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Earlier today, Jeff, one of our members, sent me the dyno chart his dyno operator generated before and after dyno tuning his 05 6-speed SSR. I promised Jeff an analysis, but realized when looking at the graph, how great a textbook example it is to highlight some generic things about dyno charts, and their strengths and limitations. So, I got a little long winded . . . .

Ok, guys, here’s what I see in that (attached) chart:

First, let’s take the hopelessly superficial view. Here, the casual observer looks at it and says “big deal, the tuner got about 5 more peak horsepower, and 4 more ft.lb. of torque. Waste of money.”

Then, there’s the way that the advertisement writer for an unscrupulous tuner would write up these results. He’d say, Wow, on an actual dyno test on an 05 SSR, the combination of our hardware and tuner expertise got UP TO 42 more horsepower and UP TO 76 more ft.lb. of torque. Buy our supergizmo package and go LOTS faster!!

BOTH of these views are technically “true”, but actually deceptions, because they focus in each case on one narrow result. The first statement focuses on the 5500 to 5800 rpm band where the “peak” power (NOT torque) occurs, while the second focuses specifically on 3000 rpm, FAR from where meaningful power is being produced.

Let’s analyze this chart using a more structured approach.

First, let’s examine the “documentation”, which is, I’m afraid, rather skimpy – an unfortunately common trait among tuners, who are always more interested in doing the work than documenting afterward exactly what they did. First, the dyno operator failed to specify which SAE standard he used for his correction factors. Correction factors correct the “raw” torque and power to allow for the favorable or unfavorable effects of ambient conditions at the time and place of the dyno testing. This operator has stated only “SAE DJ” which is NOT a valid SAE test procedure. The valid ones are SAE1349 and SAE607. The key difference between these two standards is the “standard temperature” to which all raw results are corrected. Without writing a book (again) here, the SAE607 procedure, commonly labeled “SAE STD” by aftermarket dyno builders, generates results that are on average 4 to 5% higher than SAE1349. This is WHY most aftermarket tuners use SAE607, so they can show “happier” results to a customer! So, if this graph shows SAE607, then an SAE1349 correction would yield about 4 to 5% more power across the board than the chart shows, and a peak of about 357 rwhp versus the 342 shown. If this graph is corrected to SAE1349, then correction to SAE607 would lower the peak power to 327 rwhp. This is the more likely scenario for an 05 6-speed SSR. However, since the operator did not specify, we simply don’t know. Sigh . . .

The next point of confusion is the type of dyno and software used. The chart says “Superflow”, which is a brand of dynamometer that can run in EITHER steady state or inertia mode. The results are usually notably different in the two modes, due to driveline inertia and other effects. The chart fails to specify in which mode the results were run. Again, sigh.

The next problem is that the operator HAS gone to great pains to everywhere specify “DJWhPw-C Hp” for power and “DJWhTq-C lb ft” for torque. These are likely abbreviations for “Dynojet Wheel horsepower – calculated per formula C” and “Dynojet Wheel torque calculated per formula C”, neither of which are “standards” outside of the strange and wonderful world of Dynojet. In fact, I have NO idea what “DJWhPw-C Hp” is supposed to say, and I have an engineering physics degree and have been playing with driveline and dyno data for about 37 years!

Dynojet is frequently, and correctly, criticized by other dynamometer manufacturers because they use “blackbox” formulas to “factor” the raw results and refuse to disclose their formulas. Most knowledgeable dyno experts have concluded that Dynojet factors up the raw results to try to account for inertia and other effects, which would otherwise show lower power and torque curves (never a good thing when dynoing someone’s personal project vehicle!). Because Dynojet makes ONLY inertia dynos (which they lamely adapt to steady state operation via accessory brakes), inertia and other dynamic effects ARE more likely to affect their results – BOTH ways (better and worse power and torque, depending on technical factors). By using a “blackbox” approach, Dynojet immediately alienates any knowledgeable dyno expert.

WHY is this Superflow dyno operator using Dynojet “filtering”? Good question. I do know it is NOT because he is using Dynojet software; the “WinDyn” note at the bottom of the chart tells me that the software being used is WinDyn, the software provided by Superflow. Lord only knows why “DJWhPw-C Hp” and “DJWhTq-C lb ft” are being used instead of the STANDARD and NORMAL SAE1349 or SAE607. And of course, the danger is that use of those DJ formulas on a dyno that is NOT a Dynojet dyno is completely inappropriate.

