Converter 101!

[jbradsh1]

So for us beginners, can someone explain how a higher stall torque converter benefits performance? I understand that the stock G8 converter is a 1700, but I've heard mentioned a 2400, a 2800, a 3000, a 3200, and a 3600. What benefit do you get as you go up in number and why get one at all for that matter? If anyone can explain this it would be a big help without being too technical that is.

Kooks shorties + high flow cats, VMS tune, hsrk, R-F

[GRRRR8]

A stall lets the car launch at a higher rpm getting it to and help keeping it in its power band easier.

[99-LS1-SS]

This is from Yank Converters website.
http://www.converter.cc/faq/

I've taken some out for the sake of space.

What will a higher stall torque converter do for my car?

A higher stall torque converter will multiply the torque of your engine to put more power and torque to the tires! The high stall torque converter will "slip" the engine into a higher rpm range where there is more torque and horsepower. This will make your car haul ass!


What kind of performance gains will I see with a high stall torque converter?

Our customers typically see a .5 reduction in quarter mile times, traction permitting. Highly modified cars with ported heads and bigger cams have seen gains of over 1 second!


What is the difference between "brake stall" and "flash stall"?

Flash stall is the maximum your engine's torque can stall a torque converter. In essence flash stall and full stall are nearly identical. If you had a transbrake, you could find full stall by putting your foot to the floor and reading your tach. For argument sake, let's say we're testing a 3500 stall Yank ST 3500. If you had a transbrake, you would see around 3500 rpms. If your motor was at idle and then you suddenly floored the throttle, you might see slightly more (maybe 100 rpm more) stall for a half second as the momentum of the motor's internals "flashed" the converter a small bit above its true stall rating. Brake stall, on the other hand is a very subjective thing. For most, it's the highest stall you can achieve before your tires spin. This varies greatly based on many factors: Traction, gearing, brake clamping force, and engine torque. With a ST3500, I may only be able to get 2200rpm "brake stall" on the street with street tires...any higher rpm and the motor torque would overwhelm the tires. But if I was at the track with racing slicks on the starting line, I might be able to get 3200 brake stall before the motor torque overwhelmed the tires. See...brake stall is very subjective. Yank rates their converters based on their intended application. A ST 3500 will stall 3500 rpms in a stock LS1. If you had a 422 and wanted a ST 3500, the converter you received would still stall 3500 because it would be built around the torque of a 422, not a stock displacement LS1. Yank checks the stall of their converters and their competitors by using either a trasmission dyno or a "tranny tricker" in the vehicle tested. With the tranny tricker, you can place the vehicle in 2nd or 3rd gear and stab the throttle to the floor...making it easy to read both flash stall and full stall.


What will happen to my fuel economy?

Very little. If your vehicle originally came with a lock-up clutch, your Yank Performance Converter would also have a lock-up clutch. You may need to apply slightly more throttle for driving around town, but you should not see a noticeable drop in fuel economy.


Which converter should I choose?

This explanation is so long I'm making a link to it. Click Here (http://www.converter.cc/faq/#7)


How am I able to reduce my ET while at the same time, increase my finish line mph and rear wheel horsepower?

The superior design of the Yank Performance Converter adds a great deal of efficiency over the stock converter and our competitor's offerings. Our 265mm and 258mm converter housings are based on 1990's General Motors torque converters. These converters have come light years ahead in efficiency compared to those used so often by our competition. The tight tolerances between the pump, turbine, and stator are critical to maintaining a high degree of efficiency and reducing internal heat buildup.


Is a transmission cooler needed with my Yank high stall converter?

Not typically with the street strip converters below 3000 stall. The superior efficient design of the Yank converters generate less heat than our competitor's offerings, making trans coolers unnecessary in street/strip applications. For more hard-core racing applications (or converters over 3000 stall speed), a trans cooler is always cheap insurance to protect the transmission when "hot-lapping" the car.


Is a shift kit required or recommended?

Yank Performance Converters can achieve maximum performance and efficiency without the use of shift kits. Shift kits dramatically raise transmission line pressure to increase shift firmness. Increased shift firmness will not increase performance, but create unnecessary stress on the transmission and other drive-line components.

[jbradsh1]

Wow! Thanks for the great post. The only thing I didn't fully understand is, believe it or not the word stall, as it's used here. Is that the rpm where the converter fully engages as a clutch would, but slips until that rpm is achieved? Also, it sounds like for a good street car with a mild cam, shorty headers, cai, & tune a 2400 to 2600 stall converter would work well. Or should I go with a 3000 to 3200 stall, figuring around 460 crank horseppower?

