99Hawk262

iTrader: (19)

**Updated DA info on Page 2 Post #27**

Thought I better start my own thread instead of posting this information repeatedly in other threads. As many of you know, I've always been a huge Yank fan and a fan of big, loose converters. My past Yanks have been the ST3500, SS4000 and PT4400 which was my favorite by far.

As more and more folks starting picking up Circle D converters, I couldn't help but be impressed by their results and the obvious quality of their converters. When the opportunity arose for me to try something bigger from them, I was all in. Chris went over my setup thoroughly and then built a 230mm 4500 stall.

The first thing I noticed about that stall was how tight it was on the street. It reminded me a lot of my old SS4000, but was slightly tighter. To accelerate with traffic only took ~2200. I went to the track and was able to get a good comparison with weather and car setup being the same. Here's how it broke down:

~3650 race weight, !front sway bar, factory Bilstein Level II suspension, stock 10-bolt with 3.23's, 17X9 front wheels/tires, 16X8 rear wheels with Hoosier DR's at 18 psi, weather in the low-40's.

Yank 245mm PT4400 2.5 STR

DA -456
60'- 1.581 (best ever 60' was 1.57-see sig for video)
330'- 4.729
1/8- 7.382 @ 92.36
1000'- 9.682
1/4- 11.625 @ 116.08

Circle D 230mm 4500 2.7 STR

60'- 1.588
330'- 4.736
1/8- 7.395 @ 92.43
1000'- 9.705
1/4- 11.666 @ 114.49

Shift extension was ~5300 as compared to 5700-5800 with the Yank. It was awesome on the street, but a little too tight for me and sacrificed some topend. So Chris made some adjustments to it and I received it back as a ~5000 stall speed.

After putting it in, it was immediately apparent that it was a completely different animal. Topend was awesome, and it hit extremely hard from a roll. Shift extension is ~5600 and once again, for its stall speed it's surprisingly docile on the street. It's actually slightly tighter than the Yank. The Yank required ~2500 to accelerate with traffic whereas this one will do it with ~2300-2400.

I finally got it to the track, but weather was not ideal. Car setup was identical to previous runs, but the weather was in the high-60's, low-70's.

Circle D 230mm 5000 2.7 STR

DA 1161
60'- 1.579
330'- 4.751
1/8- 7.429 @ 91.71
1000'- 9.747
1/4- 11.704 @ 115.02

Based on the launch, I really thought I was heading to a new PB, and I truly believe that with better weather I would have seen one. A buddy watching from the side swears I pulled the front tire a couple inches, which would be a first. It certainly felt amazing throughout the entire run and that was the hardest lauch I've ever felt with my car.

So based on the limited data that I have, these two converter are surprisingly similar. Both companies come to the table with different approaches, but the end product is a work of art. I have nothing bad at all to say about Yank, but I'm certainly a big Circle D fan. Having a converter this large drive as good as it does says a lot about their quality.

With Memphis closing down, I don't think I'll be able to get more numbers. My goal was to keep everything as equal as possible (car setup, weather, etc.) but unfortunately the weather didn't cooperate this past November. I do have some plans for the car this April and I'm very anxious to see what results I have. Right now I'm looking at adding TFS 215's, custom cam, a FAST 102mm intake/TB, dyno tune and 3.42's. Hopefully Memphis will re-open so I can get new numbers.

Bottom line is that Chris goes the extra mile every time. I'm thrilled with the service and the quality. And remember that this converter can be adjusted quite a bit for individual setups (stall speed, tightness, etc.). Hopefully Chris will chime in and explain this one better. This converter is used in a lot of high-powered cars but this shows that it works just as well in a cam-only, stock-cubed setup. I included some photos of the two converters and a video of the 11.70 run. It's not a great video as it was filmed from behind and above the car, but it'll give an idea of the launch. Thanks again Chris...can't wait to grow into this converter!

mikefirehawk0623

iTrader: (8)

that a big stall

DannoWS6

iTrader: (5)

Thanks for sharing the results. Great info!
I'm about due for a converter swap myself and those 2 companies are my top pics. I'm considering the SS4000, should give me a nice 1/8 with 3.91's. The PT series looks tempting but I think it might be too loose once the car starts making more power.

