Converter too loose?

[turbojimmy]

I have a Vigilante 5-disc converter in my car. It seems the car has slowed down since I ditched my 9x11 and replaced it with this converter. The 9x11 was not locking up anymore, but even so it seemed more efficient at the top end.

The Vigilante seems okay at launch - not too loose. Seems to be stalling around 3200-3500 RPM as it should be. By the time I get to the end of the track I'm at 5700 RPM at only 115 MPH (3rd gear) with the converter LOCKED. According to my calculations, with the converter locked at 5700 RPM I should be at 138 MPH.

In the graph below you can see a small dip in RPM when the converter 'locks' at around the 8:19 mark (the numbers on the bottom are seconds). I e-mailed Vigilante and they said it's not likely the converter but a pressure loss in the trans that the 2004-Rs are 'famous' for.

http://turbojimmy.4t.com/062207-1_log.htm

When not locked, is the 5700 RPM @ 115 MPH 'normal' or should the converter be tightened up anyway? Should I just go with a non-LU and be done with it? I hate to do that after investing so much in the Vigilante but I'm tired of wrestling with this problem year after year.

Jim

 

[TURBO 6]

You have 28" tires right?

 

[turbojimmy]

You have 28" tires right?

Yes - 28" tires.

Jim

 

[aquickv6]

Do you have the modified pump with the lock-up tube kit?

 

[norbs]

That does not sound too good your slip comes out to about 20% You might have to ditch the lockup, as it only takes out the direct clutches anyway. I know the ATI converters and PTC converters non-lockup converters only slip about 5% max above there rated stall speed. Presently my converter is bad, so i feel your pain.

TCI - TECHNICAL INFORMATION: Racing Calculators

 

[Chuck Leeper]

??

Was the MPH at 138, B4 the 911 clutch took a dump?
Will your logger log driveshaft rpm? [A direct comparo to engine speed]
My calcs agree w/ Norbs.. right at 18-20%.
IF, the Vigilante is actually locked, then the slippage has to be in the trans... Something that should rather quickly show up, in the form of fried components.
Seeing abnormally high trans temps?
Maybe, a log of the trans PSI would confirm/deny the suggestion from the folks at Vigilante.

My $.02... I'm betting the converter is not locked 100%.

It's going to take a considerable amt of "steam", to run 138 mph.. My calcs show about 760FWHP @ 3700#:biggrin:

 

[turbojimmy]

Was the MPH at 138, B4 the 911 clutch took a dump?
Will your logger log driveshaft rpm? [A direct comparo to engine speed]
My calcs agree w/ Norbs.. right at 18-20%.
IF, the Vigilante is actually locked, then the slippage has to be in the trans... Something that should rather quickly show up, in the form of fried components.
Seeing abnormally high trans temps?
Maybe, a log of the trans PSI would confirm/deny the suggestion from the folks at Vigilante.

My $.02... I'm betting the converter is not locked 100%.

It's going to take a considerable amt of "steam", to run 138 mph.. My calcs show about 760FWHP @ 3700#:biggrin:

I think you're correct - the converter is not locking 100%. I know my car won't go 138 MPH, but if the converter were really locked and I crossed the finish line at 5700 RPM (which I did) then I'd be going 138 MPH. I'm not going 138 MPH, which is telling me that there is slippage somewhere. If it were truly locked I'd be crossing at substantially less RPM at 115 MPH.

Regarding efficiency, doesn't that only come into play on non-LU converters? When locked shouldn't a LU converter be 100% efficient, or do none really completely lock? If I use the tool in the link above, I get 43.5% slippage at 90 MPH (in 3rd gear, just before lockup, I'm at 5300 RPM at 90 MPH). Too much, right?

I don't have a temp gauge on the trans, but the fluid looks good. It's new (last fall) as is the Vigilante converter. I believe CK modified the pump and installed the tube. He actually asked me about the tube when I told him I was sending him a Vigilante to pop into the new trans. It was in the box.

Before the 9x11 took a dump it trapped almost 118 MPH w/out lockup (lockup clutches were toast). Ever since the new trans and the Vigilante I can't break 115 MPH no matter what I do. The more power I make the more it slips. I turn up the boost and it still goes 115, but crosses the line at a higher RPM.

