badpanda

iTrader: (4)

Ok, so I am planning on putting in a Midwest Fab 9'', and while I am selecting gears, I thought that I would get rid of the Vig 4400 for something a little more efficient. I am currently running a 4.10 gear, but figured that since the car gets no track time, I should aim for something in the 3.5-3.7 range. I plan to keep the car as a 99% street car (but not my DD), and while I would like the car to hit relatively well off of the line, high speed efficiency is equally, if not a little more important to me.

I plan to keep the car N/A which is why I was originally looking at the pt 3800 or 4000 (I hear the 4400 likes the high revs/cubes and right now I am only H/C). But as of late I have heard of some really good reports comming out of the Circle D camp.

So my question is, are any of you running one of the above converters with one of the above gear ratios? (If your running a different gear, fill me into why you chose that one). Also, how loose or tight is the car? How efficient do you find it to be? Any numbers to support your whip lash? Also, if anyone has ran both in their car please chime in and let me know what they think about each.


*Edit: Btw, if you are running a Circle D, please list the specs

Thanks guys.

Patrick@LMR

I daily drive my Circle D 4C which is in 3800 range with a 373 gear. It drives great on the street but I don't have any good track numbers due to traction issues at the track. I can tell you I went from a 13.06 to 12.63 with a 1.98 sixty(due to poor track conditions and lack of tire)Only change was the Circle D 4C and a Century Stg. 3 Trans.

Hope that helps a little.

Patrick

badpanda

iTrader: (4)

Thanks for the reply Patrick,

I have read numerous threads on the pt 4000/4400, but almost nothing on the pt 3800 and only a couple informative threads about Circle D. So any information would be appreciated

TXCAMSS

iTrader: (60)

I have run quite few torque converters trying to optimize our cars set up. Of the Tcs I've tested included Yank and Circle D. Both Yank and Circle D make a great torque converter, but I found the Circle units gave us everything we were looking for in terms of torque multiplication and efficiency. I also have personally tried the PT3800. It's a good converter, but like most PT series converters, it likes a higher rpm powerband for it to really shine.

I ran the Circle D 4C when we were doing a lot of street driving and racing at tracks that had poor to marginal track prep. It is a tighter feeling converter and kept us just under our peak torque and allowed us to hook consistently. When the better air rolled around and we wanted all out NA performance we went with the Circle D 5C. It was the hardest hitting and best all around converter for us when traction was possible. We put the car on the bumper on the first test pass with the 5C after swapping from the 4C. I should have tuned the suspension for the change.lol.

If you do not need a lock up converter, they also make a very sweet 8" race style converter that has very good street manners and is very efficient.

Of course your vehicle weight, HP/TQ level, gearing etc will need to be factored in to get the proper build for your application. Give Chris at Circle D a call. He'll build you a good solid unit to meet your needs.

I hope this helps. Good luck!!

badpanda

iTrader: (4)

Thanks for the reply TXCAMSS, this is exactly the sort of information and comparisons that I am looking for. Btw, what gear ratio were you using with the Circle D 4C?

Thanks

cals400ex

iTrader: (27)

i recently purchased a pt 3800 but i don't have the car up and going yet. i am not saying this is the one to go with because i have nothing to compare it too, plus i don't even have any time on it. the pt3800 isn't even listed on their website unless they changed that recently. i know they made it a while back and then stopped if i remember correctly. however, it came available again. i don't know how the older version is but the one i have has a str of 2.0. the car will not be going any time soon with my school schedule otherwise i would give you a report.

SSIRBY

iTrader: (44)

i have the pt4000 and love it. just working on getting the suspension and hooking dialed in. my best 60' was a 1.56. also running a 4.11 gear. its good for street and strip also. full weight car also. hope this helps.

badpanda

iTrader: (4)

Hey SSIRBY, sounds like a good set-up, is the 4.11 gear keeping things nice and tight?

