L99: Sloppy shifts at WOT?

[Revo1]

Anyone else experience this?

Finally put the car on the strip recently. Launched great, pulled hard through first, and then came... Second. The shift felt spongy, and I felt the power fade as second came up. At this point I'm still out ahead of my buddy's LS3 by almost a cars length. The power finally makes an appearance, and the car starts to pull hard through 2nd.

Then came the shift to third. By this time Ryan is starting to pull on me, and I can see him in my peripheral vision... Then the car shifts into 3rd and falls flat. I knew right away my lead was doomed as soon as I felt the shift.

The rpms dropped, and the power waned. The LS3 surged ahead, and it was all I could do to stay with him, and keep him from extending his lead any more :(

Now I was running a JRE tune at the time, but long story short, was. 93 tune on my CA 91 gas, and had a long tube setup on a tune for stock exhaust. So various factors could have contributed to the loss, but I recently got myself a fresh tune from Ted, and he car does feel better- all except for the shifts.

Now I definitely don't need anyone tellin me to trade for an LS3 or any of that macho junk. My 4th gen is auto, and chirps third... This thing, not a chance. :(

Car was running without TC, but with the stabilitrak... Anyone have any ideas?

[Revo1]

Sorry about any typos, on my phone lol

[Revo1]

[kmcd]

I don't know if it would make any difference, but I kill both the TC and the StabiliTrak when I'm racing.

It's more likely that your tune is not optimized. With all due respect to Ted, it's hard for a mail-order tune to measure up to a custom dyno tune. When I had mine done, my tuner was logging pull after pull to fine tune all the variables. Long after I thought it was good to go, he still wasn't satisfied and kept tweaking it. Then we drove it while he made the final adjustments to the tranny tune. He ended up cutting nearly 4 tenths of a second off my ETs.

No two cars are the same, so a mail-order tune is a little like buying a suit off the rack instead of having one custom tailored.

[Rhino79]

I run stock pressure and .25 shift times and mine shifts great. I run no tq mgt. Prior to that I had the pressure bumped up by about 10-20% in some areas and it would chirp third easily, and on the 1-2 shift it would literally spin from 38 mph to 50 mph. That seemed a bit aggressive and too much needless wheelspin, so I went back to stock pressures. It feels nice but not too rough now.

[Revo1]

Thanks fellas. Rhino, I gotta admit, I'm not familiar with pressures...

I hear ya though kmcd, I'd like to do a custom tune. I couldn't stand the thought of driving it much longer on a tune fitted for the wrong exhaust AND the wrong octane, and dropping $500 on a custom tune just isn't in the budget right now.

I'm assuming the shift strength can be adjusted? I just feels like I'm coming into the next gear too low or something... Rhino, maybe you can elaborate?

[kmcd]

What was your ET and trap speed?

[Rhino79]

The shift pressures will help firm the shifts up, but the biggest thing is getting the shift times right. The stock shift times are closer to .5 sec, and with tq mgt, it pulls timing to reduce power on the shift. I run no tqt mgt and shift times commanded to .25. Even with stock pressure it shifts solid and very quick.

[Revo1]

Here's my timeslip for the night, and a video of the run- from Ronin's car:

[kmcd]

Find a 330-ft track, and you'll own him!

[kmcd]

Did you make any passes using tap shift?

[Revo1]

Lol right??

I only did one pass, knowing that the tune was wrong infield want to push her too hard for too long... :/

[SRT10KLLR]

Just tell Ted to give you a more aggressive tranny setting.

I used to chirp on the 1-2, 2-3 and even the 3-4 in the Camaro but had it turned down a little because it would spin too much at the track.

Datalog some runs so you can see if it has any KR.

[kmcd]

Here are two races against my son in his C5 Corvette (both of his runs are 12.95). I ran a 13.3 (mail order tune) in the first race and lost. The second race is a rematch after I had the car dyno tuned. In the interest of full disclosure, I was also running drag radials in the second race. The only other mod change was a Vararam intake instead of the AirRaid I had the first time.