It will lock very firmly when not under a load. I have noticed, however, that it is slow to lock (shows up on the chart too). My 9x11 would lock the instant I threw the switch. The Vigilante waits a couple of seconds, but then it is firm.

Shifts look good on the chart and feel good too. I'm thinking I need to take the converter out and see if they'll tighten it up and check the clutches.

Thanks,
Jim

 

[turbojimmy]

Does anyone have data that shows a good lock up that I can plot?

Thanks,
Jim

 

[Chuck Leeper]

???

An "assumption", in the form of a ??, here...
If the converter is slipping at a 20% value, wouldn't the rpm drop when the lock is achieved, be more than the change indicated on the log??
I would think that if the engine is at 5300, and the lock up actually ocurred, then the drop should have been much more than the 100 [+/-]. that I see on the log.

I think U R "driving thru" the lockup clutches...
Just did a bit more on the "what if" calcs.
If the converter was REALLY locked, and the MPH was entered as 117, the engine speed should have been 4803RPM... Looks like we have a discrepancy of right at 900 RPM...Hmmmnn.

 

[bison]

Maybe converter is not filling completely with oil. Do you have a 700 R-4 lockup solenoid in the trans?

 

[turbojimmy]

Maybe converter is not filling completely with oil. Do you have a 700 R-4 lockup solenoid in the trans?

Yes, I believe that's what CK puts in all his transmissions. He describes it as a heavy-duty solenoid.

I think I am plowing through the clutches for some reason. The question is why. It really is acting like it's not locking at all. There is a slight reaction in the data but that's it.

The converter is not really any more loose than the 9x11. Here is a sample:

In 2004, with the 9x11:
1-2 shift: 5225 RPM @ 31 MPH
2-3 shift: 5300 RPM @ 61 MPH
Toward the end of the track: 5375 RPM @ 108 MPH

In April, 2007 w/ the Vigilante:
1-2 shift: 5450 RPM @ 35 MPH
2-3 shift: 5275 RPM @ 61 MPH
Toward the end of the track: 5575 @ 108 MPH

On both runs the converters were 'locked' but neither were really locking. Normally I'd blame the trans, but the converters were in two completely different transmissions.

Jim

 

[Bent6]

Looking at your log, it doesn't appear that you're getting lockup. The RPM hits are obvious on the 1-2 and 2-3 shifts. If it were hitting LUP, you would have another big RPM dip along with a slight boost spike. If you are getting any form of LUP, it's not locking completely. Could be some problem with the LUP tube not evacuating the converter completely. Have you verified the solenoid is working? Looks like you could have an internal pressure leak which could cause these symptoms. Do you have another trans you could swap in using the same converter?

 

[Lee Thompson]

Just went through this with a friend's trans

Never did find what was actually wrong but it was definatlly in the pump (switched the pump out). I put his convertor in my car and it DID lock. FWIW --I have a #6 (3600 stall) pump PI multidisc. With 29 in. tires and @ 5600 RPM I cross the traps @ 139 MPH. Lock the convertor # 5800 @ the top of 3rd--RPM drop to 4800. Best of luck.

 

[turbojimmy]

I guess the consensus is that it's not locking up - makes sense. It will definitely lock up under around-town conditions. It's a solid lock but it is slow. It just can't do it at the track. I think it tries, hence the small blip in the RPM, but it's not doing it.

What is the purpose of the tube? When you say maybe it's not evacuating the converter completely, is that what it does? How is it different than the stock arrangement and why is it necessary on the Vigilante?

Lee: Based on your RPM and MPH it looks like you have a good, solid lock. I don't recall what pump I have in mine, but the target stall was 3500 RPM. Probably a #6? I don't have another trans to swap over, but it's a new CK-built transmission. I'll have him take a look at it.

