shift kit, torque converter, valve body

[tyler_s18]

so one of my friends wants his chebby to go faster. he said his tranny was chewing up power. so he thought of a shift kit. what do they do? i suggested a high stall torque convertor. what are the pros and cons to them? and if he wants it more for the strip i suggested a manual valve body. i am a stick shift guy so dont know much about autos but would still like to learn more so tell me what you know about how to get more power to the wheels thru an auto tranny in general

 

[69B-Cuda]

Here is how the shifting in an auto was explained to me.... when an auto is shifting from 1st to 2nd, it is more of a controlled slip between the 2.... 2nd gear starts grabbing, and 1st starts slipping.... 2nd grabs more, 1st slips more, finally, 2nd is engaged all the way and 1st is disengaged. The more slippage, the softer the shift. Slippage = heat and wear... not so good on the tranny but it makes for a nice smooth shift. A shift kit, cuts down on that slippage, giving you a "harder" shift which, while not a smooth and comfy, it is better on your tranny (less slippage, wear, and heat). I had a manual shift body in the tranny in my Willys wagon, it was GREAT for wheeling, I don't have a full manual valve body in my cuda but I do run a shift kit...

 

[fishy68]

First off your friend don't understand auto transmissions at all or he'd know they all use up some hp due to friction and a shift kit will do absolutely nothing to remedy that. All a shift kit does is make the shift quicker or in another term firmer. A good kit always improves the action and life of a trans. Think of a high stall converter like this. Test #1, when you race your 4 spd. car pull up to the line and give it just enough gas to rev 1200 rpm and let out the clutch. Test #2 pull up to the line and give it enough gas to rev the engine to 3000 rpm and let out the clutch. As you know it'll take off much faster revving it to 3000 rpm before you let out the clutch. A high stall does the same thing. It lets the engine rev higher before it takes off allowing the engine to get up into the higher power rpm's before taking off.

Pro's are the car will be faster and if your running a big cam it lets it idle in gear better since it slips a little. Cons is it creates more heat so a external trans. cooler is required if the stall is over about 1800 rpm. Another con is you might get less fuel mileage.

A good shift kit and higher stall converter will most definitely make it faster.

 

[tyler_s18]

ok lol. he knows some but not a bunch like me lol. i know what he is feeling and it really feels like something in the tranny is holding it back. i think the crispness of a kit would fix it up pretty good so i think he is gonna do that then if he still wants more he will do a converter. its just a 3.8 regal na so there is not a whole bunch of power yet just potential

 

[fishy68]

The 3.8 is a good engine but if it's naturally aspirated sure isn't going to be fast in a heavy Regal unless you do quite a few mods. What he may be feeling is just a lack of power more than a problem with the transmission. The best and first thing he should do to it to make it quicker is install lower gears to help get all that weight moving. I seriously doubt a shift kit will improve the performance very much at all. Just make the transmission shift crisper. If he's lucky that might knock off .1 sec in the 1/4. If it's a 700R4 there a major PITA to install a shift kit on. I helped a buddy of mine do one for his S10 and it took both of us some finagling to get the new pressure relief spring changed in the pump. What a stupid design. If it's a 350 turbo there not bad to install a kit on and the B&M kit works fine.