951 and the GT-k turbo
09-24-2007, 05:08 PM
#46
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perhaps the turbo pump relay/sensor were bad? you can test this by simply disconnecting the connector at the end of the wire where it attaches to the temperature sensor nipple, and grounding it somewhere. it should start the turbo pump up and run for 30 seconds. it's also a convenient way to 'reset' the timer if you want after a hot shutdown.
i'm not saying the oil temperature will rise, i'm saying the turbo center section temperature will not be cooled down as effectively, which is the main source of the oil coking issue. as long as the motor is running, hot exhaust is flowing through the turbo hotside, which transfers heat to the center section where the oil cokes.
shutting the motor off and pumping coolant directly through the center section is more effective at keeping the center section temperature down. this should be obvious.
i'm not saying the oil temperature will rise, i'm saying the turbo center section temperature will not be cooled down as effectively, which is the main source of the oil coking issue. as long as the motor is running, hot exhaust is flowing through the turbo hotside, which transfers heat to the center section where the oil cokes.
shutting the motor off and pumping coolant directly through the center section is more effective at keeping the center section temperature down. this should be obvious.
I dont think all of the cars we work on had bad temp senders.I wasnt out their with a stop watch either. Now there is an aftermarket temp switch we use which can keep the pump running longer but it is not the stock one. If the oil drains out of the center section after shutdown,then water running through the housing will not do much except cool the residual oil a little which could prevent coking,I guess over a long period of time.The idea behind keeping the car running after full boost runs(aka turbo timer) is to allow the oil to keep circulating through the center section and the oil will be much cooler after it idles the it is right after a hard boost run.
09-24-2007, 05:22 PM
#47
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I run watercooling on my turbo and I still always idle it before I shut it down if I run it hard.
Nize watercooling has its positives and negatives like deleting it makes the engine bay simpler, the coolant cooler and less places to leak
Nize watercooling has its positives and negatives like deleting it makes the engine bay simpler, the coolant cooler and less places to leak
09-24-2007, 05:32 PM
#48
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@porschefile:
I am aware about the similarity of the HKS and the Garret turbos. I was just wondering why suddely there is such an interest in the turbonetics turbos although at least HKS already had the drilled compressor housings a year before turbonetics sold it as a big inovation. At the time it appeared on the market it looked like a "quick fix" anti surge housing even though it was actually more expensive than other turbos. I though it was a reaction to the increased sales of anti surge housings and how do you do this if you still have a lot of non vented housings? You start drilling some holes into the exsisting housings and I think it is a good idea with some advantage over the std Garrett anti surge housings. I really hope that turbonetics would back up their advertisement with data to validate.
Not planing it either. One car runs on a lindsey S75 and will switch to E85 during the next week(s) for enviormental reasons.... My second, more track orientated car will run a GT30R on a 2.8 stroker for respons (almost finished).
-your engine is a RB20? does not look like a 26.
I am aware about the similarity of the HKS and the Garret turbos. I was just wondering why suddely there is such an interest in the turbonetics turbos although at least HKS already had the drilled compressor housings a year before turbonetics sold it as a big inovation. At the time it appeared on the market it looked like a "quick fix" anti surge housing even though it was actually more expensive than other turbos. I though it was a reaction to the increased sales of anti surge housings and how do you do this if you still have a lot of non vented housings? You start drilling some holes into the exsisting housings and I think it is a good idea with some advantage over the std Garrett anti surge housings. I really hope that turbonetics would back up their advertisement with data to validate.
Not planing it either. One car runs on a lindsey S75 and will switch to E85 during the next week(s) for enviormental reasons.... My second, more track orientated car will run a GT30R on a 2.8 stroker for respons (almost finished).
-your engine is a RB20? does not look like a 26.
09-24-2007, 05:58 PM
#49
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My turbo water pump runs 27 sec after every shut-down irrespective of coolant temperature. If the coolant temperature is above the thermo-switch level (110 ºC), then it will run and continue another 27 sec after the temperature has gone below the thermo-switch level, all this with and without the ignition on or even the key inserted and all on OEM components.
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
09-24-2007, 06:45 PM
#50
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My turbo water pump runs 27 sec after every shut-down irrespective of coolant temperature. If the coolant temperature is above the thermo-switch level (110 ºC), then it will run and continue another 27 sec after the temperature has gone below the thermo-switch level, all this with and without the ignition on or even the key inserted and all on OEM components.
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
This center section does not have water jackets.
09-24-2007, 10:58 PM
#51
Three Wheelin'
@porschefile:
I am aware about the similarity of the HKS and the Garret turbos. I was just wondering why suddely there is such an interest in the turbonetics turbos although at least HKS already had the drilled compressor housings a year before turbonetics sold it as a big inovation. At the time it appeared on the market it looked like a "quick fix" anti surge housing even though it was actually more expensive than other turbos. I though it was a reaction to the increased sales of anti surge housings and how do you do this if you still have a lot of non vented housings? You start drilling some holes into the exsisting housings and I think it is a good idea with some advantage over the std Garrett anti surge housings. I really hope that turbonetics would back up their advertisement with data to validate.