Next, examine the “rpm” scale. Nte that the operator has shut down testing at 6250 rpm. Any knowledgeable dyno operator knows that this is not the redline for a 6-speed equipped LS2 engine (6500 rpm is). I suspect he shut it down at 6250 for the same bad reason as many other dyno operators do: in the bad old days, engine rpm was often limited mechanically long before the engine ran out of air, and dyno operators would run to the point of peak power and then shut down because if you went further, you could do mechanical damage. On a GM Gen III engine like the LS2, this is NOT the case. 6500 or even higher is safe with stock valvetrain and lower end. It is VERY valuable to get torque and power data for rpm BEYOND the peak power point, as the quickest acceleration is NOT obtained by shifting at the peak power point, but rather some distance beyond. How far beyond depends on the gap between gears n the transmission. The gap between 1st and 2nd in the Tremec 6-speed used on the SSR is large enough to warrant shifting as high as you can safely go. So, by shutting down early, the dyno operator did Jeff a disservice by denying him important upper rpm data. Fortunately, because the torque curve is relatively constant slope after 6250, we can extrapolate the results, feed them into modeling software, and tell Jeff where he actually SHOULD shift – with different potential shift points for each gear, depending on gap between gears.

Next, the operator did something really good. He showed the air/fuel ratio on the right hand vertical scale. Now, such data can sometimes “lag” the engine under inertia testing conditions, but since we don’t know if the operator did steady state or inertia, we can’t factor lag in accurately. We DO know it exists, because I can SEE it at around 4000 rpm wit the stock (red) torque and power curves! We’ll just have to accept the data as shown (another sigh).

Because the operator honestly showed the A/F data, we can figure out rather easily why the torque and power spiked upward in the stock SSR at 4000 rpm. That was where the power enrichment delay finally ceased. Because of space limitations here, I’ll just say that power enrichment is the richening of the air/fuel mixture for maximized power and engine safety under wide open throttle conditions. The factory tune delays power enrichment for a second or two after full throttle is applied, and until a threshold rpm is achieved, for technically conservative reasons. Jeff’s tuner has reducd that delay a lot. You can see it clicking in between 3400rpm and 4500 rpm, but rather more gently than the factory’s version (4100 to 4700).

Note that from 3000 rpm to 3400 rpm, the a/f ratio for factory and tuned are very close, although the tuned is slightly richer (lower number).

By manipulating a/f, timing, and power enrichment KNOWLEDGEABLY (don’t try this at home!), Jeff’s tuner has achieved wonderful results all the way from 3000 rpm to almost peak rpm. See how much higher the “tuned” torque curve is versus the “factory” torque curve? This translates to the 42 more hp and 76 more ft lb of torque at 3000 rpm mentioned early in this posting. That’s a HUGE gain via only electronic tuning (versus physical modifications). Furthermore, he has maintained a gap ranging from 10hp to 20 hp above the factory curve all the way to almost 5500 rpm. At 5500, the engine’s MECHANICAL inability to flow more air limits what he can with electronic tuning, so he peaks at “only” about 4 or 5 hp above the factory peak – but he does so at about 200 rpm lower than factory, showing his superior a/f and timing management of the air he has available to work with.

Did Jeff get his money’s worth? I sure think he did. That midrange has to feel AWESOME now compared to before. Should be be disappointed that he got “only” a few hp at the top end? No way! Remember that his tuner did not have the opportunity to make physical mods that could actually change the physical air flow (which is what makes more power). He could only “optimize” electronically the management of what air Jeff’s engine is already pulling in. I think he did a good job.

Jeff sent me the text note from his tuner that accompanied the chart. In it, I noted two things that I am not normally comfortable with: his tuner removed the speed limiter, and also entirely removed the torque management.

The speed limiter bothers me because it is there for a very specific reason on the SSR: the tock tires are not rated to run at speeds above the limiter value. On a heavy vehicle like the SSR, this is even more important than normal. I feel that the limiter should ethically not have been removed unless the tires had been changed to a higher rated type capable of higher speed.

The complete removal of torque management on this 6-speed SSR is probably fine (the Eaton rear axle is reasonably strong), but would be a major error on an automatic-equipped SSR. The automatics used on the SSR, whether the older 4L60-E or newer 4L65-E are technically too weak for these engines, especially during the critical time periods during gear shifts. Because the torque converter in an automatic transmission multiplies the engine torque by a factor of up to TWO during gear shifts, there is real danger of doing serious damage to the transmission if the torque management is entirely disabled and left that way. I support MODERATING the torque management, but do not endorse removing it entirely. I have graphical proof of the dangers attached along with the dyno chart to this posting. If you look at the two shift points in this attached graph, you can visibly SEE the doubled power spike during the shifts.

