Stone0fFire

PT4000 2.7 vs. SS4000 2.6

thats all i want to know.
got to get rid of this midwest.
when i got it,
it makes lots of noise,
and its not getting better.
tranny guy says its rotational noise from not being balanced?

V6 Bird

iTrader: (15)

pt4000 all the way. I have not seen any significant advertised gains or from personal use between the two. i ran the pt4000 and had a best of 1.39 60 foot on a stock internal car with a 125 dry shot. Another friend of mine did the same converter and same shot with FULL interior and is running 10.7's @ 125 with low 1.4 60's on his stock rear end.

Mike

Stone0fFire

so whats the difference between the two?
is the PT really 2.7 STR?
is that the only difference?

help.
colonel.
help.
yank.
help.

Ragtop 99

iTrader: (7)

PT 4200 is a killer converter. Excellent 60' and great top end pull. The downside is that it is loose! The SS4000 will have better daily driver manners.

Stone0fFire

whoa whoa buddy.. im barely convinced i should get a 4000!

unless.. how bad would it be with 3.73's?
}=]

quickWS6

WIth 3.73s, it shouldn't be be bad at all. In my opinion, if you can handle a 4000, you can handle a 4400. Now, a SS4000 to a PT4400 might be a slight difference, but if you are going to get a PT converter anyway, might as well get the big daddy. There are some differences between the two, which are listed on Yank's website.

I wouldn't do a converter swap with anything less then a 4000 stall these days.

Stone0fFire

good god an effn PT4400 on a daily driver?!
this is my only car, you know.
really think it is tolerable w/ 3.73's?

right now i am barely running a gay 3400/2.0
but im used to the loose w/ 2.73

so whats up w/ SS vs PT?
shouldnt the PT be tighter since the STR is 2.7
compared to the SS being 2.6?

any PT4200/4400 daily drivers here?
or will i have to create a separate thread?
YARRRRRRRRRR!!!!!

Raughammer

The TP 4200 is a pretty dog gone loose converter. If you have a quiet exhaust it is not too bad if you do not mind driving around revving at every take off from a red light. If you drive slow and easy it's not TOO bad. If you are an agressive driver... it wil slip, it will drink mucho gas and it will be obnoxious if you have a loud exhaust.

With all that said... it will rule the kingdom at the track.
I have used the TP4200 in a daily driver for years.. but it does take some getting used to, And if you have a loud exhaust.. .. lordy is it a head turner. (cop magnet)

The SS series was made to kind of bridge the gap between the race crowd and the street crowd and it does so very well.

For a "normal" street car (street racer) i would recommend the SS, but if you want the big daddy you have to look at the TP.

stock internals...yank tranny and yank tp4200 verter 11.5's at 116.
heads and C1 cam/yank tp 4200 10.8 124, 1.4 60's
heads cam C2 cam/yank tp 4200 10.6 126, 1.3 60's
heads cam x1cam/yank tp4200 10.6, 127, 1.4 60's

The TP4200 is the king of the hill... in e.t., mph and 60's.
Look no further for the off the shelf king of LS1 converters.
But... it is pretty loose for the street. Tolerable to some, but loose.

Stone0fFire

oh man now i want one.
if im gonna suffer a loose stall,
i might as well make it worth it..
so.. PT4200..
might as well PT4400
will 3.73's make it better?
has anyone tried PT4400 w/ 3.73's?

four gear trans =

JNorris

iTrader: (4)

Unless you are a hard core racer I would not go with a PT series (or any 4000+rpm converter). They are very loose for a daily driver.
The PT series converters do rule at the track as long as you get one that is efficient. I did not. My PT4400 with 3.23 gears had an average efficiency of 73% over the 1/4.
For a daily driver with 3.23 gears I would not go above a 3500 stall.

If I were you I would take a good look at the TCI 3500 as well as the Precision Industries Vigilante 3200. Both are very good converters. Both companies stand behind their product and their warranty as well as provide their customers very good support. Believe me not all companies do that. Some like to Yank you around.

John

Raughammer

And beleive me, the Yank TP series is worth it. The Big 3200 (really a 3800 rpm stall but whose splitting hairs) is pretty good but it is not very efficient on the big end.

If your car is light let Mike know (@Yank) so he can make sure you get the correct verter. The TP4400 will stall a bit lower if the lighter the car is. (like 4200)

The Yank nay sayers all will be watching your tail lights. Get the best, get a Yank. Nothing is more efficient off the shelf and nothing off the shelf will get you the top end charge of a Yank Thruster Pro. Great 60's and pulls like freight train up top. Yes, it's the kingo the "E.T. list for a reason.... It dominates. In tq converters, you get what you pay for. Pay less? Get less.
Premium internals cost more money than cheap ones. Again, you get what you for.

Good luck

BADFNZ

iTrader: (19)

I went from a Midwest 3500 to a PT4400. Yeah it was loose but it's nothing I couldn't get used to. Took about a day or so.

