TSE EFR 6758 & Supermiata engine
05-04-2017, 04:33 PM
#61
Hopefully the mods can clean this thread up.
Goodwood,
Thanks for your additions to the forum in general, seriously. Its a cool build, you seem to know the car well and are willing to share.
Several years ago the legacy members and key vendors here began a real campaign to protect the integrity of the information stored here with certitude and diligence. I think it may have started with the exhaust manifold stud mega thread and me using SM lap records to filter out the slow guys who's data was irrelevant and polluting the data points used to quantify and analyze the problem. The quality of this board has benefited greatly. It is now quoted as a source with almost unparalleled veracity in the Miataverse. This is rather unique in automotive forums and we are very proud of it. Andrew is particularly proud
So, make sure you state facts and data/pics/kittens to back it up. If not, share them as conjecture, not facts. But still share the cat pics.
Goodwood,
Thanks for your additions to the forum in general, seriously. Its a cool build, you seem to know the car well and are willing to share.
Several years ago the legacy members and key vendors here began a real campaign to protect the integrity of the information stored here with certitude and diligence. I think it may have started with the exhaust manifold stud mega thread and me using SM lap records to filter out the slow guys who's data was irrelevant and polluting the data points used to quantify and analyze the problem. The quality of this board has benefited greatly. It is now quoted as a source with almost unparalleled veracity in the Miataverse. This is rather unique in automotive forums and we are very proud of it. Andrew is particularly proud
So, make sure you state facts and data/pics/kittens to back it up. If not, share them as conjecture, not facts. But still share the cat pics.
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05-04-2017, 04:40 PM
#62
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Fair enough. I was wrong about the numbers. I wasn't looking at my chart when I made the claim that the power was more at 4k, I thought I was closer to 200hp. Wrong. I feel like this thread has been completely highjacked, and I regret that. I'm going to try and let this die. :-)
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05-04-2017, 05:00 PM
#64
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Sorry for being pissy. The implication in your posts, whether intentional or not, was that there was some impropriety in calling the results impressive. Just asking the question implies that dishonesty/impropriety, since if the results weren't impressive, the thread never would have been created. As you may have noticed, I'm not particularly fond of being called a liar, hence my attitude in every subsequent reply. 
I asked you for a dyno because, quite simply, I did not believe you.
The quip about your dyno source was not meant to be snarky (as it came across), but more as cautionary advice.
To answer your earlier question about boost, in detail: It is really, really hard to compare forced induction dyno figures at altitude to those taken at sea level.
My 200kpa at 101.3kpa (sea level) is ~98.7kpa of boost. Your 200kpa at FM was 114.8kpa of boost, or ~16.5psi. The reason why the boost pressure above sea level matters is because your turbo is exhausting into an 85kpa atmosphere, whereas mine is exhausting into a 101kpa atmosphere.
The issue gets even worse when you factor in standard corrections. The 30-second explanation is that SAE J1349 establishes a standard for absolute pressure and temperature figures for dyno testing. If you dyno a car in 100 degree weather, the "uncorrected" figures will read really low, because the air is less dense. The J1349-corrected figure will read higher, because the standard applies a known correction factor. My PTE car in 2013 made 137whp on a sea-level Dynojet, and it made similar corrected power figure on a different Dynojet in Tooele, UT. The correction factor to get those "similar" figures was ~21%, due to the altitude difference.
FM's current Dynocom unit spits out uncorrected numbers which are equitable to "uncorrected" Dynojet sea-level figures. That is to say, a Miata making 110whp on a Dynojet at sea level will make 110whp uncorrected on FM's Dynocom. The manifold pressure would be ~100kpa at sea level and ~85kpa at FM. If you add a turbo to that car and add 10 pounds of boost at both places, the power figures should still be the same, but the car makes ~170kpa at sea level and ~155kpa at FM. Same power, but different absolute manifold pressures. (Because the turbo has less air with which to spool up in the first place, though, the shape of the curve is going to differ slightly.)
With EBC targeting absolute pressure, it actually becomes impossible to compare the figures. That same Miata targeting 170kpa at altitude will make another ~20whp or so on FM's dyno, because suddenly the turbo is working harder and forcing more air in. To come back to your F1 example, the reason F1 cars made the same power at Mexico City was because they were tuned to do so. The strength of the engine doesn't change, but the output is reduced as you go up in altitude, so they simply turn up the boost to compensate. Your EBC valve isn't privy to altitude data, so it sees 185kpa at WOT and simply commands less wastegate DC% until it sees what it wants on the MAP sensor.