Note also that the removal of torque management on this 04 SSR (300hp LM4 engine) did NOT affect power transmitted anytime EXCEPT during shifts. Now, I don’t know if the 05 / 06 SSR torque management affects power only during shifts, or at other times too. If only during shifts (like the 03 / 04), then disabling it did NOTHING anyway on a vehicle equipped with manual transmission!

Jeff’s tner also says he raised the SPEED of the engine cooling fan. I am not sure of this, but I don’t believe you CAN raise the speed of the fan. I think you can only change the temperatures at which the fan’s two FACTORY speeds are activated or shut off (the stock fan is a 2-speed in the 03 / 04 and I assume it is the same fan in the 05/ 06). He MAY have meant that he activated the higher factory speed sooner than the factory tune does. Again, we don’t know.

So anyway, this is a “brief” analysis of this dyno chart . . .

DETAILED analysis would take too much thread space . . . :)

Jim G
 

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Well Stated

Jim,

What an awesome write up given the sparce amount of information provided. I have to get myself a programmer for Christmas :D

My Best,

Rob
 

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Jim,

Thanks learned a lot.
 

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JimGnitecki said:
Earlier today, Jeff, one of our members, sent me the dyno chart his dyno operator generated before and after dyno tuning his 05 6-speed SSR. I promised Jeff an analysis, but realized when looking at the graph, how great a textbook example it is to highlight some generic things about dyno charts, and their strengths and limitations. So, I got a little long winded . . . .

Ok, guys, here’s what I see in that (attached) chart:

First, let’s take the hopelessly superficial view. Here, the casual observer looks at it and says “big deal, the tuner got about 5 more peak horsepower, and 4 more ft.lb. of torque. Waste of money.”

Then, there’s the way that the advertisement writer for an unscrupulous tuner would write up these results. He’d say, Wow, on an actual dyno test on an 05 SSR, the combination of our hardware and tuner expertise got UP TO 42 more horsepower and UP TO 76 more ft.lb. of torque. Buy our supergizmo package and go LOTS faster!!

BOTH of these views are technically “true”, but actually deceptions, because they focus in each case on one narrow result. The first statement focuses on the 5500 to 5800 rpm band where the “peak” power (NOT torque) occurs, while the second focuses specifically on 3000 rpm, FAR from where meaningful power is being produced.

Let’s analyze this chart using a more structured approach.

First, let’s examine the “documentation”, which is, I’m afraid, rather skimpy – an unfortunately common trait among tuners, who are always more interested in doing the work than documenting afterward exactly what they did. First, the dyno operator failed to specify which SAE standard he used for his correction factors. Correction factors correct the “raw” torque and power to allow for the favorable or unfavorable effects of ambient conditions at the time and place of the dyno testing. This operator has stated only “SAE DJ” which is NOT a valid SAE test procedure. The valid ones are SAE1349 and SAE607. The key difference between these two standards is the “standard temperature” to which all raw results are corrected. Without writing a book (again) here, the SAE607 procedure, commonly labeled “SAE STD” by aftermarket dyno builders, generates results that are on average 4 to 5% higher than SAE1349. This is WHY most aftermarket tuners use SAE607, so they can show “happier” results to a customer! So, if this graph shows SAE607, then an SAE1349 correction would yield about 4 to 5% more power across the board than the chart shows, and a peak of about 357 rwhp versus the 342 shown. If this graph is corrected to SAE1349, then correction to SAE607 would lower the peak power to 327 rwhp. This is the more likely scenario for an 05 6-speed SSR. However, since the operator did not specify, we simply don’t know. Sigh . . .

The next point of confusion is the type of dyno and software used. The chart says “Superflow”, which is a brand of dynamometer that can run in EITHER steady state or inertia mode. The results are usually notably different in the two modes, due to driveline inertia and other effects. The chart fails to specify in which mode the results were run. Again, sigh.

The next problem is that the operator HAS gone to great pains to everywhere specify “DJWhPw-C Hp” for power and “DJWhTq-C lb ft” for torque. These are likely abbreviations for “Dynojet Wheel horsepower – calculated per formula C” and “Dynojet Wheel torque calculated per formula C”, neither of which are “standards” outside of the strange and wonderful world of Dynojet. In fact, I have NO idea what “DJWhPw-C Hp” is supposed to say, and I have an engineering physics degree and have been playing with driveline and dyno data for about 37 years!

