I don't know, I just saw it on their website.

"HeavyDuty/Street (10.5”)

Coming Soon!

Built for lower stall speeds, this converter will simply feel better on the street than any other converter built. This converter is also great for very high powered cars that need to keep stall down, stay strong, and outperform the competition!"

It also says for stall speeds 2400-5500

 

Hmmm i just asked John about it so we'll see.

 

That's true, but the efficiency discussion was about WOT efficiency. Essentially, how much rwhp will the converter eat up? (and consequently how much trap speed will he lose?)

One other note, on the giant STR's converters, such as the 2.9's, etc, they usually rate them on a "spike" of 2.9, so they sometimes can really make the launch tough. You would essentially have a converter that's mostly 2.4-2.5, with just a brief peak of 2.9 (which may only last 100rpm), which tends to snap the tires loose as soon as it comes up. So they can actually really be rough on your 60ft, because you have to be all over the place with the throttle. There's somewhat of a physical limit on how much sustained STR a converter can provide, so these are just designed to "spike" to make them sound like the nastiest thing on the road. They're just not great for winning races, whether from a roll or from a stop.

 

you seem to think that a 2.1 STR is a "low" STR..
heh.

i've a fuddle 3600 / 1.8STR
had/have a lot of trouble launching, couldn't get traction from a dig.. can't just floor it. but thats on stock tires.. waiting for my new tires to come in, we'll see then.

 

hmmm. Need some more input. If i had to order right now i think id get the 3800 2.1 str.

 

Right, that is why I suggested he get one he can lock at WOT. Takes the slip and inefficiency out of the equation. Should be better then stock.

Street tires and stall converters were mentioned in another thread. Basically the two don't mix without tire spin or throttle modulation. He may be OK with large DRs on the back. Or he may just have to learn to be careful = no WOT launches. Part throttle until traction then roll onto the gas. Takes a little practice but you get used to it.


Superman, I am voting 4000, but only if you follow my plan and get one that can handle locking at WOT (otherwise, maybe the 3800). It will be loose, remember that.

 

Yea i know it will be loose, i can handle that, i jsut want something o nthe street that will basically give me an edge over all the other cars without power increase. There will be bolt on LS1 M6s and cam LT1s and im hoping if i can get the best performing stall for me i will take them. Big stlal size to get that jump off the line and keep the RPM's high and a lwoer STR to keep it efficient in higher speeds and help with traction

 

if your car is going to be strictly for the street i would consider an even lower str like 1.8, if it is for both track and street get the 2.1 like you said, to be honest i dont think i could hook up WOT launch with a drag radial on the street with my converter. Unless the street was prepped with some VHT. So if you wan WOT on the street and hook go with your 3800 1.8 str, if you like the track just as much get a 2.1-2.2

 

ok thanks, well i wont be gunning it from a stop hardly at all on the street, if i ever go WOT its usually around 30 roll ish

 

I got a 3800 Yank SS and have been completely pleased with it so far. A4 with a big stall is the only way to go.

 

99slobird, what STR do you have and what tires are you running and can you describe how traction is. Thanks!

 

Gotcha, but that's not really possible on a stock 4L60E. It would destroy the internals of the transmission really quickly. He *could* lock it in 3rd gear only, but that's not really going to be worth anything with 3.23's.

The converter soaks up the "slack" on every shift. If the transmission were to attempt a shift w/ a locked up converter, all of that slack would be taken up by the clutches in the transmission, and, needless to say, this would eat a 4L60E alive VERY quickly. The guys that run locked up at the track are on fully built 3-speeds, etc.

The other option is to lock it in 3rd gear (for him). This is simply not going to be worth much, as he'll basically only be able to lock for just a few seconds out of the entire 1/4. You have to be pulling really hard on the topend to make this worthwhile (such as a blower car, or big nitrous car). Even in that case, it's still debatable.

People lock on the dyno at WOT all the time, but that's because there are no shifts taking place.

If you need any more explanation about this, just let me know, but please, don't try that on a stock 4L60E.

 

Yea, im going with areg verter that will lock up at cruise speeds. Im going to get it to lock up in 3rd at like 40 ish and in OD at 50 ish only at cruise speeds. I want it to pull like a raped ape up top! I bascially want it to pull like a sucker, keep RPMs high and keep it efficient and tire spin not horribly uncontrollable. Thanks a lot so far guys. LS1tech is saweeet

 

I'm buying a yank 3800 with an str of 2.2 Gonna buy weld alumastars with some bf drag radials along with it. Just got my BMR ladder bar in, hopefully that will eliminate some of those traction problems. Hope your happy with the fuddle, lot of guys tell me they like them.

