4L80e Converter

[Silverback]

So after lurking here for years I have a few questions (after thinking about it I’ll post them as separate threads)…

Those of you doing 4L80 swaps, what are you using for a converter? How do you like it? Do you have recommendations?

It seems like everyone I talk to gives me contradictory information which quite often even contradicts the same company’s published info, so I don’t know what to thing/believe. I’ve actually had 2 different people at ATI tell me that I can use the same converter as the 700r4, and it seems that everyone that I’ve talked to that has one of the converters that I’m considering has some problem with it.

FWIW, in my case it’s replacing a 700r4 that I just toasted, behind (don’t be offended, it’s not in a sy/ty) a turbocharged small block chevy that also sees some spray. The thing is actually driven on the street a few times a week (to work, it’s as close to a daily driver as I have, but doesn’t have to be), so streetablility is an issue, but I’m figuring that I want something with a stall in the low/mid 3K range leaving off the boost, and high 3K range on boost (fairly tame engine, 236/230/114.5 cam, worked aluminum heads, ~9:1 compression, don’t know how much boost it will tolerate in the long run, 3.50 rear gear…)

I don’t know if you guys have even looked into stall torque ratios, but as of right now I’m thinking that I’d like to keep that on the high side since I’m loosing the steep, 3.06:1 first gear in the 700 which did make things fun on the street…

So is there a point? Seems like the transgo HD2 kit is the way to go, but I’m not sure how the electronic control, which I guess can control shift firmness will affect this?

I’m somewhat leaning towards going with the transgo setup, if there are any choices going for as firm shifts as possible and then if they’re too firm “turn them down” using the controller, but I’m hoping someone here has experimented with it to know for sure.

For that matter, what about the B&M (much cheaper and easier to get)?

 

[Crimson93Ty]

Re: 4L80e Converter

Any company that says the 4L80E and the 700r4 use the same converter has no idea what they are talking about. Just thank them for their time and move on. The vigilante series from PE has been used with much success and Protorque is also a good model.

Use the HD2 kit from Transgo. It also has a special plate and instructions to make it a dual feed direct clutch. The instructions are very specific about tailoring it to your likes on shift feel. Even has recommendations on converter diameter size and orifice tweaking to get the shift feel right. The kit also has the valves and special assemblies to prevent the known pressure issues and filter failures that can cause hazardous conditions(like throwing the trans into reverse during a 2-3 shift).
Most places just drill the 2nd, 3rd and 4th feeds and call it a shift "kit". Don't do that. Just get the transgo kit and do it right.

 

[JSM]

Re: 4L80e Converter

As Crimson said a 700 and 80e are two different convertors.

Now if you got creative with a case of JB weld, you might be able to drive it a mile or two.

The shaft on the front is larger and engages with 2 flat spots -vs- the 700 that has notches.

Turbotime and I are using a custom built unit for our trucks. It is a bit more than the others but they are working great. Jeremy loves his and has given it a workout.

 

[Silverback]

Re: 4L80e Converter

Any company that says the 4L80E and the 700r4 use the same converter has no idea what they are talking about. Just thank them for their time and move on.

Heh, that was my reaction also, but it’s hard to resist at least _trying_ if you’ve got a dealer contract with them and their price is ½ of what anyone else wants. I finally got the name of someone that had a clue through a friend that has a customer sponsored by them, and as soon as I gave him a rough idea of what I was doing I got, “well, anything that we’re going to be able to build you you’ll break…”

But we did have a nice, longer conversation of what is good and bad about the rest that I was considering, since ATI does also make the equipment that they use to service their own stuff and has had most of them taken apart.

The vigilante series from PE has been used with much success and Protorque is also a good model.

My sort list right now is down to PE and Yank.

Seems like no one is absolutely thrilled with PE, but everyone is happy, and I like the availability of the 3disk clutch that I was told can be used in anger at up to 1600hp and my general familiarity with them and the fact that I and on one I know has ever had problems with them. I (and after talking to a few people it seems like I’m not the only one) just felt that they’ve always made a killer street converter for serious cars, but only an OK track clutch, that it doesn’t hit as hard in a full out application as it can. I also find it funny that they recommended EXACTLY the same converter and stall speed as EVERY other turbo SBC + 4L80e combination that I’ve been able to come up with info on.

