Dyno Tune VS. Datalog Tune...

[MJ]

I understand the concept and pros/cons of both methods, but am looking for opinions from the knowledgeable folks on this forum that have experience with both.

Edit: To be more specific; datalog tuning with EFI-Live or HP Tuners. I was looking for opinions on dyno tuning vs. tuning on the road/track.

Btw- there are tuners close to me... one uses EFI-Live on Dyno, the other uses EFI-Live on the street/track to tune.

[aj2ssrs]

I purchased a cai and diablo trinity tuner as a package first, knowing that down the road I will be installing lt headers and getting a dyno tune also. I went this route thinking that after I got the car dyno tuned, I could use the Trinity to revert back to the stock tune in case I needed warranty work down the road. ( The dyno tune is saved on my Trinity tuner). I played around with the Trinity for a little while.

Plusses for the Trinity canned tune:
1. Turns off skip shift.
2. Eliminates torque management on the engine side.
3. Squeezes a little more HP out of the engine.
4. Enables you to monitor and datalog almost everything.
5. Numerous user settings can be changed (tire changes, speed limiter, etc.)

Minusses for the Trinity:
1. After datalogging and getting injector fuel slope dialed in, parameters may need to be changed for different weather conditions. It's not a 1 shot deal.
2. Was told by the person doing my dyno tune that adjusting the injector fuel slope is NOT the proper way to dial in the engine.

Plusses for dyno tune:
1. Does everything the Trinity tuner plus more.
2. Eliminates torque management on both engine and transmission sides. (I have an LS3 and was told there is still TM on the manual tranny)
3. Once the car is tuned, there is note need to re-dial in settings based on the weather.
4. Car is being tuned by someone who knows what they are doing.

On a side note, if you are doing upgrades that include lt headers, hi-flo cats cai, and more, I would recommend a dyno tune to squeeze all you can out of the mods and get the the engine dialed in. If money is no object, get both so you can revert back to the hand held tuner in case of warranty work.

With just a cai and exhaust change but no headers, a canned tune would probably be fine. The LS3's come tuned pretty good from the factory. GM didn't leave much on the table HP wise. I can't speak for a L99 all my experience is with the LS3. Hope this helps.

[MJ]

Sorry AJ, I should of been more specific and said datalog tuning with EFI-Live or HP Tuners. I was looking for opinions on tuning on dyno vs. tuning on the road/track.

Btw- there are tuners close to me... one uses EFI-Live on Dyno, the other uses EFI-Live on the street/track to tune. Both have good reps.

[JR-Vette]

Originally Posted by MJ

I understand the concept and pros/cons of both methods, but am looking for opinions from the knowledgeable folks on this forum that have experience with both.

Edit: To be more specific; datalog tuning with EFI-Live or HP Tuners. I was looking for opinions on dyno tuning vs. tuning on the road/track.

Btw- there are tuners close to me... one uses EFI-Live on Dyno, the other uses EFI-Live on the street/track to tune.

Controllers for powertrain and drivetrain use adaptive strategy, learns, adjusts and requires valid drive time.

This cannot be done using a static dyno drum that

1. Most cases the drum is hundreds of pounds lighter then car/driver and thus cannot produce the same engine loads as in real world

2. Static dyno pulls are only in 1:1 gear ratio, uses only WOT functions and is less then 1 minute of drive time.

3. Games that can be played on a dyno is stacking the results, simple to make the BEFORE numbers or after tune numbers slanted the way dyno operator wants by playing with tire pressure, how car is strapped down, if a weather station is used for valid D/A corrections to doing run with hood open

Changes that are made are not done every second or minute, some functions like fuel trim adjustments are only done once every 10 minutes of run time, cannot be seen at all on a static drum dyno.

Every time the controllers ( PCM for engine, TCM for A6 trannie) are flashed they also are flushing out everything they relearned, adapted or averaged thus doing this on a dyno give zero time for the controllers to even get a short amount of relearn time.

Cars do not live on a dyno, nor driven on one or only see WOT thus if you want a good full custom tune you need to see real world drive conditions and engine functions from startup ( hot/cold, A/C on/off) to the 7 other modes the PCM has for idle (park, neutral, brakes on, A/C on, etc) to part throttle ( flatland, up/down hills) decel, power enrichment and finally WOT

Non of this can be seen on static dyno drum

Add mod changes like radical CAM grinds, heads, boost, etc and the only way to dial all these is with real world data and street/track drive conditions.

In custom tuning for 15 years I'd say 80% of the tunes I get are to clean up tunes that someone had done on a static dyno drum.

Load bearing dyno would allow more drive conditions to be done but they coast more money then static units and thus those shops want to spend even less time per car on a load bearing type.

Best case, car owner drives the car with his drive style using all engine conditions as about along with shifting, braking, cruise control, decel,
if auto trannie also auto and manual shifting, both trannie types also downshifting.
Tune, drive car for a day or 2 and then do another testrun with a OBD scanner, analyze and then tweak tune. Assure if auto trannie to give good relearn drive time for TCM to adapt and then make changes to TCM.

As to what tuning tool ?

The tool is nothing but a user interface (GUI) that peeks and pokes user values into memory address offsets, its the person behind the keyboard that makes a good or bad tune
Some tuner product vendors hype their tool for marketing and treat you like a crook.

If wanting an American Product and workers, efilive is not, hptuners is a mix of American and their scanner comes from efilive.

All American is LS2edit, product was the first on market in 2000 and would be my first choice for new cars using the newer GM controllers, older ones choice to me is LS1edit or Tunercat.

The PCM is a dyno it is needed for torque management and thus you can obtain your cars hp/tq from street drive and use of a OBD scanner connected.

[MJ]

Good info... thanks for taking the time to explain !!!