Not planing it either. One car runs on a lindsey S75 and will switch to E85 during the next week(s) for enviormental reasons.... My second, more track orientated car will run a GT30R on a 2.8 stroker for respons (almost finished).
-your engine is a RB20? does not look like a 26.
I am aware about the similarity of the HKS and the Garret turbos. I was just wondering why suddely there is such an interest in the turbonetics turbos although at least HKS already had the drilled compressor housings a year before turbonetics sold it as a big inovation. At the time it appeared on the market it looked like a "quick fix" anti surge housing even though it was actually more expensive than other turbos. I though it was a reaction to the increased sales of anti surge housings and how do you do this if you still have a lot of non vented housings? You start drilling some holes into the exsisting housings and I think it is a good idea with some advantage over the std Garrett anti surge housings. I really hope that turbonetics would back up their advertisement with data to validate.
Not planing it either. One car runs on a lindsey S75 and will switch to E85 during the next week(s) for enviormental reasons.... My second, more track orientated car will run a GT30R on a 2.8 stroker for respons (almost finished).
-your engine is a RB20? does not look like a 26.
Nope, it's an R33 Rb26.
Actually, Precision Turbo has been drilling compressor housings exactly like the GT-K stuff for years, so it isn't anything new. All it is is the holes (or slots on some anti-surge housings) are drilled to a level lower than the top of the compressor inlet, and then farther down from the top of the center section of the compressor housing, the housing itself is drilled or cut into "vents" to allow excess pressure to bleed back towards the top. It's tough to explain, but very simple in concept. Here's the best picture I could find to show what I'm talking about:
This is the style anti-surge housing that uses the typical "slit" design like you normally see on Garrett, HKS, Holset, and lots of other OEM stuff. Notice the smaller center section of the comp. housing directly surrounding the wheel. Now notice the small slits at the bottom of the housing? That's basically all there is to it. Basically it's just creating a path of lower resistance.I'm interested to see how these GT-K turbos perform. I'm a staunch advocate of the GT-R series stuff however, competition is great for any market and really only serves to create better products as a result.
09-24-2007, 11:04 PM
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this thread is written like its the first ever to put a nice garret based turbo on a non garrett car. Well it has been going on for a while and out in the back woods of australia if you wanted to use a cheap or should i say cost effective garrett on a IHI turbo car you would just have a run of turbine housings made to suit have a look at AVO APS or even KOKELN .
I find it disappointing that an operation as professional as yours Tim does not offer the a bolt on turbo if not correct housing even change over crossover and dump pipe is a reasonable compromise and not so hard to implement.
I find it disappointing that an operation as professional as yours Tim does not offer the a bolt on turbo if not correct housing even change over crossover and dump pipe is a reasonable compromise and not so hard to implement.
09-24-2007, 11:15 PM
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well here is what i understand of surge it is when we try to go left of the map so high boost low flow the slits shown in the above pic allow more air to enter the secondary (shorter) blades . the only way you will ever see surge not on a deisil is with a small exhuast a/r and perhaps some on/of driving you can just tune it out selecting the turbine housing ,
I have never seen any evidence to sujust there are any performance gians available with anti surge set ups . when you spend big on a new turbo just buy one with a big enough inducer to support your power ambitions
I have never seen any evidence to sujust there are any performance gians available with anti surge set ups . when you spend big on a new turbo just buy one with a big enough inducer to support your power ambitions
09-24-2007, 11:22 PM
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this thread is written like its the first ever to put a nice garret based turbo on a non garrett car. Well it has been going on for a while and out in the back woods of australia if you wanted to use a cheap or should i say cost effective garrett on a IHI turbo car you would just have a run of turbine housings made to suit have a look at AVO APS or even KOKELN .
I find it disappointing that an operation as professional as yours Tim does not offer the a bolt on turbo if not correct housing even change over crossover and dump pipe is a reasonable compromise and not so hard to implement.
I find it disappointing that an operation as professional as yours Tim does not offer the a bolt on turbo if not correct housing even change over crossover and dump pipe is a reasonable compromise and not so hard to implement.
The thread was written because of some new technology that is the first to be adapted to the 944t. I know the GT series using aint surge housings,etc....but the innovations that Turbonetics made have easily eclipsed what Garret has done for the past 10 years.They did win five awards at Sema including best new product.I think that should say enough.
I am sorry that you are dissapointed that the KKK housing is not available for the GT-k yet. We do have the two piece crossover pipe and downpipe for the GT-k though. I dont know why you thought otherwise?
09-24-2007, 11:36 PM
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In light of the plumbing offered i apologize for my hasting flaming .It was not mentioned in this thread so i didn't consider it .
Please consider my high expectation's of you a compliment spawned from your web page and involvement on the forum .
Please consider my high expectation's of you a compliment spawned from your web page and involvement on the forum .
09-25-2007, 12:33 AM
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No problem. No offense taken.
