03 G35Coupe 300hp
Originally Posted by trey.hutcheson
I guess it all comes down to preferences then.
Mustangs, Dynojets, DynoDynamics, Dynapaks, and all the rest, all have different methodologies used to measure and exatrapolate the collected metrics.
Some guys, like the tuners over at Dinan, prefer a load based dyno like Dynapaks. But guys like Doug Stewart obviously prefer dynojets. I understand where you're coming from, but to issue such a wholesale statement as you did earlier is patently false, in my opinion. Not calling you out on anything, just disagreeing.
Let's examine your reasoning. You reaffirm a mustang dyno's numbers based on numbers collected by your Cipher, correct? I'm not attacking your choice to road-dyno with the Cipher, just making sure I understand. You argue that your analysis of said numbers seem to confirm the mustang's numbers, thus you arrive at a drivetrain loss of roughly 30%. Do I believe a drivetrain loss of 30%? Absolutely, when examined in the context of how the numbers were collected. Obviously, if one chooses to collect the numbers by a different means, the numbers will be different. This little "alarming fact" apparently bothers many on these boards, but makes complete sense to me. But does this fact necessarily mean that the mustang "way of doing things" is indeed the *best*? Absolutely not.
Now let me ask you another question: exactly what number are you attempting to reach when you are deriving "crank hp"? Again, different methods of measuring crank hp will yield different numbers. The Nissan/Infiniti numbers are *certified* against the SAE standard(can't remember the revision number). Those numbers no longer apply in light of the new standard, hence the numbers will be different. Likewise, the numbers would be different than those collected 20-30 years ago.
Again, maybe I'm just confused, but I just can't understand how the fact that you choose to exclaim that the crank numbers are nowhere near published when examined through a very narrow set of filters. Choose another means of measurement, and of course the numbers will change. What's the big deal?
Let me elaborate through an example. My company measures media consumption, for the use of advertisers. One of the numbers we publish is Reach, which is basically the number of people exposed meeting certain criteria. We collect our data through various means, from interviewing respondents over the phone, to having panelists track media consumption. We also have multiple Reach Models to calculate the reach numbers. Certain models better fit with certain data(meaning the way the data were collected), and don't make much sense with other data. Does this fact invalidate the models? Absolutely not. It's a bit like economics. The mere fact that the entire media and advertising industry "believes" in these disparate models validates them, giving them "currency". The same can be said of the various forms of dynos.
Saying the mustang dyno is superior to others is like claiming that the Baptist church is a better denomination than Methodist.
And by the way. Have you ever operated a dynojet? I'm pretty sure that when the dyno is first installed and setup, some calibration is performed, and some "magical fudge factor" may be setup in the system(basically a weight factor), but that is a one-time deal. At most, it may be updated from time to time to calibrate the roller. But a dynojet operator does not augment the measured numbers. If you've experienced otherwise, first hand, I'd like to know the model number of the dynojet.
Mustangs, Dynojets, DynoDynamics, Dynapaks, and all the rest, all have different methodologies used to measure and exatrapolate the collected metrics.
Some guys, like the tuners over at Dinan, prefer a load based dyno like Dynapaks. But guys like Doug Stewart obviously prefer dynojets. I understand where you're coming from, but to issue such a wholesale statement as you did earlier is patently false, in my opinion. Not calling you out on anything, just disagreeing.
Let's examine your reasoning. You reaffirm a mustang dyno's numbers based on numbers collected by your Cipher, correct? I'm not attacking your choice to road-dyno with the Cipher, just making sure I understand. You argue that your analysis of said numbers seem to confirm the mustang's numbers, thus you arrive at a drivetrain loss of roughly 30%. Do I believe a drivetrain loss of 30%? Absolutely, when examined in the context of how the numbers were collected. Obviously, if one chooses to collect the numbers by a different means, the numbers will be different. This little "alarming fact" apparently bothers many on these boards, but makes complete sense to me. But does this fact necessarily mean that the mustang "way of doing things" is indeed the *best*? Absolutely not.
