Dandy street tuned my motor, however we did it on 2nd. I'm not doubting his abilities, but I just wanted to know if that is the best gear to tune an EU with an auto. What are the pro's cons of 2nd or 3rd (OD off).

Thanks,

 

I think on an AT the 2nd is where you get the most power, if you shift you gear manually the 1st will hit the red line quickly, but 2nd will get you close to 100Km/hr if I recall correctly, ( my max has been under rebuild & sitting in my home garage for the 42 months so it's been a while since I drove it ) I'm pretty sure that's the best gear to tune.

 

Currently tuned on 2nd I can get up to 140km/h (about 85mph if I calculated properly) .

 

I have done all of mine in 2nd gear. First gear is way too short and in 3rd you're going to be way too fast for a street tune.

 

What about dyno tune?

 

On a dyno I would say 3rd gear is best because you get a much higher resolution in your tuning software.

 

Always locked my automatic into third gear for me on the dyno... it's low enough to pull from 3K up to fuel-cut at 6500, but high enough to be close to straight-through gearing. I never paid any attention to indicated speed, but somewhere around 110 MPH as I kinda recall.


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It always annoyed me with my auto Cefiro that they dynod' in 2nd and not 3rd - is the power figure going to be lower in 2nd? They said the reason they did that was to prevent the kick down when the did the power run (apposed to mixture check)

 

You always wanna tune in 3rd, its the closest gear to 1:1. Just make sure you take off OD, accelerate till its above 60MPH (above 3K RPM), then floor it. It will not kick down, just to be sure, go to a higher mph/rpm like 65mph or 3200 or so. you wont be able to tune below that rpm, but you will be able to get the best resolution possible. If your tuning on the street and dont have a safe empty highway then do 2nd gear.

 

Kev I would say 3rd gear for the dyno, 2nd for the street. The reason for doing street runs in 2nd (and why we did it that way) is simply speed... 50 over the limit and you lose your car if caught, I'm not taking that chance.

 

I tune on the street ALL the time, but only in 2nd, even then I am way over the limit. It would be nice, but the Bonneville Salt Flats are too far away. A 2nd gear tune is safe, just not as accurate as 3rd.

When I am at the track, I confirm the tune.

Dan did it right.

 

Makes sense. Once I get the exhaust in and go see Mike, I will get him to re-tune on 3rd since it will be on the dyno.