I finally have a bulletproof rear end in my car, (Moser 9" 33 spline axles 4.10's and spool). Im still running the stock converter with the stock tranny w/shift kit and cooler. Motor is stock with headers, cats deleted with dynomax. Ram-air thru foglights with BBK throttle body. MSD box, A/C delete, smog delete, TPIS custom prom, 160 stat, 150 shot of nitrous. 255/50 16" MT drag radials. Chassis mods are Spohn sfc's, drag struts/shocks, lakewood lift bars, front swaybar removed..
On the motor the car runs mid 13's around 101mph. with 1.8 60''s. On the juice its running 12.0's around 114mph with 1.7 60's. The car seems like it runs out of steam after 4500rpm.
My questions are:
what is the stock stall rpm?
How much improvement will a mild stall give me?
Will the new converter be hard on my 140k tranny?
Would it be better to put the money towards higher flow runners and plenum?
thanks.

 

All converters "stall"

You want a converter to match the cam grind. A properly matched converter will allow the engine to get into the cams powerband quicker and keep it there. All the other components of the car also need to match the cam grind.

Most stock converters stall around 1800 rpm. A mild upgrade to 2200-2500 will normally work with a stock cam.

 

Will a 2500rpm stall do much for lowering my ET?

 

It should improve the 60 foot, there for decreasing elapsed time to get through the quarter mile traps.

 

Any idea how much it will help? I will definately do it if it shaves .2 seconds or more of total ET.

 

All converters aren't created equal. They can be different physical sizes (rotating weight and multipliers), flash speeds, and internals (anti-balloning plates, non-lockup, lockup).

The cheaper converters are just advertised RPM, which can differ depending on the torque output of the motor, because they're just pulled off a shelf and handed out. More expensive ones normally are custom spec'd to your build and sometimes even give you an option to send it back again to get it changed to a different flash speed.

They also make lockup and non-lockup converters. Lockup converter needs to be used with a lockup style transmission to function but it reduces the slip of the converter at higher speeds such as highway use. That basically keeps the converter from flashing when you drive down the highway and step into the gas a little. It should unlock the converter if the brake is used, lots of throttle used, and etc to prevent the motor from stumbling. At least that's how my custom soldered wiring is setup.

When I ordered my ACT from Pro-Built Automatics Dana recorded my CI, transmission, rear gear ratio, camshaft specs (I found them in the Haynes manual), and the purpose of the car. At that time I was seriously thinking about an ATI procharger so it was stated with some boost it should be flashing around 2800+ RPM.

My stock 350 TPI seemed to wake up quite a bit with a 2400 RPM 9.5" converter. That being said I lost some time off the 0-60 mph with street tires because of the increased torque off the line. Not only was this due to the RPM increase at launch but the 9.5" had a slightly higher torque multiplier.

As mentioned above you'll want to match your entire combo to the converter selected. I consider lockup a must for street use. It's not fun driving around with a slightly "loose" converter with crap gears like 3.27s. Anyways I'm rambing now.

Here's some quick links:

http://www.carcraft.com/techarticles...ers/index.html

http://www.carcraft.com/techarticles...ers/index.html

 

thanks for the good info fireturd350.

 

I'm late on this but 2400-2800 on that motor will drastically drop your ET, especially on the shot.

You are only 1.7's on spray. My exhaust only L98 with 2800 stall on slicks was doing 1.75's and few more bolt ons/gear/tune later, hit 1.70-1.71.

Your car on spray with 2400-2800 ish will do low 1.6's easily and get you atleast .2 ET and likely more.

Spec the converter to stall at 2600-2800 on spray and it should be abit lower on motor alone.

 

Trav,

I have a new 2200 - 2500 rpm lock-up converter that came with one of my 700's... Let me know if you want it.

 

that would be great Mike! What would you want for it? You could have my old one too.lol

 

Drive up to Madison and you can have it...

 

wow! I can't beat that deal! I can at least buy lunch somewhere. What is a good time? I work second shift. I can come up on the weekend.

 

I'll be around on Saturday afternoon... I work OT in the morning. Check your PM.