Getting a cheap converter to live
Thread Starter
TECH Junkie
Joined: Dec 2012
Posts: 3,614
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From: Iowa
Getting a cheap converter to live Ok, before I get flamed for this, I'm going to start out with a couple notes.
First off, this is not for me. Secondly, I know that a converter is not a place that it makes sense to skimp on. Some people will spend 10k on an engine, heads, cam, etc, for top of the line stuff, then look at converters and figure they're all the same. This is more of a "CAN I" rather than a "SHOULD I" conversation.
Now into the business. I know it's a consensus on here that cheap converters are easily identifiable as a small diameter converter with an adapter ring welded on to match the LS flexplate bolt pattern. They are typically re-stalled caviler cores which have terribly small lockup clutches that simply won't hold up to our car's torque.
My question is, why couldn't you make it live. There are people that street non-lockup th400's all the time. Why couldn't you adjust the tcc tables to only lockup under absolutely ideal conditions (or maybe never at all) and when it does install, make sure it's tuned to get all the pressure it can.
I don't think there's anything wrong with using the 10" body of the converter, and if you can crutch the lockup so it doesn't tear itself apart and plug the valvebody full of clutch material, why wouldn't you be able to get away with a 4k stall for $400 rather than $800 for a billet front unit?
Has anyone tried this? any thoughts?
First off, this is not for me. Secondly, I know that a converter is not a place that it makes sense to skimp on. Some people will spend 10k on an engine, heads, cam, etc, for top of the line stuff, then look at converters and figure they're all the same. This is more of a "CAN I" rather than a "SHOULD I" conversation.
Now into the business. I know it's a consensus on here that cheap converters are easily identifiable as a small diameter converter with an adapter ring welded on to match the LS flexplate bolt pattern. They are typically re-stalled caviler cores which have terribly small lockup clutches that simply won't hold up to our car's torque.
My question is, why couldn't you make it live. There are people that street non-lockup th400's all the time. Why couldn't you adjust the tcc tables to only lockup under absolutely ideal conditions (or maybe never at all) and when it does install, make sure it's tuned to get all the pressure it can.
I don't think there's anything wrong with using the 10" body of the converter, and if you can crutch the lockup so it doesn't tear itself apart and plug the valvebody full of clutch material, why wouldn't you be able to get away with a 4k stall for $400 rather than $800 for a billet front unit?
Has anyone tried this? any thoughts?
I ran a $200 Revmax converter for a few years and several thousand miles behind a 370rwhp engine (and later a 450rwhp engine). That car was used daily as a fun driver, but also took it to the drag strip and even some road course HPDE events. So it lived a pretty harsh life, especially being beat on constantly for 20 minutes straight on a track.
I didn't have a single issue with that unit. Maybe it was luck, but it worked for me.
Looking back I probably wouldn't go with a $200 unit again, but there's nothing wrong with most of the budget converters in the $400 range.
I didn't have a single issue with that unit. Maybe it was luck, but it worked for me.
Looking back I probably wouldn't go with a $200 unit again, but there's nothing wrong with most of the budget converters in the $400 range.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
TH350/400 aren't really the same situation as there is no overdrive, which is where lock-up tends to help most by reducing heat generation under this type of load. If you only allow lock-up under the most ideal possible conditions to crutch a weak TCC, you'll be missing most of that benefit (vs. stock TCC lock-up parameters.) Lock-up was introduced prior to the OD automatic (TH350-C), but it's not a critical component for a non-OD trans.
just swapped out my Daaco 2800 converter for a Yank SS3600. Had a pump blow up so did the swap instead of getting the Daaco cut and cleaned. Actually don't notice a huge change between the two except for the clutch, the Yank clutch seems like it grabs a lot harder but never had an issue with the Daaco clutch.
Thread Starter
TECH Junkie
Joined: Dec 2012
Posts: 3,614
Likes: 1,326
From: Iowa
TH350/400 aren't really the same situation as there is no overdrive, which is where lock-up tends to help most by reducing heat generation under this type of load. If you only allow lock-up under the most ideal possible conditions to crutch a weak TCC, you'll be missing most of that benefit (vs. stock TCC lock-up parameters.) Lock-up was introduced prior to the OD automatic (TH350-C), but it's not a critical component for a non-OD trans.
