qwiktim

iTrader: (7)

Stock or aftermarket converter................... This is very common in the turbo Buick world as well as with the automatic '99+ Mustangs, and usually is worth .2 and 3-4 mph......... I see nobody here talking about doing it... any comments from those who have actually done it?

Not just what you hear, or what you think, but from people that have actual experience with it please.

usd2sing

iTrader: (15)

here's a bump bro. im highly interested in this also.

qwiktim

iTrader: (7)

Thanks, just curious a to why this isn't ever mentioned.

My '99 Mustang GT automatic picks up a solid .2 and 4-5 mph at the track when manually locking the converter...... and it's only a 13.20 car....

My Turbo Buick will pick up at least .3 and 5 mph manually locking the converter........

Fuddle offers a converter for our LS1 cars that is advertised to be able to withstand WOT locking............

2mffZ28

I'm interested also///////////////

MNR-0

Indeed Fuddle does offer a converter built to handle full WOT LU. But the 4L60E will need to be modified to deliver enough non-modulated line pressure to actually engage the WOT LU without slip. You may also need to look at higher viscosity ATFs than DEX3.

Im currently experimenting with it in my car, and so far have managed to achieve 60rpm slip at WOT LU even after a stage 3 tranny rebuild and elimination of pulse width modulation. Trialling differnet fluids and additives and possibly the Redline High-Temp ATF. Wont go F-Type racing as its a daily driver - cant afford a rebuild right now if it lunches my clutches.

Results at the track so far have been mixed. I havent been able to hook up off the line yet to say it helps or not. I did one run 120PMH WOT LU and the next 122MPH unlocked. My guess is it wont really help, but its too early to definitively say.

AFTICA

iTrader: (8)

Haven't tried it with the SS4000 but with my 2800 Vig it netted me exactly nothing. Averaged 3 runs locked vs 3 runs unlocked on the same night and got exactly nothing in mph or ET. Why? I really don't know. I suppose the added efficiency of a locked converter is offset by pulling the rpm down out of the prime power range.
As stated above, in our cars, the converter never locks completely @ WOT either.

BlackHawk T/A

iTrader: (3)

It also depends on when you hit it.

I would imagine at a high RPM in 3rd, to bring it down a bit and wind out all you can from the gear. Keeping it in the powerband, I could see this to be beneficial. Especially if you have steep gears and are trying to stay out of 4th.

wdtiger

I can see it being helpful to stay out of 4th, though. However, if you're not running into 4th, what good would it do that late into the run?

AutoRoc

Good info from a quick LS1 Head/Cam car that ran GREAT to begin with. He's using a Pro Thruster 4400 FYI.

"Back from C.A.R.S.

--------------------------------------------------------------------------------

Well I'm back from C.A.R.S. getting my first ever dyno tune. Sean is good, very, very good. Dedicated and knowledgeable. This is the depth of his knowledge. When he was having trouble getting the car to idle with his calibration he asked if I had a ported throttle body? I said yes so he jumped up to take a look at it. He said that the epoxy job blocked too much of the IAC port for a cammed car. We took the TB off and he ground the opening back out. I put it back on and the car started and idled reaching thru the window to turn the key.
Car only made 366hp and 310tq with the Predator tune but the wide band showed 13.6 average AFR, wouldn't idle in gear, and took warming up to get it to idle out of gear.
After 3 hours and probably 1000 or more changes it dynoed 366hp and 310tq but it starts and idles great and the AFR is 12.5 right straight across the sheet.
Then we tried locking the converter to see what happened and gained a little............................................ .................................................
398hp and 366tq.
I'm blowing right thru the converter on the top end so we played with lock-up mph on the 1/4 mile simulator until we got the best results. With a soft 1.65 launch it pulled a 11.28 @ 119.94. Now we all know that this car will pull a high 1.4x 60' so we know that there's a little more in there.

This was all done for a free tune up certificate that he gave away at M10. He wouldn't even take any extra cash for having to screw with teh TB.

Sean has the ability and know how to tune any GM fuel injected vehicle, TBI, TPI, LT1, LS1, but not LS2s yet.
Brad if you really want your car to run right?? Take it to C.A.R.S. and get Sean to make it scream.
__________________
Al
2000 Formula A4 H/C & bolt-ons
1.483 7.118@95.67 11.242@118.74 before tune
Tuned by Sean @ Collinsautomotive@sbcglobal.net "

AutoRoc

That car ran 11.24 and now it's putting 32hp and 56 more lb-ft to the ground at mid track with JUST the converter locked. He's gonna have a huge smile when he sees 10's

BlackHawk T/A

iTrader: (3)

But when did he lock it?

I still think it would be best to wind out all you can from 3rd.

s346k

iTrader: (4)

the car will shift at the same mph at wot regardless of converter size...assuming the same trans. settings.

fast98

iTrader: (16)

have you tried the new dexron fluid??? it sounds like it might be worth trying for you. here is what gm says about it.

General Motors Powertrain has recently upgraded to DEXRON®-VI ATF with the start of 2006 vehicle production.

Only 2005 and prior models that currently use DEXRON®-III may use DEXRON®-VI as a replacement.

All 2006 and future models that use DEXRON®-VI are to be serviced with DEXRON®-VI fluid only.

DEXRON®-VI is an improvement over DEXRON®-III in the following area:

DEXRON®-VI

Extended Factory Fill For Life
160,000 km (100,000 mi) For Cars and Light Duty Trucks*

80,000 km (50,000 mi) (Severe Use) For Cars and Light Duty Trucks*

Clutch Friction Stability
Improved 100%

Clutch Durability Due To Fluid
Improved 120%

Oil Film Thickness
Increased 20%

Fluid Oxidation
Improved 100%

Foam / Aeration
Improved 150%

Shear Stability
Improved 200%

MNR-0

I'll hunt some down and try it after Ive had a chance to log some runs with the DexIII + 180ml diff fluid (as a fluid stabiliser). I dont think its available here in OZ yet...

gold86vette

I used to lock the converter on my 700r4 transmission when my car had the 350 in it.

I had a toggle switch taped to the shifter at the track that I would switch on while foot brake staging (yes -on- on launch).

The brake pedal overrides the converter solenoid and would allow the converter to flash and then immediately lock up.

AWESOME results. The converter would lockup in first gear within 1.5 seconds and improved my 60 foot from a best of 1.82 to a 1.80. only had a 2400 converter at the time.

Anyways- the results: .29 seconds and 3.8+ over my best time.
12.651 @ 108.31 to a 12.361 @ 112.04.

When the converter locked up in first it felt like a small nitrous hit coming on. As an added bonus: the shifts were violent.
As a big time downer: Cracked the output shaft.

Definitely try it and Good luck.

BlackHawk T/A

iTrader: (3)

Would unlocking it through the shifts have helped?

AutoRoc

Not if it's so called, "Blowing through" the converter. At the top end of the track, the converter may be slipping TOO much. In Al's case, it is! It gets him out of the hole like a champ and locking it after the 1/8th should help the top end charge efficiency that results when there is NO slipping in the drivetrain.

seadoo

more info please...

usd2sing

iTrader: (15)

awesome thread gang. can somebody tell us how to create a switched lu???
what wires to tap etc.????

for the 4l60e.

back4more

there is a company i know of that has a lock up out of an allison 1000 in a 4l60e he said it will lock up almost 100% with near 1000hp. has anyone tried a true synthetic like mobil 1 it will definetly take the heat. the problem if you tap into a smitch manually you will trip a code unless you alter the computer but if you do that you may aswell tel the computer to lock it up