My stock TCC says DGHG 2025. Doing my research online I figured it means 1400 stall. Here is the article. This article ia about GM Torque converters. Dunno if they have different line for vettes.

According to this article. It is not necessarily 1400, but a range anywhere between 1400 and 1600. All depends on HP/torque of the engine wheel/tire size and rigidity of suspension.

Doing my online research I found that stall number changes performance of the car, but it does it at the cost of MPG. As they say the higher the number then softer it'll shift due to not full contact before "lock up" number. Say TCC is 2800 stall it will lock up at 2800 rpm, therefore will shift softer, but reading reviews... driver have to rev the engine to move the car and it takes more gas and driving becomes more "sport" than "city". Higher number helps to accelerate faster and it multiplies torque better than lower stall number. But again higher rpm higher tranny's temperature - higher chance to loose 3-4 clutch again.
Lower number - won't shift as soft, but it'll lock up, say 1600 rpm. And in normal driving condition as i remember my rpm don't go any higher than 2000, I mean cruising with 55-60 mph or city 0-35 mph, taking in consideration that I'm not stepping on gas pedal, but softly touching. Here in Miami toooooo many cops now.....

As I understood if TCC is 1400 in corvette it'll be actually around 1600. And if TCC is 1600 in vette it'll be ~1800. And so on...

Well here is dilemma: stock or higher number??? What is better? Cons and pros of both?

Correct me if I'm wrong. And I would love to hear some advices and personal experience on torque converters.

About my vette: it is 95 LT-1 and i had 3-4 clutches burned so I rebuilt tranny myself and car is still sitting in the garage for almost 2 years. Now I'm looking forward to put tranny in but need to choose right TCC before. Do not want to risk with my old torque converter since some debris probably got into it and it can ruin my freshly rebuilt tranny. So I'm thinking of upgrading TCC, but need to know how this number affect everything not based on some online articles, but on real experience. Thanks everyone!

 

After I fried the 3-4 pack I had my A4 rebuilt early this year and a 2,400rpm 12" lockup TCC installed (don't know brand) and love the effect.

It's still pretty "streetable" but now really launches hard at the strip but I wouldn't go higher in stall for a street machine.

 

Lots of opinions on this, but in my mind for LT1s the stall should be over 2000 no question. I would not go more than 2400 in my own machine if I were driving it daily though. I just dont like the way the transmission feels. I don't think you'll find a significant difference in mpg.

 

I run a 2800rpm 9.5 in lockup converter in my street car. Love it, just make sure you install a nice sized tranny cooler and you will most likely have no issues.

 

I agree. But not from 1st hand experience.
I have sold many in the 2600-2800 range for LT1 cars with mild mods, and the feedback I received has been excellent.
If it is a 9.5incher, it will be about 14 pound lighter than stock, and very efficient. It will almost feel stock in normal driving, but turn into an animal when smashing it from a dead stop, or a kickdown.

 

Pete K's 2800 9-1/2" converter... best performance mod that I have made and very street friendly

 

Used these guys for several blue ovals and a TC for the Vette...

http://www.phoenixtrans.com/

 

See what I mean
Thanks Tony!

 

It seems that the most recommended is 2000-2600.

What is ALMOST stock in normal driving?

How does it feels? RPM higher? Do you need to push gas pedal more with higher number?

Why 2000+ is better than any?
What are the "symptoms" if i go with lower number or higher number?

 

There is no way to exactly describe the differences. It is subjective to the driver. Extra stall is extra slippage, therfore extra rpm. The efficiency of the converter affects the feel (or slushyness) of a converter.
a 9.5 inch converter will almost always feel "tighter" than an equal stall 12 inch converter.
Remember that when a converter locks up, all slippage goes away, and the internals are locked 1:1.
Best advice is to drive some cars with different stall converters.

My newest converter (in my car) foot brakes to about 2500 rpm, but flashes to about 3100 or so. I wish I went higher because it feels so nice on the street.

 

its like an oar in the water, with the oar, angled less than 90 degrees, you will compromise propulsion, and so you apply more effort to motion the same amount, for engines modified to operate at higher rpm, the "slip" provides a pathway to get to the "optimal" power bandwith sooner and not get bogged down by splashing around in an rpm range it has trouble getting out of.

I have a 2100, and flashes to 2600 or so, a tad too slippery, rear gears and your mods plays a major role, from what i have seen, and told by my shop, (800hp) supercharged GXP, stock stall is fine for the street and you can play with your tune to dial it in. my 2 cents anyways.

If I can do it all over again, I would go with a 1700 instead

 

So if you transfer the idea to manual transmission - instead of shifting on 2000 it'll shift on 3000 therefore more torque on wheels?

Unfortunately I don't have an option of driving 'vettes with different torque converters.

foot brakes at 2500 - which one you have 9.5" and stall 2400? But you have a lot of mods on your vette...

Why is it feels nice on the street? Smooth shift? If you drive slow would it shift before reaching 2400 rpm?

 

Yeah, mine is not 800 hp.
How can I tune TCC?

WHY?

