Modifications to stock converter (kinda long read)

[uhoh5.0]

Modifications to stock converter???

I have a question about torque converter work. There is a local transmission shop that specializes in custom torque converters. The guys there seem very knowledgable and I am considering letting them do some work for me. I enquired about a custom built converter, and their answer was to basically build a new converter based on modifications to my factory converter. I just wondered what everyones thoughts were on this? There seems to be some very good positives to this method:
1. maintains 12" diameter which would cut down on heat
2. maintains lock-up feature
3. custom stall based on existing vehicle modifications up to about 3300 rpms
4. Very cost effective

Don't get me wrong, I'm not trying to get off cheap, I just hadn't planned on getting into this type of modification yet because I thought it would be much more costly. However, the guy I spoke with said that many of the aftermarket companies have a huge mark-up on their products and in many cases they are doing exactly what he plans on doing by modifiying a stock converter. He mentioned 3 parameters that he could modify to adjust stall speed: modifications to the stator, fin angle inside the converter, and something called the A/B ratio I think. Anyway, he said he would make these modifications then tig weld in several areas inside the converter to reinforce and add to the overall strength of the unit and this would only set me back a few hundred dollars including installation. Almost sounds too good to be true, but seriously they sound like they know their stuff. Also, they have two pro-mod cars that they professionally drag race.
Give me your thoughts, I'm curious as to anyone that has gone this route.
Thanks

 

[clockstopper]

well, honestly, I dont know why you would spend a few hundred plus install to modify your existing converter, when you could go out and spend that much, if not less, or a NEW one. I dunno, but I know I'd feel better off knowing I had a new one instead of a "frankenstien" so to speak. JMO

 

[san~man]

A "good" convertor will cost more than a "few" hundred bucks.

Try more in the area of 800-1000 at minimum.

IMO, go with an aftermarket version that's proven.

 

[uhoh5.0]

I don't know, I mean a good precision industries converter with the lock-up feature can run anywhere from $750 to $1000 dollars. I just seems kinda logical to start with a well made factory converter and make the necessary changes from there and end up with a quality piece at a fraction of the price. I'm sure it would cost $500.00 plus to replace the factory converter from ford and when you consider a few hundred to modify and reinstall it you're actually in the neighborhood price-wise of a new aftermarket converter, you're just cutting the price by using existing parts. I don't know it this is a fair analogy and I know this is another can of worms, but why spend $200 dollars plus on a plenum elbow from accufab when dyno tests consistently show that no matter what brand you go with even with the addition of a larger throttle body you're only going to pick up ~5rwhp. My point, port your factory plenum and upgrade your throttle body. You would have spent less than half the amount of money you would have on the accufab and you'll end up with the same performance increase and you can spend that extra money on something else. JMHO

 

[san~man]

Well, it's your money in the end.

I haven't seen a factory ported plenum match the same #'s as an Accufab model.

 

[04YELLOWGT]

I was looking at doing the same thing and then I started thinking what if something happens to it then what. I found a guy that would rebuild mine for about $400. But Ive decided to get a PI instead.

 

[propellerhead]

Sounds like a neat idea. It crossed my mind too but I never went out to look for someone who would do it. If it's going to run out about $400, it may not be worth it since you can get a good aftermarket one for just a little over a hundred more. If they can do it for under $200, I'd say it's worth a try.

FWIW, the aftermarket ones are smaller so they spin up faster. Less rotating weight.

 

[Mike97gt]

Well there is some major differences between the stock converter even if you modify it to change the stall speed and a quality aftermarket unit.

First thing is a aftermarket unit in the 1000 dollar range will have multi disc lockup this feature comes in handy when used with a lock up switch after you get out of the hole. pretty much on one of these units you can lock up the converter at WOT and cut down on drivetrain loss. plus with a aftermarket unit you get a anit balloning plate and a better overall case, from what I have heard the stock unit is not very stong at all. Plus the smaller 9.5 inch converter has less rotating mass and has other benefits too.