Now let me ask you another question: exactly what number are you attempting to reach when you are deriving "crank hp"? Again, different methods of measuring crank hp will yield different numbers. The Nissan/Infiniti numbers are *certified* against the SAE standard(can't remember the revision number). Those numbers no longer apply in light of the new standard, hence the numbers will be different. Likewise, the numbers would be different than those collected 20-30 years ago.
Again, maybe I'm just confused, but I just can't understand how the fact that you choose to exclaim that the crank numbers are nowhere near published when examined through a very narrow set of filters. Choose another means of measurement, and of course the numbers will change. What's the big deal?
Let me elaborate through an example. My company measures media consumption, for the use of advertisers. One of the numbers we publish is Reach, which is basically the number of people exposed meeting certain criteria. We collect our data through various means, from interviewing respondents over the phone, to having panelists track media consumption. We also have multiple Reach Models to calculate the reach numbers. Certain models better fit with certain data(meaning the way the data were collected), and don't make much sense with other data. Does this fact invalidate the models? Absolutely not. It's a bit like economics. The mere fact that the entire media and advertising industry "believes" in these disparate models validates them, giving them "currency". The same can be said of the various forms of dynos.
Saying the mustang dyno is superior to others is like claiming that the Baptist church is a better denomination than Methodist.
And by the way. Have you ever operated a dynojet? I'm pretty sure that when the dyno is first installed and setup, some calibration is performed, and some "magical fudge factor" may be setup in the system(basically a weight factor), but that is a one-time deal. At most, it may be updated from time to time to calibrate the roller. But a dynojet operator does not augment the measured numbers. If you've experienced otherwise, first hand, I'd like to know the model number of the dynojet.
Anyhow, I do not claim that any dyno is universally "better" than another. You need to define what makes a good dyno before you can start to do that. But I think claiming "better" means "more accurately measures true power output at the wheels on the street" is a pretty good definition. I only claimed that the mustang put out very similar numbers to what I physically measured on the street, which is what it's designed to do.
Personally I care how much power my car is actually putting down on the street, because that is what is accelerating my car. Trying to quote crank numbers is just for marketing and trying to impress your buddies. With the 20 Hz data rate of vehicle speed, I can get very accurate curves in 3rd and 4th gear. Screw the dynojet, it doesn't represent any real world situation, plus they throw a fudge factor on it.
Regarding the crank numbers, another car I have experience with road dynoing is the STI. Those things are also rated at ~300 crank hp. And guess what, they put out 220-230 whp on the road (and virtually identical numbers on a mustang dyno). And that's through an all-wheel-drive drivetrain!
Last edited by MechEE; Feb 13, 2006 at 03:16 PM.
I myself am not a dynojet fan. There's just entirely too many variables that can cloud the results.
And example. Back in November, I dyno'd my car in 4th gear with a peak of 250/227. About 6 weeks later, I did another baseline before running a muffler "experiment" and saw 239/217 in 4th gear. Before you ask, I dyno in 4th because the sedan's speed limiter engages at about 145mph, which prevents me from going to redline in 5th.
Same dyno, almost identical conditions. Why was it 11hp off and 10lb-feet off at peak? I had changed my highflow cats from Kinetix to Crawfords. I was also running a different brand of gas. But back in November, I was running around 40psi in my rear tires, but in December I was running right at 30psi. I think the greatest factor was the tire pressure.
Despite the fact that I'm not a dynojet fan, that what I'm going to use. That's what I did my first dyno on, so now everything will be compared against that initial baseline. Also, to my knowledge there are only two chassis dynos in Birmingham, both dynojets. So I'm a bit limited in how I dyno.
However, dynojets have a place. They are the "affordable" dyno, and due to that fact, outnumber all the other dyno brands. They are also almost a complete turnkey solution, meaning there's little training and calibration/configuration needed by the host garage. Therefore, the majority of dynos are perfomed on dynojets, which means that all of the forum dyno-racing being performed is usually based on dynojet numbers. Dynojets are so prevalent that many dynos use a flat correction weight/factor to attempt to adjust *to* dynojet numbers.
