Although I have an LS1 I had the same thoughts as you regarding a converter. As you can see by my sig I went with the SS4000. Here's my thought process. How much do you race where the slight difference between a PT and SS is going to make a difference? Do you have tires and/or suspension to make full use of that difference in performance? Now think about how much you just drive the car around without racing. A loose converter that might perform better (assuming traction) will annoy you more simply because you drive the car more than you race it.

I would compromise and have your SS3600 restalled to a 4000.

Also someone above had some wrong info on STR ratios. The higher the ratio the tighter the converter.

 

i could see the SS series launching a little better with their higher STR's. i do a fair share of roll racing, thus i went with the PT. it kind of depends on what you are looking for. if i could pull 1.7 60's then i would be happy. i don't go to the track more than one time a year but i will do more street racing/playing around more than once a year. regarding this yank said if i want an immediate hard hit get the SS. if i want a little softer hit that will be faster from a roll and more efficient once the car move go with the pt. once again, every car is so different that i don't know how universal these statements are.

 

I do alot more roll racing than I do drag racing at the strip so the higher SS4000 STR (2.6) vs. PT4000 (2.2) doesn't mean much to me and I do have the stock 10 bolt also. Dave said my car would ET faster with the PT4000 than it would with the SS4000. I like the tightness of the SS but I want the PT for roll racing. I have M/T's and full suspension minus drag shocks/springs so I'm not worried about traction issues. I just dont want to be driving down the road and mash the gas halfway or 2/3 the way down and it slip bad before it engages like Im worried the PT will. I wouldnt mind the looseness from a dead stop too much at all just at part throttle that would be annoying to me. I really can't make up my mind yet. I also talked to Chris at Circle D and like their 4C+ Converter for my setup which may be nice to get since its completely different.

 

Yank says the PT is a better converter for all out NA applications, and IMO and in my experience, the PT is much better than the SS. I had them both, back to back. You've only had the SS3600 and SS4000, so you "think" the SS is better, but until you throw a PT in and try it out, you can't say what would or wouldn't happen. Sadly, I don't have track data to share, but the performance gain was obvious nonetheless. Dave at Yank said the SS will out 60' the PT, so no one's denying your claim there. You're comparing a 2.6 STR to a 2.25 STR. I don't know that you'd ET better with the PT? But I'd bet big that you'd gain MPH.

I also seem to remember Matt D running some pretty insane times full bolt-on, stock internal, with a PT4400 and weight reduction. I'll see if I can find out what his times were. I'm in no way trying to take away from the SS4000. I'd say it's more popular than the PT any day, and it was a great converter when I had it. I just wanted to step it up and the PT does just that. It was a huge improvement for my car and what I use it for. It's a different animal than the SS, and they each have their strong points. The PT just does what I want better!

Chris, I'm not trying to argue with you....your car obviously does what it does extremely well with your setup. It works for you....mine works for me, and we're all happy. But to say one is better than the other without having had both is just plain opinion. I'd love to see you try a PT and give an objective review, but that's an expensive review and I doubt we'll ever see that. If I had some extra cash floating around, I would have tried out one of Circle D's newer converters(4500ish ) just for the sake of a legitimate comparison here on Tech and because I'm pretty impressed with their stuff. I don't have the cash right now, so unfortunately that isn't going to happen for awhile. Tell you what though, when that day comes, I'll send you my PT4400 if you're interested and you can put it to the test. All I ask is that you send it back when you're done.

 

I assure you the PT is not much looser than the SS at all. There is no mid-throttle slippage or anything like that. It acts just like the SS4000, but it pulls much harder from any speed. I'll try to get a hold of my tuning data logs. My tuner was amazed at the difference....he tuned both the SS and the PT.

