i wanted to know the difference between a lockup and a non-lockup tc... which one would be better for racing and why? thanks guys, i really dont know smack about auto trannys, lol

 

A lockup converter has a clutch in it that effectively locks the two halves of the converter solid (no slipage) at hgihway speeds in 4th gear. This gives you better gas mileage and less heat from converter slip.

Most racing converters are non-lockup, because they are easier to manufacture, and less expensive. Once stall speeds get north of about 3,000 it is hard to find a lockup, becuase the converter manufacturers know that these converters are going into strip only machines.

 

since i dont know squat about tc's, im taking a stab at this... tell me if im wrong...

if i buy a lock up tc, could i install a switch to unlock it whenever i wanted to race and lock it when im on the highway to save gas? woudl this be ideal? thanks for all your help

 

You don't need to unlock it to race. The computer will only activate the lockup function in 4th gear. If you need 4th gear in the 1/4 mile you've got a much more serious car than I do.

 

so wuts the deal with all the stuff ive been hearing about unlocking a lock up tc and stuff?

 

You want it to lock in 4th gear only, but it needs to unlcok when you apply the brakes, or the trans downshifts into passing gear. In any other gear the converter doesn't lock up, so there's no need to even think about it with the factory system in place. The difficulty arises when people remove the computer and go back to a carb, or an aftermarket EFI that doesn't have a function for the TC lockup, or they just don't want to wire it in.

 

ooooo, ok, i think i got it now. most of my racing will be at the track, but some will be on the street when i'll have to go into 4th... you think it would be wise to wire a switch to unlock it if im going to run it in 4th then?

 

Is your trans modified to shift into 4th gear at WOT (wide open throttle)? If not then there's no point, because as long as your foot is in it you'll be in 3rd.

 

yes sir

 

I don't know if the converter being locked or unlocked has any negative affect on the acceleration of the car. At the speed where you'd need a 4th gear upshift at WOT (probably well over 100MPH) I think the effect would be negligeable.

 

When the convertor 'locks' what happens that you'd notice or feel? Does that mean in OD the rpm's shouldn't "fall" down to idle? (Mine does this in all gears.)

I think after a certain speed into 4th, the rpm's will "hold" and drop slowly as they should when I let up off the gas. (Rather than dropping right down to idle speed.) It does that only at a pretty high speed- not that fast, but higher than any legal limit in my state (55 max).

I don't know if I explained that well, but I'm curious if that is what locking/unlocking the convertor is.

If it makes any difference-
91 bird
3.1 fi to 350 carb
Computer is rarely plugged in
700r from a Caprice, don't know any more than that

Thanks,
Scott

 

When the converter locks at a speed lower than the rated stall speed the RPM will drop a little bit, but most likely not back down to idle, unless you are going really slow. This should only happen in 4th gear though.

 

For some reason, my converter locks up in 3rd or 4th, at WOT or cruising.

I actually like it though cause I can hammer on it and once it gets to about 4 grand in 3rd, I'll feel it lock up and the car kinda gets a little faster. I guess due to no slippage.

My rpms only drop about 2-300 rpms when it locks up also.

BTW, do you still post over at Stangnet TKO? Been a while since I've been over there...

 

i heard that if you lock up your tc, you actually go faster... i dunno though

 

I've never posted on Stangnet. I use this same handle on two WRX websites (www.fastwrx.com and www.wrxtuners.com), and eBay, but nowhere else. That's funny too, because I do own a Mustang...

 

That's wierd because someone who owns a GTA has a name very similar to yours. Not sure though, it's been a few years since I've been over there.

 

Wow, that is odd. There aren't that many of them left. Particularly the fastbacks like mine. Thanks to Gone in 60 Seconds the price on them had skyrocketted. Thanks Nick Cage!

My car is Raven Black with red GT stripes. The interior is black. I've got AC, t-signal hood, foldown rear seat, and not much else. Motor's a 289 4V (A-code), trans is a C4, rear is an 8" Traction Lock with 3.55s. It's been restored back to showroom stock, with a few minor modifications that can't be easily seen.

 

Sounds awesome. I hear ya about the Gone in 60 Seconds thing. Before the movie came out, I had a chance to buy an R code 68 1/2 GT that needed floor pans and some other little stuff. Factory front power disk car with A/C and power steering. Coulda picked it up for $1500

Saw one on ebay last month go for like $8000 WITHOUT THE FRICKIN MOTOR OR TRANS (and it was in worse shape!)

 

I hear that. I had a chance to get a '68 GT500KR for $7,000 plus my car in trade about 7 years ago. It was driveable as it sat, just needed some very minor detailing and a few apearance items to be perfect. My Dad wouldn't front me the money to buy it. I could have made thousands on it then. I don't even want to think about what they are selling for now.