 

Ok cool, after you install it, let me know how she drives and what tractions like!

 

That is what I was thinking. Only in 3rd. Never really thought about the other gears, but what you said about destroying the tranny makes sense.

If he is doing street races though, he would spend more time in 3rd. Do you think locking it then would be worth it?

 

Have to check, think the STR is 3.2. I'm running Kumho 285/40's right now, but I've just got about 500 break in miles on the car right now. As for traction, from what I've seen on the street, there's not much to be found on street tires. Needing Drag radials in a bad way. Needing cash in a worse way. A buddy of mine suggested knocking off a liquour store, but we were worried that we'd get sidetracked and just come out with beer.

 

hahaha, well. you can always sell some beer to pay for mods, and drink the rest while installing...... anyways, 3800 2.1 str, who doesnt think this is the perfect set up for my needs?

 

Checked and I was wrong, STR on my converter is 2.5. Don't know where I got 3.2.

I would say for street setup 2.1 would have to be better, but I haven't tried drag radials yet, so who am I to say. But if the beer heist goes as planned, that will all change

 

Most likely not, because, taking into account the 3.23's, he'll probably not gain anything with it locked. I'll explain,

So let's say we have a stock 4l60e, the top of 2nd gear is about 80-81mph with the stock shift points (and stock cam). So if he keeps it unlocked from 2-3, he'll probably drop down into the 4400-4800 range (depending completely on the converter, some people with big stalls stay over 5000rpm) when he hits 3rd. If he were to lock it right after the 2-3 shift, it would drop down to about 3420rpm as it goes into 3rd. So essentially, in the midrange of 3rd gear, the shift extension is a greater gain than locking it up would be. So you'd just end up with a really big "bog" as you hit 3rd.

To get around this, we could just lock it up higher, and I think it's accurate to say that locking up in 3rd gear at around 104-105mph (with 3.23's) would be faster on the topend (remember, if we lock up before this speed, it will simply drag the engine rpm too far down out of the powerband, not unlike hammering it from a stop in 2nd gear). So, basically, we can't lock below 80mph, because there are still shifts left to make, and locking between 80-104 will create a bog, so it's really going to be an issue from a real real fast roll.

But let's think of it this way. If 2 cars are going from an 80mph roll on the highway... both cars A4 in 3rd gear, same gearing, same converters, same mods. The only difference is 1 locked and 1 unlocked, the unlocked car will actually win this race from the 80mph roll, because as soon as they take off, the unlocked car will be putting down quite a bit more power, and will pull away (due to being closer to peak torque). By the time the locked car reaches the powerband where it's actually putting down some torque, the unlocked will probably already be pulling away at a few mph, so this difference would have to be made up just to *match* the unlocked car's speed, before you can even start reeling him in, which probably would not occur short of 130mph.

It's deceptive to look at the dyno figures, because a lot of people do see higher rwhp with a locked converter, *however*, if we think of where this occurs on the street, it's up around 135mph (5700rpm+ depending on cam) with 3.23's. In other words, the unlocked car is faster just about everywhere underneath 130mph. It's also confusing, because you can think about an M6 car, which is obviously quite a bit faster from a roll, and think, well if I lock up, I should be this fast, right? But the problem is, the M6 gearing is so much closer, that after every shift, they still stay in the powerband. A4 needs the shift extension (which is simply less rpm drop after a shift) to compensate for the wide-spaced gears.

The more important thing to look at is applied torque, to the wheels, from an entire 0-140mph run, OR, more simply, trap speed. A lot of people have actually gained .5mph or even 1mph after a converter install (but ONLY with a moderate stall or STR). To clarify on this, have a look at the torque dyno on this link:

https://ls1tech.com/forums/automatic-transmission/435178-how-much-hp-do-you-lose-when-you-add-stall.html

You can see that the SS3200 actually picks up torque all the way from idle to redline, and, consequently, maybe about 5-9rwhp (around 3% peak hp, just from eyeballing it). This is a 2.1 STR, so as the STR increases, those numbers will generally start dropping. Because of this, it usually seems like the best idea to try to keep from going overboard in the converter selection. It's 100% true that you can pick a 3.0STR and then just feather the thing off the line, but then once you get traction, the guy next to you in the 2.0 is going to take off on you. This is of course a completely different story if you have a 12bolt + slicks. Then you can actually use the skyhigh STR to outlaunch him, and he'd have to try to catch you. But it's just important to keep in mind whether you're going for a street car w/ drag radials, or a track car with 15" lightweights + slicks. It's just like a cam, go for the perfect match for what you want to do.