Tim
09-25-2007, 01:01 AM
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My turbo water pump runs 27 sec after every shut-down irrespective of coolant temperature. If the coolant temperature is above the thermo-switch level (110 ºC), then it will run and continue another 27 sec after the temperature has gone below the thermo-switch level, all this with and without the ignition on or even the key inserted and all on OEM components.
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
Furthermore, coolant offers a safety buffer that oil does not have, since it has very high latent heat, also meaning that a huge amount of calories are extracted once it starts boiling and the temperature simple cannot go much above the boiling temperature of the coolant (far below oil coking temperature). Oil on the other hand starts its destructive coking at its boiling point.
Tim, if the center section already has a water jacket and just need plumbing, why not design this plumbing for those who want to protect their investment and offer that as an option at a cost your business can justify?
Laust
Good info.Honestly,it has been quite some time since I sat there and monitored how long the pump runs after shutdown.The pump running after shutdown will really only cool the center housing itself and any residual oil that is in the there.Will this stop coking, I guess it will help.
Now think about it from this perspective.You drive real hard under boost with a watercooled turbo,the oil feeding the turbo rises to lets say 250F for a brief amount of time and you shut your car down abrubtly.The oil wil still be hot and the watercooliing wil definitely help cool the residual oil but I sriously doubt the temp will drop significantly.
Now you run your oil cooled only turbo real hard under full bost and instead of shutting it off abrubtly,you let the engine run for 15-30 seconds withthe oil actually still circulating.The oil temp was drop significantly since there is a good pressure and volume pumping though the turbo.Is this drop more then tha of the watercooled turbo?Hell I dont know but it brings up an interesting point.Only those scientific geek types would be willing to find this info out and let us know
Now if you did this with your watercooled turbo then ofcourse,the oil left in the turbo would be cooler then the oil cooled turbo after ****down. I am a big advocate of watercooling. Been for years.The thing is that we are talking about a turbo(at least this center section) that was designed around not having water cooling and alot of people are getting all bent out of shape
For thirty years 911's ran with no water in them at all and I think we will be ok if water doesnt run through our turbo
We will offer the fittings and parts needed to run the water lines for the watercooled turbos if people want it.
09-25-2007, 01:38 AM
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funny spelling mistake there Tim . was it the first 300zx ?that had an electric oil pup circulate after shut down . it is the still oil coking on the shaft that is the issue the oil needs to flow until the shaft is below coking temp surely oil tech is helping us these days.
i laugh at you then type cocking twice
i laugh at you then type cocking twice
09-25-2007, 02:12 AM
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tim; do you know what the average life expectancy of a turbocharger on an air-cooled 911 turbo is? i can guarantee you it's nowhere near the +200k miles it is on a 951.
09-25-2007, 03:51 AM
#60
Three Wheelin'
Couple of comments:
Watercooling is absolutely the best method of preventing coking. The turbine housing acts as a heat "battery". When you shut off the engine, temperatures in the center housing start rising and don't peak until as much as 10 minutes have passed. With proper watercooling, you'll see an effect called "thermal siphoning" that boils off coolant, blowing steam into the tank, and siphoning new coolant in to take its place. This helps regulate the temperatures of the internals of the turbo, keeping them below oil coking temps.
The holes drilled around the perimeter of the compressor inlet of the GT-K are just a fancy looking way of doing a ported shroud. These have been available on other company's turbos for years, identifiable by the large slots in the same position of the drilled holes on the GT-K. While there will be some increased flow compared to a non-ported shroud, its typically coupled with some reduced efficiency over the rest of the map. The major purpose is as the name suggests, preventing/reducing surge. During surge, the compressor outlet is at low flow. The compressor wheel is spinning, but the air has no where to go. So with this port, the air compressed by the full length blades can escape and recirculate back into the inlet, rather than adding to the surge. Here's a pickature:
Also, the GT-K still uses Turbonetic's old hybrid single bb. That means it has a traditional journal bearing on the turbine side.
Watercooling is absolutely the best method of preventing coking. The turbine housing acts as a heat "battery". When you shut off the engine, temperatures in the center housing start rising and don't peak until as much as 10 minutes have passed. With proper watercooling, you'll see an effect called "thermal siphoning" that boils off coolant, blowing steam into the tank, and siphoning new coolant in to take its place. This helps regulate the temperatures of the internals of the turbo, keeping them below oil coking temps.
The holes drilled around the perimeter of the compressor inlet of the GT-K are just a fancy looking way of doing a ported shroud. These have been available on other company's turbos for years, identifiable by the large slots in the same position of the drilled holes on the GT-K. While there will be some increased flow compared to a non-ported shroud, its typically coupled with some reduced efficiency over the rest of the map. The major purpose is as the name suggests, preventing/reducing surge. During surge, the compressor outlet is at low flow. The compressor wheel is spinning, but the air has no where to go. So with this port, the air compressed by the full length blades can escape and recirculate back into the inlet, rather than adding to the surge. Here's a pickature:
Also, the GT-K still uses Turbonetic's old hybrid single bb. That means it has a traditional journal bearing on the turbine side.