6L80E 3-4 slow.

[8850]

Can you shoot us a screen shot of the table/tables you changed to improve the 3-4?

[mondi2002]

I have the same problem. I was thinking that it was the torque converter locking up.
Would it be ok to disable lockup in 4th in anything over 70% throttle?

[Waker]

I have the same problem. I was thinking that it was the torque converter locking up.
Would it be ok to disable lockup in 4th in anything over 70% throttle?

Yes...The converter does pull from the main supply, so unlocking it would allow more volume to the clutch pack. On a stock setup you will only see about 100 RPM slip at WOT compared to zero when locked (in the Camaro). There are numerous tables that will speed up the 3-4 depending on your TM setup. 3-4 is the week link in this tranny and is being addressed by Circle D. There WILL be a fix very soon...

[8850]

Yes...The converter does pull from the main supply, so unlocking it would allow more volume to the clutch pack. On a stock setup you will only see about 100 RPM slip at WOT compared to zero when locked (in the Camaro). There are numerous tables that will speed up the 3-4 depending on your TM setup. 3-4 is the week link in this tranny and is being addressed by Circle D. There WILL be a fix very soon...

My stock 08 Corvette file shows that the converter never locks at WOT.

We need a fix to make the 3-4 consistent from hot lapping vs. starting after cool down and going WOT. Can't tune this out. It shifts fine on the street or at the track if hot lapped but very slow or sluggish after cool down or possibly even just turning ignition off.

[Waker]

My stock 08 Corvette file shows that the converter never locks at WOT.

We need a fix to make the 3-4 consistent from hot lapping vs. starting after cool down and going WOT. Can't tune this out. It shifts fine on the street or at the track if hot lapped but very slow or sluggish after cool down or possibly even just turning ignition off.

All the Camaros lock at WOT...What specifically are you trying to tune out?

[Waker]

My stock 08 Corvette file shows that the converter never locks at WOT.

We need a fix to make the 3-4 consistent from hot lapping vs. starting after cool down and going WOT. Can't tune this out. It shifts fine on the street or at the track if hot lapped but very slow or sluggish after cool down or possibly even just turning ignition off.

The table that determines WOT lock is full throttle apply release. Your car should be set to lock in 3rd and 4th at WOT.

[8850]

All the Camaros lock at WOT...What specifically are you trying to tune out?

I want the 3-4 to shift fast at the track just as it does on the street.

The table that determines WOT lock is full throttle apply release. Your car should be set to lock in 3rd and 4th at WOT.

Does not lock at WOT. See screen shot above. The Full Throttle Release table is overridden by the High Speed Lock Enable table.

[Waker]

I want the 3-4 to shift fast at the track just as it does on the street.



Does not lock at WOT. See screen shot above. The Full Throttle Release table is overridden by the High Speed Lock Enable table.

Not exactly...You need to run a WOT log from launch to see if your converter is locking. The table you are pasting is commanding lock when the output shaft speed is below this value. This is the stock setting. If you have not modified this table then your full throttle apply release table is the driving factor. During a launch from zero MPH the car immediately goes into WOT mode (uses WOT tables) any other condition uses part throttle tables. That is why your shifts feel different WOT launch compared to any other condition. Read what HP has labeled the table you are posting and it will make more sense. I doubt very seriously your output shaft speed is ABOVE this value.

[Waker]

User name thesubfloor is much more knowledgeable in the vette arena than I. I have limited experience in the vette tuning community, although successful with vettes, I mainly tune G8s and Camaros. He may chime in and give some more insight.

[Waker]

I want the 3-4 to shift fast at the track just as it does on the street.



Does not lock at WOT. See screen shot above. The Full Throttle Release table is overridden by the High Speed Lock Enable table.

Set your full throttle apply/release speeds to 300, your converter WILL NOT lock under a WOT condition in D. If you do not modify your part throttle tables and subsequently floor it from a roll, your car may still lock in 3rd and 4th while in D mode. Sport is set to be unlocked for part throttle and WOT. This is data from an 09 vette, not sure if it's the same for the 08.

[bluegoat06]

Waker, i have the same issue 8850 has at the track. trans shift fine on the street, but the 3-4 WOT shift lacks the speed in the first track run, after a cool down period. if the car is hot lapped, the 3-4 shifts like a clock at WOT as it does on the street.

Have you seen this behavior in other G8's and what causes it ?