Circle D seems to make a great converter too, but I think I'm gonna give Yank a shot.

99Hawk262

iTrader: (19)

With those gears, you can afford more looseness. The SS4000 is so tight to begin with which is one of the reasons it's so popular. Just something to think about.

And good point about loosening up with more power. I've already discussed this with Chris and I think after this next round of modding my setup will be perfect. With this converter being slightly tighter than the Yank, I think the overall outcome will be positive.

algws6

iTrader: (3)

great write up. what was your first circle d stall? 4c,4+c,....? also, i assume your current one is a 5c?

Circle-D

iTrader: (21)

Ben's converter is a new design we have been working on for a while. It is the 230mm. The 4C, 5C... those are based on our 245mm line. For an all out NA setup like Ben's, the 245mm is limited to about a 4500 stall. With the 230mm we can get the stall a little higher and still maintain great efficiency.

Super write up Ben. I really appreciate all the time and effort you have put into this.

Just an FYI - this converter still has lock up so you can have your cake and eat it to. We have also made a few multi disks for some really interesting combinations.

Chris

algws6

iTrader: (3)

thanks chris. ecs just finished up my z06 conversion and are street tuning this week. i should have some feed back on my 4+ by the end of the week.

DrkPhx

iTrader: (15)

I'm n/a and wonder if the new 230mm would be any benefit for my setup? I run the 5C and my best run is in my sig (16" DR's). The 5C is definitely tighter and slightly more efficient than the PT4000 I ran (which is still a good converter). Lockup is very solid and the shift extension is around 5800 rpms. I couldn't be happier, but you know how that goes.

99Hawk262

iTrader: (19)

I bet it would work great with your setup....I'm far from maxed out, but I wanted something that I had a lot of room to grow in to, and would still give me great performance as I sit. I'm thrilled with the performance and am really excited to take this to the next level. There are a few members running this converter with big cube motors with outstanding results. You should give it a shot .

BTW, you were the biggest reason I started looking in to Circle D. I still have the PM where we talked about your results when you swapped.

DannoWS6

iTrader: (5)

Hmm well anytime you decrease converter size you have to make up for the low end somewhere. The smaller the converter the more gear/power you need as torque multiplication will suffer. It's sounds like a good converter for a lighter/geared car that really spins the motor (7k+). The 5c like DrkPhx has was also the converter I would be most interested in, maybe even more than this "new" design for a full weight weekend warrior. 230 is not a big change but I'm just generally speaking.

It's nice to see a vendor trying things and catering to the consumers. Plus seeing real world results looks good too.

TXCAMSS

iTrader: (60)

Looking at his previous runs you can see that his 60fts were slightly better in worse air so that loss of low end multiplication theory doesn't hold up. The converter design gives you what you need for a given combination.

We ran a Circle D 230mm converter in our car with 4L60E behind the 408 stroker. It worked great with high 1.29 60fts on motor and we shifted the car at 6600 rpm and it's a proven high 9 second car. It wasn't built to make power at 7000+ so why push it that far?

We run a tighter version of the Circle d 230mm behind our quicker 445 stroker and it pushed us to 9.3s with 1.29 60fts. We are now running the CD 230mm behind the 408 again with a powerglide and it is very efficient and deadly consistent.

We went through a few PT series converters with the 408 before we found the right conveter that would hold the power and maintain efficiency. The Circle D 5C and 230mm converters are absolutely great for a max effort set up!!!

DannoWS6

iTrader: (5)

Well technically the Yank 60ft better until the converter was restalled to a 5000. But either way It's splitting hairs, I was generalizing, many factors contrubute to running down the 1/4 on different days as you know. No doubt Circle D has put out some proven converters.

