Locking converter in 2nd gear...

[LS1_Dragster]

If you have a really loose converter can you lock the converter in 2nd gear?

Will it unlock for the shift?

Being you cannot feel it shift at normal driving would it hurt to have it locked during the 2-3 shift at light throttle?

Lee

[LS1_Dragster]

Nobody? Someone has to of locked the converter in 2nd!

[joecar]

There's a table to apply the TCC in 2nd gear, see D1001 (you have to make sure D1004 is below D1001).

D2801 can be set to allow the TCC to stay applied during an upshift... altho, I'm not sure if this parameter works on all trans calibrations.

Keeping TCC applied during upshift:
if engine is making sufficient torque then the TCC damper springs may break (see item (C) in attachment)... or the TCC may slip during the upshift (it is only "half" a clutch and so doesn't "clamp" like a "sandwich" as in a manual trans clutch).

Typically a double or triple plate TCC will allow slip-free upshifts with TCC applied since the extra friction/steel plate "sandwich" is able to "clamp" tight... 2P/3P clutches don't necessarily have the damper springs.

Edit: oops, I forgot to attach attachment...

[LS1_Dragster]

This is why I was wondering if the loose 4000RPM stall converter could take it. Right now you cannot feel the shift unless your foots in it. Even though the converter is cushioning the shift does the clutch in the converter still take a hard hit? Does that make sense?

Lee

[Mr. P.]

What transmission?

Yes you can tailor converter clutch state in each gear. Separately, you can instruct the tune to also leave the converter locked during shifts.

Is it hard on the converter clutch? Hell yes. You better have a converter clutch rated for this kind of abuse, like a multiple-disc lockup clutch.

But the real worry is not the converter but the transmission - the issue is leaving the TCC locked during the shift, it hits SO HARD that with any kind of power you risk destroying the transmission input drum and/or other hard parts.

Mr. P.

[LS1_Dragster]

It's a 4L80E.

So it would still hit too hard with the high stall...

But what about just locking it in 2nd and let it release for the shift?

[Mr. P.]

It's a 4L80E.

So it would still hit too hard with the high stall...

But what about just locking it in 2nd and let it release for the shift?

When the lockup clutch is engaged there is no "stall" - the front half of the converter is physically locked to the rear-half. If you want to demonstrate this to yourself, take EFILive bidirectional menu, roll-out in 1st gear & lock the TCC, then moderately accellerate to about 20-mph and feel just how hard it hammers into 2nd under lockup :eek: Being a lightweight dragster and 80E the car actually *might* get away with shifting while locked-up, I will have to ask our transmission expert what he would do to an 80E to hold up to this but I am thinking with that trans it can be done in your application. I am going to say from certain experience a 4L60 won't take that sh!t for long lol, you will fracture the input drum even if it is 'reinforced' - now if someone were ever to make a billet input drum for the 700/4L60 that would be an entirely different story ;). For track use you SHOULD be running with the converter in lockup whenever possible. What we do on the trucks, is to make repeated runs lowering the lockup engage MPH until the fastest time/performance is achieved per each gear. Typically (in heavy trucks) we benefit from TCC lockup in 4th, 3rd, and upper part of 2nd, some of the stock trucks loose E.T. attempting to lockup in 2nd (they don't have enough torque to take advantage) so a little trial/error is expected. For street use we keep the TCC lockup point 5+ mph higher than the shift point, but on a track-specific vehicle you might be able to get more ET gain by locking-up the TCC even quicker than that.

Mr. P. :)

[LS1_Dragster]

It's not for the dragster it's for the firebird. It's a pain sometimes driving because the RPM's are screaming at 2500 and the cars going 5MPH! Hughes just built the converter too loose, I'm sending it back for a re-stall but not until the car is parked for the winter so in the mean time I was looking for a short term solution....

[MyM8V8]

now if someone were ever to make a billet input drum for the 700/4L60 that would be an entirely different story ;).
Mr. P. :)

So where would we be able to get such an item??? ;)

[Mr. P.]

Nobody makes an aftermarket drum for the 4L60. :( We are considering lathing one out of 4340 billet, but it will take a ton of time (like a straight week of milling) because the cutting tools have to reach so deep into the drum and still meet extremely close tolerances. We think we can do it, we'll see.

Mr. P.

[joecar]

Yes, the input drum is a complex piece, see the attached cutaway view from www.transmissioncenter.net (PATC):

http://transmissioncenter.net/PinHol7.jpg

[MyM8V8]

Nobody makes an aftermarket drum for the 4L60. :( We are considering lathing one out of 4340 billet, but it will take a ton of time (like a straight week of milling) because the cutting tools have to reach so deep into the drum and still meet extremely close tolerances. We think we can do it, we'll see.

Mr. P.

Sounds like a project, but not necessarily commercially viable. I'm building a 454 so if you need a guinea pig to test one out, let me know. :),

[Mr. P.]

