700R4 lock-up converters, your experience

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falcongeorge
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700R4 lock-up converters, your experience

Post by falcongeorge » Fri Oct 31, 2014 12:59 pm

Looking for feedback from guys who are running 3000+ stall lock-up converters in 700R4's on the street. What rear gear are you running it in front of, what brand, whats the "rated" stall, diameter, overall impression of quality/customer service ect.? Mostly looking for info on how "loose" your converter feels when you accelerate lightly from low/moderate speed in traffic with the converter un-locked, but feel free to add anything else. Also curious if you are locking the converter in high gear at the track and resulting gains, single disc or multi?

Heres a link to my other thread, if you want more background as to what its going in/what my requirements are...
viewtopic.php?f=1&t=41587

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Re: 700R4 lock-up converters, your experience

Post by Brian P » Fri Oct 31, 2014 7:56 pm

Don't have one but that is an old-skool transmission design. The normal shift sequence won't lock the torque converter until after it is in overdrive and the engine is at a fair bit less than full load. In a drag-racing situation, with the normal shift sequence, the lock-up conditions should not be met - except perhaps until after the finish line when you back out of the accelerator pedal.

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Fri Oct 31, 2014 9:32 pm

I've deleted two responses to this already, I'll take another shot at it. I would think it would be fairly obvious by the fact that I am asking about 3000+ converters that the trans has been modified. I can lock and unlock the converter at will, any gear, any speed, any throttle opening, simply by flicking a switch on my shift lever. Locking the converter in either 2nd or 3rd at the track is a common practice with 200R4's and 700R4's.

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Re: 700R4 lock-up converters, your experience

Post by Alan Roehrich » Sat Nov 01, 2014 9:18 am

falcongeorge wrote:I've deleted two responses to this already, I'll take another shot at it. I would think it would be fairly obvious by the fact that I am asking about 3000+ converters that the trans has been modified. I can lock and unlock the converter at will, any gear, any speed, any throttle opening, simply by flicking a switch on my shift lever. Locking the converter in either 2nd or 3rd at the track is a common practice with 200R4's and 700R4's.

So is breaking a lot of expensive parts. Yes, they've been doing it for years. Probably as long as I've been building those transmissions for performance use, and that goes back 25 years or so.

If you need to lock up your converter while you're racing, you have the wrong converter.

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Re: 700R4 lock-up converters, your experience

Post by Brian P » Sat Nov 01, 2014 10:48 am

OK, so my previous reply flushed out some more information that we were not originally provided with. :mrgreen: The rest of the internet world doesn't know what has been modified in your particular transmission. The lock-up clutch that was originally in those transmissions is not designed to handle full engine torque, nor is it designed to absorb the inertia from a potentially large and abrupt change in engine revs if it is commanded to lock under conditions when there is large torque converter slippage (i.e. high engine load and lower in the rev range). And, the original internals in the gearbox were designed for the "smoothed-out" torque from the unlocked converter. Whether your particular lock-up clutch and your particular transmission internals are different in this regard is a question for whoever built your transmission ... but I doubt it.

I don't own a vehicle with that transmission but I've known people who have broken them ...

In the original design of those, torque converter lock-up was strictly meant for highway cruise. That's why the original shift calibration only locks it above a certain speed and below a certain engine load. That combination normally only occurs in overdrive, although it can occur in third if you have selected D3 on the shift lever (e.g. for trailer tow or heavy hauling).

Modern transmissions are different and are designed to be locked up much more ... that's one of many reasons why the 700R4/4L60E is now obsolete ...

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sat Nov 01, 2014 12:55 pm

Alan Roehrich wrote:
falcongeorge wrote:I've deleted two responses to this already, I'll take another shot at it. I would think it would be fairly obvious by the fact that I am asking about 3000+ converters that the trans has been modified. I can lock and unlock the converter at will, any gear, any speed, any throttle opening, simply by flicking a switch on my shift lever. Locking the converter in either 2nd or 3rd at the track is a common practice with 200R4's and 700R4's.

So is breaking a lot of expensive parts. Yes, they've been doing it for years. Probably as long as I've been building those transmissions for performance use, and that goes back 25 years or so.

If you need to lock up your converter while you're racing, you have the wrong converter.
Thanks Alan, and this is the sort of feedback I am looking for. At this stage of the game, I am only locking the converter while driving on the highway (because I have heard the same thing as you just said re: breaking stuff), to be honest, it doesn't seem to make a hell of a lot of difference, but the converter in the truck right now flashes to less than 3000 rpm.
Are you installing lock-up converters in the OD trans you do for street/strip cars? I am specifically looking for feedback on the street manners of 9.5" lock-up converters that will flash into the 4000 rpm range behind a typical 400-450hp 350 chevy. I'm mainly looking at FTI, Yank and Coan. Any feedback/experience?

Or would you be looking more along the lines of a tight 8" with no lock-up clutch? It IS a daily driver, and I make some long (500+miles) trips in it. It has 4.56s in the back, I find this totally acceptable with the od.
Last edited by falcongeorge on Sat Nov 01, 2014 1:12 pm, edited 1 time in total.

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sat Nov 01, 2014 1:05 pm

Brian P wrote:OK, so my previous reply flushed out some more information that we were not originally provided with. :mrgreen: The rest of the internet world doesn't know what has been modified in your particular transmission. The lock-up clutch that was originally in those transmissions is not designed to handle full engine torque, nor is it designed to absorb the inertia from a potentially large and abrupt change in engine revs if it is commanded to lock under conditions when there is large torque converter slippage (i.e. high engine load and lower in the rev range). And, the original internals in the gearbox were designed for the "smoothed-out" torque from the unlocked converter. Whether your particular lock-up clutch and your particular transmission internals are different in this regard is a question for whoever built your transmission ... but I doubt it.