Dynojet is frequently, and correctly, criticized by other dynamometer manufacturers because they use “blackbox” formulas to “factor” the raw results and refuse to disclose their formulas. Most knowledgeable dyno experts have concluded that Dynojet factors up the raw results to try to account for inertia and other effects, which would otherwise show lower power and torque curves (never a good thing when dynoing someone’s personal project vehicle!). Because Dynojet makes ONLY inertia dynos (which they lamely adapt to steady state operation via accessory brakes), inertia and other dynamic effects ARE more likely to affect their results – BOTH ways (better and worse power and torque, depending on technical factors). By using a “blackbox” approach, Dynojet immediately alienates any knowledgeable dyno expert.

WHY is this Superflow dyno operator using Dynojet “filtering”? Good question. I do know it is NOT because he is using Dynojet software; the “WinDyn” note at the bottom of the chart tells me that the software being used is WinDyn, the software provided by Superflow. Lord only knows why “DJWhPw-C Hp” and “DJWhTq-C lb ft” are being used instead of the STANDARD and NORMAL SAE1349 or SAE607. And of course, the danger is that use of those DJ formulas on a dyno that is NOT a Dynojet dyno is completely inappropriate.

Next, examine the “rpm” scale. Nte that the operator has shut down testing at 6250 rpm. Any knowledgeable dyno operator knows that this is not the redline for a 6-speed equipped LS2 engine (6500 rpm is). I suspect he shut it down at 6250 for the same bad reason as many other dyno operators do: in the bad old days, engine rpm was often limited mechanically long before the engine ran out of air, and dyno operators would run to the point of peak power and then shut down because if you went further, you could do mechanical damage. On a GM Gen III engine like the LS2, this is NOT the case. 6500 or even higher is safe with stock valvetrain and lower end. It is VERY valuable to get torque and power data for rpm BEYOND the peak power point, as the quickest acceleration is NOT obtained by shifting at the peak power point, but rather some distance beyond. How far beyond depends on the gap between gears n the transmission. The gap between 1st and 2nd in the Tremec 6-speed used on the SSR is large enough to warrant shifting as high as you can safely go. So, by shutting down early, the dyno operator did Jeff a disservice by denying him important upper rpm data. Fortunately, because the torque curve is relatively constant slope after 6250, we can extrapolate the results, feed them into modeling software, and tell Jeff where he actually SHOULD shift – with different potential shift points for each gear, depending on gap between gears.

Next, the operator did something really good. He showed the air/fuel ratio on the right hand vertical scale. Now, such data can sometimes “lag” the engine under inertia testing conditions, but since we don’t know if the operator did steady state or inertia, we can’t factor lag in accurately. We DO know it exists, because I can SEE it at around 4000 rpm wit the stock (red) torque and power curves! We’ll just have to accept the data as shown (another sigh).

Because the operator honestly showed the A/F data, we can figure out rather easily why the torque and power spiked upward in the stock SSR at 4000 rpm. That was where the power enrichment delay finally ceased. Because of space limitations here, I’ll just say that power enrichment is the richening of the air/fuel mixture for maximized power and engine safety under wide open throttle conditions. The factory tune delays power enrichment for a second or two after full throttle is applied, and until a threshold rpm is achieved, for technically conservative reasons. Jeff’s tuner has reducd that delay a lot. You can see it clicking in between 3400rpm and 4500 rpm, but rather more gently than the factory’s version (4100 to 4700).

Note that from 3000 rpm to 3400 rpm, the a/f ratio for factory and tuned are very close, although the tuned is slightly richer (lower number).

By manipulating a/f, timing, and power enrichment KNOWLEDGEABLY (don’t try this at home!), Jeff’s tuner has achieved wonderful results all the way from 3000 rpm to almost peak rpm. See how much higher the “tuned” torque curve is versus the “factory” torque curve? This translates to the 42 more hp and 76 more ft lb of torque at 3000 rpm mentioned early in this posting. That’s a HUGE gain via only electronic tuning (versus physical modifications). Furthermore, he has maintained a gap ranging from 10hp to 20 hp above the factory curve all the way to almost 5500 rpm. At 5500, the engine’s MECHANICAL inability to flow more air limits what he can with electronic tuning, so he peaks at “only” about 4 or 5 hp above the factory peak – but he does so at about 200 rpm lower than factory, showing his superior a/f and timing management of the air he has available to work with.