Yank is somewhat an unknown still (mostly I haven’t had time and when I did they were out of the office…), but still in contention just because they’re a known quantity in my circle (the f-body world) and I’ve known a few people that have gone from PI to Yank and basically described it as “more aggressive feeling, on the street” and gaining .2 at the track, almost every time (I wonder if that would be the case with 4L80e stuff though, since I believe that you want to treat the stall torque ratio slightly differently with it then you do with the 4L60 that I’m more familiar with).

Protorque is a distant 3rd. They’ve mostly managed to take themselves out of the running through customer service or lack thereof. I don’t know what’s going on up there this week, but they insist on car specs on paper, web form doesn’t submit, it didn’t submit later on when I was told it was fixed, some of their email is messed up (oh, my box is screwed up but send it to X and ask him to forward it to me), and I haven’t received the 2 faxes and 2 emails that I was promised yet. Great way to annoy anyone, but especially a great way to push a “computer guy’s” buttons. That and I’ve had a number of reasonably reliable sources, including our tranny parts supplier make the same, unprovoked statement about them, that “they tend to over promise and under deliver.”

It would take a bit of convincing to put them back into serious contention.

 

[Silverback]

Re: 4L80e Converter

Use the HD2 kit from Transgo. It also has a special plate and instructions to make it a dual feed direct clutch.

Yea, I had one delivered to the shop today and have been scanning the directions. It’s pretty slick how they get 300 extra lb/ft worth of holding out of it by using both the forward and reverse feeds.

And how cool is "it just gets comfortable at about 900hp and will handle a lot more with just a few special parts" (quote from the transgo instructions)

BTW, it’s good that you brought this up, I could have sworn that I started a separate thread about it and I can’t find it…

The instructions are very specific about tailoring it to your likes on shift feel. Even has recommendations on converter diameter size and orifice tweaking to get the shift feel right.

OK, maybe you can help me there, as per the instructions:

Step 6 Selecting Shift Firmness

Holes ABC are for shift feel selection:
Average - .086 Softer = .076 Firm = .096
For off road use and with small diameter high stall converter make holes ABC .120​

Now I’m sure that the 9-9.5” >3200rpm stall converter (TCI recommended something in the low 4xxxrpm range) qualifies as a “small diameter, high stall converter” but this car is also a driver, as in it gets driven 2-4 days a week to work, 20 or so miles each way… and I’m as likely to take this thing on a road trip as any of my other cars/truck. So even though it sees the dragstrip almost weekly, I don’t think it qualifies as “off road use.” Any thoughts?

The kit also has the valves and special assemblies to prevent the known pressure issues and filter failures that can cause hazardous conditions(like throwing the trans into reverse during a 2-3 shift).
Most places just drill the 2nd, 3rd and 4th feeds and call it a shift "kit". Don't do that. Just get the transgo kit and do it right.

Well, I’ve gotten that far

Any idea of how big a hassle the last page, “Internal upgrades, if transmission is apart” stuff is? No, that tranny is not apart but obviously it’s not in the car either. Most of it looks like maintenance rather then modifying it for more durability/harder use.

My instinct is to go with transgo’s firmest shift firmness settings and then dial it back with the controller, is that possible or even a good idea? I think that I’d rather have it shifting a little on the “crisp” side rather then soft and I can’t do anything about it, but I don’t want to be unnecessarily breaking parts…

 

[Silverback]

Re: 4L80e Converter

Turbotime and I are using a custom built unit for our trucks. It is a bit more than the others but they are working great. Jeremy loves his and has given it a workout.

