automatic guys, converter lockup...
Thread Starter
Instructor
Joined: Dec 2001
Posts: 151
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From: Mobile al
automatic guys, converter lockup...
Hey, I noticed for the first time today that with the selector in drive, not od and at full throttle in 3rd at around 4500 the tack backs up to 4000 or so.
It doesn't do that in 1st or 2nd, so I'm wondering what the computer needs to see to have the converter lock up in 3rd (drive) at full throttle.
If this would be better asked in the 'Scan and Tune' sorry I'll move it.
Thanks
It doesn't do that in 1st or 2nd, so I'm wondering what the computer needs to see to have the converter lock up in 3rd (drive) at full throttle.
If this would be better asked in the 'Scan and Tune' sorry I'll move it.
Thanks
Le Mans Master
Joined: Apr 2000
Posts: 6,341
Likes: 1
From: Shelton CT
Re: automatic guys, converter lockup... (kbklt1)
Hey, I noticed for the first time today that with the selector in drive, not od and at full throttle in 3rd at around 4500 the tack backs up to 4000 or so.
Thread Starter
Instructor
Joined: Dec 2001
Posts: 151
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From: Mobile al
Re: automatic guys, converter lockup... (MrNuke)
Sorry I just read that again and it is a bit um... hard to understand.
The car will be pulling in 3rd gear and when it gets to about 4500 rpm, I think the converter locks up cus the rpm drops back to around 4000!
At least I hope the converter is slipping some then locking up and lowering the rpm.
I was wondering if anyone else had seen this happen or can explain it.
The car will be pulling in 3rd gear and when it gets to about 4500 rpm, I think the converter locks up cus the rpm drops back to around 4000!
At least I hope the converter is slipping some then locking up and lowering the rpm.
I was wondering if anyone else had seen this happen or can explain it.
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: automatic guys, converter lockup... (kbklt1)
It is normal to get TC lockup at WOT in 3rd gear with a 700R/4, but 4,500rpm should be above the TC's stall so you shouldn't get much RPM drop.
I didn't notice this till after some tranny work when I had it on the dyno. The TC lockup was so abrupt that the dyno operator thought it was shifting into 4th gear. Since I don't notice it at the strip (102mph trap speed) it must occur at near the same speed for me, but I don't recall how much the RPM dropped.
I didn't notice this till after some tranny work when I had it on the dyno. The TC lockup was so abrupt that the dyno operator thought it was shifting into 4th gear. Since I don't notice it at the strip (102mph trap speed) it must occur at near the same speed for me, but I don't recall how much the RPM dropped.
Drifting
Joined: Jun 2001
Posts: 1,997
Likes: 1
From: Lake Ozark MO
Re: automatic guys, converter lockup... (65Z01)
According to my LT1 Edit reads, there should be no torque converter lockup in any gear at 100% throttle.
LT1 Edit reports that for my car (2.59's currently) anything over 93mph means no converter lockup. I can definitely say that is true from my own playtime.
LT1 Edit reports that for my car (2.59's currently) anything over 93mph means no converter lockup. I can definitely say that is true from my own playtime.
Safety Car
Joined: Jun 2000
Posts: 4,870
Likes: 25
From: Long Island, NY
Re: automatic guys, converter lockup... (Dan Parker '96)
The torque convertor locks up on my car in 3rd gear during full throttle at about 80 - 82 mph. It does feel like the car is slowing down, but it is not.
I have experimented with no lockup in 3rd gear and there is no difference in ET's.
Vic
I have experimented with no lockup in 3rd gear and there is no difference in ET's.
Vic
Team Owner
Joined: Dec 2000
Posts: 90,675
Likes: 304
From: SE NY
Cruise-In II Veteran
Re: automatic guys, converter lockup... (Vic'89)
Vic, you might want to experiment with a lockup sw.
Pat Barrett of Level-10 told me that once you launch you want the TC locked for best ET. Of course a 700R/4 cannot lock in 1st gear, but a lockup sw on the ALDL will cause it to lock immediately after the 1-2 shift and stay locked until it drops back into 1st or till you release the sw.
I have this sw on the IROC and didn't notice any difference in time slips though haven't tried it with the Vette.
It seems as though it would help after your engine passes the HP peak but that would be difficult to rig (sort of a compromise between TC slippage and the power band).
Pat Barrett of Level-10 told me that once you launch you want the TC locked for best ET. Of course a 700R/4 cannot lock in 1st gear, but a lockup sw on the ALDL will cause it to lock immediately after the 1-2 shift and stay locked until it drops back into 1st or till you release the sw.
I have this sw on the IROC and didn't notice any difference in time slips though haven't tried it with the Vette.
It seems as though it would help after your engine passes the HP peak but that would be difficult to rig (sort of a compromise between TC slippage and the power band).
Team Owner
Joined: Apr 2000
Posts: 27,818
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From: CT
Lock
A friend's car has a major amount of power(IROC) and has a separate lock-up switch. He was advised to lock it in 2nd and keep in it for best results.
I've been saying it all along, our cars lock up when going down the 1/4. You hear a sound like it's hitting another gear. It definitely helps...you're going from loose to tight....Helping MPH.
I've been saying it all along, our cars lock up when going down the 1/4. You hear a sound like it's hitting another gear. It definitely helps...you're going from loose to tight....Helping MPH.
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Thread Starter
Instructor
Joined: Dec 2001
Posts: 151
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From: Mobile al
Re: automatic guys, converter lockup... (BBA)
Ok it looks like there might be a difference between the 700r4 and the 4L60e or at least it kind of seems that way from the replys in the thread.
I see that some are saying the converter doesn't lock up on a 96 (4L60e), and some are seeing it happen on the older 700r4.
I am assuming that the converter control comes from the ecm and can be programmed by some table.
May be I better cross this into the scan and tune or if some one knows they can point out where it is in programming.
Thanks for all the input.
I see that some are saying the converter doesn't lock up on a 96 (4L60e), and some are seeing it happen on the older 700r4.
I am assuming that the converter control comes from the ecm and can be programmed by some table.
May be I better cross this into the scan and tune or if some one knows they can point out where it is in programming.
Thanks for all the input.
Safety Car
Joined: Jun 2000
Posts: 4,870
Likes: 25
From: Long Island, NY
Re: automatic guys, converter lockup... (BBA)
vic...you might want to experiment with a TPS! If it's locking up...your not going WOT, or at least you ecm does not think you are.
Vic
