Convertor Junk?

[Nocooler]

I had my trans rebuilt at a local place - this guy builds all of the local TR trans and does a great job I might say. Well I went with his "2600-2800" stall convertor, its blue and thats about all I know about it. Everything was fine till I bolted up my TA49 w/PTE .63. Now I can't get it to spool above 2psi @ 1650-1800rpm. I recall the stock 85 turbo building 8-10psi against the brake but I don't remember the rev's. 1800rpm seems a little low for the convertor to stall out if it is a 2600 right?

Help this car is a turd.....

 

[Crazi]

Seeing as how I just changed my converter and the Trans guy put in a 2000 stall converter that was marked D5 all the way around, you probably got a rebuilt converter which could have anything from 1800 - 3000 rpm stall. I realized that after your converter comes off your car, you pretty much are at the mercy of whoever sold it to you. I know the one I had was a Dayco. Just didn't know it was in a D5 case. You could really screw someone over with these things

 

[MeanBuicks]

It does seem that the converter is not as your builder thought it would be. I'd take the car back to him ASAP to get it recitified.

 

[Nocooler]

Thanks guys, that is what I figured

On goes the stock turbo until I can fork out the $$ for another convertor.

Would anything else cause a convertor to stall low? Exhaust leaks? The convertor should still be loose enough to come past 1800 revs right?

I'm gonna put the stock turbo on tonight and see what it stalls at....
Thanks


Jeremy

 

[turbo6x2]

the converters he uses are not refurbished they are new and I see no where in your post where you even called him to ask. You may want to check other things to see what is going on. Or better yet call and see if he can take a look at it. If of course you can hook up with him, if so he can take it for a spin an figure it out. (he's done this for us before) Hope it works out.

 

[Crazi]

One more thing....

Torque converter stall is a function of torque. If you just swapped in a bigger turbo, that might have changed the equation just enough to only let you stall at 1800rpm.

For example, lets say the torque converter stalls at 2800 with 250 ft-lbs of torque going through it. And at 2800 rpm, the stock turbo is spooled pretty good so you are making enough torque to stall at the rated speed.

Then you swap the bigger turbo on and you are only making 170ft-lbs of torque at 2800 rpm. You can't even get up to that 2800rpm becuase you aren't making enough torque to go past 1800. the turbo will only spool to 2 psi at 1800 so it is part of the problem.

Now the question is, do you need a converter that stalls at a higher speed so you can build boost with the bigger turbo and therefore build torque? Or do you need to look at your chip and tuning to see if you are running rich on the low end and not allowing your turbo to spool enough to make that 250ft-lbs at 2800rpm?

Wow!! Reading is fundamental!!! I learned all that since I broke my converter and have been looking up everything I could find about torque converters. Trans guru's, is this close or am I way off?

 

[turbojimmy]

Me too?

You know, I'm starting to wonder if I don't have the same problem with my car (engine not producing enough torque to stall the converter). I put a Red Stripe in it without making any other changes and the car was a total dog. If I stood on the brake and gave it some gas, it would stall decently, but not from a dead stop. It was terrible and the fuel economy was awful (13 MPG with a combination of highway/stop-n-go). I figured it was too tight and pulled it out this past Sunday. It's MUCH better than the stock one, but I still have a dead spot for a split second from a stop. It's idling rough, too. Nothing out of the ordinary from Tlink, though.

The trans is still shifting funny, and after reading the thread on how the servo works I'm wondering if the guy that rebuilt it put the wrong servo in it. I have the "slide-bump" shift from 1-2, and 2-3 seems loose, too. If I give it gas in 4th, I get a "slide-bump" kind of action too, but it's not a shift. I was blaming all this on the TC. Who knows, I may have multiple problems, but it pulls MUCH, much better with the stock TC.

I'd think, though, that the 3.8L turbo - even in stock or semi-stock condition - should have enough torque to stall a Red Stripe converter at a higher RPM than a "regular" D5, right?