So tell me more… you have a basic idea of what the combination is, it’s in a 3700lb car that sees a ton of street and track time…

 

[Crimson93Ty]

Re: 4L80e Converter

All those "extra" things are for heavy use. :lol:
The one where you put the springs on the direct clutch return spring assembly. That one keeps the directs from partially applying during high rpm use when you are in first and second.
That wider retaining ring for the intermediate(sencond gear) stack, keeps you from blowing out the case lugs in 2nd. I also recommend removing the waved cushion plate down inside of the 2nd clutch. It's the one that sits on the aluminum piston on the center support.
The mod where you drill out the drainback hole does that same thing as it does on the 700. Keeps you from blowing out the front seal.
The pump mod is for TCC longevity. Again, not a maintenance item. What drilling that partition does is allows TCC apply pressure to be equal to pump pressure. Precision Industries (PI not PE, sorry about that) actually requires it as well as their special converter limit spring.
It will take you a LONG time to do the kit. One thing I have noticed is that the reverse slam safety mod has required me to file/sand the end of the filter down where the roll pin goes. You know, the one at the end of the manual shift valve? Don't take short cuts. Do all the stuff except the "command shift". I'd also put in the sonnax wide stator bushing and the transgo heat ring kit. Really easy to install.
Use the forged clutch hub from sonnax. It's pretty cheap if you get it from Transtar.
I used the red clutch kits that are specific to the 4L80E's made by Alto. I've used BW for the Overrun and OD. Raybestos make blues for the overrun and OD though. They are the Gen2's. Very expensive.
Make sure it has the 34 element sprag and use the transgo thrust washer kit. It gets rid of all the plastic thrust washers and replaces them with bronze. Nice kit.
You should have a fairly indestructable trans at this point.
Only weak spot then will be the input shaft. Get the stock one cryo'd or get the billet one from Transmission Center. You shouldn't need it though unless you are running a lot of nitrous with a high HP(1000 HP or more with your 3700 pound vehicle).
Every planetary failure I've been fortunate enough to see has been from lack of lube. I'd highly recommend one of the later units that has the lube fitting toward the back. If yours has it, your very lucky.

What I would do on drilling the orifices is do them at .100" if you have the drill bit for it.
Then use the software to increase the pressure. You can increase pressure but you don't want to make it shift too firm and then waste your clutches because you have to decrease pressure to make it drivable. Increasing orifice size does NOT increase pressure, it increase the RATE that the clutch pack engages when called for. You can always make the holes bigger later on but you can't go backward. Does that make sense?

Something I'll pass along is that the bands are not used unless you are in reverse, manual low and manual 2nd. If you put it in OD and take off, the bands are not used.

PM me if you want more info. I don't know if there are enough people on here that build their own transmissions to make it worth the time to put the info up.

 

[myclone]

Re: 4L80e Converter

I don't know if there are enough people on here that build their own transmissions to make it worth the time to put the info up.

There are a few of us so any info that is posted will be appreciated way more ppl than you'll hear from on this forum.

 

[Silverback]

Re: 4L80e Converter

Crimson, thanks for all the input/help, but you’re telling me stuff that I don’t want to hear but I guess it’s better to hear it now then regret it later.

That trans is supposed to be freshened up and the original plan was to just get it in the car and run it. Since I can’t leave well enough alone I was thinking “well it can’t hurt to throw a shift kit in the thing before I put it in, and man, it would be so nice to do it for once out of the car…”

So what I’m getting from you is that even though transgo treats the last page as “extras” you would treat them as “must do’s?”

(right now I’ve got “what did I get myself into this time” going through my head, think of me as the most mechanically competent person you’ll run across that has not had a 4L80 apart, I have rebuilt a couple of AOD’s and a 4L60, which somewhat shocked me that they all worked fine out of the box after I was done with them, and done dozens of transgo kits and a few lesser shift kits, but never had a 4L80 apart, and as of yet don’t have any service manuals for one or even a good blow up drawing of what’s inside in what order)

Correct me if I’m wrong, but it looks like all of the back page besides the direct clutch return spring assembly and some of the seals can be gotten to without much more disassembly then removing the pump assembly, right?

 

[Silverback]

Re: 4L80e Converter

All those "extra" things are for heavy use. :lol:
The one where you put the springs on the direct clutch return spring assembly. That one keeps the directs from partially applying during high rpm use when you are in first and second.

Are we talking high rpm like the set of springs to swap in the 700r4 transgo kit that don’t really make a difference unless you’re shifting >7k or are we talking high rpm normal engine speeds like >4500rpm?

That wider retaining ring for the intermediate(sencond gear) stack, keeps you from blowing out the case lugs in 2nd.

yea, that one is pretty self explanatory in the instructions and I’ve seen the lug tightening/repair kits for them.

