ever surge either..
when i set up my boost regulator, did my first road trip to mk1 madness i played with boost levels... below 18-21psi it surges... if the waste gate is set lower.. but cruizin at say 10-15psi no surge..
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This has been discussed many times. What your hearing is NOT surge. It's the pressure difference from having intake manifold pressure and also exhaust manifold pressure then removing the exhaust
(drive) pressure.
You say you have no downpipe. What your hearing is the exhaust side making the noise from what i explained above. Surge is what the compressor does when under load you are pushing too much psi with too low of air flow(i.e. really big compressor wheel)
Your turbo and engine are not at harm.
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My duramax has a chamber connected to the intake
Look at the center top of the engine
There is a black plastic chamber with letters imprinted on it to say duramax 6.6l
On the duramax forums- diesel place.com people block it off the make the turbo sound louder
The reason for it as I understand is to provide a place for the extra air so you don't get hammering against the turbo
So even though it may sound better to others to delete it
I'm going to leave it the way Gm designed it
Jon
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This has been discussed many times. What your hearing is NOT surge. It's the pressure difference from having intake manifold pressure and also exhaust manifold pressure then removing the exhaust
(drive) pressure.
You say you have no downpipe. What your hearing is the exhaust side making the noise from what i explained above. Surge is what the compressor does when under load you are pushing too much psi with too low of air flow(i.e. really big compressor wheel)
Your turbo and engine are not at harm.
THANK YOU!!!
thats EXACTLY the answer i was looking for!!
because it sounded like it was barking from the exhaust side, not the compressor..
ok, so i just need a downpipe..
and JB86, thats an intake RESONATOR.. it quiets the intake air going to the turbo.. it has no performance gain/drawback..
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When my exhaust was open at the end of the downpipe for a while I'd totally hear my K24 bark on shifts. Whatever you have for your intake and exhaust will greatly change what you hear. Lots of sounds disappear in to the factory parts, kinda like they planned it that way...
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When my exhaust was open at the end of the downpipe for a while I'd totally hear my K24 bark on shifts. Whatever you have for your intake and exhaust will greatly change what you hear. Lots of sounds disappear in to the factory parts, kinda like they planned it that way...
i have the stock turbo intake pipe (the one that connects to the actual turbo) and there is nothing more than a cone filter on the end of that..
then for exhaust, im prolly gonna build a downpipe today..
kinda interesting, but i drove the car yesterday, wanted to see if it would bark, and it didnt.. soo weird.
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well i wouldent say that you are in no danger of failure. i have seen what you guys are talking about snaping the turbo shafts off, alough the things i work on are slightly larger, caterpilar c15 and alot of detroit 50 series, but the things that usually break are the ones that are running 40-50 psi. as for what is causing your issue i dont know just wanted to say that it "CAN" cause problems down the road
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When my exhaust was open at the end of the downpipe for a while I'd totally hear my K24 bark on shifts. Whatever you have for your intake and exhaust will greatly change what you hear. Lots of sounds disappear in to the factory parts, kinda like they planned it that way...
i have the stock turbo intake pipe (the one that connects to the actual turbo) and there is nothing more than a cone filter on the end of that..
then for exhaust, im prolly gonna build a downpipe today..
kinda interesting, but i drove the car yesterday, wanted to see if it would bark, and it didnt.. soo weird.
Mine was running with the stock intake tube and a cone filter, FWIW...