Did Jeff get his money’s worth? I sure think he did. That midrange has to feel AWESOME now compared to before. Should be be disappointed that he got “only” a few hp at the top end? No way! Remember that his tuner did not have the opportunity to make physical mods that could actually change the physical air flow (which is what makes more power). He could only “optimize” electronically the management of what air Jeff’s engine is already pulling in. I think he did a good job.

Jeff sent me the text note from his tuner that accompanied the chart. In it, I noted two things that I am not normally comfortable with: his tuner removed the speed limiter, and also entirely removed the torque management.

The speed limiter bothers me because it is there for a very specific reason on the SSR: the tock tires are not rated to run at speeds above the limiter value. On a heavy vehicle like the SSR, this is even more important than normal. I feel that the limiter should ethically not have been removed unless the tires had been changed to a higher rated type capable of higher speed.

The complete removal of torque management on this 6-speed SSR is probably fine (the Eaton rear axle is reasonably strong), but would be a major error on an automatic-equipped SSR. The automatics used on the SSR, whether the older 4L60-E or newer 4L65-E are technically too weak for these engines, especially during the critical time periods during gear shifts. Because the torque converter in an automatic transmission multiplies the engine torque by a factor of up to TWO during gear shifts, there is real danger of doing serious damage to the transmission if the torque management is entirely disabled and left that way. I support MODERATING the torque management, but do not endorse removing it entirely. I have graphical proof of the dangers attached along with the dyno chart to this posting. If you look at the two shift points in this attached graph, you can visibly SEE the doubled power spike during the shifts.

Note also that the removal of torque management on this 04 SSR (300hp LM4 engine) did NOT affect power transmitted anytime EXCEPT during shifts. Now, I don’t know if the 05 / 06 SSR torque management affects power only during shifts, or at other times too. If only during shifts (like the 03 / 04), then disabling it did NOTHING anyway on a vehicle equipped with manual transmission!

Jeff’s tner also says he raised the SPEED of the engine cooling fan. I am not sure of this, but I don’t believe you CAN raise the speed of the fan. I think you can only change the temperatures at which the fan’s two FACTORY speeds are activated or shut off (the stock fan is a 2-speed in the 03 / 04 and I assume it is the same fan in the 05/ 06). He MAY have meant that he activated the higher factory speed sooner than the factory tune does. Again, we don’t know.

So anyway, this is a “brief” analysis of this dyno chart . . .

DETAILED analysis would take too much thread space . . . :)

Jim G
Hey everyone!

This Is Johan Mangs' response to Jim's analysis;

Whoha! Man that was interesting, well here we go, attached is a SAE607 data.
We use SAE DJ correction factor due to the fact that 90% of dyno results
published are from Dynojet dyno's, but the gains are the same in any
format you view it, it is just the peak values that change. We are not
in the business of deceiving customers we just stick to the media
standards when it comes to dyno results but as you see we have no issue
publishing the SAE values.
The runs where performed under load conditions where we input vehicle
weight and drag coefficient factor, we never do inertia runs, the runs
where also performed at the same ECT (engine coolant temps) and IAT
(intake air temps) and the ambient temp and humidity where also
controlled for accuracy. We also run a simulated air source to simulate
the amount of air entering the air intake with hood closed.
The speed limiter was removed due to the fact the dyno runs where made
in 3rd gear and with stock speed limit present the vehicle would hit the
speed limiter before the rpm limiter, ie. it topped out at 125 mph
before 6000rpm.
Also the vehicle we tested as both you and I know was an automatic not a
manual transmission equipped vehicle.
I will not go into great detail on the torque management but I never
remove it completely in automatic transmission vehicles due to risk of
damage and undesirable shifts.
Also the fan calibration in LS2/LS7 is drastically different that
previous LS1/LS6 calibrations, the parameter that I adjust is a table
which depicts the desired fan power applied at a certain temperature, so
an increase in power to the fan would normally yield a higher fan speed,
the LS1/LS6 calibrations have an on/off temp for fan1 and fan2, the
LS2/LS7 do not.
I think this should suffice. He he, i do like the depth this guy went to
analyze the data.

Sincerely:
Johan Mangs

Diablosport
Automotive Calibration/ Research and Development

1865 SW 4th Ave Suite D2
Delray Beach, FL, 33444
ph: 561-908-0041
fax: 561-908-0051

PS, yes my SSR is an auto.
 

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Discussion Starter #8
JRSSR: Thanks for Johan's response!