It works the same with your car at altitude. We define "boost" as any pressure added on top of atmospheric conditions, so whle 200kpa absolute equates to ~14.2psi of boost at sea level, at altitude, it's closer to 16.5psi. If you brought your car to a sea-level Dynojet, you should expect to need at least 16.5psi of boost to make numbers similar to what you saw at FM.
I asked you for a dyno because, quite simply, I did not believe you.
The quip about your dyno source was not meant to be snarky (as it came across), but more as cautionary advice.To answer your earlier question about boost, in detail: It is really, really hard to compare forced induction dyno figures at altitude to those taken at sea level.
My 200kpa at 101.3kpa (sea level) is ~98.7kpa of boost. Your 200kpa at FM was 114.8kpa of boost, or ~16.5psi. The reason why the boost pressure above sea level matters is because your turbo is exhausting into an 85kpa atmosphere, whereas mine is exhausting into a 101kpa atmosphere.
The issue gets even worse when you factor in standard corrections. The 30-second explanation is that SAE J1349 establishes a standard for absolute pressure and temperature figures for dyno testing. If you dyno a car in 100 degree weather, the "uncorrected" figures will read really low, because the air is less dense. The J1349-corrected figure will read higher, because the standard applies a known correction factor. My PTE car in 2013 made 137whp on a sea-level Dynojet, and it made similar corrected power figure on a different Dynojet in Tooele, UT. The correction factor to get those "similar" figures was ~21%, due to the altitude difference.
FM's current Dynocom unit spits out uncorrected numbers which are equitable to "uncorrected" Dynojet sea-level figures. That is to say, a Miata making 110whp on a Dynojet at sea level will make 110whp uncorrected on FM's Dynocom. The manifold pressure would be ~100kpa at sea level and ~85kpa at FM. If you add a turbo to that car and add 10 pounds of boost at both places, the power figures should still be the same, but the car makes ~170kpa at sea level and ~155kpa at FM. Same power, but different absolute manifold pressures. (Because the turbo has less air with which to spool up in the first place, though, the shape of the curve is going to differ slightly.)
With EBC targeting absolute pressure, it actually becomes impossible to compare the figures. That same Miata targeting 170kpa at altitude will make another ~20whp or so on FM's dyno, because suddenly the turbo is working harder and forcing more air in. To come back to your F1 example, the reason F1 cars made the same power at Mexico City was because they were tuned to do so. The strength of the engine doesn't change, but the output is reduced as you go up in altitude, so they simply turn up the boost to compensate. Your EBC valve isn't privy to altitude data, so it sees 185kpa at WOT and simply commands less wastegate DC% until it sees what it wants on the MAP sensor.
It works the same with your car at altitude. We define "boost" as any pressure added on top of atmospheric conditions, so whle 200kpa absolute equates to ~14.2psi of boost at sea level, at altitude, it's closer to 16.5psi. If you brought your car to a sea-level Dynojet, you should expect to need at least 16.5psi of boost to make numbers similar to what you saw at FM.
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05-05-2017, 12:35 AM
#66
Guys, guys.
/thread drift
The engine we built for Vegas, my new S1 is pretty much like the one in the OP but without the Billet crank. So we won't be spinning it quite as high but we expect to be able to make about the same power when we run the 6758.
/thread drift
The engine we built for Vegas, my new S1 is pretty much like the one in the OP but without the Billet crank. So we won't be spinning it quite as high but we expect to be able to make about the same power when we run the 6758.
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05-05-2017, 10:06 AM
#67
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Sorry for being pissy. The implication in your posts, whether intentional or not, was that there was some impropriety in calling the results impressive. Just asking the question implies that dishonesty/impropriety, since if the results weren't impressive, the thread never would have been created. As you may have noticed, I'm not particularly fond of being called a liar, hence my attitude in every subsequent reply.
I asked you for a dyno because, quite simply, I did not believe you. The quip about your dyno source was not meant to be snarky (as it came across), but more as cautionary advice.
To answer your earlier question about boost, in detail: It is really, really hard to compare forced induction dyno figures at altitude to those taken at sea level.
My 200kpa at 101.3kpa (sea level) is ~98.7kpa of boost. Your 200kpa at FM was 114.8kpa of boost, or ~16.5psi. The reason why the boost pressure above sea level matters is because your turbo is exhausting into an 85kpa atmosphere, whereas mine is exhausting into a 101kpa atmosphere.
