Normal to feel torque converter lockup?

[Stranger in the Black Sedan]

Hi guys, I have a 23k mile Marauder I just picked up a few weeks ago. Of course I have a whole laundry list of things I'm going to eventually get, including the race tuner so I can modify the TCC lockup speeds (I have experience burning chips for other cars). However for now I just want to verify there isn't anything wrong with my totally stock car.

We all love how the converter clutch will lock as early as 25 mph at light throttle. When it does lock, you can distinctly feel it clamp. It is not like it bangs or anything but it is not the imperceptible TCC lockup that just about every other car on the road these days except our cars have. If you jump on it right before the converter is ready to lock, you'll definitely feel the converter lock noticeably. I assume this is normal and these transmissions are just built like 30 year old Detroit typical stuff?

[Blackened300a]

I have my Lock-up come in at around 58MPH and it feels like another gear has been shifted. So yeah this is normal

[MM_BKK]

I programmed mine to lock up at 43MPH if TP voltage is less than .39V in 3rd gear and 52MPH in 4th. When it does lock up, I can feel it and see the tach drops about 200-300 RPMs, it's like a poor man's 5th gear. I have it programmed to NOT lock up at all in 2nd gear. That was annoying in the factory tune locking in 2nd! I also programmed the EEC to not modulate any engine torque while shifting for a much better shift feel. :D

[OneBADLsE]

I can feel the lockup going in and out under WOT between 45-70. ...assuming a tune with eventually fix that

[JohnE]

With a package like the pro racer from SCT, you can tune the TCC to whatever you like. There are many items which are available to control lockup. One of which is the speed ratio across the torque converter (Engine Speed vs. Trans Input Shaft). If done right, you can setup the TC to flash off first, prior to locking. This can give less abrupt locks by lowering the speed difference a lock makes. It allows the best of both worlds of having a lockup TC.

There is a steady state low rpm slip feature used in the factory settings in a few gears under certain conditions. The converter clutch slips about 12 rpms, giving a little softer coupling between the engine and the rear end. Most people set this to zero for performance feel and to reduce heat generation. Some value imperceptible changes and want to utilize items like this.

Of course you can slow the lockup rate, to make the lock take more time absorbing the speed difference across the converter clutch. Cost is heat and friction material durability.

Keep in mind that an open converter looses crank energy to heat, all of the time its unlocked. Locking in 2nd gear, helps keep the engine rpms down and the partial pedal power to the wheels. Yes you can obtain a more performance feel by leaving it unlocked, but understand the trade offs. Those with high stall converters pay even more fuel economy to heat generation.




John