I was wondering how you determine where the shift extensions are most beneficial. How can you tell where to put them? What factors do you need to know when determining where they should be placed? How important is it to get them just right? Can they be too low or too high? If so, what are the outcomes of being too low? Too high? If I remember correctly, are you supposed to set the shift extensions where it will stay in its powerband? If thats true, then how do you tell where your cars powerband is? Thanks in advance.

 

Man you remind me of this guy that used to post, onebadss. SO many questions!
To the point, Most of the time you want it around 5600-5800 with that cam. Derek is makin you a converter right? Just ask him, he will know better than I about this. Good luck with that new tranny

 

Thanks for the input! Just out of curiosity, how did you come up with 5600-5800? Im not saying its wrong or inacurate, but I'd like to know so that I know for future reference. By the way, Im sorry that I have so many questions to ask, I mean...this is a forum board right? I'd rather be the one asking all the questions rather than the one who doesnt ask any. I just want to get as much info as I can. No need to flame anyone dude. Ease up a bit. Oh and lastly, I saw you post about getting a 4000 stall converter...you purchase or installed it yet? Im interested in how it turns out. What made you go with a 4000? Thanks

 

well now that I think about it, its a little high. perhaps 5200? just depends on when you shift. I havent gotten mine yet, it hasnt even been orderd I am low on funds. I am getting tunning at MTI next week so I am one step closer to the converter. I want something pretty freakin big for a bolt on car, so I opted for the 4000. I am still a little cautious about its street manners, like how hard it breaks loose.... I had an encounter on a wet road and im still a little freaked out. But once I get it I will always be on nittoes or better. good luck

 

"Man you remind me of this guy that used to post, onebadss."

I remember him. He would ask the same damn questions over and over and over and over...and he never seemed to be able to understand the answers people (including myself) gave him. He eventually got picked on to much and he kinda faded away. I felt sorry for the poor guy.

About the shift extensions. I've never had the chance to specifically dictate them when I've bought converters. I've said what size converter, what STR, what stall speed and let the shift extension just fall where it may. I didn't realize they could be adjusted indepedently of these other factors without sacrificing efficiency. Maybe Ragtop, Patrick, or someone from one of our converter companies can elaborate on this a little more?

 

Im with Colonel on this one, I think that it varies according to the stall, and the efficiency. I am not real sure if you can change that by itself.
NV how large of a stall are you going too, str and efficiency?

 

No...I think youre on the right track. First it was 5600-5800 and now its 5200. Derek at TCS was telling me 5200-5700 so you were headed in the right direction, but the thing Im wondering is, how you all come up with these numbers. Oh...and then, when I reminded him that I was going to be running the 200-4R, he said that he was going to set it higher. (closer to 5700)
So I take it that youre never going internal? If so, good luck to you holding back...it was incredibly hard for me! Youll always want more! The more extra money you got, the more you wanna spend!
I thought "how hard it hits" is due to the higher STR and not so much the stall speed. Ill be running a 3800 2.75 STR with 98% efficiency!

 

In addition to the factors mentioned above, The amount of torque being produced by the engine will have a large effect on what the shift extention will be, given the same converter. Due to the addition of a few mods since I got the converter, my shift extentin RPM has increased by about 300 RPM. I think the engine power thing helps guys get away with using a converter bigger than my PT4200 in a stock motor car. The shift extentions will be much lower because the engine is probably 100 less torque.

IMO, with a cam or heads/cam car, a converter with a shift extention in the high 4000/low 5000 range will hurt you at the track compared to a converter with more shift extention.

 

Jorday is correct. The more power you put to it, the higher the shift extension will be (the stall speed will increase as well.) Take a converter with a 5000 shift extension. Now add a 200 shot of nitrous (a LARGE TQ increase!.) Your shift extension is probably 6000 or better now.

What your shift extension is depends also on where you shift. If you shift at 5800, your shift extension will be far lower than if you shift at 6800.

With my TCI 3500, my shift extension is 4900 when shifting at 6250. Would I go faster with more shift extension? Yes, that's what a higher stalling converter is for. I don't know that my shift extension could be set at say 5500 without changing the other characteristics of the converter (stall speed, STR, efficiency.)

BTW, stall speed has every bit as much to do with how hard a converter hits as STR does. Take a 2800 stall with a 3.0 STR and put it up against a 4000 stall with a 2.0 STR. The 4000 stall will kill the 2800 on the launch because you're leaving the line with the engine much better into it's powerband. It's a combination of the two you see.