 

Cool, I have no reason to go to the SS4000 then. Dave even said that I would ET faster with the PT4000 over the SS4000. I dont care if my 60' times are down it will just allow my crappy 10 bolt to live a little longer and make it easier for me to hook on the street. The PT fits my bill pretty much entirely. I thought about looseness and I actually think it would be cool to have to rev to 2500rpm or more to stay with traffic cause it sounds badass . If the car was my DD I would just keep my SS3600 because it is very nice and tight and launches like a **** just like they say about the SS series but since I only drive it 4-5k a year I can deal with a little more looseness. Plus I think the PT4000 will be perfect for when I stroke my motor out to a 396 and remain N/A shooting for high 10's. Looks like I made my decision!....well atleast for now I change my mind alot lol.

I may look more into the Circle D because I've seen some people going from SS and PT converters to them and being happier. Not sure of their applications though but worth a look. Chris said his 4C and 4C+ have nice drivability and are both better than what I currently have.

 

^^^It takes ~2500 to accelerate with traffic for me, and the car will move with as little as 1500. My shift points are 6500 and shift extension is 5800-5900. This is with the PT4400 and 3.23's.

 

Only 4800-4900? I guess its because your gears. My SS3600 w/ 3.73's is 4900. Dave said with 3.73's I would be at 5600rpm with the PT4000.

 

As has already been stated the SS makes more torque multiplication out of the hole. So SS will should out 60' a PT of the same stall speed. The way I understand it the PT is more effecient and will MPH better than an SS. Giving better results at roll racing, as the OP wants to do.

OP: The PT is pretty loose, but I've never driven an SS to compare. I could easily live with this everyday, though my exhaust is very quiet. If my car was loud, I wouldn't want to drive this thing anywhere near a 35MPH speed limit. It's all preference though.

 

Fixed....I was off by about 1000 RPM's . Shift extension is 5800-5900. Thanks for catching that.

Slight is a big understatement. It's similar in street manners for daily driving, but the performance difference is significant in my experience. If you only race once a year, it's still worth it to go with the PT.

 

FWIW, he PM'd me....ran 11.42 @ 116.24 with a 1.47 short time. Bolt-ons, stock internal, bad tune. He said it was re-tuned and gained 30 horse/28 torque but he never got new track times.

 

yeah you better find out what converter he used cause i raced that day at the track with him...he was around 150lbs lighter than me and i ran 11.59 at 115mph at the track he said he had a PT4400 but later in the season he was saying he had a ss4000 cause he was spraying so i have no clue that converter he had in there nor probably does he haha...

 

thanks for the offer but my dad just took out his PT4400 and if i really wanted to try it i would use his...i know what it is capable of 1.36 60fts for his 10.42 at 126mph ms3/5.3 heads...3150 raceweight...i am 1.38 cam only at 100+ lbs heavier...and to say the pt will perform better for N/A i just cant believe cause i know what my dads car has done...he has 13% slip on the top end...shifting at 7000rpms...that slip is what i call looseness cause it is giving away mph...it is not as efficient...so with 400 rpm higher stall, same str or close with 2.5...he is getting barely better 60fts...and that would be fine if the converter was not loose on the top end but it is with 13% slip...he just got his circle D so we will see what his car does now...my guess with a slightly higher stall and more efficient up top it will 60ft better and mph higher ...have your cake and eat it too...

and to perform a better ET it is all in the first 60ft...and the choice here is between a pt4000 and a ss4000 not a pt4400...

i need to log a run to see what i am going through the traps at so i can calculate my slip...i know it is low because when i was SI i gained 1mph going from stock converter to a ss3600, and lost nothing going to the ss4000 cam only...gained exactly 70 rwhp 116mph to 123mph with same DA conditions...

to each his own, i just dont like seeing that a PT is a better all out N/A converter when i have seen noone else even close to my times with a PT4000 with the same mods...my converter gets me out of the hole and stays efficient on the top end...

i would love to see a back to back well controlled test of the two converters too...

In the end they are both great converter and u will be happy with either...

 

Yes I do like it better. The pt has more topend pull to it. And I think the drivablity is about equal between the two.