I also recommend removing the waved cushion plate down inside of the 2nd clutch. It's the one that sits on the aluminum piston on the center support.

I don’t have the instructions in front of me right now but isn’t that the one that the instructions say not to remove? Why would or wouldn’t I want to do it?

It will take you a LONG time to do the kit.

heh, it took me a long time to do the full 700 kit probably 2 nights… since I’m not really a tranny guy and anal retentive I usually repeat each step (read and at least the first time I did one also look at the tape) before AND after actually doing it to make sure that I got it right and didn’t miss something. Honestly, the last thing I want to do is to have to pull the thing and have to do it again.

Oh, and after lifting that sucker out of the truck and carrying it across the yard today, that goes double for this monster. I’m 6’4”, 305lbs and a bit of a freak, and my wife was laughing at me imitating my grunting and groaning with the tranny mount bolt digging into one hand and the bellhousing trying to slip out of the other, “hey, at least you know that no one is going to steal it while we’re at the store, who else will pick it up and carry it that far?” Grrrr…

One thing I have noticed is that the reverse slam safety mod has required me to file/sand the end of the filter down where the roll pin goes. You know, the one at the end of the manual shift valve?

huh, yea, not yet, but I’m getting the impression that I will…

Don't take short cuts. Do all the stuff except the "command shift".

why not do the command shift? I’ve done it on every other transgo kit I’ve done. It only recommends not doing it for work trucks and similar vehicles. I have been wondering if any of these changes will have a negative impact on being able to do the “paddle shifter” thing with this transmission…

I'd also put in the sonnax wide stator bushing and the transgo heat ring kit. Really easy to install.

More stuff to get in next week… oh well, at least it should be cheap stuff… didn’t have time to dig into this week anyway, actually, probably won’t touch this till the day after thanksgiving…

Use the forged clutch hub from sonnax. It's pretty cheap if you get it from Transtar.
I used the red clutch kits that are specific to the 4L80E's made by Alto. I've used BW for the Overrun and OD. Raybestos make blues for the overrun and OD though. They are the Gen2's. Very expensive.
Make sure it has the 34 element sprag and use the transgo thrust washer kit. It gets rid of all the plastic thrust washers and replaces them with bronze. Nice kit.

Ok, here we’re getting into a basic rebuild… more then I’m doing at this point unless I actually find something wrong with whatever was done with it so far.

You should have a fairly indestructable trans at this point.
Only weak spot then will be the input shaft. Get the stock one cryo'd or get the billet one from Transmission Center. You shouldn't need it though unless you are running a lot of nitrous with a high HP(1000 HP or more with your 3700 pound vehicle).
Every planetary failure I've been fortunate enough to see has been from lack of lube. I'd highly recommend one of the later units that has the lube fitting toward the back. If yours has it, your very lucky.

’94… I doubt it. At this point I’ve got something that should live longer then my short block, which I suspect is going to be my next weakest link and when that lets go I’m betting that I’ll have an opportunity to pull the tranny the easy way (slide it forward in the tranny tunnel without the engine in the way) to freshen it up.

What I would do on drilling the orifices is do them at .100" if you have the drill bit for it.
Then use the software to increase the pressure. You can increase pressure but you don't want to make it shift too firm and then waste your clutches because you have to decrease pressure to make it drivable. Increasing orifice size does NOT increase pressure, it increase the RATE that the clutch pack engages when called for. You can always make the holes bigger later on but you can't go backward. Does that make sense?

Increasing the oraface size increases how much fluid flow you get, so that it does it’s deal faster. Increasing line pressure through programming does not change fluid flow (well, as much ) so it doesn’t really change how fast the clutches are applied but how hard they are applied.

I think I understand.

Using that logic it seems like maybe I should go with the standard or firm range (say around .090”) and if I want firmer engagement I can do it in software, UNLESS that would be getting me into a pressure range where I’ll be prone to damaging things.

Note to self: replace drill bits brother broke last time, will need more then what is in the transgo box

Something I'll pass along is that the bands are not used unless you are in reverse, manual low and manual 2nd. If you put it in OD and take off, the bands are not used.

it says that in the transgo instructions also. Actually, in the transgo instructions it says that it does not use the bands in D and OD

What does it do when doing the electronic triggered shifting?

