BADFNZ

iTrader: (19)

I've searched and searched and found alot of info, I just want to verify some of it:

-PT4000 shift extension is 5300 vs. 5900 for PT4400
-PT4000 has around a 2.5 STR vs. 2.7 or so for PT4400 (varies)
-PT4400 feels a tad looser but not by much
-I read somewhere the PT4000 would be better from a roll because it's more efficient but that doesn't make sense to me because of the 4400's higher shift extension
-Not much difference between the 2 at the track
-Both use same internals

Now, can someone touch on all of these subjects?

Colonel

"-PT4000 shift extension is 5300 vs. 5900 for PT4400"

This is off a bit I think. Heck, my SS4000 has a 5350 SE but this is with a ~6600-6700 shift point which will have a small effect on SE. The PT4000 is surely better than that. I'd guess more like 5500.

2.2 STR compared to 2.5 STR according to Yank's site but I believe this is customizable to a degree.

The PT4400 would be better from a roll because of it's superior SE. 400 RPM of shift extension has alot more to do with it that 1% of efficiency.

Not much difference at the track? I guess it's according to what you consider a significant amount. I'd say they are within a half tenth at the track in an 11 second car.

Yeah, pretty much the same internals I believe.

BADFNZ

iTrader: (19)

Thanks for the quick reply.

CamaroCain

iTrader: (1)

correct me if i am wrong here, i am slowly starting to learn this stuff, but as for as SE goes, wouldnt that depend on the car itself and what mods have been done, like my car only being stock internal may have a SE of 5600 with the PT4400 but a H/C car would see the 5900 SE

FYI: 1.50 60' w/YPT4400 in my stock internal car at 3400+ raceweight

Colonel

Sure, like stall speed, it's going to be effected by the power made at the RPMs that we're talking about. In other words, if our SE is 5000 then the power made at 6100 is going to have much less to do with it than the power made at 5100.

Having said that, I don't think that SE is effected in a major way by heads/cam as much as it would be larger CI.

When I give an estimated SE, it's assuming stock CI.

LS1 BU

iTrader: (13)

I get 5900 shift extension with my pt4400. I have heads and cam. I wish I could 60ft 1.50. Camaro Cain makes my car seem slow.

Ragtop 99

iTrader: (7)

-PT4000 shift extension is 5300 vs. 5900 for PT4400
Shift extension is much closer. Don't expect more than about 300, maybe 400 rpm difference

-PT4000 has around a 2.5 STR vs. 2.7 or so for PT4400 (varies)
That is pretty accurate. The 4000 may be a tad lower.

-PT4400 feels a tad looser but not by much
I have had both the 4000 and 4200 and they felt the same. Could not tell them apart.

-I read somewhere the PT4000 would be better from a roll because it's more efficient but that doesn't make sense to me because of the 4400's higher shift extension
The 4000 is more efficent. If you wind out 3rd gear in racing from a roll, I'd take the 4000's efficency over the 4400's shift extension. I went with the 4200 because from a roll it is more efficent than a 4400 and has nearly the same shift extension.

-Not much difference between the 2 at the track
For Pure track use, I'd take the 4400. The extra stall and midrange should be worth at least .05.

-Both use same internals
Pretty much. I'm not sure if the 4000 uses the same pump with a blade angle adjustment or different pump.

Hugger SS

I drive my PT4200 everyday and love it..1.5 60fts on et streets with a full weight SS and 11.50 timeslips

Patrick G

iTrader: (14)

The PT 4000 I had in my SS had crazy shift extension. Somewhere like 5800-5900. Never had a converter that was better from a roll.

BADFNZ

iTrader: (19)

I did some comparisons on this theory and tell me if it makes sense. I said that the shift extension of the PT4000 was 5400 so I multipled my horsepower above 5400 by 1% (for the 1% increase in efficency over the 4400) and I came out with 379 rwhp at 5400 rpm.

If I take the horsepower of my engine at the PT4400's shift extension (5900) I end up with 390 rwhp. So with my calculations, the PT4400 would be better from a roll for me because my engine would never drop below 390 rwhp, as opposed to 378 rwhp w/ the PT4000. Is this an accurate measure?

BADFNZ

iTrader: (19)

Make sense to anyone?

CamaroCain

iTrader: (1)

Yeah that was on drag radials too What type of suspension setup are you running? Should have brought the car down to Thunder

CamaroCain

iTrader: (1)

If you are that worried about it go in between with a 4200. I would go 4200 or 4400 and be done with it.

Ragtop 99

iTrader: (7)

Efficency comes in after the converter has come off shift extension. I'm not sure where you got your numbers from, so I didn't understand your example.

Yank does not have a comparison of the 4000 and 4400 available but take a look at the SY 3500 & SY 4000 comparison as an example.

http://www.converter.cc/super_yank_dyno_overlay.htm

I think the YTP 4000 vs 4400 will be a little closer but as you can see the higher stall gives a little more pull in the upper midrange but the advantage disappears at ~4600 rpm before the shift extension ends (~4800) and from then on there is a couple percent advantage. This pattern will be similar on the 4000 vs 4400 but the curves shift to the right a bit since they have longer extensions.

LS1 BU

iTrader: (13)

I didn't know that the Thunder race was on Sunday. I found out last minute. I couldn't see bring my car down for Fri and Sat only. My brother had to work on Monday so we couldn't stay for the race on Sunday. I run Hal coilovers on the front with moroso trick springs on the rear and a 50/50 drag shock. I also have a 1 and 3/8 rear sway bar in the rear. Front sway bar is off.

BADFNZ

iTrader: (19)

According to the Yank website, it says efficency is calculated in the 5000-6000 rpm range where these converters spend most of their time. So basically I calculated the horsepower numbers from my car by the efficency percentage and took into account the shift extensions.

But screw it, I'll just go for a 4200 and be done with it