Here are quotes from the note he sent you ORIGINALLY with the dyno chart (which you forwarded to me with the dyno chart):

Here is dyno sheet attached, it depicts stock tune vs my tune and the
lines represent horsepower, torque and air fuel ratio.
What i did in the tune was:
Add timing, not much.
Lean out air fuel ratio and allow it to go into PE mode at an earlier
%throttle position. PE mode is same as closed loop.
Remove torque management.
Remove speed limiter
Increase fan speeds and allow the fans to come on earlier.
That is the basics of what i did.
Hope the ride feels better.


I HAVE to ask:

1. As you can see, he said clearly he "remove(d) torque management". So now he says he only modified it?

2.. So he REactivated the speed limiter after the dyno run? (Becuase he did not say so in his note quoted above)

2. He apaprently sent you a NEW chart, showing the data corrected to the standard J607. Can you email me that so we can see the differences between that and the creative non-standard "DJWhPw-C" values? As Johan states in his 2nd note, he apaprently generates those for "better comparability" to Dynojet-generated inertia-based curves. (Nice way of saying "give them what they want - higher values")

I don't know how I got the impression that your SSR was a stick shift, but I apologize for that error. For an automatic, the "DJWhPw-C" values do seem a bit high.

Jim G
 

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JimGnitecki said:
JRSSR: Thanks for Johan's response!

Here are quotes from the note he sent you ORIGINALLY with the dyno chart (which you forwarded to me with the dyno chart):

Here is dyno sheet attached, it depicts stock tune vs my tune and the
lines represent horsepower, torque and air fuel ratio.
What i did in the tune was:
Add timing, not much.
Lean out air fuel ratio and allow it to go into PE mode at an earlier
%throttle position. PE mode is same as closed loop.
Remove torque management.
Remove speed limiter
Increase fan speeds and allow the fans to come on earlier.
That is the basics of what i did.
Hope the ride feels better.


I HAVE to ask:

1. As you can see, he said clearly he "remove(d) torque management". So now he says he only modified it?

2.. So he REactivated the speed limiter after the dyno run? (Becuase he did not say so in his note quoted above)

2. He apaprently sent you a NEW chart, showing the data corrected to the standard J607. Can you email me that so we can see the differences between that and the creative non-standard "DJWhPw-C" values? As Johan states in his 2nd note, he apaprently generates those for "better comparability" to Dynojet-generated inertia-based curves. (Nice way of saying "give them what they want - higher values")

I don't know how I got the impression that your SSR was a stick shift, but I apologize for that error. For an automatic, the "DJWhPw-C" values do seem a bit high.

Jim G
No attachment from Johan, I'll request it.

Jeff
 

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Discussion Starter #10
Thanks, JRSSR.

By the way, don't anyone get too mad at Johan about using the funny Dynojet scale or making a few errors in his documentation to Jeff, until you first check YOUR dyno tuner's methodology and documentation. This is regretably an industry that attempts to do something very complex with equipment, prcoedures, and people that are not all that complex. And, it tries to do so charging as little as possible so that people will actually buy. And it tries to give "happy results". As my wife has said to me repeatedly, "You should write a book on dynamometers and dyno procedures, so people would have some idea of the all issues and why it's not as easy or accurate as people think".

Don't forget that Johan apparently accomplished wat he set out to do: improve the power curve on Jeff's ride. He just didn't DOCUMENT what he did nearly as well as he did the tune. We have to hopefully assume that his actual dyno procedures were better than the documentation.

Jim G
 

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JimGnitecki said:
Thanks, JRSSR.

By the way, don't anyone get too mad at Johan about using the funny Dynojet scale or making a few errors in his documentation to Jeff, until you first check YOUR dyno tuner's methodology and documentation. This is regretably an industry that attempts to do something very complex with equipment, prcoedures, and people that are not all that complex. And, it tries to do so charging as little as possible so that people will actually buy. And it tries to give "happy results". As my wife has said to me repeatedly, "You should write a book on dynamometers and dyno procedures, so people would have some idea of the all issues and why it's not as easy or accurate as people think".

Don't forget that Johan apparently accomplished wat he set out to do: improve the power curve on Jeff's ride. He just didn't DOCUMENT what he did nearly as well as he did the tune. We have to hopefully assume that his actual dyno procedures were better than the documentation.

Jim G
So far I am extremly satisfied at the tune; and I still have to go back for a "ck up" What a difference, esp the torque and shifting!

Jeff
 
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