TWINS ??? Which Ones And Why?
09-04-2007, 07:19 PM
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The turbo should (edit: NOT) be carboning up. If you are that overfueled where carbon is building up on the turbo, I think you are losing a 40 simply due to a weak shaft.
I'm hoping you see 450 from that 4088. By my guesstimations, it should support almost 500 if the engine will breathe. That's means 450 on a 12V might be tough to do.
JMO
I'm hoping you see 450 from that 4088. By my guesstimations, it should support almost 500 if the engine will breathe. That's means 450 on a 12V might be tough to do.
JMO
I should have more fuel than this thing can burn...but I'm almost clearing it up...something's not right with the fueling. As soon as I get it back together, and get the head sealed up, it'll get dynoed if the fueling issues are fixed...if not, the pump goes to a different shop
Chris
09-05-2007, 02:59 AM
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09-05-2007, 10:34 AM
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09-06-2007, 10:52 PM
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20-30 minutes. I guess your not relacing o-rings on the connectors tubes. I got my motor hot and the o-rings where tuff to wiggle out. How do you get the connector tubes out enough to put in the new injector. I did some by just pulling out the injector but it bent the tubes ends. A hot engine, your are one heck of tuff man. I pulled out some hot injectors that where still smoking. Those babies where hot. The front was ok, the back ouchie.
09-07-2007, 01:44 AM
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I tried a hot stick swap. Melted my rubber gloves, so I decided to wait.
I decided I prefer to take more time to do a swap, and thereby avoid having to do it again when I don't do it right
I decided I prefer to take more time to do a swap, and thereby avoid having to do it again when I don't do it right
09-07-2007, 08:45 AM
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09-07-2007, 11:45 PM
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20-30 minutes. I guess your not relacing o-rings on the connectors tubes. I got my motor hot and the o-rings where tuff to wiggle out. How do you get the connector tubes out enough to put in the new injector. I did some by just pulling out the injector but it bent the tubes ends. A hot engine, your are one heck of tuff man. I pulled out some hot injectors that where still smoking. Those babies where hot. The front was ok, the back ouchie.
On my '02 I swapped the injectors no less than 50 times and never changed an o-ring. You loosen the line, pull it out of the way, and pry the connector tube out. I always used a screwdriver. Once the connector tube is backed out let the line loose on top of it (rest it on the connector tube). That helps keep the connector tube far enough out of the head to clear the injectors. When the head is hot they actually come out as well as go in easier. The steel in the head expands from the heat. A totally cold motor is actually the hardest to pull and replace injectors on. When the motor was hot I use to lay a towel over the front portion of the motor to keep from burning the crap out of my arms. A friend and I use to travel to events together and we would tow each others truck. So we changed injectors a lot and raced each other changing them often. I think the fastest I've done it with hand tools is 22 minutes and about 15 with air tools. It was always under 30 minutes even with a scalding hot motor. We did pull the back ring (for pulling the head) and left off 1 or 2 injection line clamps to speed things up.
09-10-2007, 06:37 PM
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Have you every checked for leaking fuel coming out the connector tubes. Mine used to drip fuel on the ground they where so bad. You have to wash the motor really good to see the leaks and which injector is leaking. Your still the man, 20 minutes. The fastest I've done is around the 45 minutes. Its wasn't perfect but I got different sticks in her.
09-11-2007, 03:06 AM
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I always checked for leaks external to the head. If it leaks internally it goes through the return line. I think the reason I had good luck with leaks is because I did change them often. If you leave them alone for long periods of time they tend to corrode and the corrosion causes more leaks then anything. I have actually taken all of the lines off of a few trucks to sand the tips of the injection lines due to the corrosion. After bleeding the lines I usually used brake cleaner to wash all the diesel off to check for leaks.
09-12-2007, 01:12 AM
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So what kind of horsepower would you see from a GT37/4202R twin set up. That 4202R is good enough for 1000HP alone. Would you still be able to get close to that in a twin setup with huge injectors. I have the 42 on my truck now 74.5mm/1.15ar way to laggy I need twins. It's a 2:1 ratio with these turbos 45lbs/min on the Gt37 and 95lbs/min on the 42.
09-12-2007, 01:36 AM
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The 4202 won't come near supporting 1000hp in a diesel. Big dollar Supra, sure-- but not on a 5.9CTD.
Don't just look at mass flow but mass flow AT PRESSURE. Figure about 90lb/min at 4:1 PR for the 4202.
The 4202 is good for maybe 650hp-- but that's the ragged edge.
If you want to make big power with a Garrett primary, you need to go bigger-- something more like the 4718 which is almost 140lb/min.