 

[REDS HOT AIR]

is the converter all blue or does it just have a blue stripe all the way around the outer edge?

i just tried a Dacco # 7727 converter the results suck

i can stall the converter and i can get full boost on the brakes with good tires 20#

but the problem i have is its not pulling when its in boost the only change i made was pulling the d5 and putting in the blue striped conv. and with a 20# launch the car only went a 2.01 60 ft with no wheel spin at all compared to high 1.8's with a 0 # launch on radials with stock converter..

the car lost 3 tenth's in the 1/4 and 2 1/2 mph i dont lock my converter at the track

( POS )

 

[turbojimmy]

Originally posted by REDS HOT AIR
is the converter all blue or does it just have a blue stripe all the way around the outer edge?

i just tried a Dacco # 7727 converter the results suck

i can stall the converter and i can get full boost on the brakes with good tires 20#

but the problem i have is its not pulling when its in boost the only change i made was pulling the d5 and putting in the blue striped conv. and with a 20# launch the car only went a 2.01 60 ft with no wheel spin at all compared to high 1.8's with a 0 # launch on radials with stock converter..

the car lost 3 tenth's in the 1/4 and 2 1/2 mph i dont lock my converter at the track

( POS )

Those results are identical mine. From a standing start, it couldn't get out of its own way and it did seem to be slipping a lot even on a high-boost launch. Must have been the converter because it's 100% better with the stock one. I'm glad I swapped my Red Stripe out, but not glad I got robbed $400. Inidentally, the torque converter itself is bluish in color, but it has a red stripe (I know you weren't asking me, but I thought I'd volunteer anyway).

How are you getting at the top bolts on the trans? I had a helluva time with those. I could almost get on the LH side from underneath, but not the RH side. I had to wedge a ratchet down behind the coil pack from up top and beat the crap out of my knuckles trying to turn it. Any tips other than the 3 feet of extensions (which gets pretty wobbly, I might add) and a universal?

Jim

 

[Nocooler]

Well, I put on the stock turbo and it stalls out to about 2600 without a problem. The problem lies elsewhere.

The convertor isn't a Dacco - It is all blue and as turbox2 mention it is a new convertor. BTW - I did call and leave a message with swains regarding the probelm.

Thanks for the input

Jeremy

 

[REDS HOT AIR]

it's 100% better with the stock one. I'm glad I swapped my Red Stripe out, but not glad I got robbed $400.

i bet its the same converter just painted by retailers and sold for way more money
i get dacco converters strait from dacco.the one in my car will stall right around 2800 and was $156. and they are new not refurbished

How are you getting at the top bolts on the trans? I had a helluva time with those. I could almost get on the LH side from underneath, but not the RH side. I had to wedge a ratchet down behind the coil pack from up top and beat the crap out of my knuckles trying to turn it. Any tips other than the 3 feet of extensions (which gets pretty wobbly, I might add) and a universal?

Jim [/B]

not hard at all just buy yourself a long ext. then you dont have to put alot of them together....you wont regret having one

i dont even take out my crossmember i leave it in the car..
just pull the tranny mount out of the way and let the tranny sit down on the crossmember and you get room to get to the top bolts..

and yes the trans will come right out with the crossmember still in..

The convertor isn't a Dacco - It is all blue and as turbox2 mention it is a new convertor.

im thinking b&m (painted dacco)

 

[turbojimmy]

Originally posted by REDS HOT AIR

not hard at all just buy yourself a long ext. then you dont have to put alot of them together....you wont regret having one

i dont even take out my crossmember i leave it in the car..
just pull the tranny mount out of the way and let the tranny sit down on the crossmember and you get room to get to the top bolts..

and yes the trans will come right out with the crossmember still in..

I guess I'll by a big a$$ extension, then.


I tried to leave the crossmember in, but I had to move it back to swap out the converter. The trans clearly would have dropped out without touching the crossmember. But it seemed easier to move it so I could slide the trans back and swap out the converter without dropping it down. That's ultimately what I did, but I think next time I'll just take the trans completely out. All that was stopping me, really, was the dipstick tube. Pushing that TC up there - full of fluid - with one arm while you're on your back is no small feat (and not something I want to do again).

