Dyno Results A4 Locked versus Unlocked
11-19-2003, 05:50 PM
#1
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Dyno Results A4 Locked versus Unlocked I was wondering what the hp/tq differences show on a dyno tune with the torque convertor locked up versus unlocked in 3rd gear? What benefit other than higher numbers would this matter as you 1/4 mile it unlocked. Thanks in advance for any info!! 
11-19-2003, 06:46 PM
#2
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I have done this a few times...
350rwhp u/l
375rwhp l
-with heads, cam, LS6 intake, circa 2000.
-locking up 'verter at the track in the middle of 3rd was worth 2mph for me with when I had the PI3600 stall, but after I got a Yank TP4500 the effiiciency of the converter was much higher
-These are OLD OLD numbers, I would have been more like 374rwhp u/l and 400rwhp l'd these days with the cam I had. I had 222/224//113 + GTP heads.
-I initially went 11.75@112 but after tweaking and playing with the combo I went 11.5@116mph, takes time to play with tuning, shiftpoints etc. to dial in a combo.
350rwhp u/l
375rwhp l
-with heads, cam, LS6 intake, circa 2000.
-locking up 'verter at the track in the middle of 3rd was worth 2mph for me with when I had the PI3600 stall, but after I got a Yank TP4500 the effiiciency of the converter was much higher
-These are OLD OLD numbers, I would have been more like 374rwhp u/l and 400rwhp l'd these days with the cam I had. I had 222/224//113 + GTP heads.
-I initially went 11.75@112 but after tweaking and playing with the combo I went 11.5@116mph, takes time to play with tuning, shiftpoints etc. to dial in a combo.
11-19-2003, 07:19 PM
#3
TECH Senior Member
With a stock converter you'll see about 6 RWHP difference between locked and unlocked.
Like John stated, with an inefficient converter you can gain some descent 1/4 mile MPH by locking the converter at the proper time.
Like John stated, with an inefficient converter you can gain some descent 1/4 mile MPH by locking the converter at the proper time.
11-19-2003, 07:35 PM
#6
You lock the coverter on the dyno for tuning. Why? Because with a high stall the following happens:
1) Your rpm readings become skewed and unreliable
2) The shift extension of the converter prevents you from tuning your midrange. For example, let's look at a 4000 stall car being dynoed. A 4000 stall will hold at least 5000 rpm from a punch which is what you do on a dyno. Thus you can not measure your A/F or tune from 3500 - 5000 rpm. Yet, you leave the the line at 4000 rpm so having the maximum possible torque at 3900 - 4400 is absolutely critical to your 60' time.
BTW, your dyno reading may show readings for the lower rpms, but that is part of the problem embedded in issue #1.
1) Your rpm readings become skewed and unreliable
2) The shift extension of the converter prevents you from tuning your midrange. For example, let's look at a 4000 stall car being dynoed. A 4000 stall will hold at least 5000 rpm from a punch which is what you do on a dyno. Thus you can not measure your A/F or tune from 3500 - 5000 rpm. Yet, you leave the the line at 4000 rpm so having the maximum possible torque at 3900 - 4400 is absolutely critical to your 60' time.
BTW, your dyno reading may show readings for the lower rpms, but that is part of the problem embedded in issue #1.
11-19-2003, 07:40 PM
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I have a Vig 3200 which spiked all the way to 4k on the dyno unlocked and the hp/tq was quite a bit lower than another dyno session. Thats the reason I was asking. Thanks for all the info!! 
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11-19-2003, 08:01 PM
#8
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Originally Posted by Dave00C5
I have a Vig 3200 which spiked all the way to 4k on the dyno unlocked and the hp/tq was quite a bit lower than another dyno session. Thats the reason I was asking. Thanks for all the info!!
11-19-2003, 09:18 PM
#9
How do u guys make these assumptions?
First off I have many many friends that run IHRA Top Sportsman cars that run a lockup glide.
Now they gain MPH by using this type of converter/trans in these cars.Point being just because u gain MPH from a lockup switch doesnt mean u have a inefficient converter?
U cant just make a blanket statement that if u need a LU swicth the converter is not efficient.
First off I have many many friends that run IHRA Top Sportsman cars that run a lockup glide.
Now they gain MPH by using this type of converter/trans in these cars.Point being just because u gain MPH from a lockup switch doesnt mean u have a inefficient converter?
U cant just make a blanket statement that if u need a LU swicth the converter is not efficient.
11-19-2003, 10:07 PM
#10
TECH Senior Member
"How do u guys make these assumptions?"
Joel, please point out where someone in this thread made an assumption.
"U cant just make a blanket statement that if u need a LU swicth the converter is not efficient."
Although I might agree that gaining a good deal of MPH by locking the converter in a 4L60E is an indication of an inefficient converter, I DON'T see where anyone in this thread but you has made this statement.