Is this something I’m shooting for or something to avoid? I know on the 700r4 the 2-4 band is the major headache, tends to damage the drum, warp things, loose the end pin.

Since I’m a total 4L80e noobie I’m not sure what I want, so your “do this, it will do this” responses are EXTREMELY helpful, especially since me being me, I’ll probably pound my head against this (I know, a wrench works better for most mechanical parts) till it makes perfect sense to me so I can make my own decisions based on what it does and what I want it to do, rather then “everyone says that I should do it so I will” and then spend the rest of the time with the thing wondering why it does X if that is something that I made it do by blindly following directions.

 

[Crimson93Ty]

Re: 4L80e Converter

The springs work 2 fold. High rpm is 5.5K and up. What happens is the fluid, through centripital force, pushes the piston up and the clutches will drag, shortening their life. The other thing they do is allow a crisp release of the clutches. Again no drag.

That waved plate removal is something I do. It cushions the shift into 2nd. Sounds like you don't want your shifts cushioned. I don't either. If I remember correctly, the 2nd band engages as soon as you put it into manual 2nd. And then releases when it goes into 3rd. So your not grabbing a part spinning at thousands of rpm trying to stop it. It holds, trans goes out of 2nd then releases before 3rd gear. The reverse band is the same way. Put it in reverse, band applies. Manual low band applies. Anything else no band. Much better design than the 700 IMO. I've talked with Rossler before and he highly recommends no downshifting when racing. Let it shift up, put the pedal to the floor. Of course that is drag racing. Hopefully on a road course, you've got upgraded brakes and the vehicle is slowing and a downshift isn't making the trans do all the work.

The command shift will allow you to downshift at ANY rpm and speed. So you'll be headed down the road, mean to shift it into 3rd and accidently pull it into 1st. Guess what? This kit will let you do it and you will blow your engine apart. I just avoid the possible ability for someone to blow up their engine and blame the trans when it was operator error. :rant:

If your just doing a basic build, just do the kit and do the steps for the pump. Don't use screwdrivers, make a puller or borrow one.
Get an ATSG and go through it. You'll find that this trans is easier than the 700. Only querk is you need to set front and rear unit endplay whereas the 700 just has the total unit endplay to worry about. The parts are just heavier in the 4L80. It's hard to believe the 700 planetaries hold together as well as they do when you compare them to a TH400/4L80.

Nothing wrong with repeating the steps. It's yours. That way you know its right.

I'm with you. I can throw 700s around. First time I grabbed a 4L80E, I thought I blew something out my backside. Not to self, never move a junk yard unit with the converter in it. You can strap them to a dolley to move them. I took a 4x4 and drilled a hole through the middle so the output shaft could just hang.

You've got the feed orifice deal. :tup:

 

[myclone]

Re: 4L80e Converter

I can throw 700s around. First time I grabbed a 4L80E, I thought I blew something out my backside. Not to self, never move a junk yard unit with the converter in it.

LOL... Youre not the only one that found that out the hard way.

 

[Silverback]

Re: 4L80e Converter

The command shift will allow you to downshift at ANY rpm and speed. So you'll be headed down the road, mean to shift it into 3rd and accidently pull it into 1st. Guess what? This kit will let you do it and you will blow your engine apart. I just avoid the possible ability for someone to blow up their engine and blame the trans when it was operator error. :rant:

Sounds like more of a CYA thing then anything else… I’m somewhat conserned that if I don’t do it I might end up in a situation that it really should downshift and it won’t. Is this controllable through programming?

I'm with you. I can throw 700s around. First time I grabbed a 4L80E, I thought I blew something out my backside. Not to self, never move a junk yard unit with the converter in it. You can strap them to a dolley to move them. I took a 4x4 and drilled a hole through the middle so the output shaft could just hang.

I don’t think I’m following, do you mean that you strap it to the dolly output shaft down?

You've got the feed orifice deal. :tup:

You know, you gave the bet explanation of what is going on there that I have ever heard.

