Finally tested the Yank I put in my truck!

[Y2K Silverado]

After 275 miles I finally had time to test the Yank 2400 I put in my truck. This morning on the way to work I stopped to see what the truck would do if I justed punched it from a dead stop. Before the Yank, my low end wasn't real impressive, I may get a squeek or a little squeel with 1 second of tire spin. This morning when I punched the gas, the tach shot up to 2400 rpm's and the tires just started to squeel. They kept spinning for a good 4-5 seconds, the burn out must have been 40-50 feet long. I did one 0-60 run after work, don't like to do them in the day, to many homes can see the road. My usual time was a 0-40 of about 3.3-3.4 seconds and 0-60 in about 6.4-6.5 seconds. My times 0-40 and 0-60 were 3.19 & 6.22 seconds respectivly. Yank only claims a .2-.3 second reduction in time, so I'm right there. Cool!

Jim

[americanmuscleman]

Awesome! Glad to hear you like it!

 

[Sierra5.3]

someone explain yank to me.

[TarheelZ]

someone explain yank to me.

Yank is the manufacturer of the torque converter he recently installed.

[cowboy02]

Couldn't you have also improved your 0-60 time by doing nothing more then getting the Hypertech III programer? You could set your shift points for optimum 0-60...

 

Why buy a aftermarket torque converter? That is the real question.... Unless the old one was shot.........

[cyrylyn]

Couldn't you have also improved your 0-60 time by doing nothing more then getting the Hypertech III programer? You could set your shift points for optimum 0-60...

 

Why buy a aftermarket torque converter? That is the real question.... Unless the old one was shot.........

HP3 only sets times for WOT, and the advantage of an aftermarket torque converter is a higher stall speed. not to mention lowering drops in between shifts.

[americanmuscleman]

Couldn't you have also improved your 0-60 time by doing nothing more then getting the Hypertech III programer? You could set your shift points for optimum 0-60...

 

Why buy a aftermarket torque converter? That is the real question.... Unless the old one was shot.........

HP3 only sets times for WOT, and the advantage of an aftermarket torque converter is a higher stall speed. not to mention lowering drops in between shifts.

Exactly.  The point of a torque converter is to let the RPM flash up higher to give you a better launch.  I would guess the stock converter is around an 1800rpm converter (maybe 2000?), and when you floor it from a dead stop, your RPM might be able to shoot up as high as 1600 or 1800rpm for the truck to launch.  Yank converters typically flash up to roughly what they advertise, so with a 2400rpm stall converter, your engine RPM would hit maybe 2200 or so RPM before the tires break loose.  Theoretically with traction, you should be able to hit about 2400rpm off the line.  

 

The whole idea with a higher stall converter is to get the engine RPM higher off the line (where the engine makes more power) for a better launch.  The fact that the converter lowers the "shift extension" (meaning it lowers the RPM drop between shifts), is just an added bonus.  The engine stays higher in the powerband, thus moving the truck faster.

 

Since Y2K Silverado said his converter is a "restalled" stock converter, he probably has a stock "stall torque ratio" (STR).  Normally an advantage of an aftermarket converter is a higher stall torque ratio.  A stock converter probably has an STR of about 2.0.  Meaning the converter roughly doubles in the torque coming into the transmission from the engine.  An STR of 3.0 would triple it.  

 

Here's where stuff starts getting boring...

 

I'll go ahead and explain more if someone wants to know more.  One of the advantages of a higher STR is more launching power.  Its great if you have traction.  If you don't, its useless because it will just burn your tires slowing you down.  Typically one of the trade-offs with a higher stall converter and especially a converter with a high STR, is that the converter is usually less effecient (meaning more engine power is lost through heat and inefficiency to gain more torque multiplication).  Sometimes an engine makes a lot of power, and it makes a car (or truck) faster to have a converter with a lower STR (less tire spin).  Usually the converter is more efficient, so it will translate the power better to the rear wheels than a less efficient converter.

 

I don't know if you've ever looked, but the maximum engine torque a 4L60-E is rated to handle is 380lb-ft.  The maximum gearbox torque its designed to handle is 670lb-ft.  Assuming you had 380lb-ft of torque, you could use a converter with an STR of roughly 1.75.  Anything more, and it would go over Hydra-Matic's rating of 670lb-ft for a 4L60-E.

 

Now even more boring stuff...

 

Say a stock converter in a new 4L60-E behind a 5.3L is 95% efficient.  Yank's higher dollar converters will increase the STR (from say 2.0 to 2.5) while creating a more efficient converter (say its 97% efficient).  Why is that a benefit?

 

You've increased the amount of torque you now have available while launching the truck (STR moved from 2.0 to 2.5), and the engine rpm is going to be higher when you launch (say 2400rpm instead of the stock 1800).  Less power is being lost through heat in the converter (97% efficient compared to 95% efficient for the stock converter).  