Turbo sizing of one relative to the other is a function of what matters most to you. If you want the fastest spoolup, then you'll go with a turbo where you mass flow is on the ragged edge of the right side of the map. IOW-- the 4202 would be your choice in the 600hp range.
But if you don't mind a little more lag on the big charger, you can gain efficiency by going to a bigger charger. You also need to determine how much PR your big charger will have to supply to the small turbo to meet the flow requirements, and this is a function of how much the small turbo will flow.
The GT37 for our trucks is actually closer to 70lb/min in stg 3 form.
The the first step is determining what pressure ratio the small turbo will run at. Then you calculate how much air it will take to supply that turbo and produce the TOTAL pressure ratio you need to have the airflow you require.
I've posted how to do this not too long ago, but it will take a lot of reading--- sorry that my posts tend to get so long, but hopefully they are somewhat enlightening.
Justin
Don't just look at mass flow but mass flow AT PRESSURE. Figure about 90lb/min at 4:1 PR for the 4202.
The 4202 is good for maybe 650hp-- but that's the ragged edge.
If you want to make big power with a Garrett primary, you need to go bigger-- something more like the 4718 which is almost 140lb/min.
Turbo sizing of one relative to the other is a function of what matters most to you. If you want the fastest spoolup, then you'll go with a turbo where you mass flow is on the ragged edge of the right side of the map. IOW-- the 4202 would be your choice in the 600hp range.
But if you don't mind a little more lag on the big charger, you can gain efficiency by going to a bigger charger. You also need to determine how much PR your big charger will have to supply to the small turbo to meet the flow requirements, and this is a function of how much the small turbo will flow.
The GT37 for our trucks is actually closer to 70lb/min in stg 3 form.
The the first step is determining what pressure ratio the small turbo will run at. Then you calculate how much air it will take to supply that turbo and produce the TOTAL pressure ratio you need to have the airflow you require.
I've posted how to do this not too long ago, but it will take a lot of reading--- sorry that my posts tend to get so long, but hopefully they are somewhat enlightening.
Justin
09-12-2007, 02:30 AM
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Ok I ran a few numbers. Let's say you want to run your Garrett stg 3 at a maximum PR of 3.5:1 as a small turbo in twins.
This means it will not only be able to spool a larger primary, but it will NEED a larger primary to keep it fed because it's flowing more air at 3.5:1 (about 35psi boost) than it is at 2.5:1 (about 21psi of boost).
This is where we start to get into twins philosophy, and there's no wrong way or right way. But there are two way to look at twins:
1) You are "turbocharging" the small turbo with the big turbo, so you want the small turbo to do more work.
2) You are using the small turbo just to "light" the big turbo. In this case, you want the big turbo doing more work, and you just want the small turbo to bridge the gap until it lights and the big turbo will will have the higher PR and "do more work."
Of course, there's always some middle ground, too.
Personally I always felt that it's better to try and "multiply" the small turbo using the big one and minimize the amount of gas that is bypassed around the little charger. I also thing that the PR in the cold pipe should be kept relatively low. Remember, the more PR you try to stuff into the little turbo, the more restrictive it becomes.
Anyway, if you are trying to "light" the big turbo, you'd run a little smaller primary that will come in earlier-- something like a 4202.
But if you're just trying to "plus up" the small charger, you would probably consider running a bigger turbo like the 4508 because spoolup isn't as important-- the little charger is carrying more workload.
Incidently, about the biggest primary that you can comfortably use with a Garrett stg 3 as the top charger is a GT4718 with the tightest housing, still a massive turbo.
Honestly, I think that a Garrett Stg 1 would make a better top turbo-- and paired with a 4202 with the 1.15 housing, you'd have a KILLER set of twins.
If you go with the Stg 3 Garrett, you could step up the big charger all the way to that massive 4718
That's 800hp worth of air, imo.
This means it will not only be able to spool a larger primary, but it will NEED a larger primary to keep it fed because it's flowing more air at 3.5:1 (about 35psi boost) than it is at 2.5:1 (about 21psi of boost).
This is where we start to get into twins philosophy, and there's no wrong way or right way. But there are two way to look at twins:
1) You are "turbocharging" the small turbo with the big turbo, so you want the small turbo to do more work.
2) You are using the small turbo just to "light" the big turbo. In this case, you want the big turbo doing more work, and you just want the small turbo to bridge the gap until it lights and the big turbo will will have the higher PR and "do more work."
Of course, there's always some middle ground, too.
Personally I always felt that it's better to try and "multiply" the small turbo using the big one and minimize the amount of gas that is bypassed around the little charger. I also thing that the PR in the cold pipe should be kept relatively low. Remember, the more PR you try to stuff into the little turbo, the more restrictive it becomes.