Even without ever locking it up, I still don't see the loss really. If you have non-lockup in a th400 at 1:1, surely non lockup at .7:1 would be better for cruising (although it would generate plenty of heat)
TECH Junkie
Joined: May 2012
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From: Poplarville, MS
I can't recall anyone streeting a daily driven 3600 to 4600 stall converter in a th350 or 400. The heat that much stall would put out in a non-lockup converter would kill the trans pretty fast. The lockup figure on the overdrive transmissions is what allows such high stall converters to be street driven. Just a question, is the TCC clutch the only problem with the cheap converters? My $300 TCI 10” converter only lasted 2 months before a bearing in the converter failed trashing the converter and my new trans. By the way TCI would not warranty the converter.
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From: Schiller Park, ILL Member: #317
You're right that OD will obviously still produce lower rpms for cruising, but the bolded part would be my main concern.
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Verdad Gallardo Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
I can't recall anyone streeting a daily driven 3600 to 4600 stall converter in a th350 or 400. The heat that much stall would put out in a non-lockup converter would kill the trans pretty fast. The lockup figure on the overdrive transmissions is what allows such high stall converters to be street driven. Just a question, is the TCC clutch the only problem with the cheap converters? My $300 TCI 10” converter only lasted 2 months before a bearing in the converter failed trashing the converter and my new trans. By the way TCI would not warranty the converter.
As for modern OD transmissions, heat generated by slip makes the the lock-up feature more critical when operated in overdrive range, especially with higher stall speeds.
Thread Starter
TECH Junkie
Joined: Dec 2012
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From: Iowa
Despite the massive heat generation, I would think it could be battled well enough. A large cooler with a dedicated fan, finned deep pan, and DEX VI, I don't see it being an issue.
Since installing my simple cooler with no fan, in front of the radiator, I haven't seen temps get above 170 even with a big stall and some very very hilly driving.
RPM I too know a couple guys that drive theirs on the street all the time. Mainly on 20-40 minute highway trips on cruise nights, poker runs, etc. So it definitely can be done.
As far as the rest of the quality, I'm sorry to hear that. Even a stock rebuilt unit shouldn't have bearing issues unless there were other circumstances that put way more stress on them than normal.
Since installing my simple cooler with no fan, in front of the radiator, I haven't seen temps get above 170 even with a big stall and some very very hilly driving.
RPM I too know a couple guys that drive theirs on the street all the time. Mainly on 20-40 minute highway trips on cruise nights, poker runs, etc. So it definitely can be done.
As far as the rest of the quality, I'm sorry to hear that. Even a stock rebuilt unit shouldn't have bearing issues unless there were other circumstances that put way more stress on them than normal.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
To answer your question, yes. Reduce load on the smaller clutch is ideal. Also, commanding a solid lockup, taking the slip away thats programmed into the tune is good also.
Thread Starter
TECH Junkie
Joined: Dec 2012
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From: Iowa
I tried this out today just to get an Idea of the temps the trans would experience. I disabled torque converter lockup and drove my normal 18 mile route to work. cruising in 4th at around 72, the tach showed around 2300 rpm. Not bad, but not quite that 1950 i'm used to seeing. Anyhow, the temps never got above 140. Granted it was a chilly morning for us this time of year (about 60-65) but still, I had LOADS of insurance room with it staying that cool. And I just have a single cooler with no fan. So, even though heat is an issue, it looks like you could fight it off.
Thanks for all the replys guys, looks like a 10" converter can be made to last if you're willing to work to make it do so.
Thanks for all the replys guys, looks like a 10" converter can be made to last if you're willing to work to make it do so.
Joined: Nov 2001
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From: Schiller Park, ILL Member: #317
This might not be a concern in IA, but uphill cruising might have resulted in some different temps - especially in hot weather.
All that's really been discussed is TCC though, "can it to live", etc. In my experience, cheaper converters tend to feel much looser than they actually are (inferior driveability); they usually offer poor efficiency in comparison (judging by increased trap speeds with better units of similar stall speeds.) With a top shelf unit, I feel that you're getting more than just a better TCC. Longevity certainly isn't the only factor to consider when selecting a converter or justifying cost.
All that's really been discussed is TCC though, "can it to live", etc. In my experience, cheaper converters tend to feel much looser than they actually are (inferior driveability); they usually offer poor efficiency in comparison (judging by increased trap speeds with better units of similar stall speeds.) With a top shelf unit, I feel that you're getting more than just a better TCC. Longevity certainly isn't the only factor to consider when selecting a converter or justifying cost.