But I really don't think that the dynojet's innacuracies are a big deal. Because so many people use them, dynojet numbers have a global context. That means that everyone is succeptible to the same testing conditions and innacuracies, within reason. To use a sports analogy, it's like a football game played in the rain. Both teams play under the same conditions. Therefore, it doesn't matter if my car makes 200hp on a mustang, 250 on a dynojet, and 280hp on Bubba's New Dyno. If we all invest in dynojet numbers, then my numbers can be compared to the next guys, even if the comparison is vague.
And example. Back in November, I dyno'd my car in 4th gear with a peak of 250/227. About 6 weeks later, I did another baseline before running a muffler "experiment" and saw 239/217 in 4th gear. Before you ask, I dyno in 4th because the sedan's speed limiter engages at about 145mph, which prevents me from going to redline in 5th.
Same dyno, almost identical conditions. Why was it 11hp off and 10lb-feet off at peak? I had changed my highflow cats from Kinetix to Crawfords. I was also running a different brand of gas. But back in November, I was running around 40psi in my rear tires, but in December I was running right at 30psi. I think the greatest factor was the tire pressure.
Despite the fact that I'm not a dynojet fan, that what I'm going to use. That's what I did my first dyno on, so now everything will be compared against that initial baseline. Also, to my knowledge there are only two chassis dynos in Birmingham, both dynojets. So I'm a bit limited in how I dyno.
However, dynojets have a place. They are the "affordable" dyno, and due to that fact, outnumber all the other dyno brands. They are also almost a complete turnkey solution, meaning there's little training and calibration/configuration needed by the host garage. Therefore, the majority of dynos are perfomed on dynojets, which means that all of the forum dyno-racing being performed is usually based on dynojet numbers. Dynojets are so prevalent that many dynos use a flat correction weight/factor to attempt to adjust *to* dynojet numbers.
But I really don't think that the dynojet's innacuracies are a big deal. Because so many people use them, dynojet numbers have a global context. That means that everyone is succeptible to the same testing conditions and innacuracies, within reason. To use a sports analogy, it's like a football game played in the rain. Both teams play under the same conditions. Therefore, it doesn't matter if my car makes 200hp on a mustang, 250 on a dynojet, and 280hp on Bubba's New Dyno. If we all invest in dynojet numbers, then my numbers can be compared to the next guys, even if the comparison is vague.
Originally Posted by MechEE
My stock car on a dynojet put out about 238 whp.
My stock car on a mustang dyno put out 212 whp.
I then did extensive road dynoing on the street using the high resolution speed versus time datalog from Cipher and got a very repeatable 210-215 whp. Regardless of what any dyno said, my car was physically putting out this much power to the wheels during these runs. Can't really argue with that.
Given that the car actually accelerates at a higher rate on the dynojet than on the mustang, you'd expect it to put out lower numbers since more power is being consumed to more quickly accelerate the wheels / driveline / etc. But dynojets consistently put out much larger numbers than mustangs, and this was puzzling to me, so I did a little research and called mustang and dynojet. An engineer at mustang told me they knew exactly what I was talking about with the inertial losses, and said that dynojet actually includes a hidden fudge factor to try and account for this loss which is why their numbers are so inflated. I called dynojet and asked them about it and they basically told me that they couldn't comment on how their numbers are generated.
That being said, I'll trust the true power I'm putting out on the street any day over what some dyno operator set up on the dyno. But consisently mustang dynos put out very similar numbers to that which you put out on the street, specifically because they add a speed dependent load to simulate load on the street.
So at 210-215 whp for a stock '06 that is rated at 298 crank hp gives a driveline loss of nearly 30%. Do you really think that's how much power we're losing in the driveline? No way... in my opinion the crank numbers are just highly inflated.
My stock car on a mustang dyno put out 212 whp.
I then did extensive road dynoing on the street using the high resolution speed versus time datalog from Cipher and got a very repeatable 210-215 whp. Regardless of what any dyno said, my car was physically putting out this much power to the wheels during these runs. Can't really argue with that.
Given that the car actually accelerates at a higher rate on the dynojet than on the mustang, you'd expect it to put out lower numbers since more power is being consumed to more quickly accelerate the wheels / driveline / etc. But dynojets consistently put out much larger numbers than mustangs, and this was puzzling to me, so I did a little research and called mustang and dynojet. An engineer at mustang told me they knew exactly what I was talking about with the inertial losses, and said that dynojet actually includes a hidden fudge factor to try and account for this loss which is why their numbers are so inflated. I called dynojet and asked them about it and they basically told me that they couldn't comment on how their numbers are generated.