The statement I made was...
"with an inefficient converter you can gain some descent 1/4 mile MPH by locking the converter at the proper time."
However, I didn't say that if you need a lockup switch then your converter is necessarily inefficient. Joel, did you assume that's what I meant?
Joel, please point out where someone in this thread made an assumption.
"U cant just make a blanket statement that if u need a LU swicth the converter is not efficient."
Although I might agree that gaining a good deal of MPH by locking the converter in a 4L60E is an indication of an inefficient converter, I DON'T see where anyone in this thread but you has made this statement.
The statement I made was...
"with an inefficient converter you can gain some descent 1/4 mile MPH by locking the converter at the proper time."
However, I didn't say that if you need a lockup switch then your converter is necessarily inefficient. Joel, did you assume that's what I meant?
11-19-2003, 10:09 PM
#11
TECH Senior Member
Mike, yes, the lockup is controlled by the PCM so you can lock it through the PCM or you can rig up a lockup switch...the directions for which I don't have handy.
11-19-2003, 10:42 PM
#12
i have rarely seen where locking up the convertor lessens (or gains?) ET. it is that mph in the end to look good against MN6 cars. also a good convertor is more efficient that a stock unit. yank builds a tremendous unit. i love mine, esp on the big end of the track.
11-19-2003, 10:57 PM
#13
Yank or PI and I've run them both and LOVE them both mean tee tee in the real world.
Look at the big dogs out there running glides,400,350 and u wont see these converters in the cars.They run COAN,CHANCE,ATI,TRANS KING,MIKES,TRANS SPECIALTIES,etc...
But Steve I agree with u,I read the repsonses incorrectly.My meds must be off bro
Look I LU switch IMO never helps ET but it does help wth MPH,if its that important to u just add the switch like alot of guys have done.
I did it it was worth 1.2MPH
Tootles....
Look at the big dogs out there running glides,400,350 and u wont see these converters in the cars.They run COAN,CHANCE,ATI,TRANS KING,MIKES,TRANS SPECIALTIES,etc...
But Steve I agree with u,I read the repsonses incorrectly.My meds must be off bro
Look I LU switch IMO never helps ET but it does help wth MPH,if its that important to u just add the switch like alot of guys have done.
I did it it was worth 1.2MPH
Tootles....
11-19-2003, 11:02 PM
#14
TECH Senior Member
"My meds must be off bro"
Aww, I figured it was just one too many
I'd put a Yank up against any brand out there. There's only so efficient and hard hitting a converter can get. Neil Chance makes a mighty fine converter I understand...pricey though.
Aww, I figured it was just one too many
I'd put a Yank up against any brand out there. There's only so efficient and hard hitting a converter can get. Neil Chance makes a mighty fine converter I understand...pricey though.
11-19-2003, 11:12 PM
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Originally Posted by Dave00C5
I have a Vig 3200 which spiked all the way to 4k on the dyno unlocked and the hp/tq was quite a bit lower than another dyno session. Thats the reason I was asking. Thanks for all the info!!
11-20-2003, 10:22 AM
#19
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Dave, if you want my 2 cents...
I had a PI3600 for a while and then I switched over to a Yank TP4500.
I picked up 2mph. So did the other four friends who swapped over.
I'm not telling you to get a new converter, but you need to make sure you have a handle on how this stuff works.
In the old days, folks would manually lock up their converters (GNs) and pick up like 2-3mph. So we tried that with our PI's... I picked up 2mph every time.
Now, you can try adjusting the lockup point in your programming, I want to say that it should be locking up somewhere over 90mph at WOT. If your converter never locks up during a pass you might see like 500-800 rpms of slippage and your mph will suffer. Ever seen 1100 rpms of slippage? I did, I could not hang with a hopped up DSM from a 125mph roll.
Work with your shop to figure out what part of the setup needs tweaking.
You haven't really posted any other detail, so I am just making some very general observations.
I had a PI3600 for a while and then I switched over to a Yank TP4500.
I picked up 2mph. So did the other four friends who swapped over.
I'm not telling you to get a new converter, but you need to make sure you have a handle on how this stuff works.
In the old days, folks would manually lock up their converters (GNs) and pick up like 2-3mph. So we tried that with our PI's... I picked up 2mph every time.
Now, you can try adjusting the lockup point in your programming, I want to say that it should be locking up somewhere over 90mph at WOT. If your converter never locks up during a pass you might see like 500-800 rpms of slippage and your mph will suffer. Ever seen 1100 rpms of slippage? I did, I could not hang with a hopped up DSM from a 125mph roll.
Work with your shop to figure out what part of the setup needs tweaking.
You haven't really posted any other detail, so I am just making some very general observations.
