Originally Posted by DaveRS23
Originally Posted by mxbeep
searching for a quality street/strip torque converter, not looking to cut corners or cheap out, which brands need to be avoided and which are recommended.

going into a well built 727 behind a 512ci A-body with 3.55's, 28 inch rear tires, 3000 to 6000 rpm range. i'm considering a 3000 rpm stall speed, your opinions?

thanks


Getting a converter to flash as much as you want with your combo will be no problem. And getting an efficient converter is not hard either. The biggest problem with converters on a street combo like yours is getting a converter that doesn't drive like a weak clutch on the street. 3.55s behind your high torque engine will mean that with any throttle on street pavement, you are either gonna hit the tires hard enough to not go anywhere, or flash the converter up.

The comfort zone on this is a matter of personal preference. Many guys lean towards the race feel of these converters just like they are okay with big bumpy cams. But the more a guy wants a stock feel to the car on the street, the harder it becomes to get a converter tight enough.

I have struggled with this for years. First with the 500 wedge and then with the 540 Hemi. With light throttle, the converters would move the car out just fine. But if I crowded it, they would usually flash to 4,000+. PTC was my go-to builder. I talked to them and others about this and they said the problem was that there just weren't any cores big enough to hold our big torque combos down. After several converters and many conversations, I ended up sending my PTC converter (which they had tried twice to get where I wanted it) to Lenny at UCC.

In the end, Lenny said that there was a limit of how tight they could build converters for this application because there just aren't the cores and parts to do it. What he did was to tweak what I already had (no real secrets or anything) and told me to run a BIG cooler to keep the fluid as cool as possible to maintain as much viscosity as possible. The final piece of advice from him was for me to run John Deere Hy-Guard summer fluid with just a touch of ATF to give it some color. He said that most hydraulic fluids are a compromise on viscosity with only one grade. JD's summer is a higher viscosity and as you know thicker fluid lowers the flash and 'tightens' the converter overall.

As a result, the car is much tighter around town. At low speeds, I can crack the throttle and the car lurches forward much more like the OE stuff did. Not as tight as OE, but noticeable better than before and maybe as good as I can get. In that 1,500 to 3,500 RPM range where we spend a lot of time in casual driving, the car just feels crisper and more responsive to the throttle.

You did not say how you were looking for the car to drive around town, so this may not even matter to you. And most discussions are centered on flash and stall and such. But those do not really tell the tale of how the converter feels down low when tooling around town. Getting a converter for your combo to do almost anything you want is not a problem. Except for getting a tight, crisp feel down low.

Again, this is all a matter of personal comfort and preference. Not a matter of right and wrong. I was just hoping to show a side of this that is often not discussed. In case it matters.


thanks fornyour detailed response, i ahgree with you 100% and plan on having the same struggles, i also am looking for a fairly ''tight'' converter that i can drive around town or the highway at 2400-2600 rpm without slipping