Thanks,
Jim

 

[Lee Thompson]

From what I understand

The lock up tube connects the pump suction to the lock up bore. Instead of the lockup spool having to push the fluid out of bore the pump now pulls a vacumm on the bore making for a quicker and more solid lockup. Some people use an epoxy mix to seal the lockup tube--once had a trans that the excess epoxy run into and fill the tube--would not lock. Best of luck--race time

 

[chris718]

on several vehicles using the lockup assist tube i have seen no benefits at all in lockup time.this is not based on tests specifically targeted at investigating this but based on road test and data log info studied with and without the tube.i felt quicker unlocks with the tube and saw many vehicles puke oil out the vent after adding it.oil fed from the 1/2 shift valve after it opens supplies oil to upshift the lockup valve when it is hydraulically commanded by the solenoid closing of this oil supply from bleeding back into the pan and pushing the valve upwards redirecting converter oil.debris blocking the orifice that supplies oil to the end of the lock up valve in the pump will result in no lock up.a leaky solenoid or solenoid that cant seal the supply oil at wide open throttle can also cuse no lockup.obviously on a rebuilt trans with new solenoid and input shaft o ring etc.this is unlikely.if it is locking at low power and not at high power converter clutch off oil is not evacuating or the disks in the converter are slipping.the system is very simple and usually not too hard to diagnose after inspecting the converter and trans following a specific diagnostic procedure and or visual inspection of components.

 

[turbojimmy]

Never did find what was actually wrong but it was definatlly in the pump (switched the pump out). I put his convertor in my car and it DID lock. FWIW --I have a #6 (3600 stall) pump PI multidisc. With 29 in. tires and @ 5600 RPM I cross the traps @ 139 MPH. Lock the convertor # 5800 @ the top of 3rd--RPM drop to 4800. Best of luck.

Lee, if you don't mind....how fast are you going at the top of 3rd @ 5800 RPM? Precision gets $225 for a restall (I thought the first one was free, but evidently not) and before I spend that kind 'o money I want to see if mine is really loose. I lock at 90 MPH, which is 5300 RPM. You have a 29" tire, right? I'd have to adjust for that since I have a 28" tire.

Thanks,
Jim

 

[gnxtc2]

When the old 9x11 converter went bad, did it send any junk through the trans? If so, did you change the trans cooler?

Are you manually shifting the car? How are you locking the converter?

I never had any luck with Vigilante converters. You are dropping 500 rpm between shifts, I like to see around 750-1000 rpm drops.

I have a fully billet Dynotech non-lock up trans w/converter that was freshened up this past December just sitting in the garage if you want to try it out. Just one forewarning, I think you are going to like it and won't want to give it back:biggrin:

Billy T.
gnxtc2@aol.com

 

[turbojimmy]

When the old 9x11 converter went bad, did it send any junk through the trans? If so, did you change the trans cooler?

Are you manually shifting the car? How are you locking the converter?

I never had any luck with Vigilante converters. You are dropping 500 rpm between shifts, I like to see around 750-1000 rpm drops.

I have a fully billet Dynotech non-lock up trans w/converter that was freshened up this past December just sitting in the garage if you want to try it out. Just one forewarning, I think you are going to like it and won't want to give it back:biggrin:

Billy T.
gnxtc2@aol.com

The 9x11 simply stopped locking up one day. No junk through the trans. Almost simultaneously, my trans took a dump. I'm not sure what happened, but it's happened once before. It was like it was in reverse and drive at the same time and fighting itself. No debris, so I didn't flush the coolers. I put a 'new' CK HD trans in it. Chris knows what he's doing so I have confidence in the trans. While the trans was out I had the 9x11 cut open and found that the stator was cracked. I put a new Vig in along with the new trans just this past fall. The Vig has never locked up under a load, which strangely enough was the same behavior that 9x11 exhibited. But the 9x11 was never in the new trans so it can't be the trans itself.

I'll be pulling the CK trans out to have him look at it and I'll probably send the Vig back to have it cut open, too. In the meantime, your trans/converter is intriguing. I'll PM you for details......

Thanks,
Jim

 

[gnxtc2]

Is the trans that is currently in the car now, the same one that 9-11 converter took a dump? Was any parts re-used in the current trans from the 9-11 trans?

Billy T.
gnxtc2@aol.com