Here is my tune if it helps visualize things better.
In the G8 the verter applies in 4th, but i've bumped the 4th apply a little higher so she doesn't lock right after the 3-4 shift happens. i thought if we disable the tcc lock at WOT in 4th, the car would slow down in 4th. is that right ? or disabling the lock would help the car pick up speed ? (Stock verter)

[8850]

Set your full throttle apply/release speeds to 300, your converter WILL NOT lock under a WOT condition in D. If you do not modify your part throttle tables and subsequently floor it from a roll, your car may still lock in 3rd and 4th while in D mode. Sport is set to be unlocked for part throttle and WOT. This is data from an 09 vette, not sure if it's the same for the 08.

Something like this. I believe you are correct as I read the High Speed Lock Enable table wrong.

[8850]

Not exactly...You need to run a WOT log from launch to see if your converter is locking. The table you are pasting is commanding lock when the output shaft speed is below this value. This is the stock setting. If you have not modified this table then your full throttle apply release table is the driving factor. During a launch from zero MPH the car immediately goes into WOT mode (uses WOT tables) any other condition uses part throttle tables. That is why your shifts feel different WOT launch compared to any other condition. Read what HP has labeled the table you are posting and it will make more sense. I doubt very seriously your output shaft speed is ABOVE this value.

Here are two logs although no PIDs to determine converter locking but rpm seems to show no signs of locking that I can determine. The 11.317 pass has a much slower 3-4. On the 11.224 I hot lapped and that 3-4 was much quicker. My WOT starts about frame 2234 on the 11.317 pass and 6004 on my 11.224.

And a screen shot the way my Full Throttle table was set for these passes.

[8850]

Waker, i have the same issue 8850 has at the track. trans shift fine on the street, but the 3-4 WOT shift lacks the speed in the first track run, after a cool down period. if the car is hot lapped, the 3-4 shifts like a clock at WOT as it does on the street.

Have you seen this behavior in other G8's and what causes it ?

Here is my tune if it helps visualize things better.
In the G8 the verter applies in 4th, but i've bumped the 4th apply a little higher so she doesn't lock right after the 3-4 shift happens. i thought if we disable the tcc lock at WOT in 4th, the car would slow down in 4th. is that right ? or disabling the lock would help the car pick up speed ? (Stock verter)

I see yours are set to 318. And you still have the problem. Guess we don't have a solution yet???

[Waker]

Something like this. I believe you are correct as I read the High Speed Lock Enable table wrong.

Yes sir!!

[Waker]

I see yours are set to 318. And you still have the problem. Guess we don't have a solution yet???

He has normal and pattern A set to lock at various speeds. Pattern B is the only table set for no lock. If you want to prevent lockup, all tables need to have some number set in them that the car would never achieve for the given gear. You may lose a mph or two by not locking, but your ET will remain the same depending on your converter.

[Waker]

Here are two logs although no PIDs to determine converter locking but rpm seems to show no signs of locking that I can determine. The 11.317 pass has a much slower 3-4. On the 11.224 I hot lapped and that 3-4 was much quicker. My WOT starts about frame 2234 on the 11.317 pass and 6004 on my 11.224.

And a screen shot the way my Full Throttle table was set for these passes.

You will not see an RPM drop with the stock converter because of lockup strategy. You need to log TCC apply and TCC slip if you really want to know.

[Waker]

Waker, i have the same issue 8850 has at the track. trans shift fine on the street, but the 3-4 WOT shift lacks the speed in the first track run, after a cool down period. if the car is hot lapped, the 3-4 shifts like a clock at WOT as it does on the street.

Have you seen this behavior in other G8's and what causes it ?

Here is my tune if it helps visualize things better.
In the G8 the verter applies in 4th, but i've bumped the 4th apply a little higher so she doesn't lock right after the 3-4 shift happens. i thought if we disable the tcc lock at WOT in 4th, the car would slow down in 4th. is that right ? or disabling the lock would help the car pick up speed ? (Stock verter)

Good use of the adder modifier tables. I give free tech support if you run a Circle D tranny or converter. PM me if you have any questions.

[[email protected]]

Good use of the adder modifier tables. I give free tech support if you run a Circle D tranny or converter. PM me if you have any questions.

Walker,

I currently have a Circle D 2800 stall converter in the car. This issue happened to me at the track once, and after that it started hitting the rev limiter on every gear. Took care of the rev limiter issues they are gone now after the changes i made, but this issue still persist. Can you take a look at my tranny tune? I used bluecat's spreadsheet to set my shift points and tcc apply/release settings.

[Waker]

Walker,

I currently have a Circle D 2800 stall converter in the car. This issue happened to me at the track once, and after that it started hitting the rev limiter on every gear. Took care of the rev limiter issues they are gone now after the changes i made, but this issue still persist. Can you take a look at my tranny tune? I used bluecat's spreadsheet to set my shift points and tcc apply/release settings.

I'll look when I get home.