First of all, let me say I don't know squat about auto trannys. When my truck was new I don't remember it downshifting to go up any hills around here. After I stuck on the 33s it started unlocking the torque converter on almost every overpass, and even downshifting on some. I have had those tires on for around 25K miles now. But after the turbo almost ALL downshifting and unlocking stopped. But now on the rare occasion that the torque converter unlocks, it seems that it never wants to lock back up again. I can let off the gas real fast and then get back on the gas, and it will unlock the converter and stay unlocked for a few seconds, even with very little throttle applied. I don't think this is supposed to happen.

So here is my question, with a FTVB fix this problem, or do I need a new torque converter or both? Or can it be fixed with computer tuning? I have a 4.6 4X4 with the 4R70 by the way.


Thanks,

Marlon

 

I think you're problem is going to require alot of work. The engine computer needs to be tuned for your application, The stock converter just will not do, and the FTVB will do the rest.
Alan

 

Thanks for the reply,

So you think I need to buy a new converter, maybe from Factory Tech, and the FTVB too, and also have the chip tuned for it? I was just about to buy the FTVB and also have a custom chip tuned for my truck, but if I need a new torque converter I would like to do it all at the same time.


Thanks,

Marlon

 

I would suggest a new converter.
You said the truck is turbo? At what rpm does boost come in? Figuring out the correct stall speed for your truck will be tricky. Too much will have you thinking the transmission is slipping, not enough will make the turbo lag bad. Turbo works well with less rotating mass. It wouldn't be a bad Idea to change to small pattern flexplate and smaller diameter converter. I don't usually suggest that for trucks ,but yours is the exception. If you decide to do that let me know and I will get you a part number.
Alan

 

Thanks for the info man. I am only running 6psi of boost right now and I hit that somewhere just under 2500 rpm. But really soon, after some fuel upgrades and intercooling, I will be running 10-12 psi of boost, so I will hit max boost somewhat higher in the RPM range.


Marlon

 

HI!... If I were you I would go get a PI (PRECISION INDUSTRIES) stall converter. I would suggest a 2600-2800 stall. I'm running one after ballooning two stock converters and two heavy duty race ones. The PI comes with a 2 year unconditional guarantee, and free stall adjustment for the 1st year. I have the 9.5" STALLION. It is a 2800 stall but stalls closer to 3000RPM. The PI converters are good for just over 2000H.P.

 

2000HP,,,, HA

Want to see internal pictures of one?

 

HI!... Actually I know what one looks like inside. PI has one of the best built TQ's worldwide. Several of the local guys here run them in their 1200h.p to 1600h.p drag cars. No problems at all. All the lightning guys in the 10's and 9's are also running them. No problems there either. 80% of the 9 second or faster auto MUSTANG's are running the P.I converter. It's been known as one of the best converters around for years. So don't try to discredit the company or the converter, you will just look like a fool. It's a proven converter over and over again.

 

See you are talking about 2 completely different converters. Lightnings have 4r100's in them. This is a 4r70w. The fact is that a 4r70w can not handle 2000hp and the sprag assembly used in the single plate PI converter can not handle more than 400ftLB. I have no input on the triple plate,but I don't like the single plate. The only thing it has going for it is the billet front cover. See I don't have to worry about making myself look like a fool because I speak the truth and have the proof to back what I speak.
Here is the truth
If you are going to buy a PI 4r70w converter spend the $1200 and buy the triple plate.
I can assure you that all 10 sec lightnings do not use a PI converter. Have you ballooned a Factory Tech Total Dom?
Alan

 

HI!... By the way I have the triple plate TOP OF THE LINE P.I converter. Thats the one I'm suggesting to FREDMAN. I never said the 4R70-W will hold 2000H.P. I said the P.I converter (triple plate) will hold it and is guaranteed under warranty for that much. I know the LIGHTNING's use the 4R100. I was proving a point. Go over to the LIGHTNING forum, I bet 85% of them that have gone to a after market converter are running a PI. You obviously didn't get it. Anyway go with whatever TQ you want, I don't really care. It's not my truck. I've got what I want........ a PI TQ.

 

I am on the lightning forums. I know of several 10 second lightnings running the FT converter. I hear about most of them because I build the converters. Does PI even build a single plate for the lightnings? I have seen the 4r70w ones. They look like this inside.

http://forums.tccoa.com/showthread.php?t=50811