Now the $64,000 question, do you think that something along the lines of a .090” hole (or whatever the closest drill bit size to that that I can find) would keep me happy or am I going to be pulling it apart right away and going with your suggested .100” (I actually don’t mind the firm 1-2 shift that the typical 700 has, and hate the soft 2-3 shift they have)? At this point I think I want maximum durability, if that compromises shift feel on the too harsh or too soft side I’ll live with it, I just don’t want to be breaking things. Max durability usually implies some compromise between aggressive engagement (keep the clutches from wearing and even heating up as fast) but not so hard that you start breaking hard parts. Unfortunately, I don’t have a good feel for how hard is too hard, just that I’m better at breaking axles/gears then anyone I know (the Moser 9” with 35 spline axles that is going in should fix that).

Are these passages also used to drain?

 

[Silverback]

Re: 4L80e Converter

How heavy is the converter? I've got mine strapped to the front of the trans to protect the input shaft...

 

['JustDreamin']

Re: 4L80e Converter

Just FYI

#45 drill bit = .0820"
#44 drill bit = .0860"
#43 drill bit = .0890"
#42 drill bit = .0935"
3/32" drill bit = .0938"
#41 drill bit = .0960"
#40 drill bit = .0980"
2.5mm drill bit = .0984"
#39 drill bit = .0995"
#38 drill bit = .1015"

7/64" drill bit = .1094"


Of those, the 3/32" drill bit is probably the easiest to find (or maybe not if your drill index looks anything like mine and all the popular sizes are either broken or missing). Also note, that most drills don't drill exactly on size. They're usually a little oversized (so a .0935" drill bit may actually create an .095" hole, but it depends upon a bunch of stuff, including material and drilling pressure). If you need absolutely dead on size (which I don't think is the case here), use a reamer, that's what they're for.

'JustDreamin'

 

[Crimson93Ty]

Re: 4L80e Converter

That's what I did. My #40 actually drills .100". I took a micrometer and checked the chuck end vs the cutting end and found slight variations in my set and #40 actually gave me what I needed.
As far as shift firmness, it is all to taste. Your opinion of "hard" might be another guy's "firm". You'll have to tailor it to what you want. You can boost pressure a little bit on the tables in the TCI controller because it has a WOT setting and it will change the feel "some".
The huge difference you will see in the 4L60 vs the 4L80 is the gear ratio change.
In the 4L60 your dropping from a big 3.06 to a 1.63. That's what causes the "BANG".
4L80 your only going from a 2.48 to a 1.48. You won't burn the tires off of it now(as bad) when you launch.
Since it's not such a large change, you don't get the big thud and you spend longer in 1st. So you get more time in the powerband. I personally believe that is the reason the trans swap that Jeremy did resulted in the better performance despite that slight increase in weight. IMHO the weight difference is HIGHLY overexaggerated. The only thing I believe as far as the weight is concerned is that a 13" converter will kill performance. Use a 10.5" or smaller diameter converter.
As far as the CYA on the "command shift".....when doing your own, you have yourself to blame, no one else. When you do one for a buddy who doesn't understand and revs it to 8000 rpm and blows a crank, it is then "my" fault because I made it so he could do that....as weird as that mentality sounds, that is what happens. Just make it "idiot" proof as much as possible.
Seat of the pants feel to me is that the 13" converter weighed almost as much as the transfer case I picked up the same day. Many guys have told me not to move transmissions with the converter on the end because there is no flywheel to support it causing excess strain on the pump, stator and input shaft. You do what is most practical for you though. Yeah, I just move mine around on a dolley, output shaft down with a towel under it to catch anything that comes out(I drain them first).

 

[Silverback]

Re: 4L80e Converter

If your just doing a basic build, just do the kit and do the steps for the pump. Don't use screwdrivers, make a puller or borrow one.

Ok, looking at the last page:

if I’m understanding it looks like you’re suggesting doing 3, 4, 5, but also telling me that if I can handle a 700 that going completely through a 4L80e should be a relative piece of cake.

Get an ATSG and go through it.

dumb question, where do I get one? Is this the deal that tansgo sells for it as documentation (something like 30 pages or so)? All the other trannies I’ve ever messed with have had penty of info online, this one doesn’t, like I said, I haven’t even found a good blow up drawing of it.

