I'm trying to decide on a converter for pure street driving. The car practically never goes to the track.

My decision is between the Yank SY3500 with a 3.73 gear upgrade or the TCI SSF -- also a 3500 stall.

The SY3500 is more expensive but with the softer STR and higher efficiency, along with the 3.73 gear seems like a good combo for street tires. This combo would be used with my Goodyear GS-D3s 315/35/17's on 11" wide TTIIs.

The SSF has a higher STR and will hit harder -- maybe too hard for just street tires / driving?

Comments?

 

I think the SY will be more street-friendly, in the sense
that a little pedal will produce more "push" with the
lower STR than a higher one. Though less, at the big
end.

My SF3000/2.2 I consider very streetable and the
SY3500/(2.0?) probably about the same. My 2.2 STR
and 3.23s would just roast F1s and still had plenty
more than GS-D3s would hold, they just hold on a
lot longer into the pedal. I can't see you hooking up
with 3.73s and either 2.0 or 2.5 STR. Now I am on
3.42s and a T-2R and can still light 'em (both, now)
up from a roll anywhere in 1st. I think unless you are
going to run drag radials or slicks the 3.73s are going
to not help you.

All the comments I have seen on the SY are favorable,
just the hardcore guys seem to move on and move up
from it eventually.

Now, TCI does do custom stall/STR combos and if you
describe your priorities, efficiency requirement, etc. to
them their custom converter might still come in lower
priced than the SY (dunno about custom converter lead
time or pricing, but check it out).

 

I'm running 3:73's and after my TCI SSF 3500 failure and much debating, I decided for a VIG 3200 with shift extensions matching my shift points/drop and 2.5 STR.
I should have it by month end and will post a comparison between it and the SSF 3500.

I'm running YOKO's 285/18 street and 26/11.5 ET's strip.

 

The attraction of the SY3500 is that is has a 1.67 STR -- actually a bit less than stock but with the RPM flash and shift extension of the more hard hitting convertors.

I'm thinking an STR of 2.0 or more is going to be too much for just radials regardless of size.

 

I had my 4L60E swapped for a T56. So the following is for sale.

Yank SY3500 torque converter 1.61 STR - $500.00
B&M SUPERCOOLER 19,000 GVW rating - $25.00

These items have less than 10,000 miles on them.

I'm located in the chicago land area. If you are interested, please email me at Bp333Bp@aol.com. I have pictures I can send ya.

Let me know,

Brian

 

SY 3500 is great on the street. From a dig, SY 3500 & 3.23s is the way to go. You don't need 3.73s unless you highway race and cut off around 115 mph.

 

What about looseness with the SY3500? Should that be a concern with the low STR and day to day driving around town?

 

Had the SY3500
NOW HAVE VIGILANTE 3800 BETTER
YPT 4400 BEST

 

SY3500 is tight for day to day

 

Higher the str and lower the gears Higher numbered gear Tighter the converter.
The ss converter is tighter than the SY
mY SY pulled great but was looser than my VIgilante
3.42 with the SY str 1.67
3.73 with the Vigilante 3800 2.5 STR
The YPT 4000-4400 is the hands down best 1/4 mile converter
The SY is easiiier on tires ,but not much launch with ET streets 1.79 60's

Yank is coming out with a variation of the ss converter called the PS
Pro stock or pro street ?
Might be worth the wait
Thats why I have a Vigilante ,no wait

 

I think the 3:73's had something to do with that, I could be wrong.

 

I think what people call "tight" / "loose" is maybe not
a universally-understood aspect. I suspect I don't
have it right myself.

A high-STR converter will slip a lot with no "thrust"
out back, until you get closer to the stall RPM and
then, Bam!, it "hits hard" and you get a lot of thrust.

A low-STR converter has a softer, lower "slope" on
the coupling profile. So you get more pavement push,
lower down in RPM and less of a final multiplication.

I drew up a little "cartoon" of this which I think is
pretty correct. If you look at it, see how the lower
STR converter gives more light-throttle "push" and
the high-STR comes in later, harder. Which of these
is "looser" in part throttle street driving? And is this
different than the "loose" converter designation?

 

Looseness is relative term. I've driven the SY 3500 & 3.23 combo. Yes it is looser than stock but not real bad. I think the stock feel sucks. You have converter slip, yet the slip is so little it doesn't do any good performance wise. The SY has more slip, but it feels better because you get enough to really feel the extra power when you get to 25% TPS and the converter spins up to 2800 rpm or higher.

A quiet exhaust helps. A loud exhaust will make you think a converter is loose.

Jimmy:
Your slope theory does work, but your graph would make more sense if it sloped the other way. Then you would see true TQ multiplication vs RPM.

 

Perhaps; I was drawing with slip RPM as the X axis.
I know the multiplication also drops with absolute RPM
but don't know how to represent that (let alone,
simply).

So of the three lines, which would you say is the "loosest"
as you understand the usage? The one with the soft, but
early coupling or one with later, high-slope coupling?

 

Jimmyblue, as I understand it, the top line would be "loosest," and that is where the SY3500 should be. Remember, STR is the amount of torque multiplication delivered to the input shaft when it is still. Therefore, the higher STR SSF3500 delivers more instant throttle response and hits the tires harder than the "looser" SY3500, which multiplies torque more gently, and thus more gradually, as it slips up toward the stall rpm. That's why the SY3500 is easier on tires. But it also means that it feels less "torquey" and requires more throttle from a stop. But it is more efficient on the top end. Your SF3000/2.2 is regarded by some as great street converter. What do you think of it?

 

ill tell you what i think of it.
its a kick *** veter. it feels stock and today at the track i dropped 5 tenths of e.t from that veter.
i still have another tenth to drop if i could hook better.
my best 60 foot was 1.830

 

This is a great thread. Seems like I got a converter that was even more matched to my liking than I thought. I wanted one that wouldn't hit too hard on the street, but also had decent partial throttle response. I had thought that lower STR would give me less of a kick, which is does, and hence less kick with partial throttle input. I am pleasently surprised to see I was wrong. This explanation makes me understand the relationship between STR and throttle input much better.

Thanks for the info guys!

 

The best info is on the Yank site .
Check out the dyno shop
Good Luck
Love my Vigilante 3800
Yank ypt4400 would be better

 

Yeah the SY3500 is an ideal converter for the street. It was also great from a roll since a lower STR is more efficient across the rpm range. My trap speed increased with the Yank.

I'm sure the YPT4400 is a great converter, but for the strip and not the street IMO.

 

My 99 SS with a SY-3500 on Nitto's was a bracket racers dream. Car cut low 1.7 60ft's all day long with ET's falling within a .10th on every run.

Like others are saying above. More STR does make a converter "feel" tighter on the street. But it also increases the chances of spinning the tires.

What's considered a "great" street converter is VERY subjective. If someone in your area has an A4 with a converter, I'd suggest going for a ride.

IMO, of all the converter combo's I've driven, my Yank TP-4200 & 3.73 combo is best for a hot street car. Stock Internals or Heads & Cam.