SSIRBY

iTrader: (44)

yep. and no whine at all from the rear. i thought that my speed was gonna change down the highway but it didnt. i'm running a th350 right now with 28 tall tire and at 3000 i'm running 65ish. and when ya just wanna get on it in 3rd while ya cruising, it throws ya back. my friends love my car also. what tranny you running?

SSIRBY

iTrader: (44)

and i have the yank eliminator since i'm running a th350, not the pt..

DannoWS6

iTrader: (5)

I'm interested in this also specifically the PT4000 vs Circle D.

Any advice on what would work better in my car regarding the 4C or 5C? Car is about 3600lbs race weight, H/C shift at 6,600, 3.91 gear 12 bolt. Potentially I want it to work behind more cubes as well, but still wont spin to 7k.

Regarding drivability, if it has a lockup clutch than it's driver firendly in my book. I want the best track performing converter.

badpanda

iTrader: (4)

4l60e- FLT level 4

JohnDaMan

iTrader: (7)

I had a 2E 3800 stall from Chris @ Circle D. It took a few days to get used to, but from a roll this converter was nasty. The car picked up A LOT going from a stock stall to the Circle D unit. As a benefit acceleration felt a lot smoother too. I would say with that stall you need shift points of 6+k rpms to maximize the benefit. I was running a stock cam and felt like it needed a few hundred more RPMs to better use the efficiency of the converter.

TXCAMSS

iTrader: (60)

IMO - The 5C is ideal, especially if you are going with bigger cubes later down the road. The PT4000 is a pretty decent track performer, but won't work very good when you step up to the stroker. The 5C has a slightly lower shift extension and will provide better 60fts.

Your best bet is to give Chris a call so he can best match the right TC to your application.

DrkPhx

iTrader: (15)

TXCAMSS summed it very well and helped me alot when I had similar questions. Definitely give Chris a call. He's a nice guy who will make sure you get the right converter.

I went from a Yank PT4000 to a Circle D 5C. I'm going to the track next weekend, so hopefully I will have good results to report back. The shift extension is not as high on the 5C (about 5600 rpms vs 6000 for the PT4000). It has a solid lockup and is a great 'frum roll" converter if that is your thing. Street manners for a large converter like this are not as bad as you would imagine (no looser than the PT). Overall I'm very happy with my choice.

SSIRBY

iTrader: (44)

the circle d will be my next choice to experiment with.

kdavis

iTrader: (14)

I am running a 4c in my trans am. It is my daily driver and i have 342 gears. i love it. i have hit 1.6 60s on the motor with all stock internals. great converters. went from 13.5s to 12.5s with converter and headers swap.

badpanda

iTrader: (4)

Thanks for the info, I am starting to lean more and more towards Circle D.

ws6t3rror

iTrader: (3)

I have a circle d behind my lt1 Chris was great to deal with. I asked him what he suggested for what I wanted and called him up later that day to order. Two days later I had the converter in my hands. Its a full size street stall that behind my engine will hit about 3000 rpm. I drive it about 500 miles a week and have had it for probably 12k miles now. It literally basicly drives like stock, the difference at the track has been substantial to say the least. I was stuck in the lower 12's before the stall, and after quite a bit of rework on the suspension and my launch technique to get it hooking again I am now in the low 11's, my trap speed actually increased with this stall over the stocker.

The lockup clutch Chris uses is no joke either, that baby locks up HARD. People think its another shift when they ride with me.

I plan on dealing with them pretty much exclusively in the future, he was very up front with me about what the converter had in it and why he chose that to fit what I wanted. When I called they had to go out into the shop to get him, which imo is always a good sign, it says alot to me that he would be out there next to his employees rather than hiding behind a desk all day.

KBG

iTrader: (32)

+1 ...that joker locks up so hard it feels like a WOT 1-2 shift!!!!

I have the 4C on my daily driver.....went from a 1.7 to a 1.6 60 ft (previously had a Yank SS3600) with stock springs, shocks, struts, etc.