You have to remember the torque multiplication and efficency of the converter is in the strator design. With a smaller converter and smaller strator you have less fluid. The design of the blades evacuating the fluid will determin the STR. Having a smaller surface area you are giving up the ability to hold centrifical force of the torque multiplication. The way to make it up is the angle of those blades (among a few other tweaks) but it can also negate efficency (as you can see with the lower mph). By increasing the stall you are increasing the coupling speed and potentially loosing even more efficency but you do extend the torque multiplication effect. A 2.7 STR and 5000 stall looks pretty awesome if it doesn't drive like a underpowered snow mobile on the street.

Every car is different and every car needs a different converter to be optimal. On the extreme side there are reasons why you preferably don't throw a 7" converter in a non race oriented setup. Anyways I don't want to go on a tangent. I love reading up results of new setups and taking them for what they are worth. I will say for my own use I'm not 100% sure If I'll go with Yank or circle D next, but I know it is between those 2 vendors (as I already metioned to Chris at circle d ).

For me like many members who have a track/street car if I can get the same or better performance out of a converter that drives "friendlier" I'm all about it. If anything these results help to establish that.

99Hawk262

iTrader: (19)

I forgot to add that I have not been re-tuned for this converter. I don't know how much would really need to be changed, but I imagine it could be tweaked some. If time and circumstances allow, I may put both converters to the test again once I finish my current plans for the car. Probably not until fall though, I really want to upgrade the rear before I start hammering it again.

DannoWS6

iTrader: (5)

Thats a good point too. You might see minor improvements fine tuning those shift points. Any time you change converters you change the optimal mph/rpm between shifts even slightly. You never hit the limiter though right?

Yank

iTrader: (181)

Good write up!!
But it looks like you have the older PT4400 Extreme converter with the 6 bolt cover the newer PT4400 has 3 bolts and is a few LBS less in weight and this alone might yield a better 60Ft. time for you at the track.

TXCAMSS

iTrader: (60)

Those are all very good points and I can not argue with the technical info provided. The beauty of the 230mm is you don't have to have a sloppy feeling converter to get a 5000ish stall and the benfits it offers (shift extension and efficiency). Being able to keep the lock upfeature is an added bonus for the street driven cars.

I would love to see another back to back test with the new mods that are in the works. I know it's a pain to swap for testing purposes only, but that would be good info.

99Hawk262

iTrader: (19)

No, it shifts on the money every time.

I didn't know that. I assume it would take purchasing a new PT4400 to get the updated version? Are there other differences in the new model that are noteworthy?

Hell I'm a pro now.....I've got access to a lift and start to finish is only a few hours. I wish I lived closer to the track because I'd love to take a comparable FTI and throw it into the mix. Maybe I need to start from scratch at Centerville which is about an hour and a half from me.

Yank

iTrader: (181)

99Hawk262
The PT and all models are updated as new products and or processes designed by Yank are ready for release.
Over the past 2 years we have changed the PT 4400 with 3 updates which include Turbine blades,Clutch and Stator mods if you want more info on this, give a call with the date of your converter and we can review.
Thanks for the question about your converter.

StoneOfFire

iTrader: (1)

and how much monies was this 230mm 5k 2.7?

omore01

iTrader: (1)

Talk to Chris, he will explain it to you, figure spending about $700 on a single disk converter, and up to as much $995 for a top of the line multi disk converter. In my opinion, it is more than worth the money for the improvement in track times and better drivability. Their torque converters have positive feedback everywhere.

On a side note: I'm about to compare 2 different 4L60E torque converters: a TCI 4K stall single disk (current set-up) to a Circle D multi disk 3.6K stall (Thread soon to come). From what I have come to understand, the TCI single disk set-up will not hold the torque the car is currently making (at the lowest possible boost setting), let alone the torque it will soon be making .