The issue gets even worse when you factor in standard corrections. The 30-second explanation is that SAE J1349 establishes a standard for absolute pressure and temperature figures for dyno testing. If you dyno a car in 100 degree weather, the "uncorrected" figures will read really low, because the air is less dense. The J1349-corrected figure will read higher, because the standard applies a known correction factor. My PTE car in 2013 made 137whp on a sea-level Dynojet, and it made similar corrected power figure on a different Dynojet in Tooele, UT. The correction factor to get those "similar" figures was ~21%, due to the altitude difference.
FM's current Dynocom unit spits out uncorrected numbers which are equitable to "uncorrected" Dynojet sea-level figures. That is to say, a Miata making 110whp on a Dynojet at sea level will make 110whp uncorrected on FM's Dynocom. The manifold pressure would be ~100kpa at sea level and ~85kpa at FM. If you add a turbo to that car and add 10 pounds of boost at both places, the power figures should still be the same, but the car makes ~170kpa at sea level and ~155kpa at FM. Same power, but different absolute manifold pressures. (Because the turbo has less air with which to spool up in the first place, though, the shape of the curve is going to differ slightly.)
With EBC targeting absolute pressure, it actually becomes impossible to compare the figures. That same Miata targeting 170kpa at altitude will make another ~20whp or so on FM's dyno, because suddenly the turbo is working harder and forcing more air in. To come back to your F1 example, the reason F1 cars made the same power at Mexico City was because they were tuned to do so. The strength of the engine doesn't change, but the output is reduced as you go up in altitude, so they simply turn up the boost to compensate. Your EBC valve isn't privy to altitude data, so it sees 185kpa at WOT and simply commands less wastegate DC% until it sees what it wants on the MAP sensor.
It works the same with your car at altitude. We define "boost" as any pressure added on top of atmospheric conditions, so whle 200kpa absolute equates to ~14.2psi of boost at sea level, at altitude, it's closer to 16.5psi. If you brought your car to a sea-level Dynojet, you should expect to need at least 16.5psi of boost to make numbers similar to what you saw at FM.
I asked you for a dyno because, quite simply, I did not believe you.
The quip about your dyno source was not meant to be snarky (as it came across), but more as cautionary advice.To answer your earlier question about boost, in detail: It is really, really hard to compare forced induction dyno figures at altitude to those taken at sea level.
My 200kpa at 101.3kpa (sea level) is ~98.7kpa of boost. Your 200kpa at FM was 114.8kpa of boost, or ~16.5psi. The reason why the boost pressure above sea level matters is because your turbo is exhausting into an 85kpa atmosphere, whereas mine is exhausting into a 101kpa atmosphere.
The issue gets even worse when you factor in standard corrections. The 30-second explanation is that SAE J1349 establishes a standard for absolute pressure and temperature figures for dyno testing. If you dyno a car in 100 degree weather, the "uncorrected" figures will read really low, because the air is less dense. The J1349-corrected figure will read higher, because the standard applies a known correction factor. My PTE car in 2013 made 137whp on a sea-level Dynojet, and it made similar corrected power figure on a different Dynojet in Tooele, UT. The correction factor to get those "similar" figures was ~21%, due to the altitude difference.
FM's current Dynocom unit spits out uncorrected numbers which are equitable to "uncorrected" Dynojet sea-level figures. That is to say, a Miata making 110whp on a Dynojet at sea level will make 110whp uncorrected on FM's Dynocom. The manifold pressure would be ~100kpa at sea level and ~85kpa at FM. If you add a turbo to that car and add 10 pounds of boost at both places, the power figures should still be the same, but the car makes ~170kpa at sea level and ~155kpa at FM. Same power, but different absolute manifold pressures. (Because the turbo has less air with which to spool up in the first place, though, the shape of the curve is going to differ slightly.)
With EBC targeting absolute pressure, it actually becomes impossible to compare the figures. That same Miata targeting 170kpa at altitude will make another ~20whp or so on FM's dyno, because suddenly the turbo is working harder and forcing more air in. To come back to your F1 example, the reason F1 cars made the same power at Mexico City was because they were tuned to do so. The strength of the engine doesn't change, but the output is reduced as you go up in altitude, so they simply turn up the boost to compensate. Your EBC valve isn't privy to altitude data, so it sees 185kpa at WOT and simply commands less wastegate DC% until it sees what it wants on the MAP sensor.
It works the same with your car at altitude. We define "boost" as any pressure added on top of atmospheric conditions, so whle 200kpa absolute equates to ~14.2psi of boost at sea level, at altitude, it's closer to 16.5psi. If you brought your car to a sea-level Dynojet, you should expect to need at least 16.5psi of boost to make numbers similar to what you saw at FM.
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well played
