TC's and shift kits...

[firebird1]

hasn't been a topic on TC's in a while. i need some #'s and some opinions.

looking for a converter to fit my needs.

absolutly streetable.
mpg not that important.
mostly street driving under 50mph.
shorter 1/4 mile times.

with a transgo kit and servo, is a Trans cooler the safe way to go? this will take care of my firmer shifts. but how much will it be in the way when a SC or turbo install happens?

[Arctc Wolf]

"streetable" is different for everybody. for me, i want one that is balanced as far as efficiency and torque multiplication. my TC will be 2.5 str and 96.8% efficient w/ lock-up. urs may be different. As far as shift kits go, KDS performance has some killer kits. their shift kits/rebuild kits go from 300 all the way up to 1250. I've found some cool stuff on there. the 2 things I like the most are the servo's they have. their main servo is 35% bigger than the corvette servo, and they also have an overdrive servo for shifts up to 4th and down to 3rd, so when the car downshifts from 4th to 3rd when u step on the gas, it engages quicker and isn't as sloppy.

[firebird1]

wanna translate that into something i can understand? i havent really read up on TC's.

[Arctc Wolf]

torque converters have 3 main values that mean something to us drivers. Stall rating is one of them. The stall rating is at what rpm ur car will launch at when u floor it off the line. this is usually matched to the powerband of ur motor. if ur motor is gonna make a bunch of torque in the low end, the stall rpm will be lower. if it makes it's powerband higher, then the stall rpm should be higher.

The 2nd value is STR. STR is the number of times the torque converter multiplies the torque coming out of ur engine. so, say u have a TC with a stall of 3000 rpm, and ur motor makes 200 torque at that rpm, and the TC u have is rated at 2.5. 2.5 times 200 is 500 torque. this is only good off the line tho, because the multiplication goes down as u build up speed untill it just sends normal engine torque to the rear wheels.

the 3rd value is efficiency. since the TC isn't mechanically connected to the motor, u will lose some power through it. the efficiency rating tells u how much power is being transmitted through the TC to the rear wheels. a 97% efficiency rating means that 97% of the power ur making is getting to the rear wheels. this is only applicable when ur not launching off the line.

how this all comes together. STR and efficiency go hand in hand. more efficiency means that less str will be made, and the opposite is true, the mroe str, the less efficiency. on the dragstrip, a high str will get u a great launch off the line, but the car won't pull as hard at the end because of the lower efficiency. also true, u might get a crappy launch, but if the converter is efficient, the end of the run will have a higher mph.

The TC i told u about is the one that I'm looking at getting. it's a balanced one, with good str and efficiency.

oh yea, 1 last thing, for highway driving, u shoudl get a TC that comes w/ lock-up. this is a mechanical thing that ties the motor directly to the tranny so u get better gas mileage.

[Chuck Wilson]

What converter would that be?

[Arctc Wolf]

a custom made Edge TC. already talked 2 andre about the specs being 2.5 str and 96.8% efficient. haven't decided on the stall yet, but we'll see.

[firebird1]

let me know what stall you decide, what did u hope to achieve with these specs? maybe get a lower price on two? ;)

[Arctc Wolf]

edge already has great prices. i was quoted around $450 for mine. i'm looking for about a half second drop on my 1/4 times since i'm at about 14.8-14.9 right now. keeping traction with this tc will drop me maybe another tenth or 2.

[firebird1]

anyone have more info on this "wake up kit"?

will replacing all the servo's or clutch packs give me what i want, making the transgo obsolete?

im not interested in changing shift points at all.
i was thinking around ~3000 for stall speed, but i like the 96.8% and 2.5str

[ October 29, 2003: Message edited by: firebird1 ]</p>

[Arctc Wolf]

yes, adding more/replacing clutches and adding bigger servo's will make the shift kit obsolete. also, shift kits tend to wear out tranny's more because of the increased fluid pressure they cause. The 2 ways to stiffen shifts in an auto is to increase line pressure or replace the internals with parts that will hold more torque. the stock internals are meant to have a certain pressure placed on them. more pressure will make them wear faster. upgraded components will be made to take the extra torque and still last as long or longer. Check out these shift kits: www.kdsperformance.com/4l60e4.html These seem to be the best value out there, plus they also seem to be the most advanced and complete kits that I've found.

The 3000 rpm stall seems to be a good point for our cars. Most people here w/ TC's have stalls in the 2800-3300 rpm range.

[White95]

How hard is it to install a kit from that site? Has any one tried it before??

[Arctc Wolf]

servo's can be installed while the tranny is in the car. Many guys on here have swaped in bigger servo's before in a few hours. As far as the rest of it, I have no idea. I would assume u'd wanna have a reputable tranny shop do the work with any clutches or the rest. I know someone on here has a tranny kit from KDS, but I forget who.

[Pro Built Automatics]

I have found that the "modified" Trans-Go Performance Shift will do everything that is needed to keep these units alive without the oversize apply servos, in everything up to 650+ horsepower. I do change the 3-4 clutch count to either 8 or 9 Borg Warner Hi-Energy's, depending on what is needed/required, same with the 2-4 band, Hi-Energy. I have found that the Blue Plate Specials do not offer anything over the Hi-Energy's, in fact they do not hold up quite as well on the street. The Hi-E's are about 1/3 the cost of the BPS's. The 5 pinion planets are a waste of money in most cases, the 4 pinions are not known to break. The GM HD sunshell or the Sealed Power "beast" is a good improvement. Add the HD input drum when going over 550-575 horsepower or HD 4wd off road vehicles. If the pump came with a 10 vane setup do not change it to a 13 vane setup, there is more than the just addition of a 13 vane rotor on the late 4L60E's. I hope this helps.

[Bliggida]

Every automatic tranny should have a trans-cooler. The radiator only done an "acceptable" rating for stock vehicles. You start adding power and driving hard...you need more cooling capacity.

Also, I would reccommend a deep sump pan with a drain plug, and a filter relocation kit so that you can use a spin on style PH8A oil filter. That will allow you to change out your tranny fluid as easy as an oil change. About every 4 oil changes (or 20,000 miles)

[Jerriko]

I use a 3200 stall TC in my car. Granted, I am still using a 2.8L (haven't had time to install the 3.4L yet) but the difference was very noticeable. At the same time, I also completely rebuilt the rotating assembly and installed a shift kit from TransGo. All of the planetaries were replaced as were the shafts. The trans operates far more efficiently and seems to have less parasitic draw since my gas mileage has improved. I would like to point out that stall speeds are calculated by power braking. That is, while power braking, the rpm that actually makes the car move is the stall speed of the converter.