I don't own a vehicle with that transmission but I've known people who have broken them ...

In the original design of those, torque converter lock-up was strictly meant for highway cruise. That's why the original shift calibration only locks it above a certain speed and below a certain engine load. That combination normally only occurs in overdrive, although it can occur in third if you have selected D3 on the shift lever (e.g. for trailer tow or heavy hauling).

Modern transmissions are different and are designed to be locked up much more ... that's one of many reasons why the 700R4/4L60E is now obsolete ...
So you figured I was looking to put a 3000/4000 stall converter in front of an otherwise bone-stock 700R4?? :shock: REALLY Brian?? [-X

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Re: 700R4 lock-up converters, your experience

Post by Brian P » Sat Nov 01, 2014 1:27 pm

No, of course not, but the rest of us don't know anything about your particular vehicle, and you didn't tell us anything other than the new stall speed.

And, torque converter lock-ups on those transmissions were only designed for highway cruise, and I would consider it highly unlikely that an aftermarket torque-converter place would be able to sufficiently strengthen the lock-up clutch (and that's assuming they even bother strengthening it at all).

My original reply DID flush out that you had other intentions for using that lock-up clutch.

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sat Nov 01, 2014 1:39 pm

Brian P wrote:No, of course not, but the rest of us don't know anything about your particular vehicle, Well then Brian, perhaps you should have checked the link I thoughtfully provided?And, torque converter lock-ups on those transmissions were only designed for highway cruise, and I would consider it highly unlikely that an aftermarket torque-converter place would be able to sufficiently strengthen the lock-up clutch (and that's assuming they even bother strengthening it at all).

My original reply DID flush out that you had other intentions for using that lock-up clutch.
What intentions? I asked for other guys experiences. In fact, at thist point, I have not locked the converter at the track, and based on what i have read elsewhere as well as here, I have no intention of doing so. I asked for OTHER guys experiences with it
Ok, well the main info I am looking for is first hand experience re: the street manners of 3000-4000 stall, 9.5" lock-up converters. Dont discuss your experiences re: locking it in high gear or not, it'll offend Brian, and I dont want the ensuing drama to de-rail the main subject of the thread... :) Good enough? Moving on...
PS, No, the trans in my mid 12 second streeter is not bone stock :roll: . Shouldn't really have much effect on anyone relating info re: the street manners of thier converter.

Can we PLEASE get this back on track now?

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Re: 700R4 lock-up converters, your experience

Post by BOOT » Sat Nov 01, 2014 3:51 pm

I use a JET lock up delay module on my 700r4, don't think they make them anymore, but might be worth looking into. Hope that's not too off topic!
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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sat Nov 01, 2014 5:36 pm

BOOT wrote:I use a JET lock up delay module on my 700r4, don't think they make them anymore, but might be worth looking into. Hope that's not too off topic!

Hopefully Brian will let it slide... :lol:

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Re: 700R4 lock-up converters, your experience

Post by dave brode » Sat Nov 01, 2014 7:19 pm

falcongeorge wrote:
snipped

I am specifically looking for feedback on the street manners of 9.5" lock-up converters that will flash into the 4000 rpm range behind a typical 400-450hp 350 chevy. I'm mainly looking at FTI, Yank and Coan. Any feedback/experience?

Or would you be looking more along the lines of a tight 8" with no lock-up clutch? It IS a daily driver, and I make some long (500+miles) trips in it. It has 4.56s in the back, I find this totally acceptable with the od.
Fwiw, I don't think that you would be happy with the non lock-up 8" in o.d. Are there even any that are made with lock-up and flash well over 3K?

Dave

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sat Nov 01, 2014 7:45 pm

dave brode wrote:
falcongeorge wrote:
snipped

I am specifically looking for feedback on the street manners of 9.5" lock-up converters that will flash into the 4000 rpm range behind a typical 400-450hp 350 chevy. I'm mainly looking at FTI, Yank and Coan. Any feedback/experience?

Or would you be looking more along the lines of a tight 8" with no lock-up clutch? It IS a daily driver, and I make some long (500+miles) trips in it. It has 4.56s in the back, I find this totally acceptable with the od.
Fwiw, I don't think that you would be happy with the non lock-up 8" in o.d. Are there even any that are made with lock-up and flash well over 3K?

Dave
TCI, FTI, Yank, Vigilante, PTC, Coan, Circle D all make lock-up 9.5" (TCI actually makes an 8" with a clutch, but they are not high on my list) converters into the 4K range. There are probably others

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Re: 700R4 lock-up converters, your experience

Post by dave brode » Sat Nov 01, 2014 10:10 pm

falcongeorge wrote:
snipped

TCI, FTI, Yank, Vigilante, PTC, Coan, Circle D all make lock-up 9.5" (TCI actually makes an 8" with a clutch, but they are not high on my list) converters into the 4K range. There are probably others
Good to know. Good thread.

Dave

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Re: 700R4 lock-up converters, your experience

Post by falcongeorge » Sun Nov 02, 2014 12:28 am

FTI seems to rate really high with most of the LS guys (they are mostly 4l60E but the guts of the two converters are the same, so the experience should transfer over). So far, I am leaning that way. I was hoping to hear from some other guys though, as the LS guys generally seem to run rear gears between 3.42-3.73, I am running 4.56's, that will make a BIG difference in "feel" at low speeds/small throttle openings, but if they feel the FTI converters feel ok with 3.42s behind them, the part throttle efficency should be even better with 4.56's.

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