That being said, I'll trust the true power I'm putting out on the street any day over what some dyno operator set up on the dyno. But consisently mustang dynos put out very similar numbers to that which you put out on the street, specifically because they add a speed dependent load to simulate load on the street.
So at 210-215 whp for a stock '06 that is rated at 298 crank hp gives a driveline loss of nearly 30%. Do you really think that's how much power we're losing in the driveline? No way... in my opinion the crank numbers are just highly inflated.
Originally Posted by RBull
You should add that grounding kit you've been wanting. Must be good for at least 25hp.
Originally Posted by trey.hutcheson
But I really don't think that the dynojet's innacuracies are a big deal. Because so many people use them, dynojet numbers have a global context. That means that everyone is succeptible to the same testing conditions and innacuracies, within reason. To use a sports analogy, it's like a football game played in the rain. Both teams play under the same conditions. Therefore, it doesn't matter if my car makes 200hp on a mustang, 250 on a dynojet, and 280hp on Bubba's New Dyno. If we all invest in dynojet numbers, then my numbers can be compared to the next guys, even if the comparison is vague.
Last edited by MechEE; Feb 13, 2006 at 09:22 PM.
Originally Posted by drewbagel423
221*1.21=268hp at the crank
if the car really is putting out 280 crank it's ~26.7% loss
if the car really is putting out 280 crank it's ~26.7% loss
221/ 280 = .789
1 - .789 = .211
280 *.211 = 59.08
280 - 59.08 = 220.92
This is merely conjecture, but I believe the AT loss is closer to 20 percent, rather than 21%.
Consider: Earlier I mentioned that my baseline on my 6MT, using Doug Stewart's figure of 17%, was within 2% of published peak hp and torque figures. On the same day that I dyno'd, my wife dyno'd her 04 5AT Sedan(rated at 260/260), and a friend dyno'd his 05 5AT Coupe(rated at 280hp and 270 torque?).
My wife's numbers were 217.5hp/208.41. Plugging in 20%, this yields: 271.875/260.5. She was bone stock. If a 20% drivetrain loss is correct, then her peak hp is pretty strong versus the published crank hp.
The guy in the 05 5AT Coupe had a peak hp of 225(I don't know the decimal value, nor his torque). Using 20%, that's a peak hp of 281.25. Pretty close to the published crank of 280.
If the drivetrain loss for the automatics is indeed 21%, then my wife's crank numbers would have been 275.3/263.8, and the coupe's peak crank hp would have been 284.
Either way, we're talking about 1%. Pretty close.
Consider: Earlier I mentioned that my baseline on my 6MT, using Doug Stewart's figure of 17%, was within 2% of published peak hp and torque figures. On the same day that I dyno'd, my wife dyno'd her 04 5AT Sedan(rated at 260/260), and a friend dyno'd his 05 5AT Coupe(rated at 280hp and 270 torque?).
My wife's numbers were 217.5hp/208.41. Plugging in 20%, this yields: 271.875/260.5. She was bone stock. If a 20% drivetrain loss is correct, then her peak hp is pretty strong versus the published crank hp.
The guy in the 05 5AT Coupe had a peak hp of 225(I don't know the decimal value, nor his torque). Using 20%, that's a peak hp of 281.25. Pretty close to the published crank of 280.
If the drivetrain loss for the automatics is indeed 21%, then my wife's crank numbers would have been 275.3/263.8, and the coupe's peak crank hp would have been 284.
Either way, we're talking about 1%. Pretty close.
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Posts: 6
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between the 06 version & the other coupe 6mt, differences are: lowered upper plenum design, variable exhaust system, as call rev-up engine they rev higher & also they fuel mapping is different...
Between the Z & the G, 7 hp are NOT gained with the Z-Tube but by a different mapping, you also have to know the gear ratio between a Z & a G is different (450 more rpm on a G are req'd to get the same speed) & also the exhaust lenght is slightly different (2in shorter on a Z)..
So that's plenty of little things that make little difference!