[GRRRR8]

2800-3200 is about perfect in a everyday driver.

[jbradsh1]

Good to know. I'm looking at a mild cam along with my current 1,2,4,7. After reading the post from 99-LS1-SS above, what do ya think about the stealth 2600 Yanks?

[99-LS1-SS]

I had a 99 Camaro that had a Yank 2800 in it and it was a good all around converter. Helped performance and still maintained good driving manners.

[GRRRR8]

I had Circle-D build me a converter for my application to get the most out of my combo. You may want to give them a call.

[jetttstream]

I have riden in a Circle-D'd TBSS and it was a great ride, very impressed!

-Mike

[Mike P]

I heart torque converters!


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[jbradsh1]

Thanks everyone for your great responses. From what I've gathered so far, the tq keeps the revs up almost as if you had a clutch and then it fully engages at 2800 or 3000 rpm or whatever tq you have. That about right?

[jbradsh1]

last question Anyone: So if you are running with a hotter cam than stock, that's when the TQ can really help because it helps pick up off the line to help make up for some loss of bottom end torque due to the cam. Is that the case?

[Circle-D]

last question Anyone: So if you are running with a hotter cam than stock, that's when the TQ can really help because it helps pick up off the line to help make up for some loss of bottom end torque due to the cam. Is that the case?

Correct. It puts you in the power band of your motor.

Quick info on converters:

We will talk about flash stall:

This is the RPM at which the converter "flashes" to before the car wants to move. Simple test, go WOT of idle and the tach will immediately jump to a certain RPM and then slowly climb. Sometime traction may be an issue and clouds the data. This is the flash of the converter. When you go to a higher stall converter, your flash is higher. So you will be in a higher RPM before you start to move, meaning more power sooner. That is the beauty of a converter, it does not really add power, just let you use your power more effectively.

Chris

[jbradsh1]

Thanks for the simple and clear explanation. Now I got it.

[99-LS1-SS]

Torque converters can be one of the biggest seat of the pants mods that you can do with the exception of a power adder (turbo, supercharger).

[Mike P]

Torque converters can be one of the biggest seat of the pants mods that you can do with the exception of a power adder (turbo, supercharger).


+1 Amen! :)



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[jbradsh1]

OK, so do you have to install a trans. cooler when you have a converter, say a 2600 - 2800 stall? How's the drivability compared to stock? Does the converter impact transmission life or other driveline components much and if so, how much? As you may be able to tell, I'm sort of on the fence regarding adding a TQ. But, I need the answers to these final questions regarding the TQ to be able to make a decision and so all input is most welcome.

[99-LS1-SS]

With a 2800 I don't think a transmission cooler is necessary. It might not be a bad idea but I think you'll be fine without it. Outside of the performance difference, you'll notice that you'll have to push the gas a little more to get the car moving. Plus if you are on a slight incline you might notice your car will be more likely to roll back when it stayed still with the stock converter. I'm not completely sure how it will affect the transmission life. It didn't seem to bother my transmission and I drove the hell out of my car. I never had any drive train failure either. In my honest opinion, I think you'll be VERY pleased with a 2800 as far as drive-ability and performance. Just make sure you get the car tuned after the install. That is an important part to enjoying your converter.

Hopefully others will chime in.

[jbradsh1]

Interesting. So how does the TQ give increased performance i.e., faster e.t.'s and perhaps more mph at the track? I mean, does it launch the car harder and the upshifts have more snap?

[-Ray-]

The difference between horse power and torque.
Horse power gets you too the wall, torque carries you through it.

[99-LS1-SS]

Torque is the twisting force. The more twisting force that you have the faster a stationary object can get moving. The way I think of it is that torque starts you moving and horsepower speeds you up once you're moving.

I'm going to try to give an analogy using a vehicle with a manual transmission. Think of the stall speed as the RPM that the clutch engages. Since we're talking about a 2800 stall speed we'll use that number. Let's also assume that the stock converter has a stall speed of 1400.

Now if you had a car with a clutch and you launched the car releasing the clutch at 2800 RPMs and you did another launch at 1400 RPMs. Which launch do you think would take off harder? The 2800 RPM launch obviously. It's not a totally accurate analogy but it will give you a mental image so you can understand the way a converter works.

The next benefit is that the 2800 stall converter will drop the RPMs less between gear shifts keeping you in the power band longer. More time in the power band means faster times at the track.

[GeorgeInNePa]

Torque is the twisting force. The more twisting force that you have the faster a stationary object can get moving. The way I think of it is that torque starts you moving and horsepower speeds you up once you're moving.

