98Blubrd

iTrader: (13)

I have tuned some things for my friends converter (Yank 3600) on his 02 corvette. I saw a setting in HP Tuners for TCC LOCK DURING SHIFT OPTION. We enabled it and took his car for a spin and it felt great. I was wondering if it would hurt anything. Thanks for any input.

Tiger2o69

iTrader: (16)

Wont hurt anything but wont help anything either.... It's only for trucks i believe.

DevonsZ

iTrader: (20)

So will this keep the converter locked from 3rd gear into 4th gear at wot?

joecar

My 2001 WS6 has it enabled from the factory.

It's okay to have it on.

PCM will keep TCC applied during 2-3 shift (if TCC is applied in 2nd) and during 3-4 shift,
except above 80% TPS.

Refer to the TCC MPH vs TPS release tables and you'll see that at 80% TPS the curve jumps up to 256 MPH, giving a release (release occurs on transitions to underneath this curve).

joecar

This will keep the TCC applied during 3-4 shift as long as the MPH vs TPS falls above the the 3rd and 4th gear TCC release curves;
these curves jump up at 80% TPS forcing TCC to release;
WOT is greater than 80%, so, TCC is released at WOT in 3rd and 4th gears
Edit: (3rd gear TCC released (WOT, above 3rd gear TCC release curve), shifts to 4th, TCC still released (WOT, above 4th gear TCC relase curve).

98Blubrd

iTrader: (13)

It seemed like it made it shift better on the 1-2 shift as well. His car shifted loose as heck with his converter before the change and it felt like it was shifting better during all the shifts under WOT. R u guys sure it only adjusts the 3-4 shift? He was very happy with how different the car shifted. I guess I will just leave it on for him. Any other things I could change for his converter. I have already changed the shift speed/RPM, removed torque management and raised the rev limiter a bit. Thanks for everyones input.

joecar

It applies the TCC to all gears that have the TCC apply curve.

On my car, the 2nd gear TCC apply curve is all at 256 MPH which means mine does not apply the TCC in 2nd gear.

Check his 2nd gear TCC apply curve, if it has sensible values, then his TCC is applying in 2nd gear;
otherwise if the whole curve is above his usual 2ng gear speed (i.e. at 256) then the TCC won't apply in 2nd.

98Blubrd

iTrader: (13)

What does the 3rd C in TCC stand for? I am pretty sure i checked all of it and it was at a decent speed with the exception of the 3-4 shift (which i think was at 256) I will check his stuff again. Thanks for your help.

jimmyblue

iTrader: (11)

I had read that the TCC would release anyway, across the
shift, or so I recall.

Seems like if you don't like the shift extension, you've got
the wrong converter. It would be interesting to see track
or log results from lock-through and no-lock conditions, to
determine which produces best acceleration result (being
another matter entirely from shift "feel").

98Blubrd

iTrader: (13)

That is exactly why I am trying to get all this stuff ready. We are heading to the track again tonight. I have 3 different tunes for him to try each has slight changes. We will try it with the TCC lock during shift option on and off to see if there is any drastic change in his et. He will be on slicks so traction shouldnt be an issue. Hopefully we can get some good consistant results and be able to tell if there is any real differance. His car is a stock 02 vette except for exhaust, smooth bellow and a yank SS 3600, the last time we went out his best was a 7.40 (1/8th) with a 100 shot and a 1.79 60' on street tires (I thought was pretty impressive for the mods on street tires). We are shooting for high 6's or very low 7's with a 150 on the slicks which I think should be very possible. Any other changes I should make to his tune other than I noted in my previous post? Thanks.

joecar

TCC = Torque Converter Clutch

You're welcome, no worries.

joecar

I believe that the mechanism that unlocks the TCC during the shift is the TCC apply and TCC release curves for the gear that you're shifting from;
i.e. the 3rd gear TCC apply has a sharp rise to 256 MPH at 80% TPS;
so if you're at WOT, the TCC is not applied while in 3rd and going into 4th;
then when in 4th at WOT, same thing, the 4th gear TCC apply curve has a sharp step up at 80% TPS, so TCC is still not applied.

At least that's my understanding of it;
I haven't yet had the chance to reduce the sharp step down to a reaonable value and log what happens.
Edit: My understanding is that the step up at 80% is because the TCC can't handle full torque since it's only "half a clutch" (only 1 friction surface instead of 2 or more).

joecar

I am not sure of the terminology (too many terms and acronyms)...
Could you explain the term "shift extension" to me, please...

Yes it would be interesting to see the acceleration differences between locked and unlocked
(actually the terminology I'm used to is 'applied' and 'released', different books I read or something... )

Regards
Joe

horist

shift extension: the rpm the converter slips to after a shift (example, at WOT w/my converter, after a shift at 6400 RPM i only go down to about 5700RPM, whereas a smaller converter would drop even lower)

at non WOT, a looser/big converter will have higher RPMs after a shift.

By locking the converter during a shift, you're eliminating much of the slip so after a shift RPMs should be lower than w/out it locked

joecar

98Blubrd, very nice colour F-bird... :two thumbs up:

98Blubrd

iTrader: (13)

Thanks. Joecar. I will have some track results for this maybe on saturday if I decide to go on the net and post them. Monday would be the latest I will post them. Then we will have some #'s to go by rather than just thoughts. I would think that since he is spraying a 150 shot the car should do better with the TCC locked during the shift cause of the extra power and less slippage but N/A it might be slower if the car drops to much RPM going into the next gear. Correct me if I am wrong.

joecar

Okay, so it's the RPM difference between what the new gear wants and what the TC slips to (which will be higher than what the gear wants).

Stall converters (looser) will allow a higher RPMs.

Okay, I understand the term (I had previously called it "stall slip" or similar), thanks.

Regards
Joe

joecar

Theory and practice both go like this:
if TCC is slipping between gear changes,
it allows higher RPM going into new gear,
so engine is higher up on torque curve;
also, a slipping TC is multiplying torque,
which helps to start pulling in the new gear.

So we'll see, we're interested in your track results,
thanks in advance for posting (take your time).

Regards
Joe

fast98

iTrader: (16)

i have it enabled and have put 5k miles on it that way. it still unlocks on the shift.

joecar

Oh, there is another table for each gear...
the TCC Throttle Release table, and is typically set at 100% TPS;
if the TPS reaches this value, the TCC releases.

jimmyblue, you're correct, this is probably what you meant.

Regards
Joe