Locking the Torque Converter at the Track

[Smokie]

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[Smokie]

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[HwyCruiser]

Smokie,

The Diablo tune locks the tc at WOT in the middle of 2nd gear (not sure of the rpm right off the top of my head) and right after the 2-3 shift. You're not spending enough time in 1st to make any difference.

Watch my videos taken at Milan and you'll hear the tc locking up in 2nd.

[Smokie]

Smokie,

The Diablo tune locks the tc at WOT in the middle of 2nd gear (not sure of the rpm right off the top of my head) and right after the 2-3 shift. You're not spending enough time in 1st to make any difference.

Watch my videos taken at Milan and you'll hear the tc locking up in 2nd.
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[Smokie]

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[cyclone03]

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Smokie, I read your post but had no time to post a reply(I type slow)
So my take on your question is to parot what I've heard in the past.
First gear you NEED the converter to do it's thing,you have a PI right,so you know how it feels from a dead start.
The converter unlocked may help in second too,now the trick,at what point can the engine carry the car without the help of the converter?
The cross over point is unknown to us.

Third should be able to pull without the converters help over 75mph.

You mentioned locking the converter at 4000rpm,I think thats too low.Our torque peak is 4200 so locking at 4000 with a 3000rpm or so converter would pull the rpm down about 300-400rpm and you would feel a bog.The trick would be locking the converter and keeping the rpm above 4200.

Now the problem,I THINK the lockup programming is done by MPH not RPM and how that lays over the gear position is unknown to me.

With a lockup in third the MPH may come up but the ET may not change.

One of big converter companys (I forget who) played with lockup conveters in Super Stock racing with some HEMI cars (SS/AA, 8 second range in the 1/4 mile cars),and found the MPH picked up locked, but ET suffered.

At the track I think the good converters we have available to us work very well unlocked, on the track where we're looking for the best ET's.
On the street in day to day driving I would like the converter to lock in 3rd and OD and stay locked in OD and unlock in third only with more than 1/2 throttle.

Smokie thats my take what do you think?

[Smokie]

First gear you NEED the converter to do it's thing,you have a PI right,so you know how it feels from a dead start.
The converter unlocked my help in second too,now the trick,at what point can the engine carry the car without the help of the converter?
The cross over point is unknown to us.

Third should be able to pull without the converters help over 75mph.

You mentioned locking the converter at 4000rpm,I think thats too low.Our torque peak is 4200 so locking at 4000 with a 3000rpm or so converter would pull the rpm below down about 300-400rpm and you would feel a bog.The trick would be locking the converter and keeping the rpm above 4200.

Now the problem,I THINK the lockup programming is done by MPH not RPM and how that lays over the gear position is unknown to me.

With a lockup in third the MPH may come up but the ET may not change.

One of big converter companys (I forget who) played with lockup conveters in Super Stock racing with some HEMI cars (SS/AA, 8 second range in the 1/4 mile cars),and found the MPH picked up locked but ET suffered.

At the track I think the good converters we have available to us work very well unlocked on the track where we're locking for the best ET's.
On the street in day to day driving I would like the converter to lock in 3rd and OD and stay locked in OD and unlock in third only with more than 1/2 throttle.

Smokie thats my take what do you think?Thanks for taking the time, I have a stock converter (about 2200 stall) and transmission, with the T-Kit I am at 350 ft/lbs of torque at about 2100 rpms and peaked at 375 by 3500 rpms , thats why I asked.

I thought the torque multiplication feature of the T/C only works below 3500 rpms and the converter is about 90 to 94% efficient,so unlocked you lose some of the engines output.

I had hoped some people with a greater understanding of tranny's would chime in... it didn't happen.

[cyclone03]

I had hoped some people with a greater understanding of tranny's would chime in... it didn't happen.



Ouch.....

With a stock converter you don't hit your torque peak until about 50-60ft out of the gate.
When you hit it off the line the car takes off and then has to wait for the rpm to come up to 3500 then the car realy takes off.

Of course a loose converter lets the rpm hit 3000-3500 right off the line so there's no waiting.


Back to locking the converter as long as you lock it above the torque peak and the rpm stays above that rpm you shouldn't loose. But finding that cross over point will take some time on your part.

I think your biggest gains will come in 3rd gear so start there.

[Smokie]

Ouch.....I am sorry I didn't make myself more clear, I meant more knowledge of tranny's than myself..:) which is not all that hard...:D .

I do appreciate your input very much, I had hoped for more responses....sometimes the silliest threads are the ones that attract the most responses..

Thanks again for your input.:)

[David Morton]

(deleted by David Morton) reason: MM03MOK doesn't like the way I share my experience with you guys, so, Goobye MM03MOK. It's all yours now.

[CRUZTAKER]

That post explained alot for me.

Thanks.;)

[David Morton]

My pleasure.

[JMan]

. . . Read this thread. Only one reply necessary -
Morton, you are AWESOME!
J

[BlueThunderPerf]

I set my T/C to only lock in 3rd and OD. Hurts mileage slightly, but it pulls like hell all the way to the redline in 1st and 2nd. I found locking it in the first two gears really puts too much strain on these DOHC engines with their high torque peak. I don't recall the MPH i have it lock at in 3rd, but it's well over 4000 rpm.

[RVT04]

My pleasure.
when i was younger and thought the only way to do the 1/4 was with a four speed
then along came the torqueflite and i started to see the light but i never fully understood
when i got tired of replacing clutches and broken u-joints
etc....
then to watch a sloppy shifting 03 mm get a dose of dr tune with a laptop and fix the slop i thought man i have arrived
now that you have lined up all my braincells
i understand
thanks
and i absolutely love the level II kit dr put in my mushbox

[Marauderjack]

I have a Diablo Predator tune with my FIT blower and my question would be.....If you spin all the way through first gear and at the 1-2 shift wouldn't the locked converter just accentuate the spinning in second??:confused: I have no TC lockup until 4th gear above 40 MPH and really like it that way but I don't drag race the car!!:rolleyes:

The top fuel guys slip the clutch on purpose to keep from going "Up In Smoke" so I would think the TC being unlocked would help not hurt 1/4 mile times and speed if your spinning anyway (better traction control).....BUT I'VE BEEN WRONG BEFORE.....JUST CAN'T REMEBER WHEN ANYMORE!!!:beer:

Marauderjack:burnout:

[David Morton]

If you don't have those big Nitto Extreme Drag Radials, get 'em. I have a set just for the track and shows.