Between the Z & the G, 7 hp are NOT gained with the Z-Tube but by a different mapping, you also have to know the gear ratio between a Z & a G is different (450 more rpm on a G are req'd to get the same speed) & also the exhaust lenght is slightly different (2in shorter on a Z)..
So that's plenty of little things that make little difference!
Originally Posted by Skyline-V35
between the 06 version & the other coupe 6mt, differences are: lowered upper plenum design, variable exhaust system, as call rev-up engine they rev higher & also they fuel mapping is different...
Between the Z & the G, 7 hp are NOT gained with the Z-Tube but by a different mapping, you also have to know the gear ratio between a Z & a G is different (450 more rpm on a G are req'd to get the same speed) & also the exhaust lenght is slightly different (2in shorter on a Z)..
So that's plenty of little things that make little difference!
Between the Z & the G, 7 hp are NOT gained with the Z-Tube but by a different mapping, you also have to know the gear ratio between a Z & a G is different (450 more rpm on a G are req'd to get the same speed) & also the exhaust lenght is slightly different (2in shorter on a Z)..
So that's plenty of little things that make little difference!
final drive: 3.54
The 350z's ratios:
1 - 3.79:1
2 - 2.32:1
3 - 1.62:1
4 - 1.27:1
5 - 1.00:1
6 - 0.79:1
G35 6MT's ratios:
1 - 3.79:1
2 - 2.32:1
3 - 1.62:1
4 - 1.27:1
5 - 1.00:1
6 - 0.79:1
Originally Posted by trey.hutcheson
This is merely conjecture, but I believe the AT loss is closer to 20 percent, rather than 21%.
Consider: Earlier I mentioned that my baseline on my 6MT, using Doug Stewart's figure of 17%, was within 2% of published peak hp and torque figures. On the same day that I dyno'd, my wife dyno'd her 04 5AT Sedan(rated at 260/260), and a friend dyno'd his 05 5AT Coupe(rated at 280hp and 270 torque?).
My wife's numbers were 217.5hp/208.41. Plugging in 20%, this yields: 271.875/260.5. She was bone stock. If a 20% drivetrain loss is correct, then her peak hp is pretty strong versus the published crank hp.
The guy in the 05 5AT Coupe had a peak hp of 225(I don't know the decimal value, nor his torque). Using 20%, that's a peak hp of 281.25. Pretty close to the published crank of 280.
If the drivetrain loss for the automatics is indeed 21%, then my wife's crank numbers would have been 275.3/263.8, and the coupe's peak crank hp would have been 284.
Either way, we're talking about 1%. Pretty close.
Consider: Earlier I mentioned that my baseline on my 6MT, using Doug Stewart's figure of 17%, was within 2% of published peak hp and torque figures. On the same day that I dyno'd, my wife dyno'd her 04 5AT Sedan(rated at 260/260), and a friend dyno'd his 05 5AT Coupe(rated at 280hp and 270 torque?).
My wife's numbers were 217.5hp/208.41. Plugging in 20%, this yields: 271.875/260.5. She was bone stock. If a 20% drivetrain loss is correct, then her peak hp is pretty strong versus the published crank hp.
The guy in the 05 5AT Coupe had a peak hp of 225(I don't know the decimal value, nor his torque). Using 20%, that's a peak hp of 281.25. Pretty close to the published crank of 280.
If the drivetrain loss for the automatics is indeed 21%, then my wife's crank numbers would have been 275.3/263.8, and the coupe's peak crank hp would have been 284.
Either way, we're talking about 1%. Pretty close.
Last edited by MechEE; Feb 14, 2006 at 03:53 PM.
Joined: Oct 2005
Posts: 1,112
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From: Miami, FL
Headers,Y-pipe,exhaust,Plenum,intake,and you dont think you can get to 300 crank you are nuts... Thats over 2 thousand in parts and you think you will only get a little gain!?!?
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Joined: May 2002
Posts: 241
Likes: 1
From: Tempe, AZ.
Originally Posted by 2FastG354U
Headers,Y-pipe,exhaust,Plenum,intake,and you dont think you can get to 300 crank you are nuts... Thats over 2 thousand in parts and you think you will only get a little gain!?!?
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