Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
04-05-2010, 07:20 PM
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Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
Hey guys, today I decided to look into understanding compressor maps, I've been looking into boosting my 92 teg, so I started looking into turbos to use.
I have access to a free t25, so I looked into that, and according to the map I would be way out of the efficiency range of the turbo. So I looked into a big 16g, and it seems to be a good choice. Heres what I did today, everything is roughly estimated. Please tell me if I did this right? This is for an ls motor, being conservative on the intake temp and volumetric efficiency (should exceed 100% easily, correct?)
After doing all of this, I am confused now how people run t25s and make like 200whp+ with d series??? According to the map, it looks like you'd be way out of the efficiency range, so what's the deal? Maybe I'm just looking into this too much, but I feel like I have a pretty good idea of how these work now.
Am I right about the spool rpm for each power level?
I have access to a free t25, so I looked into that, and according to the map I would be way out of the efficiency range of the turbo. So I looked into a big 16g, and it seems to be a good choice. Heres what I did today, everything is roughly estimated. Please tell me if I did this right? This is for an ls motor, being conservative on the intake temp and volumetric efficiency (should exceed 100% easily, correct?)
After doing all of this, I am confused now how people run t25s and make like 200whp+ with d series??? According to the map, it looks like you'd be way out of the efficiency range, so what's the deal? Maybe I'm just looking into this too much, but I feel like I have a pretty good idea of how these work now.
Am I right about the spool rpm for each power level?
04-05-2010, 07:52 PM
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Re: Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
https://honda-tech.com/forums/showpo...3&postcount=23
Some of my previous ramblings. I think it will help you.
Some of my previous ramblings. I think it will help you.
04-05-2010, 07:54 PM
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Re: Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
After looking at a 14b map, I think I can use a t25 (stock 300zx turbo) and get away with it, just make sure I have a decent size intercooler lol.
250whp @ ~15psi sound accurate? That's what I roughly came up with.
250whp @ ~15psi sound accurate? That's what I roughly came up with.
04-05-2010, 08:30 PM
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Re: Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
There are a bunch of T25's. They've found their way on to a lot of different cars. With that said, they typically only flow about 20-25lbs a min. Not only is the compressor fairly small, so is the turbine wheel. That will probably be the biggest limitation. So, could a T25 make 250whp? Maybe, but it won't make much more than 250. 15-18psi is probably what it would take. I just wouldn't expect the torque to hold very well after it makes the power. Even worse than a LS normally does. Turbo just can't keep up with the air flow at higher rpms(6000+).
T2's are not especially popular on Hondas. T3s are. So if you go with a T25, finding an inexpensive manifold/downpipe may be difficult. Upgrading later will also be expensive since the only one using the T2 flange is Garrett with their GT line. You should also realize that a T25 turbo will spool very early/easily. This will make the car bit of a handful with the amount of torque steer it will have. All FWD cars have torque steer. A B18b engine with a t25 making about 250whp will be a handful to control.
I don't know what your goals are. If you just want to do a quick and dirty turbo setup and you have access to welders and tools, a good condition free turbo is always a great place to start. If you are going to buy a lot of your parts, don't have access to a welder, and aren't that handy, a T25 wouldn't be my first choice. I'd typically suggest a 60 trim T3 or a 50 trim t3/t04e in that case. Another lovely, inexpensive turbo, is the Evo8 turbo but it requires a lot of custom fab.
T2's are not especially popular on Hondas. T3s are. So if you go with a T25, finding an inexpensive manifold/downpipe may be difficult. Upgrading later will also be expensive since the only one using the T2 flange is Garrett with their GT line. You should also realize that a T25 turbo will spool very early/easily. This will make the car bit of a handful with the amount of torque steer it will have. All FWD cars have torque steer. A B18b engine with a t25 making about 250whp will be a handful to control.
I don't know what your goals are. If you just want to do a quick and dirty turbo setup and you have access to welders and tools, a good condition free turbo is always a great place to start. If you are going to buy a lot of your parts, don't have access to a welder, and aren't that handy, a T25 wouldn't be my first choice. I'd typically suggest a 60 trim T3 or a 50 trim t3/t04e in that case. Another lovely, inexpensive turbo, is the Evo8 turbo but it requires a lot of custom fab.
04-05-2010, 09:35 PM
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Re: Analyzing a compressor map, did I do this right? (big 16g for an ls motor)
There are a bunch of T25's. They've found their way on to a lot of different cars. With that said, they typically only flow about 20-25lbs a min. Not only is the compressor fairly small, so is the turbine wheel. That will probably be the biggest limitation. So, could a T25 make 250whp? Maybe, but it won't make much more than 250. 15-18psi is probably what it would take. I just wouldn't expect the torque to hold very well after it makes the power. Even worse than a LS normally does. Turbo just can't keep up with the air flow at higher rpms(6000+).
T2's are not especially popular on Hondas. T3s are. So if you go with a T25, finding an inexpensive manifold/downpipe may be difficult. Upgrading later will also be expensive since the only one using the T2 flange is Garrett with their GT line. You should also realize that a T25 turbo will spool very early/easily. This will make the car bit of a handful with the amount of torque steer it will have. All FWD cars have torque steer. A B18b engine with a t25 making about 250whp will be a handful to control.
I don't know what your goals are. If you just want to do a quick and dirty turbo setup and you have access to welders and tools, a good condition free turbo is always a great place to start. If you are going to buy a lot of your parts, don't have access to a welder, and aren't that handy, a T25 wouldn't be my first choice. I'd typically suggest a 60 trim T3 or a 50 trim t3/t04e in that case. Another lovely, inexpensive turbo, is the Evo8 turbo but it requires a lot of custom fab.
T2's are not especially popular on Hondas. T3s are. So if you go with a T25, finding an inexpensive manifold/downpipe may be difficult. Upgrading later will also be expensive since the only one using the T2 flange is Garrett with their GT line. You should also realize that a T25 turbo will spool very early/easily. This will make the car bit of a handful with the amount of torque steer it will have. All FWD cars have torque steer. A B18b engine with a t25 making about 250whp will be a handful to control.
I don't know what your goals are. If you just want to do a quick and dirty turbo setup and you have access to welders and tools, a good condition free turbo is always a great place to start. If you are going to buy a lot of your parts, don't have access to a welder, and aren't that handy, a T25 wouldn't be my first choice. I'd typically suggest a 60 trim T3 or a 50 trim t3/t04e in that case. Another lovely, inexpensive turbo, is the Evo8 turbo but it requires a lot of custom fab.
My car has a b16 trans too, so idk how that'd work with a super fast spooling turbo on the eway. I just want something fun to drive around in.
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