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Discussion Starter · #1 ·
Got the word back from Andre at Edge that I should be fine to lock up the converter at the end of the track w/ my converter and setup.

Now I guess the question is... should I? What can be the expected benefits compared to a 1/4 mi run with it unlocked the entire way? Any drawbacks?

What's the usual technique when doing this, lock it up right before the final traps... or in a majority of 3rd gear?

Boltons car w/ 3.73's. Possibly 4.10's in the future. I have a manual TCC switch so no goofing w/ programming for me.
 

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Doing this is EXTREMELY hard on the transmission and has no real benefit.

so WHY?
I agree with Shane. You may gain 1 MPH with a bolt on car but you probably won't see any ET gain. I've been down that route before with the bolt on car.

I ran my bolt on car down to the 12.60's with 3.73's and weight reductions. It's all about location..location...location.

Pat Gish and Stumpy's best bolt on times were at Cecil County and I ran mine at Fayetteville NC.
 

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Doing this is EXTREMELY hard on the transmission and has no real benefit.

so WHY?
Hmmm... I lock up my 5-disk Vigilante on the top end. Do you think that could be what is taking out my 3-4 clutch pack???? I thought that it would be harder on the converter clutches than the tranny since the tranny clutches are already fully applied when the TC locks up. If it is just "hard parts" and not clutches in the tranny that are affected, I'm not so worried about it.
 

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Discussion Starter · #5 ·
Thanks for the replies Shane/Eric. It is something I have seen on a few of the Top ET entries. I've read a few threads on non B-Body forums but do not know how it applies for our cars. Figured it was at least worth asking!

However, I would be curious to know why this is hard on the trans. Something to do with it not slipping as much and therefore not cushioning the engine torque to the transmission... or something else?
 

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Discussion Starter · #6 ·
I thought that it would be harder on the converter clutches than the tranny
That was my original thought, that the TC clutches would be the weak link in doing this, which is why I ran this by Edge. Didn't really think about harm to the tranny
 

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Hmmm... I lock up my 5-disk Vigilante on the top end. Do you think that could be what is taking out my 3-4 clutch pack???? I thought that it would be harder on the converter clutches than the tranny since the tranny clutches are already fully applied when the TC locks up. If it is just "hard parts" and not clutches in the tranny that are affected, I'm not so worried about it.

Doing so is an extreme shock to the transmission internals to include the 3/4 frictions which are applied when you are on the big end. I can pretty much guarantee this is probably why you are having repeat 3/4 clutch failure if this is your practice.
 

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You better listen to him Terry, he's pre-med.
 

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That was my original thought, that the TC clutches would be the weak link in doing this, which is why I ran this by Edge. Didn't really think about harm to the tranny
Correct me if I'm wrong, but a TC doesn't have clutches. It's a turbine working against a stator, and fluid coupling. No touching parts, just fluid at very high force against the stator.

Yea, I'd say locking the converter is putting more force on the clutches. It would probably be worse if you did it at low RPM and WOT than high RPM and WOT. My understanding is that Pat does it near top end, not all of 3rd gear. IMHO, it's really only gaining you some MPH, and possibly hurting ET depending on when you lock it.
 

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Discussion Starter · #10 ·
Correct me if I'm wrong, but a TC doesn't have clutches. It's a turbine working against a stator, and fluid coupling. No touching parts, just fluid at very high force against the stator.
Referring to the torque converter clutch (TCC) engaged at lockup conditions. It is a clutch applying to the front cover of the converter if I remember right.
 

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Doing so is an extreme shock to the transmission internals to include the 3/4 frictions which are applied when you are on the big end. I can pretty much guarantee this is probably why you are having repeat 3/4 clutch failure if this is your practice.
Well... you may be right. I've been looking for a "smoking gun". I added the 5-disk lock-up TC in the spring of 2007 and had Bryan Herter add the WOT lockup to my program at the same time. The converter only locks up at WOT on the top end of the 1/4-mile. There is not enough room to achieve lockup in the 1/8th mile, so only the 1/4 mile passes affect this.