Thread Starter
TECH Junkie
Joined: Dec 2012
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From: Iowa
Absolutely agree with that!! A higher dollar unit will be more efficient for sure. But for the guy building a junkyard car, wanting to save every penny they can, this might be an option.
Joined: Aug 2007
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From: Turnin' Wrenches Infractions: 005
Trans temps scorch around here even with lockup. I wouldnt dream of not having it. Temps really stabilize when you get to a comfortable cruising speed.
There is a huge amount of misinformation out there about converters.
The difference between a cheap "ring kit" converter and a higher end billet converter is primarily the clutch lockup area.
A very nice converter can be built using the ring kit that is just as efficient as a much more expensive setup. In my experience, seeing inside many of the various converters out there, many of the billet setups are nothing more than a stock core with the billet "kit" installed. No sprag upgrade, no tig welded fins, even if advertised as such.
There's cheap 10" converters and there's cheap 10"
converters, and some are just too cheap while others
can live just fine (and you will not find great agreement
on this latter, which and whether, although there are
some which people agree just plain suck.
Like TCI Streetfighter series. But my Fuddle custom,
not much more $ and generally disparaged, has been
good and tough (even pulling in at full power lockup,
although once was enough to show it wasn't any help).
Everybody says "you get what you pay for" but that
is folklore, reality could go either way. Got to get to
the specifics of the piece and how you help it stay
in its "happy place" and not sand down the clutch by
making it try and fail where it's incapable.
converters, and some are just too cheap while others
can live just fine (and you will not find great agreement
on this latter, which and whether, although there are
some which people agree just plain suck.
Like TCI Streetfighter series. But my Fuddle custom,
not much more $ and generally disparaged, has been
good and tough (even pulling in at full power lockup,
although once was enough to show it wasn't any help).
Everybody says "you get what you pay for" but that
is folklore, reality could go either way. Got to get to
the specifics of the piece and how you help it stay
in its "happy place" and not sand down the clutch by
making it try and fail where it's incapable.
I've always ran TCI in my th400's and a friend of mine always ran B&M. In fact I ran the same TCI Street Fighter for 8 years behind a big block while my friend had at least 3 B&M's fail behind small blocks.
I remember taking a B&M out of the box for him one day and almost cutting my hand from a spot on the converter where it looked like it slid across a concrete floor. If they don't care what the outside looks like why do they care about what the inside looks like, no one can see the inside so who knows.
The part of the lock up and clutch slipping, it's going to want to slip if you have a 4k stall speed and you cruise down the highway with it. Sure it can be tuned to unlock instead of slip, but whats better it's going to slip during the apply.
I would buy a converter with no lock up clutch and a TransGo 4L6-CCV, this way you have an overdrive with non overdrive converter that flows more oil and doesn't rely on lock up to stay cool.
Otherwise I just don't see the point of a $400 converter, if it fails you either buy another $400 converter and have the $800 investment with a $400 converter still or realize a $400 converter was actually a bad idea and get a $800 converter having spent $1200 to get there.
I remember taking a B&M out of the box for him one day and almost cutting my hand from a spot on the converter where it looked like it slid across a concrete floor. If they don't care what the outside looks like why do they care about what the inside looks like, no one can see the inside so who knows.
The part of the lock up and clutch slipping, it's going to want to slip if you have a 4k stall speed and you cruise down the highway with it. Sure it can be tuned to unlock instead of slip, but whats better it's going to slip during the apply.
I would buy a converter with no lock up clutch and a TransGo 4L6-CCV, this way you have an overdrive with non overdrive converter that flows more oil and doesn't rely on lock up to stay cool.
Otherwise I just don't see the point of a $400 converter, if it fails you either buy another $400 converter and have the $800 investment with a $400 converter still or realize a $400 converter was actually a bad idea and get a $800 converter having spent $1200 to get there.
TECH Fanatic
Joined: May 2016
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From: St. Louis
We disabled the PWM in the tune so it's basically on or off and it only locks up in 4th above 45mph or so. We also set it to only stay engaged under light throttle to keep from unduly stressing the clutch. It's taken a little getting used to driving this way but it's not a big deal. I put maybe 2-3 thousand miles a year on the car so as long as it runs good at the track I'm happy with it. That being said I haven't made any passes with it yet but I'm hoping for some good times!