Anyway, if you are trying to "light" the big turbo, you'd run a little smaller primary that will come in earlier-- something like a 4202.
But if you're just trying to "plus up" the small charger, you would probably consider running a bigger turbo like the 4508 because spoolup isn't as important-- the little charger is carrying more workload.
Incidently, about the biggest primary that you can comfortably use with a Garrett stg 3 as the top charger is a GT4718 with the tightest housing, still a massive turbo.
Honestly, I think that a Garrett Stg 1 would make a better top turbo-- and paired with a 4202 with the 1.15 housing, you'd have a KILLER set of twins.
If you go with the Stg 3 Garrett, you could step up the big charger all the way to that massive 4718
That's 800hp worth of air, imo.
09-12-2007, 01:03 PM
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Ok I ran a few numbers. Let's say you want to run your Garrett stg 3 at a maximum PR of 3.5:1 as a small turbo in twins.
This means it will not only be able to spool a larger primary, but it will NEED a larger primary to keep it fed because it's flowing more air at 3.5:1 (about 35psi boost) than it is at 2.5:1 (about 21psi of boost).
This is where we start to get into twins philosophy, and there's no wrong way or right way. But there are two way to look at twins:
1) You are "turbocharging" the small turbo with the big turbo, so you want the small turbo to do more work.
You can do it this way but the results are less than stellar
2) You are using the small turbo just to "light" the big turbo. In this case, you want the big turbo doing more work, and you just want the small turbo to bridge the gap until it lights and the big turbo will will have the higher PR and "do more work."
This is the way to get the best overall performance. It gives up a slight amount on the bottom for the best midrange and top end.
Of course, there's always some middle ground, too.
Personally I always felt that it's better to try and "multiply" the small turbo using the big one and minimize the amount of gas that is bypassed around the little charger. I also thing that the PR in the cold pipe should be kept relatively low. Remember, the more PR you try to stuff into the little turbo, the more restrictive it becomes.
The more work the little charger does the higher the drive pressure and top end egt's. Sizing is critical to keep from having the small turbo being such a restriction.
Anyway, if you are trying to "light" the big turbo, you'd run a little smaller primary that will come in earlier-- something like a 4202.
But if you're just trying to "plus up" the small charger, you would probably consider running a bigger turbo like the 4508 because spoolup isn't as important-- the little charger is carrying more workload.
Incidently, about the biggest primary that you can comfortably use with a Garrett stg 3 as the top charger is a GT4718 with the tightest housing, still a massive turbo.
Honestly, I think that a Garrett Stg 1 would make a better top turbo-- and paired with a 4202 with the 1.15 housing, you'd have a KILLER set of twins.
If you go with the Stg 3 Garrett, you could step up the big charger all the way to that massive 4718
That's 800hp worth of air, imo.
This means it will not only be able to spool a larger primary, but it will NEED a larger primary to keep it fed because it's flowing more air at 3.5:1 (about 35psi boost) than it is at 2.5:1 (about 21psi of boost).
This is where we start to get into twins philosophy, and there's no wrong way or right way. But there are two way to look at twins:
1) You are "turbocharging" the small turbo with the big turbo, so you want the small turbo to do more work.
You can do it this way but the results are less than stellar
2) You are using the small turbo just to "light" the big turbo. In this case, you want the big turbo doing more work, and you just want the small turbo to bridge the gap until it lights and the big turbo will will have the higher PR and "do more work."
This is the way to get the best overall performance. It gives up a slight amount on the bottom for the best midrange and top end.
Of course, there's always some middle ground, too.
Personally I always felt that it's better to try and "multiply" the small turbo using the big one and minimize the amount of gas that is bypassed around the little charger. I also thing that the PR in the cold pipe should be kept relatively low. Remember, the more PR you try to stuff into the little turbo, the more restrictive it becomes.
The more work the little charger does the higher the drive pressure and top end egt's. Sizing is critical to keep from having the small turbo being such a restriction.
Anyway, if you are trying to "light" the big turbo, you'd run a little smaller primary that will come in earlier-- something like a 4202.
But if you're just trying to "plus up" the small charger, you would probably consider running a bigger turbo like the 4508 because spoolup isn't as important-- the little charger is carrying more workload.
Incidently, about the biggest primary that you can comfortably use with a Garrett stg 3 as the top charger is a GT4718 with the tightest housing, still a massive turbo.
Honestly, I think that a Garrett Stg 1 would make a better top turbo-- and paired with a 4202 with the 1.15 housing, you'd have a KILLER set of twins.
If you go with the Stg 3 Garrett, you could step up the big charger all the way to that massive 4718
That's 800hp worth of air, imo.
09-12-2007, 02:19 PM
#74
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