 

If you were to guess or if you know for sure, where about should my shift extensions be? 3800 stall speed/2.75 STR/98% effeciency/417+hp/388+tq/rev limiter at 6700. Oh...and by the way, if the limiter is at 6700, where should I set the shift points at? What factors do you need to know for setting it where it should be? Thanks everyone for all your input!

 

You should call Derek at TCS. I custom ordered a TCS Phoneix 4000 with 2.5 STR, 5200 shift extensions, 98% efficiency and even asked him to "tighten up" the loosness at throttle; which he did. I asked him if this would compromise efficiency and he said no it would not.
He did explain how he could do all of this, but honestly I don't remember everything. I did talk to him 3 different times to confirm this (I was a PITA ).

 

NV, look at your hp curve where does it fall, 6500? I would guess that you would need to shift at 6400-6600. Once agian just talk to Derek. And is your 700 built? It if no then it might be a bad idea to spin that high.

I was talking about how hard it would break loose with the stall and effiecency staying the same, just the STR changing. So Im still thinking about it, but I feel that I will go with what I had planned. And I will go internal, just go with a bigger converter

BLKTA you have a PM

 

Looking at my chart...the hp curve rises all the way up to 6400/6500 and then levels out all the way till 6700 until it drops. But Im thinking it drops because thats where they layed off the gas. (its a straight drop) The rev limiter is set at 6700. Will converting to an auto. have any affect the power curve, the shift points, or the limiter? With the info given, can you determine where about it should be shifted at?

What do you mean by that?

Changing STR is going to change how hard the converter is going to hit. The higher the STR, the harder it hits.

I meant internal. But Im sure you already knew that! Just curious, but what are you going with as far as specs on the verter?

 

I am not the guy to answer for the last word, but id say shift at 6500 if not a little higher.
your getting a 700r as a tranny right? Is it built, like is it beefed up?
C'mon give me some credit, I know that
Its going to be a 4000 stall, 2.5 str and 98% effiecent

 

I know you may not be THE person to talk to, but I just wanted your opinion and whoever else that would like to chime in. Ive already gotten Derek's opinion, but I wanted to hear others.

I will be running a fully built 200-4R by Mike Kertz at Century Auto and Transmission. I know what built means, I just didnt know what you were referring to as 700. But then it hit me...a 700-R4.

I figured you did, but I just wanted to point that out so that it seems that I know what Im talking about. Im just stealing all the knowledge that I obtained from Derek! But if you already knew that, then how come you wanted to know about the converters street manners and how hard it would break loose and if changing only the STR would affect how easy it breaks loose?" I dont know...maybe I dont follow.

Sounds like its going to be a winner for an stock internal car. Are you keeping this car as your daily?

 

sorry i thought you were getting a 700r4...
I can talk and hear about STR all day long, till I drive one I dont know how it feels to me. ya know?
Hopefully the converter will rock!

 

Exactly! To some that may feel something is hard hitting is soft to others. Hopefully soon, I will be able to justify. I hope that I made the right choices in specs for my converter.

 

From what I understand, you can't simply change thing. I'm starting to think that some people think you can just open it up and change either the shift extention shim, swap the stall spring or maybe change out the STR bearings and every other aspect will be the same.

 

Yeah, I get that feeling too...and I don't think that's the case at all. I wish one of the converter manufactures could come in here and elaborate a bit on how all of this ties together.

 

It sounds like we are thinking along the same line here, see what you think of this...

It seems to me that shift extention RPM isn't something that you build into the converter. I look at the shift extention as the result of your power level, gearing, STR, stall speed, shift point etc, and probably a bunch of other things that I've failed to mention. I changed from the B1 cam to a large XER cam, tossed my Mac headers for LTs and installed true duals and made a couple of minor PCM changes and my shift extention changed by nearly 300 rpm with the same shift points. The shift extention on my car is higher by probably 100 rpm on a 40 degree night vs. a 100 degree day just due to the difference in power because of the weather. Based on my observations with my car I don't understand how you can call a place and say I want my shift extention to be 5437.6 RPM, even if you give your entire mod list, everyone knows no two cars respond exactly the same to mods.

I talked to Mike from Yank about this on a couple of different occassions. He basically said that if you change something inside the converter it will change other stuff, you can't simply adjust one aspect of a the converter independantly of the others. If you change one thing, other stuff changes with it. Look at the PT line of converters. I know for sure they make from 3800 up to at least 4600 in that converter series. Even though they are all very similar converters, Mike says each different stall PT has a STR unique to it, or different from all the other PTs I should say. If you try and change the STR, the stall speed will be affected.