I'm going to try to give an analogy using a vehicle with a manual transmission. Think of the stall speed as the RPM that the clutch engages. Since we're talking about a 2800 stall speed we'll use that number. Let's also assume that the stock converter has a stall speed of 1400.

Now if you had a car with a clutch and you launched the car releasing the clutch at 2800 RPMs and you did another launch at 1400 RPMs. Which launch do you think would take off harder? The 2800 RPM launch obviously. It's not a totally accurate analogy but it will give you a mental image so you can understand the way a converter works.

The next benefit is that the 2800 stall converter will drop the RPMs less between gear shifts keeping you in the power band longer. More time in the power band means faster times at the track.


Now that I've fixed my shifting and rev limiter problems, I notice that my RPM drops to 4600 after the shift at WOT. That's just about perfect.

I have a Yank 3200.

[jbradsh1]

Torque is the twisting force. The more twisting force that you have the faster a stationary object can get moving. The way I think of it is that torque starts you moving and horsepower speeds you up once you're moving.

I'm going to try to give an analogy using a vehicle with a manual transmission. Think of the stall speed as the RPM that the clutch engages. Since we're talking about a 2800 stall speed we'll use that number. Let's also assume that the stock converter has a stall speed of 1400.

Now if you had a car with a clutch and you launched the car releasing the clutch at 2800 RPMs and you did another launch at 1400 RPMs. Which launch do you think would take off harder? The 2800 RPM launch obviously. It's not a totally accurate analogy but it will give you a mental image so you can understand the way a converter works.

The next benefit is that the 2800 stall converter will drop the RPMs less between gear shifts keeping you in the power band longer. More time in the power band means faster times at the track.

OK. That's just about what I thought. Thanks to everyone. It seems to me that a TQ wouldn't really be necessary but so what performance improvement really is? None are necessary but man are they fun! Does everyone who has a TQ really feel the improvement was worth the expense & labor to install?

[Featherburner]

If you have never ridden in or driven a car with a higher stall converter (and from the sound of it you haven't) I would find someone with a converter and ask for a ride. They are not for everyone. Find out if you'll even like it before you pull the trigger.

[G8GTlawride]

OK. That's just about what I thought. Thanks to everyone. It seems to me that a TQ wouldn't really be necessary but so what performance improvement really is? None are necessary but man are they fun! Does everyone who has a TQ really feel the improvement was worth the expense & labor to install?

High stall speed converters allow the engine to engage in the peak RPM range of the cam that is installed before it locks up. So, with that said, say you had a cam with a peak power range from 3000 RPM. Match the coverters lock up (stall) with the peak power (RPM) produced by the cam and presto, instant off the line launch and peak power from the get go. Simple, yes?

[jbradsh1]

Yes, very, very simple and thanks to both you guys. If I knew of someone that had a TQ in their car I would, but I don't but what you're saying about testing it makes sense. It will be my last mod, if I do it. After the cam. But I do like your description of the effect it has on performance particularly if the cam has been upgraded.

[LDV60]

Nice explanation guys.
Good analogy.

[g8_795]

Couple of questions to add here. Nice descriptions BTW.

How difficult is this for you DIY'ers?

Do I have to completely drop the trans to do this?

Any G8'ers having any problems with there stall?

What trans cooler is everybody using?

Thanks for any info.
-Robert

[Got 8?]

Ok when I had my truck I put in a pretty healthy cam for a 5.3 (222/224 .566 .568 on a 112LSA) and I drove around on it like that for awhile. So after I saved up some cash and I found a good deal I got a converter. Here is the driving impressions: Simply put I could drive around no problem with the cam in and even pulled a 4000 pound boat to the water and yank it out of the water no problem even though some said " it won't pull down low and you'll lose power down low". Now after the converter (Yank TT3000) I could no longer go full throttle from a stop or from a roll under 30mph, for that matter, without liquefying the Yokohamas on the street or track and had to get slicks for the track to get a good launch to get my ET's down. Plain and simple...

And with the way I designed the tranny would even scratch third gear at the 1000ft mark (yeah I didn't believe it either till I reviewed the tape...). So IMHO if absolute performance is what you want get the converter and if you want something that drives close to stock get a Yank, if you want something that will hit the tires extremely hard and slips a little more get a P.I. Vig.