 

He said those times were with the PT4400. After the retune, he never ran it again before swapping in the SS4000 so he could spray it.


I believe Yank knows their product as well as anyone, and they have always told me the PT is a better NA converter than the PT. My experience directly concurs with this. To say that no other car with a PT has come close to yours isn't saying much at all. There are too many factors to take into account. On top of that, your car is just a monster. I don't know that your car is capable of a fair comparison....it's insane .

Yank has also told me on multiple occasions that the PT is very effiicient. Was your Dad's in good shape? I only ask because I'd like to find out if 13% slip is common to the PT's, or just his. I'll see what I can do about calculating mine.

I'd love to see the results of your Dad's swap to the Circle D. Like I said, if I had the funds, I'd be doing the same thing. Hopefully he'll post some results. Either way, I agree with you that both converters are great choices depending on application.

 

i have ran chris1313 at the track last year & his car screams for cam only.....him & his dad are great guys & very informative!!!! they do things right.

its to bad he red lighted on our 1 run & he got me by a long car length,it would of been an awesome race other wise,i know he just hit the 10s for the first time that night & i ran a 11.08 @ 121 with a 1.48 60' full weight.
i have the FLT lvl4 & pt4000 in a heads & cam car & make 407 rwhp & chris1313 makes 422 rwhp cam only car.

i would say chris1313 is running right where he should be at 10.8x with 422rwhp & lightened up, whats astounding to me is that his car makes 422 rwhp CAM ONLY!!!!!!!!!!

they are obviously doing something right...........................

 

I was looking at the fastest S.I. list and I found it interesting that of the 50 cars on there, 2 were running SS series converters and 22 were running PT's........


Also, here's a quote from Yank that would seem to support the claims about the PT being a better NA performer:

Here's a quote claiming 96% efficiency with the PT4200. I can't find any other good claims for or against the efficiency. I saw a long thread where the claim was between 60 and 75ish %, but the method for gaining the info was suspect. I also read that Yank claimed 96% efficiency for the PT's, so Ragtops results would seem to support that:

 

And 4% slip on the top end that is very unbelievable…when my dad talked with a couple trans guys and even yank they said that his slip was right in the ballpark and if anything maybe a hair high…but he is using all of the converter shifting at 7000K and only having 800 shift extension…he was scared when he first got it cause he thought that was not enough but yank reassured him it was about right…

Like I said we will see what the new converter has in store if it is worse (which I am sure it wont be) we can always throw the PT back in…or maybe even a ss4000…that would be interesting to see in a H/C/I car…

 

yeah I know you got me nervous… it is always a blast racing with you…I am kind of excited for this season we need to line up again, I hope this ported 92 fast I got helps around 12-15rwhp…I haven’t seen my dads yet but what he is saying is that I am going to be very disappointed with mine…he sent his into a different sponsor than I bought mine from…I am going to take some pictures of the differences and hopefully this problem can be fixed by the sponsor, or things will become public…still cant wait to get a 92 on the car and see what it redyno's at speed or an apples to apples comparision, although on seperate days but i guess that is what SAE numbers are for...

when is opening day…march will be here next week…

 

Sorry about using the lists....I looked at the other ones, but they were so jumbled and most didn't say what converter, just the stall speed. Come on, the SI list proved my point....the other lists didn't . J/K. The 60' was never an argument....you own that one. The only PT I saw that came close to you was a PT4000 spraying out of the hole (75-shot) on a 3000 pound car. That netted a 1.39....I'll see if I can find it again. The next closest was like 1.42 or something like that (on the SI list).

I read these forums a lot, and I've always been told and seen the PT to be a ***** out performer, but I'll admit that you have shown the SS4000 to be just as insane at the track. I don't know that your results are typical as you're the only one doing it. Either way, I believe folks on here are more educated now than they ever were when it comes to these converters and choosing one that works best for them. Is the PT really better? For me it was (however, I really wish I'd gotten some track times with it), but you've proven the SS to be a serious contender, and possibly the better of the two.