Performance Tuning - The Myth -

[Geronimo '74]

Loren, learn to use the friggin' quote button.

[Lorenfb]

"No, he said there is little to no gains."

Please re-read the initial post, and for more testing data on this topic, read here:
http://www.systemsc.com/tests.htm

[T77911S]

Originally Posted by Geronimo '74

Loren, learn to use the friggin' quote button.

+1
its confusing to read his posts when he does pastes instead of quotes. i think he does that to cause problems, much like a lot of his posts.
i dont understand why someone with a buisiness gets on here and does what he does.


far from an expert on tuning, but from the research i have done, just slamming the timing up to the point of detonation does not always provide the most HP gains. there is a point where advancing no longer gives you any more HP and going further (even though not at the point of detonation) may even reduce HP.

[Lorenfb]

"just slamming the timing up to the point of detonation does not always provide the most HP gains."

Where is that said? Another one that didn't fully read the post or failed to understand it!

[brads911sc]

Loren, Why do you care?

[Lorenfb]

"Why do you care?"

And what are the purposes of a forum? Isn't one of them to discuss issues and to
debunk mis-conceptions about various viewpoints? Without an expression of ideas
how can one determine what is fact or hyperbole? Do we all need to have a singular
viewpoint and just join all the lemmings without challenging issues? It appears that
some have that outlook and hate to have their 'bubble' burst.

[Reaper930]

Last time I checked tuning was done to "tune" the car to the customer's use for it, not to be a broad spectrum car for the entire world as it left the factory. Some like them louder, with more torque and same HP or are willing to accept a 80k mile engine versus a 200k mile engine.

Most of these cars left the factory over 25 years ago - you think there aren't updates since then to improve drivability and/or safe power? Not so long ago we "tuned" a 3.8tt using old school 935 parts & modern electronics to do what the factory could only dream of. A super high hp motor that is docile and runs smoothly no matter what RPM or load. Back in the 70's they had MFI to firehose fuel into the cylinders...

True tuning, as in improvements for specific applications for the customer isn't BS. Most of the parts out there in mass produced catalogs are hype or pose minor improvements at best - which is why we at DZ started our own brand of schit that actually works. When you have dedicated individuals like most on this board make a product of some home grown variety, usually it comes from factory knowledge and decades of improvements both in materials and technology that wasn't avalible back in the day.

True tuning is continuing on the passion and research that Porsche Motorsport, the original D-Zug started and somewhere along the path dropped off to go mainstream. Its the little gruppe of individuals that seeks perfection for a sports purpose application that can also be driven on the street.

[ant7]

Originally Posted by Reaper930

Last time I checked tuning was done to "tune" the car to the customer's use for it, not to be a broad spectrum car for the entire world as it left the factory. Some like them louder, with more torque and same HP or are willing to accept a 80k mile engine versus a 200k mile engine.

Most of these cars left the factory over 25 years ago - you think there aren't updates since then to improve drivability and/or safe power? Not so long ago we "tuned" a 3.8tt using old school 935 parts & modern electronics to do what the factory could only dream of. A super high hp motor that is docile and runs smoothly no matter what RPM or load. Back in the 70's they had MFI to firehose fuel into the cylinders...

True tuning, as in improvements for specific applications for the customer isn't BS. Most of the parts out there in mass produced catalogs are hype or pose minor improvements at best - which is why we at DZ started our own brand of schit that actually works. When you have dedicated individuals like most on this board make a product of some home grown variety, usually it comes from factory knowledge and decades of improvements both in materials and technology that wasn't avalible back in the day.

True tuning is continuing on the passion and research that Porsche Motorsport, the original D-Zug started and somewhere along the path dropped off to go mainstream. Its the little gruppe of individuals that seeks perfection for a sports purpose application that can also be driven on the street.

Good post!
A...

[Steve W]

Originally Posted by Lorenfb

"However, when i put a wideband 02 sensor on my stock 3.2 i saw high 11's at full throttle at high RPM. It does not take a lot of dyno experience to understand that 11 AFRs are stealing real HP."

Really, then let's see the data to corroborate that claim. My graph indicates that
there's little to no effect, i.e. Just look at the graph! If you don't have the supporting
data, then buy some dyno time to prove it. That's what I did.

Folks, the dyno charts posted is complete BS. It's not even the same car, the power curves in each are completely different. Furthermore, the dyno chart does not even resemble any 3.2 as claimed. It's obvious these are charts from a Dynojet and a 3.2 does not produce 227 ft/lbs of torque at 5000 rpm - ever. So if the OP is lying about this, what else is being made up? You have to wonder.



In comparison, here are the dyno charts of two true Carrera 3.2s I've dyno tuned in the past two months. These engines are internally stock spec and fresh per club racing rules built by some of the best engine builders in the nation. In the examples below, ignition timing was left unchanged, only the air/fuel ratios were adjusted.

