Is this an issue with my GT350 or an issue with my tune?

Long story short -- Car has been tuned by Lund a few months ago and I haven't had any issues other than trying to do dyno pulls. Earlier this week I went WOT and back down to cruising speeds. As I tried to hit 6th gear, the car revved up about 500 RPMs and I quickly put it in neutral out of a panic. I just drove down the interstate (only 2 exits anyway) in 5th. Figured it was just a one-time issue.

Today it happened again after going WOT and back down to cruising speeds. Tried going from 5th to 6th and, again, the car revved up about 500 RPMs and dropped down after a second. It revs up about 500 RPMs even when going from 5th to neutral.

I've brought it up to a few people and some suggested it's rev hang and built into the tune, others think it's possibly a sensor and has something to do with the heaters and heat. I've gotten the car much hotter than this on both track days so I'm not quite sure personally.

I took a video and sent some logs off to Lund and waiting to hear back. Really curious to hear some feedback from anyone who may have had a similar issue in the past. Here's a video if anyone's interested:

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TL;DR Car is revving in between gear changes, including neutral. Not sure if it's tune-related or something else.

I'm no expert, but I'm willing to bet it's tune related. Did this happen when sending logs back and forth to Lund?
Good luck Alton!

Stage_3 said:

I'm no expert, but I'm willing to bet it's tune related. Did this happen when sending logs back and forth to Lund?
Good luck Alton!

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Nope. Been tuned since late last year now I believe and so far this is the first time it happened. :( Thanks a lot man!

No tune or mods on mine and I don't believe mine has ever done that.

TDC said:

No tune or mods on mine and I don't believe mine has ever done that.

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Yeah I'm really hoping it's something related to the tune. Waiting to hear back from Lund :(

i used to hate hitting 6th to coast after passing a couple cars at triple digit speeds...but different situation and mine was never THAT bad. I'd holler at lund pronto

So far no updates from Lund (hit them up a week ago). Followed up with him today and he mentioned he'd get back with me tomorrow. Tried going WOT today and the same thing happened. I honestly can't drive this car comfortably anymore until I figure out what this is. It's driving me crazy.

Were you able to attach that video in your communication with lund?

A bit off topic but did you notice a difference in performance tune vs stock?

I'd ditch that tune.

Can you go back to stock tune and see if that fixes the problem?

jvandy50 said:

Were you able to attach that video in your communication with lund?

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Yep I just linked the YouTube video. Still waiting to hear back though.

Kurac said:

A bit off topic but did you notice a difference in performance tune vs stock?

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Not much if at all to be honest.

BoomBoy said:

I'd ditch that tune.

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ChevyNick said:

Can you go back to stock tune and see if that fixes the problem?

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Yeah I'm gonna see if I can load the stock tune today and replicate the issue. Very strange.

It seems like it is rev matching but very weird, if you can't get in touch with the tuner go back to stock.

Keeping an eye on this as I also wanted to go Lund. A lot of people here have Lund software on their cars so maybe someone can contribute...

Interesting OP says it was hard to do dyno pulls! Why? Was it hard stock? I'm asking this, because as soon as the brake in is over, and after the oil change, I'm planning to do a dyno on stock and then another one after headers + lund and see if there is any difference...

I'll bet it's the tune. A little different but when I did heads and cam to my C5 Z06, I had really bad rev hang in the higher gears. It took a few trips back to the tuner to get it worked out. Hopefully Lund comes through.