[Mike P]

Ok when I had my truck I put in a pretty healthy cam for a 5.3 (222/224 .566 .568 on a 112LSA) and I drove around on it like that for awhile. So after I saved up some cash and I found a good deal I got a converter. Here is the driving impressions: Simply put I could drive around no problem with the cam in and even pulled a 4000 pound boat to the water and yank it out of the water no problem even though some said " it won't pull down low and you'll lose power down low". Now after the converter (Yank TT3000) I could no longer go full throttle from a stop or from a roll under 30mph, for that matter, without liquefying the Yokohamas on the street or track and had to get slicks for the track to get a good launch to get my ET's down. Plain and simple...

And with the way I designed the tranny would even scratch third gear at the 1000ft mark (yeah I didn't believe it either till I reviewed the tape...). So IMHO if absolute performance is what you want get the converter and if you want something that drives close to stock get a Yank, if you want something that will hit the tires extremely hard and slips a little more get a P.I. Vig.


Nice post Got 8?

So your saying that I will see a 'drastic' increase in power when I do my cam swap, because I already have a Torque Converter?

If so, I cannot wait.

Again, good story & analogy.... :)


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[Mike P]

Bump for Got 8, Charlie, or any of the more experienced gear heads that could answer this question.

Question being: Already having a torque converter, will I see an extreme performance upgrade when I get my cam swap?


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[g8_795]

Good info. I was looking at that Yank 3200. Are you saying this will be pretty tame?

Anybody know what problems wreck was having with his TC?

[-Ray-]

Bump for Got 8, Charlie, or any of the more experienced gear heads that could answer this question.

Question being: Already having a torque converter, will I see an extreme performance upgrade when I get my cam swap?


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I guess one would need to define extreme. You will be able to keep your G8 in the power band with your converter. Only the dyno will be able to tell you net hp gains.

[wreckwriter]

Anybody know what problems wreck was having with his TC?

I'm not going to discuss that until all the facts are in. For now let's just say it didn't work well in my car. Others have had much better experiences.

[Chewy]

Good info. I was looking at that Yank 3200. Are you saying this will be pretty tame?

Anybody know what problems wreck was having with his TC?

Why not the Circle D unit?

[Got 8?]

Bump for Got 8, Charlie, or any of the more experienced gear heads that could answer this question.

Question being: Already having a torque converter, will I see an extreme performance upgrade when I get my cam swap?


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Sorry I haven't been on all day and just decided to check the site on a whim...


I'm saying that with my setup that I had I didn't see a drastic loss of torque down low that everyone was claiming I would see when I swapped cams, and I had what was considered a healthy cam for a 5.3L truck engine. Hell it was a mild cam in a 5.7L LS1 in the F-bodys.

Now when I changed my converter out this is what happened....



http://img.photobucket.com/albums/v627/storm53/TT3000/P6010034.jpg
http://img.photobucket.com/albums/v627/storm53/TT3000/P6010033.jpg

This was with a Yank Truck Thruster 3000 (TT3000)...

Before the converter it would barely spin the tires over on this road but once it got moving it would pull like a ape with it's ass on fire....


Oh, and this was just flat-footing it, no brake stalling....and letting out cause it started to hook to the right and head for the mailbox and ditch...not the white one in the foreground but the black speck down the road on the righthand side...LOL

[Got 8?]

Good info. I was looking at that Yank 3200. Are you saying this will be pretty tame?

I can only speak for the TT3000 personally and if it is like the rest of the Yank line then it will be tighter than the PI Vigs. The easiest way to describe the difference between the two would be to say when you put the Yank into gear and release the brake it will creep forward at idle, with the Vigs that I've seen they won't move untill you step on the gas and get the revs up. But I personally think the Vigs "hit" harder...from my observations.

This was also on the older models a few years ago and PI built nothing but billet converters. Yank built only billet on their high end full race converters if memory serves me correctly...

Also PI wanted all the info you could give them (dyno sheets, what bolt- ons you had, ect.) before they would build a converter for my buddy's truck when he called.

Yanks were kinda off the shelf units....

But I heard good things from both sides..

[Mike P]

All: Thanks for all the information & pictures. It's sound like it will be very nice when I do the cam swap! :)

Not sure when it's going to be though..... :(


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[GRRRR8]

The TQ converter is a must if you want to go real fast. I use Circle D Specialities. They will build it per application and if you talk to Chris you are talking to the owner and will get great service.

[Circle-D]

Thanks for everyone mentioning my name, I appreciate it. We have been doing a lot of R&D on the 6L80 and have some great results. We have one of the fastest NA 6 Speeds in SSEnforcer, very happy with his results. If you are interested in a converter for your car, please give me a call, PM, or shoot me an email. I would be happy to answer your questions and hopefully win your business.

713-895-8834

Chris