As far as the CYA on the "command shift".....when doing your own, you have yourself to blame, no one else. When you do one for a buddy who doesn't understand and revs it to 8000 rpm and blows a crank, it is then "my" fault because I made it so he could do that....as weird as that mentality sounds, that is what happens. Just make it "idiot" proof as much as possible.

Oh, I totally understand, but I also tend to subscribe to the “if I did something dumb it’s my fault, and if you’re an idiot I can’t really do anything about it besides hopefully letting you take yourself out of the gene pool before you procreate.” I just wanted to make sure that there wasn’t something there besides the CYA bit.

 

[Silverback]

Re: 4L80e Converter

Seat of the pants feel to me is that the 13" converter weighed almost as much as the transfer case I picked up the same day. Many guys have told me not to move transmissions with the converter on the end because there is no flywheel to support it causing excess strain on the pump, stator and input shaft.

Oh, don’t get me wrong, I was having a cow doing it, I thought it was a bad idea but when I bought the thing it actually had a big strap across the bellhousing that looks like it’s going to take a set of bolt cutters to get off, and I really didn’t want to pull a converter while it was on the carpet in my K1500 blazer.

I suspect that when I get the thing off this thing will actually be a piece of cake to move, and I’m not moving it any further then I have without getting that monster off…

This brings us back to my original question:

Use a 10.5" or smaller diameter converter.

Preferences?

JS, you said something about a custom converter, but haven’t given any info…

Right now my top contender is a PI 9.5” with a triple disc clutch, they are recommending a 3200stall, and are saying that it will stall as close to that as the information that I give them is accurate (I was thinking that I really wanted a slightly higher stall, but I’m starting to debate that). I like that the triple disk setup is rated for 1600hp and that’s the weakest part of the thing (I may end up using it since I want to run this car at Maxton). ~2.66 STR

My second place contender is Yank, who are trying to convice me that I’ll be much happier with an 11” converter. I get the impression that is actually the only thing that they can build that will live long tern in this application. It is a single disk that they say is rated at 1000hp but “that I’ll never want to lock it when racing,” I’m not sure why not unless they expect that I’ll break it. They are recommending a 3000 stall supercharged/n2o converter (oh, I don’t know if I mentioned this but that small block also has an N2O setup that I’m not sure if I’m keeping yet), but that “it will probably stall around 3400rpm.” ~2.3 STR. This one will run me about $100 more then the PI.

Protorque took themselves out of contention by not returning anything, not sending anything they were supposed to… TCI seems to want more for their converter then anyone else an it’s rated for the least hp, but interestingly they were recommending something that they thought was going to stall in the low 4000rpm range (really closer to what I expected that everyone else would be recommending for the car)

I’m thinking that the PI is a stronger converter for a better price, but my usual comparison of PI to Yank in the 700’s is that the Yanks tend to hit harder off the line and run a little faster, but I’m not sure that this will be the case here with the bigger diameter converter. The triple disk setup on the PI both sounds like a good idea and worries me a little. I know that some multiple disk setups do rattle some, but the people that I talked to that had that particular converter said that they didn’t notice anything. Yank suggested that the extra drag from the 3disk setup will cause it to run slower. Right now my feeling is that I might gain the typical .2s with the yank (which is tempting) but the “there is no way that I’ll blow it up” and cheaper price of the PI is swaying my decision for now.

 

[JSM]

Re: 4L80e Converter

JS, you said something about a custom converter, but haven’t given any info…

Yes, we have worked with a major company to develop a convertor just for this application.

No I don't plan to share the company name, information. I have been burned in the past on several projects I don't care to open up in public forum. With that said I no longer share information like I once did and would really like.

In that regards the whole community has taken a turn in the wrong direction, but so it goes.

When you invest months developing and testing something, and thousands in development, tooling, etc I have a need to recover those costs in time/$$.

 

['JustDreamin']

Re: 4L80e Converter

ATSG manual for the 80E is about 100 pages, give or take. Available from alot of transmission rebuilders. I ordered mine through Summit, but it was something they had to order. I think Jegs may also stock it.

'JustDreamin'