One last thing I would be very skeptical of a stall converter that is a couple of hundred bucks installed.

 

[uhoh5.0]

Well, the shop I mentioned previously is doing my valve-body today. This way I will get a chance to gauge their work and talk to them personally about converter options. I'll let you know what I decide. By the way, like I mentioned these guys primarily drag race and have this shop to support two pro-mod cars (whatever that is?) so all of their work is track tested on their own vehicles and the converters they are running are custom built from scratch. They are squeezing me in today, before leaving for some race in atlanta this thursday.

 

[Mike97gt]

Well keep us posted.

 

[san~man]

What are they doing to the valve body?

 

[uhoh5.0]

Got my car back this afternoon. They did the j-mod to the valvebody. Makes it shift much better and firmer even with the pressure backed down on my diablosport. The j-mod along with the 4.10s has really brought the car to life. Still trying to decide what to do with the converter, I get a lot of different answers from a lot of different people???

 

[TripleBlk]

Got my car back this afternoon. They did the j-mod to the valvebody. Makes it shift much better and firmer even with the pressure backed down on my diablosport. The j-mod along with the 4.10s has really brought the car to life. Still trying to decide what to do with the converter, I get a lot of different answers from a lot of different people???

Ask the converter guys if they have a stall/torque dyno - there is no way to measure stall/torque ratio on the car.

Remember, once the converter i sbuilt, there is no way to "look inside" to see if they did a good job or not. Kinda like "blind faith".

 

[san~man]

Got my car back this afternoon. They did the j-mod to the valvebody. Makes it shift much better and firmer even with the pressure backed down on my diablosport. The j-mod along with the 4.10s has really brought the car to life. Still trying to decide what to do with the converter, I get a lot of different answers from a lot of different people???

What setting did you go with? I did the most firm setting when I initially did mine but I installed the TC at the same time.

 

[Gearbanger 101]

Withought going into its specs (you can seem them in My Garage) I went with one of the Circle D units out of Texas. I don't think I'm going to be dissapointed.

 

[san~man]

Withought going into its specs (you can seem them in My Garage) I went with one of the Circle D units out of Texas. I don't think I'm going to be dissapointed.

I've only read of one guy who had a problem with his Circle D unit....wish I kept the link.

 

[BlackenedSVT]

Well IF you do decide to let them do some work for ya, i would ask if they would garauntee their work or warranty it or something

 

[uhoh5.0]

I went with the highest settings on the j-mod. They say once you add a higher stall converter that it kinda takes away from the shift firmness so they recommended that I go with the largest openings in the separater plate to begin with since I am thinking of going with another converter. It's crazy trying to decide what converter to go with though. It's almost like, "I have brand X and I would only buy their stuff and I don't have any problems. Then the next guy is like, "I went with brand Y and it's the greatest thing since sliced bread, but as long as you don't buy brand X you will be fine." Then the third guy says, " Brand X and Y suck you gotta buy this one its the super duper greatest model!"

 

[BlackenedSVT]

I went with the highest settings on the j-mod. They say once you add a higher stall converter that it kinda takes away from the shift firmness so they recommended that I go with the largest openings in the separater plate to begin with since I am thinking of going with another converter. It's crazy trying to decide what converter to go with though. It's almost like, "I have brand X and I would only buy their stuff and I don't have any problems. Then the next guy is like, "I went with brand Y and it's the greatest thing since sliced bread, but as long as you don't buy brand X you will be fine." Then the third guy says, " Brand X and Y suck you gotta buy this one its the super duper greatest model!"

Yeah welcome to the world of buying mods. Which is why here, companies reputation is what really makes or breaks the deal. Which is mostly why people here are telling u to get tested tried and true aftermarket converters, and staying away from these guys who tinker around with custom work. Not to say there stuff is bad at all, maybe its perfect....but they just have no reputation

 

[GT12207]

I don't mean to hijack the thread, but I have a very simple question related to the topic.

Would a good aftermarket torque converter such as the PI one that sells for $750+ have less parasitic lost than stock?