1 goal, 3 turbos...which do I pick?
09-07-2010, 11:40 AM
#1
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1 goal, 3 turbos...which do I pick?
So we're in September already, and this winter I would finally like to pull my engine and do a hone / re-ring and install m-tuned rods. I also want to do a mild port / polish on my head, and clean it up. I will use my current MS2 standalone, I will be running my FM Stage 1 clutch, and I want to run RX-7 550's. Here's the confusion...
1) I have a small assed SR20 turbo, that uses a 56mm 60 trim wheel. G pop shop can bore my compressor to accept a 60 mm 60 trim wheel, so this will make my turbo more like a journal bearing version of a GT2560, instead of the GT2554 size that it is now. This process is very inexpensive to do, so I like that. If I do this setup, I will be running 7psi wastegate daily driven, and probably like 15 psi on EBC.
2) I just say F it and order a GT3071 from FM for $1495. They claim it'll make 250 whp by 10 psi, and it'll be spooled by 4,000 RPM.
3) I go with a 2871 which I feel would be a little more streetable than a 3071.
Whatever I decide, I want to use a .64 A/R turbine. My power goal is not to excede 300 whp. I just feel that the 2871 or 3071 are overkill for that kind of power goal. Why stay under 300 whp? Cause I don't need to run 20 psi and throw down 400whp just to drive to work. As fun as that may sound, I'm being realistic, and just looking to run mid 12's at the dragstrip on a friday night, and then drive it every day and be happy.
1) I have a small assed SR20 turbo, that uses a 56mm 60 trim wheel. G pop shop can bore my compressor to accept a 60 mm 60 trim wheel, so this will make my turbo more like a journal bearing version of a GT2560, instead of the GT2554 size that it is now. This process is very inexpensive to do, so I like that. If I do this setup, I will be running 7psi wastegate daily driven, and probably like 15 psi on EBC.
2) I just say F it and order a GT3071 from FM for $1495. They claim it'll make 250 whp by 10 psi, and it'll be spooled by 4,000 RPM.
3) I go with a 2871 which I feel would be a little more streetable than a 3071.
Whatever I decide, I want to use a .64 A/R turbine. My power goal is not to excede 300 whp. I just feel that the 2871 or 3071 are overkill for that kind of power goal. Why stay under 300 whp? Cause I don't need to run 20 psi and throw down 400whp just to drive to work. As fun as that may sound, I'm being realistic, and just looking to run mid 12's at the dragstrip on a friday night, and then drive it every day and be happy.
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09-07-2010, 11:45 AM
#2
2871 w/ .64 A/R sounds pretty good for your goals. I don't know how different the spool will be vs 3071...but 3071 is more than you need for your goals, and there's really no point buying a turbo way larger than your goals, big turbos aren't always very efficient at low power levels.
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09-07-2010, 03:28 PM
#9
Thirdgen, don't you remember this thread?
https://www.miataturbo.net/showthrea...t25#post428055
https://www.miataturbo.net/showthrea...t25#post428055
Gpop's reply:
Thank you for your interest. The T25 compressor wheel is Max flow rated at 250 HP, and the Big T28 wheel is rated at 340HP. So, at max flow the difference is 90HP. On your engine combo we would think that you could gain 15-40HP with the big T28 wheel. Sometimes it is not just the compressor wheel that is the restriction though, you might want to get the turbine wheel upgrade as well and go with the complete Big T28 upgrade. These turbos are rated at 340HP and have been dyno'd on many applications over 300HP. The price for a HP rebuild (a rebuild that does not require any hard parts: comp wheel, turbine shaft/wheel, or bearing housing) and upgrade to Big T28 specs would be $695.00 plus $25 return shipping. The first step in the rebuild is a full inspection. If any of the hard parts are found to be damaged at this point, we would give you a full quote for repairing/replacing parts.
Our turnaround time for standard rebuilds right now is +/-12 business days. If you would like to ship the turbo to us for this service, please enclose your contact information and send it to:
Thank you for your interest. The T25 compressor wheel is Max flow rated at 250 HP, and the Big T28 wheel is rated at 340HP. So, at max flow the difference is 90HP. On your engine combo we would think that you could gain 15-40HP with the big T28 wheel. Sometimes it is not just the compressor wheel that is the restriction though, you might want to get the turbine wheel upgrade as well and go with the complete Big T28 upgrade. These turbos are rated at 340HP and have been dyno'd on many applications over 300HP. The price for a HP rebuild (a rebuild that does not require any hard parts: comp wheel, turbine shaft/wheel, or bearing housing) and upgrade to Big T28 specs would be $695.00 plus $25 return shipping. The first step in the rebuild is a full inspection. If any of the hard parts are found to be damaged at this point, we would give you a full quote for repairing/replacing parts.
Our turnaround time for standard rebuilds right now is +/-12 business days. If you would like to ship the turbo to us for this service, please enclose your contact information and send it to:
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09-07-2010, 06:50 PM
#12
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Yeah the email I got from them was more like $250 and that was just for the compressor boring, cause I told them I'd rebuild the CHRA myself. Still though...I'm just wondering if it would be worth it.
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