 

My shop's car is the GXP not me, me only 500hp

I don't race,but drive aggressive rarely anymore and I played with my timing and fueling to where the slipping seemed less apparent, the slipping generates heats, which kills stuff.

slips more than my liking and gas mileage sucks

the converter clutch can be manipulated to behave a certain way; locked or unlocked in differing driving scenarios, in your bin file, my guess (don't know) if you have a 4L60e, then shift points as well.

you will need to add a cooler for the slipping stall, yet another expense, what are you mods going to be??????, determine it's final configuration, then decide on the stall, I heard you can have fun with stall without mods, this you must search in the archives.

if you are not going to modify the car, and the car is in tip top shape I say leave sleeping dogs lay, and save the money, spend it on your wife and kids.

 

Stall speed is the speed that the internal impeller comes up to the same speed as the fixed impeller, welded to the converter shell.
It does not compare to a stick. If you have a 3000 rpm stall speed, it mean that the floating stator comes up to speed at approx 3000, thus stall.
Your car will still move from idle speed and up, but the rpms will climb a little, sort of like slipping a clutch in a stick car.
Shift point are not affected by the torque converter, that happens via the governor, and the governor works with rpm, centrifical force and line pressure to force a part or full throttle shift.

 

If you have a stock to slightly modified lt1 or plan on doing mods down the road I would use at least a 2600 stall,you really can't tell the difference between stock once you start driving with it and your mileage won't suffer to bad.I have had a 2600 and currently have a 3000 and love it and my latest mileage was 15.6 a gal.,not too shabby for lt4 heads and hot cam and thats for around town not highway.Highly recommend a vigalante or a yank convertor they are the best out there. good luck

 

true! especially in South Florida.

No mods so far. I don't really know what counts for mod. I did change some parts before, including inside tranny. And I still have to change distributor and all spark wires.

Well, no wife and kids yet, but student loans. I don't think it is a good idea to install TCC that might have some debris from my fried 3-4 clutch. And I so do not want to dismount tranny again if TCC fails or 3-4 clutch again.. vette has been standing in the garage for too long. I was thinking it will be same money for me to get new TCC. With all this car insurance registration and parking prices then time put in in mount dismount all that stuff...

It seems that everyone is suggesting numbers higher than 1400.

Your recommendation is 1700? It is street drivable and doesn't overheat and no MPG increase?

 

Thank you for explanation! Reading your post and looking at TCC diagram I understand it better now.

So let's say i have 2200-2400 stall. I drive slowly, tranny tends to shift at ~2000 rpm. It shift and shifts softer than on 1400TCC(stock) but I have to add a tiny bit more gas cause TCC is not locked up at 2000 rpm. But it does multiply torque on rear wheels with all this impellers before it reaches its stall 1:1? But doesn't it add a lot of friction if parts are ALMOST touching each other? Or it's mostly on fluid movement?

And if I'll smash gas. With throttle wide open tranny tends to shift anywhere from ~3000 to ~4000 rpm. At this point engine has more torque and when it shift TCC locked up but it gives it some time to reach it's effective RPM's.

According to many comments, with stall 2000-2600 I won't loose normal street driving won't gain much heat and won't loose much MPG, but at the same time if I'll floor it it'll be the beast!

 

I guess I have stock. And this is my daily ride. Wouldn't 3000 or 2600 be a little too performance?

I agree mileage not bad, I don't really remember my MPG number. I remember when I was driving to key west it reached 33MPG ( I have video ), but in city it was about 14 to 18. Sometimes 11. May be wrong...

How does it feels when you accelerate slowly in 30 or 45 MPH zone with 3000 stall? ( taking in consideration that you obey speed limit )
I mean comparing to stock. I have driver stock and manual vette. So I can compare. How it shifts, what is tranny temp in your vette in city driving?

Well again it is my everyday car and I'm afraid that it would be not street friendly with high stall number.

 

I will give you my opinion. That opinion is based on my personal preference (primarily) and the feedback i get from others. Keep in mind I am very conservative, and normally suggest less stall speed, camshaft, compression ratio etc. In the performance world (again, my opinion) to error on the small side is preferred.
For your car, I would suggest a 9.5 inch, 2600 stall speed.
From a red light, stop sign etc, it will feel stock.
When you drive it hard, it will flash nicely, giving you instant throttle response.

The preferred size is 9.5 inch

A 12 inch converter with 2600 stall is not as "tight" as a 9.5 inch with the same stall speed.
A 9.5 incher is 14 pounds lighter.
Both contribute to drivability, and accelleration.

Keep in mind though there are always con's in any performance mod.

Smaller size means less fluid capacity. About 2 quarts less in a 10 qt system.
Added stall combinded with smaller capacity = more heat.
I would recommend an inexpensive cooler, and a deeper pan to remove the extra heat you will make (or cannot shed due to the smaller system capacity).
2 inexpensive mods that counteract the "cons".

For a builder to make the correct stall, he needs to know as much of the following as possible:
Vehicle weight
Rear end gear ratio
Approx hp and torque at the flexplate
Desired stall
Cam duration on the intake @ .050

Correct inputs in the formula, enable to builder to achieve the correct output (stall).

Take a ride up to Boyton Beach. Maybe toptechx6 will take you for a ride. He is running one of my 3000 stall converters.