In the chart below, note the progression in HP and torque increase as the air/fuel ratios are adjusted from a starting point of the blue run, where the AFRs range from a very rich 11-12, to the final adjustment of the green run, at a more optimal 13 AFR. The car has achieved 11 more rwhp and 10 ft-lbs of torque overall, just by fueling adjustments! Notice the fluctuation pattern of the blue run as the AFRs dip to 11.6 at 6000 rpm and how the HP dips below that of the red curve at that point, and the same trend at 7000 rpm. Again, no ignition timing changes!



Example 2:

Here is a chart of another spec 3.2 race car where the baseline AFR started at a lean ~14 AFR, the blue curves. Just by refining the AFR curve to a more optimal ~13, the engine has acheived 13 more rwhp and 10-15 ft-lbs more torque overall, the red curves.



I could go on all week as I have hundreds of cars and thousands of runs in my dyno database but it would be a waste of time. Take the above for what it's worth, and to the OP, cut the BS and go back to doing something you have a clue about.

[Reaper930]

My God...not........FACTS........

Great post Steve, there are some in life that pursue perfection at what they do, and others who dedicate themselves to muddying the water.

[Tippy]

Wow. 13whp is huge for NA engines. Definitely feel that.

[LJ851]

Although my personal experience of dyno tuning is primarily Ducati motorcycles, the graphs Steve posted above are exactly similar to the hundreds of bikes i have tuned (fuel adjustment only). Hell, you can audibly tell the difference between an 11 AFR pull and a 13 AFR pull !

I'm more and more confused by loren's posts. Clearly he has some knowledge ,but chooses to start threads about things he obviously does not know about.

[db_cooper]

Originally Posted by Lorenfb

"Why do you care?"

And what are the purposes of a forum? Isn't one of them to discuss issues and to
debunk mis-conceptions about various viewpoints? Without an expression of ideas
how can one determine what is fact or hyperbole? Do we all need to have a singular
viewpoint and just join all the lemmings without challenging issues? It appears that
some have that outlook and hate to have their 'bubble' burst.

Oh, start drinking...go to pick an online fight and quarrel..insult others and imply your superiority?

I don't think so.

[Lorenfb]

"the dyno charts posted is complete BS. It's not even the same car, the power curves in each are completely different. Furthermore, the dyno chart does not even resemble any 3.2 as claimed."

Actually, it really is a 911 3.2. The power curves are just different runs with a 3-4 degree timing
change. So now with these latest graphs, it appears that some so-called tuners are not really as
capable tuning 911 3.2 engines as they thought!

"Hell, you can audibly tell the difference between an 11 AFR pull and a 13 AFR pull !"

So, where're the data?

"there are some in life that pursue perfection at what they do"

Please!

"Most of these cars left the factory over 25 years ago - you think there aren't updates since then to improve drivability and/or safe power?"

Drank the cool-aide!

[LJ851]

"Actually, it really is a 911 3.2. The power curves are just different runs with a 3-4 degree timing change. "



What octane fuel was used in your test loren? Was it oxygenated?

[Steve W]

Cut the BS, your lying is so obvious.

[winders]

Loren,

Anyone that has tuned engines on a dyno knows that air/fuel ratios in a 2 point range change torque and horsepower significantly. Even 1 point, as Steve Wong shows above, can make a significant difference.

You are full of it.......you really should just stop posting about this stuff because you just don't know what you are talking about. You are embarrassing yourself...again!

Scott

[Lorenfb]

"What octane fuel was used in your test loren?"

Race gas was used to prevent any detonation while doing the tests.
The tests were only done to show how sensitive torque is to timing changes
and how insensitive torque is to AFR tweaking when the AFR is close to the
ideal of 12.6. That's it!!!!!!!!!!!!!!

"Anyone that has tuned engines on a dyno knows that air/fuel ratios in a 2 point range change torque and horsepower significantly."

Have you done the tests personally, I doubt it? My tests show otherwise! If you disagree,
then buy some dyno time and do your own tests.

Some have a vested interest in selling the need to tweak the AFRs of a stock 911 3.2.
Many will realize over time that that's a waste of time and money as now indicated by the data.

[Wayne 962]

As I wrote in my book, chips trade horsepower for other compromises, such as the need to use higher octane fuel, and higher timing ranges. The gains are real, not imaginary, but they do come with tradeoffs.

-Wayne

[LJ851]

Originally Posted by Lorenfb

Race gas was used to prevent any detonation while doing the tests.
The tests were only done to show how sensitive torque is to timing changes
and how insensitive torque is to AFR tweaking when the AFR is close to the
ideal of 12.6. That's it!!!!!!!!!!!!!!

Just as i thought. Running an engine with much higher octane than necessary will reduce it's power output. An engine fueled that way will be insensitive to AFR changes and very sensitive to timing changes. Your test shows nothing of value to someone considering getting the most performance out of their motronic 911.


Your above quote is right on the money except it is a less than a point range and is around 13-13.5, not a 4 point range as you previously stated.