Thanks for the reply,

Jim

 

[MeanBuicks]

Originally posted by turbojimmy
Any tips other than the 3 feet of extensions (which gets pretty wobbly, I might add) and a universal?

Another suggestion: if your universal joint is loose & floppy, wrap some duct tape around it. That way it'll still move without trying to fall off the bolt head all the time.

 

[Crazi]

NoCooler,

The stock turbo is smaller then the 49 and needs less exhaust to spool. When it does spool you make torque and get the converter to stall. The 49 needs more exhaust and so you can only build 2 psi before you run out of exhaust energy to spool it. It is kinda like trying to run up a hill that gets steeper the farther you go. You can make it up a ways with a running start but then it gets steeper and you start to slow down until you stop. The stock turbo will make it farther up this hypothetical hill of stalling the converter then the 49. You need torque to stall the converter and the 49 isn't making enough boost to make torque to stall the converter.

If you still think it is something else, try dropping the fuel pressure a few pounds. What are your O2's while you are testing the stall? That should let you know whether you are running rich or not. Turbo's spool better with a lean mixture.

By the way, I am about out of my league now so would someone else like to help me out.

 

[Nocooler]

Red - not sure but I know it isn't a B&M.

I'm working on the probelm with no luck.

http://www.turbobuick.com/forums/showthread.php?s=&threadid=11123

 

[TurboJim]

Originally posted by Crazi
One more thing....

Torque converter stall is a function of torque. If you just swapped in a bigger turbo, that might have changed the equation just enough to only let you stall at 1800rpm.

For example, lets say the torque converter stalls at 2800 with 250 ft-lbs of torque going through it. And at 2800 rpm, the stock turbo is spooled pretty good so you are making enough torque to stall at the rated speed.

Then you swap the bigger turbo on and you are only making 170ft-lbs of torque at 2800 rpm. You can't even get up to that 2800rpm becuase you aren't making enough torque to go past 1800. the turbo will only spool to 2 psi at 1800 so it is part of the problem.

I see your point, but disagree. A 2600 stall converter shouild slip to 2600 under 200 or 300hp. It might FLASH higher at 300hp. If the converter stalls at 1600 its too tight.

In light of his follow up post, I will agree that the stall will be higher under higher torque (as in stock turbo spooling at a lower RPM) but I think that is happening because the power IS being made at a lower RPM and not where it should be, while the larger turbo hasnt started breathing yet.

Whjat I think he has is a converter too tight, and the stock turbo is flashing it to 2600

 

[turbo6x2]

Originally posted by Nocooler
Well, I put on the stock turbo and it stalls out to about 2600 without a problem. The problem lies elsewhere.

The convertor isn't a Dacco - It is all blue and as turbox2 mention it is a new convertor. BTW - I did call and leave a message with swains regarding the probelm.

Thanks for the input

Jeremy

We still have the box from ours, Karl said you might have to go with a big converter??? Good luck with the call...... HMMMMMMMMM Anyways I will look at the box it says something about a blue in the part number I was going to write it down and see. The one above post explained what you might be experiencing with the bigger turbo, which would mean a difference due to the larger turbo. Sounds like an adjustment can be made. Then you should see better times then last Wednesday. We are thinking of having a camp out at swain's to see what's up with him lately. Game? Hope you have better luck then us with him lately, if he does call you back get right over there and have him check it out.

 

[Nocooler]

Thanks for the help Jim - I am thinking way to hard about this and tend to agree with you. I believe that the convertor is way to tight and will cough up the money for a better one as you mentioned in the email.

Turbo6x2 - I left a message and have not heard anything back from them, I know that they are busy and I'd rather not pester them about this - I haven't even had a chance to let him test drive it, but everything but the stall speed is exactly the way I want it. I'm wishing you luck on that beast of your - none of us are having any luck this year.

 

[Crazi]

Thanks for the clean up Jim!! At least I was close.