Can you feel it? What does it feel like?
At what stock RPM does this occur?
With higher than stock TC's does it occur at proportional rpms to stock?
Is lockup rpm programable?
:confused:

 

Yes, you can feel it, it feels like another shift almost although very small.

I can't tell you what rpm, but it is programmable so someone with LS1Edit could tell you as they've seen the numbers.

 

Thanks Buck, I was hoping you'd respond...

I've been trying to "feel lockup" but don't know what I'm feeling for.

Should the TC lock-up at or just above the stall speed?
or is it a personal thing,or performnace thing.

I' ve been considering swapping for higher stall TC but I'm confused about the lock-up. I'm also on overload on stall speeds and STRs. But with my 3.15 I think I want 3000/1.86 maybe a little lower. :rolleyes:

 

What makes it lock-up? I thought there are no moving parts in the TC. :confused:

 

It's really an efficiency thing. By design, you want to lock the converter at *lower* RPM. You don't want to be cruising around everywhere in the neighborhood of stall RPMs, right? Locking at normal road speeds makes for much more efficient power transfer. From a performance perspective, that efficiency means more power to the ground.

The most annoying TC lockup design I have seen from the factory is in my Expedition. :cuss Letting off the throttle at cruise speeds and reapplying results in an RPM surge that feels exactly like a slipping tranny (because it is, the converter is unlocking and then locking.)

 

[/QUOTE]

Letting off the throttle at cruise speeds and reapplying results in an RPM surge that feels exactly like a slipping tranny (because it is, the converter is unlocking and then locking.)
[/QUOTE]

Soooo, that's what it feels like, *ell, i feel it now.

And.. so it locks up above stall speed right :confused:

 

Well, that particular example was from my Expy and is a result of the release occuring too quickly (i.e. very little change in road speed.) My A4 didn't behave that way even before I tweaked the programming. The lockup is a function of both vehicle speed and throttle position, not just a simple RPM thing. If you're seeing an annoying release/reapply scenario, the release may being triggered by the misfire detection logic. You still have the stock converter and programming (the HPP3 doesn't do anything wrt the TCC), right? Maybe you could talk a little bit more about exaclty what you're experiencing...

 

Would the TTS Powerloader II help with this?

I've got an A4 with the 3.15. I'll be cruzin' at about 40 or 45 (what is stall speed?) and go to "goose" it and the d*mn thing seems to up-shift. All performance is now lost because I have to push the pedal harder to get it to down shift again.

Anyway, will the Powerloader help with this?

 

here is a stock '99 pcn file for t/c lockup. It is locked up by MPH, just like the shift points.

%TPS 0 6 12 18 25 31 37 43 50 56 62 68 75 81 87 93 100

3rd apply 28 28 29 35 43 50 56 87 87 87 87 87 87 255 255 255 255
(in mph)

in 4th it applies at 42 mph until above 81% of the TPS.

So basically it looks like at WOT you are not locked, only locked until about 81% of WOT.

Using LS1Edit or any programmer such as Steve Cole you can program the t/c lockup. :cheers:

oh yeah just to be clear, that 0, 6, 12, etc table, the corresponding MPH are directly below.





[Modified by intel55, 2:01 PM 3/12/2002]

 

I really wanted to know the topic title but I've learned a little more...that lockup is programmed and can be changed. But I think I know what you mean.

yes i still have stock TC
No i've reprogrammed 1-2 +2mph, 2-3 +4mph, 3-4 stock...75% firmness
I have no misfires, in fact everything is schweet xcept for the shifts
I'm not happy with the downshift when I mash it still feels slushy too me. I guess the slush I feel is what needs to be taken out by transgo shift kit.


[Quote So basically it looks like at WOT you are not locked, only locked until about 81% of WOT. ]


Is this to protect the drive line from the higher Horsepower?
:confused:

 

TC Lockup is one of the most difficult aspects to tune on the A4. You have personal driving preference... You have SOTP feel... You have mod's to the car including TC and gear changes. Not only do you have lockup of the TC, you also have the unlocking of the TC. MPH is only one factor in managing the TC. Throttle position also plays a part in the TC lockup and unlock, as does WOT lockup and unlock speeds. Other factors which will impact the SOTP feel and performance are torque management in its various forms.

The spread in mph between lockup and unlock in a given gear is what results in the fundamental characteristics you will feel SOTP. Now add in to that, shift firmness which clouds what may be happening (lockup and unlock feels like a shift point). Tuning the A4 in this area, the mph spread and resultant curves is what we watch number 1.

The funny thing is, tuning the engine for peak performance is relatively easy compared to tuning the A4 to suit a particular individuals SOTP feel.

Hope this helps.

 

Bill, say HI to Dan for me. He may not remember me but I was in Dallas several weeks ago and looked Speedworks up. I was there for the "flying airbridge" incident.

From what all's been said lock-up is a compromise..... trial and error adjustment... with precise adjustment available for certain driving conditions...x-cross, drags or street. something not easily accomplished.

Just like picking a cam. :cry

 

intel55

your data seems to say that there is no lockup in first or second gear; which is what I have noticed on mine.

 

I am usually very aware of the lockup and it's quite noticeable if you know your car's behavior well enough (especially with a high stall TC)

How to tell if it is NOT locked:
a) if you are cruising at a constant speed, let off the gas. if the RPM guage swings down a few hundred RPM, it's NOT locked
b) if you are coasting (on highway, etc) and give the car a quick bit of gas, you will see the RPM guage swing up a few hundred RPM and then swing back down

The TC >>IS<< locked when the following happens:
a) if you are cruising at a constant speed, (not accelerating or anything) let off the gas. if the RPM guage stays more or less in the same area/range, it is locked
b) if you are coasting (on highway, etc) and give the car a quick bit of gas, you will see the RPM guage stay in roughtly the same area/RPM.. maybe it will jump up a bit, but not much.


Oddly enough, I notice the TC activity more so on my Jeep Grand Cherokee Ltd than the Vette. That must be because of the gearing for towing/etc.

A good visual way to see when TC lockup occurs is to accelerate quickly to highway speeds from a stop and then level out to a nice cruising speed. If you watch your tach, you will notice that after a short while, you will feel some activity in the driveline and the RPMs will drop 100+ RPMs with no change in vehicle speed. That was the lockup.

 

Actually with the Y3000 I cannot tell if car's in lock up mode easily.
George

 

With the PI Vigalante 2800 stall, there's no doubt when the lockup occurs, you definately feel it just like another shift. The TC's are not designed to lock up in 1st or 2nd, but do lock up in 3rd and 4th (OD). From a programming standpoint, we can adjust the throttle pct increase which will cause the TC to unlock and spin up for more torque, the range between when it locks and when it unlocks under normal driving conditions as a % of throttle position, and also when it locks in 2nd, 3rd and 4th at WOT. It is possible to program a lockup in 2nd, but I wouldn't advise it. Too hard on the tranny.

 

From the above posts, I think I'm hearing that the TC will be unlocked under WOT, regardless of anything else. Has anyone noticed what their RPM is under WOT at high speeds? With the 3.15 axle it should take something like 210 mph to hit 6,000 rpm in 4th. But if the TC is unlocked, then the RPM would be higher at any given speed, which is just fine. Any comments?

 

That doesn't do anything to either (a) TCC lockup or (b) desired shift time.

You don't have to have misfires. You just have to engage the misfire detection logic (which unlocks the TCC in order to simplify the detection problem.) Based on your comments, I don't think you have lockup issues.

I think you want to be playing with desired shift time, shortening the shift. You can do this through the PCM or with the kit.



[Modified by ToplessTexan, 12:37 PM 3/13/2002]