Sounds like a project, but not necessarily commercially viable. I'm building a 454 so if you need a guinea pig to test one out, let me know. :),

I hear ya - in my case I'm already stuck with the 4L60 because I want to keep the AWD in my Silverado SS; by the time I figured the costs of building a 4L80 conversion versus a custom 4L60 with a $2000 one-off billet drum it will end up about the same :sigh: Plus everyting in my 4L60 is 300M billet now, so I've already got a lot vested in this unit. I won't get to that project until next season at least, I'll decide then as the time gets closer. Or if I grenade something first LOL.

Mr. P. :)

[MyM8V8]

I hear ya - in my case I'm already stuck with the 4L60 because I want to keep the AWD in my Silverado SS; by the time I figured the costs of building a 4L80 conversion versus a custom 4L60 with a $2000 one-off billet drum it will end up about the same :sigh: Plus everyting in my 4L60 is 300M billet now, so I've already got a lot vested in this unit. I won't get to that project until next season at least, I'll decide then as the time gets closer. Or if I grenade something first LOL.

Mr. P. :)

I must ask. What kind of power and torque do you reckon your 4L60 will take with all your modifications?

Reason I'm asking is that I can't get a 4L80 into my truck without major surgery, it's quite small compared to what you guys run in the States.

So I need to build mine as strong as I can. Luckily I've got a brand spanking new 4L65E coming over from Australia at the moment at a really cheap price.

Any help gratefully received. :cheers:

[Mr. P.]

I must ask. What kind of power and torque do you reckon your 4L60 will take with all your modifications?

Reason I'm asking is that I can't get a 4L80 into my truck without major surgery, it's quite small compared to what you guys run in the States.

So I need to build mine as strong as I can. Luckily I've got a brand spanking new 4L65E coming over from Australia at the moment at a really cheap price.

Any help gratefully received. :cheers:

Well if the transmission is for the vehicle in your sig, a well-built 4L65 will happily live; we have a Silverado SS AWD truck here locally that goes 11.8's with one of our 4L65's on a stock LQ9 + bolt-ons + 225-shot right outta the hole!! That's a 5600-lb truck with almost 600-rwhp, I will have to ask about the converter he used but I want to say it was a cheap 3400 stall... The trick with the 4L60 is that it is VERY unforgiving, we have found there is only one certain setup that will work - the build has to be right, the valve body mods have got to be right, and the TUNE has got to be right. AFA how strong my own transmission is, hell who knows... LOL the number that I've been told by a couple persons is 700+, we'll see in time. Remember that vehicle weight is a big factor in transmission life, it's not only that we are throwing 650+ hp at it, but also that we are doing so in a 5600-lb truck; if the vehicle was 2000-lbs lighter (like a vette or fbody) then reliability would be far better I'm sure.

Mr. P.

[MyM8V8]

Well if the transmission is for the vehicle in your sig, a well-built 4L65 will happily live; we have a Silverado SS AWD truck here locally that goes 11.8's with one of our 4L65's on a stock LQ9 + bolt-ons + 225-shot right outta the hole!! That's a 5600-lb truck with almost 600-rwhp, I will have to ask about the converter he used but I want to say it was a cheap 3400 stall... The trick with the 4L60 is that it is VERY unforgiving, we have found there is only one certain setup that will work - the build has to be right, the valve body mods have got to be right, and the TUNE has got to be right. AFA how strong my own transmission is, hell who knows... LOL the number that I've been told by a couple persons is 700+, we'll see in time. Remember that vehicle weight is a big factor in transmission life, it's not only that we are throwing 650+ hp at it, but also that we are doing so in a 5600-lb truck; if the vehicle was 2000-lbs lighter (like a vette or fbody) then reliability would be far better I'm sure.

Mr. P.

Your box sounds like an awesome piece of work. I should've said that the new box I have is stock, and we are going to build that. I'm researching finding the right parts to build it strong enough at the moment. I have time because the short motor is 16 weeks away.



My Ute is only 3300lbs and people have said that I need to ditch the 4L65E. I don't want to do that because of the tuning possibilities with EfiLive, which pound for pound has been the best piece of software I have EVER bought.

Hey, Thanks for your feed back, it has given me more confidence to persever with what I am doing.

[LS1_Dragster]

I downloaded a tune from holden for a 2001 Camaro and D2801 Upshift TCC Lock was set to Yes, is this normal or did someone change it?

Lee

[joecar]

I downloaded a tune from holden for a 2001 Camaro and D2801 Upshift TCC Lock was set to Yes, is this normal or did someone change it?

LeeThat is the factory stock setting...

but notice that the TCC is still unlocked at WOT (see the TCC Release tables D1004-D1009).

[MyM8V8]

trying to get the car to lock into 3rd gear for street tuning, i cant seem to get it to work from the pcm controls in the scanner. even though i tell it to it will still downshift and i want to get a full read from the gear to get wot as good as possible.

unless im doing the locking part wrong...


Don't know whether this helps. I had the same problem:

http://forum.efilive.com/showthread.php?p=107364#post107364