Since the 5-disk and WOT lock-up program install, the first set of 3-4 clutches (Alto Reds) were gone after 2589 miles and 13 1/4-mile passes. The 2nd set of 3-4 clutches (Zpak) were gone after 2554 miles and 19 1/4-mile passes (SSHS10).

I still have the same dyno-tune program without the WOT lockup. Sounds like I should give that a try.
 

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Correct me if I'm wrong, but a TC doesn't have clutches. It's a turbine working against a stator, and fluid coupling. No touching parts, just fluid at very high force against the stator.
You are wrong. A lockup converter has a mechanical clutch that locks the converter to direct drive (no slippage). This was originally done to improve fuel economy. A conventional non-lock up converter functions as you described.
 

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You are wrong. A lockup converter has a mechanical clutch that locks the converter to direct drive (no slippage). This was originally done to improve fuel economy. A conventional non-lock up converter functions as you described.
Thanks, guys.
 

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What is he doing for seperator plate feed sizes? Third accumulation? What clearance is being used? Theres alot more to making the third clutch last than just the clutch itself.
 

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If you lock the TCC at the right time, it helps ET by a tiny amount, probably .02 or so in your car. If you're in a close race at the stripe, it CAN be enough to surge you forward by a couple of feet; it can also cause you to break out if you've set your dial from a non-locked run! But lock it too soon and you'll lose ET for sure.
It helps mph by a little with some converters and a lot with others. With the Yank 3000 and Yank 3600 converters in my bolt-ons setup, locking it anywhere between 100 and 200 feet before the traps added less than 1/2 mph trap speed. Rpm drop was about 100 rpm. With the Edge 3400 I had in it, locking it 200 feet from the traps added nearly 2 mph; rpm drop was 500 rpm!.....that converter erred on the high/loose side for a bolt-ons motor. It's not going to be that drastic with yours.

Shane, I don't follow you at all how that can be so hard on 3-4 clutches when they're already engaged under hydraulic pressure. The 2-3 shift itself, arresting relative motion in the clutch/steel pack would seem to be much harder on them. Unless the TCC apply robs that much pressure from that holding the 3-4's.
 

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If you lock the TCC at the right time, it helps ET by a tiny amount, probably .02 or so in your car. If you're in a close race at the stripe, it CAN be enough to surge you forward by a couple of feet; it can also cause you to break out if you've set your dial from a non-locked run! But lock it too soon and you'll lose ET for sure.
It helps mph by a little with some converters and a lot with others. With the Yank 3000 and Yank 3600 converters in my bolt-ons setup, locking it anywhere between 100 and 200 feet before the traps added less than 1/2 mph trap speed. Rpm drop was about 100 rpm. With the Edge 3400 I had in it, locking it 200 feet from the traps added nearly 2 mph; rpm drop was 500 rpm!.....that converter erred on the high/loose side for a bolt-ons motor. It's not going to be that drastic with yours.

Shane, I don't follow you at all how that can be so hard on 3-4 clutches when they're already engaged under hydraulic pressure. The 2-3 shift itself, arresting relative motion in the clutch/steel pack would seem to be much harder on them. Unless the TCC apply robs that much pressure from that holding the 3-4's.
Pat are you still on your original tranny?
 

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Pat are you still on your original tranny?
Nope, broke a roller clutch last year with a nitrous launch on a bad starting line, where it regrabbed traction in 3rd gear. 3-4 clutches were 3/4 gone, but it still shifted perfectly right up to that point. It did me right for 13 years!
 

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What is he doing for seperator plate feed sizes? Third accumulation? What clearance is being used? Theres alot more to making the third clutch last than just the clutch itself.
Yes, I realize that. I don't know the details of these questions. But I will ask. I do know that he has several trannies behind strokers that have lasted much longer than mine; his has over 120K "Bobo Miles" on it and is a similar build. I also don't know what the pressure tables in my program call for, only that it is what Herter put in there. I'm looking for "What's different?". It may not be the culprit, but the TC lock up is different.

Shane, I don't follow you at all how that can be so hard on 3-4 clutches when they're already engaged under hydraulic pressure. The 2-3 shift itself, arresting relative motion in the clutch/steel pack would seem to be much harder on them. Unless the TCC apply robs that much pressure from that holding the 3-4's.
The "engineer" in me is struggling with this question too.
 
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