Did some dyno tuning in 3rd, now 2nd feels lethargic on the street?

[240z4u]

I made all my pulls in 3rd gear to get my a/f's sorted out and check knock etc..

Car feels fast from a roll in 3rd gear, but very lethargic in 2nd! Am I pushing the car into a different part of the fuel/timing map in 2nd and its running rich or something of that nature?

I was not sure if this was normal, my mods are in the sig and I was running 19psi when tuning. I had some problems with my BOV blowing open on the dyno so the numbers are not right from the printout.

Evan

[Joe]

the ecu does not know a difference between gears. it just knows airflow.

your butt dyno is broken.

[240z4u]

I have the biggest butt dyno this side of the mississippi! No way it can be broken! lol

Thanks Kamin, it could very well be wheelspin also.

I just wanted to confirm my craziness, and make sure I was not overlooking something!

Evan

[gawdzilla]

the difference between 2nd and 3rd gear may be putting you into different load cells and taking a slightly different path. Did you try logging how it travels on the cells in 2nd vs. 3rd?

[240z4u]

I have not logged 2nd yet. I need to have a passenger with me to run my laptop. It happens so fast that its hard to stop and start it in time.

I have a feeling its going rich like you say. Ill find out.

Ill be at the track this coming sunday. DNI!

Evan

BTW, I was having trouble holding boost but I made 375ft/lbs of torque on a dyno dynamics dyno.
Modified by 240z4u at 7:00 PM 3/10/2008

[blurrbosi]

try tuning in 4th.

[240z4u]

Ill do that next time I hit the dyno.

Did you have better luck in 4th?

Evan

[blurrbosi]

yes. Slightly longer log than 3rd. With your setup, I imagine 3rd is quick.

Also, what rpms are you starting your sample?

[240z4u]

3rd does not take too long, but the pull is on a dyno dynamics dyno so I am making a pull against a brake. It was wierd, I had been making pulls all morning then all the sudden he hit the brake to start my last run and I lifted off the gas like the car blew up LOL. Paranoia at its finest.

Thanks for the help. 3k is where I am starting from.

[blurrbosi]

I start sampling @ 2500 in 4th. The way i'm tuning it gives me more cells to control spool and wg spring pressure. Damn stock turbos!

I am against dynos that apply load as you sample. I have seen too many setups go home on a truck with that method.

Good Luck!

[gawdzilla]

your 2nd gear should be basically useless with anything short of a 275ish good compound tire or drag radial once you get in boost. if its not then something is wrong