 

Say an engine makes 300hp.  A 4L60-E soaks up about 18% of the power an engine makes with a stock converter.  With a Yank converter with a 97% efficiency, maybe now you have only a 16% loss through the transmission and converter.  This translates to more horsepower and torque at the rear wheels.

 

I could go on and on and on about this.  Needless to say I'm tired of typing, and I know maybe one person will read this far down this post, hahaha.  

 

Anyway, if something didn't make sense, or you have any questions... I'd be happy to try to answer them.  

 

You'll see a MUCH larger gain with a converter than with a Hypertech programmer.  

[Sierra5.3]

Where can i get one?

[Wingnut]

I could go on and on and on about this.  Needless to say I'm tired of typing, and I know maybe one person will read this far down this post, hahaha.  

I did, very informative.

 

Thanks for the class.

 

It's why some of us are here.

[americanmuscleman]

Glad to hear someone got something out of it!

 

Torque converters are really interesting devices.  I didn't even talk about different diameter converters, the heat they produce, lock up and non-lock up converters, or anything like that.  There's just so much to torque converters.  Maybe if I get some time I'm try to cover that stuff too incase anyone wants to know about that.  

 

Y2K Silverado, I didn't mean to steal the thunder from this thread by going off on converter details... I just got on a role and kept typin  

[americanmuscleman]

Where can i get one?

Yank Converters Yank's Website

 

I think Yank builds some of the best converters in the industry.

[cowboy02]

I guess the   in me is showing...........

 

I still don't see why you would spend the cash on a converter just to get a better launch... You could hold your foot on the brake also and get "CLOSE" to the same effect.  (Yes I realize this is hard on a few components and not the same, but it would net the same result).  However the real issue is why spend the cash to improve your launch time when you could drop the cash on a belt driven supercharger and get more bang for the buck

 

Maybe I'm just missing something or being  :werd:

[MarkD]

Typical converter costs $300-$1000

1/4 mile gains .2-.5 seconds

 

You cannot get the same results by holding your brake on a stock converter.

 

The best comparison I have heard is water skiing.

 

With little or no slack in a ski rope, a skier will be pulled out of the water gradually in direct proportion to the torque applied by the boat. (not too difficult to hold the rope)

 

Now put about 5 ft. of slack in the rope.  Let the boat take off and try to hold onto the rope.

 

Now put about 10 ft. of slack in the rope.  If you can hold onto the ski rope,  you will probably pull an arm out of socket.

 

That is how a "loose" torque converter helps.

 

Apply the same logic to pulling a stump with your truck.

 

Apply the same logic to "popping/dumping" the clutch on a manual transmission.

[americanmuscleman]

I guess the   in me is showing...........

 

I still don't see why you would spend the cash on a converter just to get a better launch... You could hold your foot on the brake also and get "CLOSE" to the same effect.  (Yes I realize this is hard on a few components and not the same, but it would net the same result).  However the real issue is why spend the cash to improve your launch time when you could drop the cash on a belt driven supercharger and get more bang for the buck

 

Maybe I'm just missing something or being  :werd:

A higher stall torque converter typically improves the "quickness" of a vehicle (hence the advertised .2 or .3 drop in ET with a Yank 2400 converter). With a really nice converter and tires that hook, there is no doubt you couldn't drop half a second off your ET (elapsed time) in one of these trucks.  

 

A supercharger will increase how "fast" your truck is.  Your truck might gain 10mph worth of trap speed (in the 1/4 mile) with a supercharger, which might intern give you the same half second drop in ET like the converter would, but you didn't have to spend $3500 to do it.  A good converter will often increase how "fast" you are as well.  It isn't uncommon to gain a few mph in trap speed with an efficient converter.

 

Basically what I'm saying is... a stock 5.3L 1500 chevy with a Yank 3500 converter and traction could run the same ET as a stock 5.3L 1500 chevy with a supercharger.  The convertered truck would jump out of the hole and the supercharged truck would do catchup.  Obviously, the supercharged truck would pull hard on the stock engined truck from a roll though.  

 

What's awesome is when you put them both together.  The truck launches with the engine right in the meat of the powerband and stays in the powerband better (lower shift extension) while travelling down the track.

[Black02Silverado]

I could go on and on and on about this.  Needless to say I'm tired of typing, and I know maybe one person will read this far down this post, hahaha.  

I did, very informative.

 

Thanks for the class.

 

It's why some of us are here.

That is what is so great about this forum. You never stop learning.

 

A ton of information. Thanks. Now I might not remember it all but I did understand it and made perfect sense to me.  

 

I'm more of a straight drive person myself. Love to drive my 65 and just run through the gears. Not to mention let the clutch fly at 5k.