JNorris

iTrader: (4)

I think the PT series is a good converter line. I do not have a problem with the performance aspect of the Yank converters. As long as you get a GOOD ONE they seem to be good performers. My problem with Yank is their lack of customer service and their unwillingness to HONOR their warranty.

When I switched from the Vig 3200 to the PT4400 I went almost .2 quicker in the ¼. The reason for that was NOT because of the infamous Yank efficiency but because the higher stall speed put the motor in its power band longer in a some what efficient manor for a big stall converter.

As far as efficiency goes my vig3200 stall SHAMES the PT4400 in my car. In fact the PT4400 performs worse at the big end of the track than it does in the 1/8. This is because you loose the advantage of gear torque multiplication (in 1st and 2nd gear) as you are in 3rd gear which has a 1:1 ratio.

Want proof of how efficiently the PT4400 performed in my car? Take a look at the link below for the efficiency numbers. The data is the entire ¼ run.

Link below

ftp://members.aol.com/jnorris404/PT4400Eff1123.htm


John

JayLS1-327

iTrader: (2)

John (JNorris), I can't access your site.
It's looking for log-in info

JNorris

iTrader: (4)

Strange that it is not working for you.

What is your email address and I will send it to you.

I sent you a PM

John

Ragtop 99

iTrader: (7)

Measuring efficency overy a quarter mile makes no sense. A converter with a higher stall and the longer the shift extension will always have a lower efficency (computed accross the quarter mile) then a stock (or low stall) unit, but we all know which will be much faster.

Efficency refers to the post coupling up performance of a converter (i.e. after the converter comes off its shift extension). It is normally measured 2 ways: 1) Difference in HP between locked and unlocked.
2) Difference in rpm between the input and output shaft.
I focus on HP lost. The second measure, IMO, is only significant when you are close to running out of rpm due to your trap speed & gearing.
The Yank YTP's are very efficent in not eating high rpm HP.

Yes 3.73s do help the feel as does raising your part throttle shift points.

JNorris

iTrader: (4)

Measuring TC efficiency in the real world (not dyno) makes all the sense in the world.
The converter feels the full load of the car and drive train and this lowers the efficiency.
What I am looking at is what you are putting to the ground while going down the track.

Again, the reason the higher stall converter will win the race is NOT only because of its efficiency but because it allows the motor to get into a specific power band and hopefully keeps it there. The trick is to make a converter that is efficient in the desired power band. When this is done the engine generates more HP over the ¼ and when done efficiently puts more HP to the ground. A lower stall converter does not let the motor get into its power band and that is why you go slower.

With 3.32 gears (26” tires) and crossing the traps at 119mph your driveshaft is turning at ~5000 rpm. With a Yank PT4400 your engine is turning ~6400 rpm (78% efficiency). The difference in HP between 5000 and 6400 rpm could be as much as 125+ with a good H&C package.

Where is that 125hp going? It is being dissipated as heat in the converter and not going to the ground.


John

JNorris

iTrader: (4)

I think you mean the engine RPM and Input Shaft. The difference in RPM between the input shaft and output shaft of the transmission will be determined by the ratio of the gear being used. If 3rd gear is 1:1 then the difference will be 0. If 1st is used then the input will be will be 3.06 (1st gear ratio) times higher than the output and so on for 2nd gear.

The method I use is transmission input shaft rpm divided by the engine rpm at WOT. Only the converter is between these two points.


Really? I am not so sure about that.

Ragtop 99

iTrader: (7)

John your explanation makes partial sense if you are measuring efficency only on the top end of the converter, not off the line. You said across the quarter mile. That means your calculation includes the launch, when the converter input shaft is at 4400 and the output shaft is at zero. However if you are looking at your rpm on the top end of the track, then yes that is a measure of efficency.

I see 2 issues:
1) you should not be seeing a 1400 rpm stretch like that on a H&C car. If you were seeing that much stretch on an NA 346 motor, then something was wrong. I guess from your sig that there was a problem.
2) Yes, some HP is lost as heat, but your comparison is doesn't make sense. The engine is putting out a given HP at 6400 rpm. Assuming you were slipping to 5000 on the output shaft, some amount would be lost as heat. How much heat has nothing to do with what the engine can produce at 5000 rpm. Think about it some more and apply that theory to how you launch the car (output shaft at very low rpm and engine at 4400) and you'll realize that it does not work that way.

No I meant the converter's input shaft and the converter's output shaft. Sorry for not being clear.

Race a few from a roll. You'll see the YTP's generally win, all other things being equal. You'll also observe that Yank YTP's pretty consistently out mph other brands at the track for a given ET. I'm not saying 100% of the time, but most of the time.

BADFNZ

iTrader: (19)

I think the PT's are so good from a roll because they have good midrange power, where you usually start the race from. I've seen quite a few PT dyno graphs and they show a good midrange power gain but it levels off on the top end. Here's exhibit A:



PT4000 in BLUE
Midwest 3500 in RED

No other changes to the car.