hey guys i am very seriously lookin into burning my own chips. i have recently installed a vigilante 2600rpm stall converter and i am going to want the converter to lock only at highway speed like 45mph or higher. i know i can change this by burning a new chip, but my car is an 86 305TPI car, how does the computer know how fast the car is going? i dont have a VSS or anything. one of the biggest reasons i want to burn my own chips is to change this setting but if i cant change it, then it may not be worth it to me to buy the stuff to burn my own chips. thanks for the help guys.

 

If the car is stock it has a VSS. Look for a lime-green box in and around the instrument cluster. Three molded together wires up to the speedo, and a connector on the other end.

RBob.

 

woah so there is a speed sensor connected to the speedo somehow? that is amazing i didnt nkow that at all. the car is all original so i am sure it has that up there, i was just unaware that we had a VSS up there. cool thanks for the info

 

Increasing your minimum lock-up speed is a trade-off that is not to be made lightly.

I increased my lock-up speed to 50mph before last summer. Since my car isn't a daily driver anymore, i preferred to keep it loose during low speed driving to keep the power always on tap. This did 2 things. It about killed my cruising gas mileage, which isn't a big deal and also could have to do with i was driving it in a more spirited fashion compared to the old DD figures i was comparing to.

More importantly, the tranny ran A LOT hotter. The difference between locking the converter at 35mph and 50mph in stop and go traffic and low speed cruising up to 45mph was a solid 20-30°. With the converter locking at 35 i rarely had problems keeping the tranny at 165-ish. Waiting to 50, since it would never lock, it would easily get up to 195 if you weren't careful.

Just something to keep in mind. 40 isn't a bad number to go to, just warning you in case you decided to go higher down the road.

 

You could always install a lock switch.
Making the prom lock and unlock as you wish is a great feature but I also wired a ground switch to mine , allowing you to keep it locked as much as you want, and not come unlocked while on and off gas.
Since installing a 4200 stall in my car this winter, needless to say I keep mine locked as much as possible.

 

The lock up convertor locks in 4th gear anyway and from what I have heard and been told is not to run in OD unless doing 50mph+. If you use OD in lower speeds you will reduce transmission life. You might be saving some $$$ on gas and have better mileage but you are hurting the transmission.

I mean that is the same as driving around in 6th gear doing 30-40mph don't think many people do that.

 

.The stock AUJP code locks in 4th gear at 38 mph.
My stock 87 prom locked @ 41 with a 2.77 gear.

Stock LT1 and LS1 6 speed cars skip shift from 1st to 4th gear.

 

Yeah that's if you leave the car in OD if you leave it in D around town you are never going to lock the convertor. Once you get on the hwy etc then throw it in OD and the lock convertor settings take place what ever you have it set to.

All I was saying that it is bad on the transmission running in OD under 50mph.

 

Not trying to start an arguement or bust your ***** but you are wrong, If you leave the car in (d) or (od) it does not matter converter still locks when commanded. which is 38 mph for high gears and 36 for low which is second gear - thats right the converter even locks in second.
I also don't know who told you its bad on a tranny to run in od under 50 - the only time its not good is if converter is (unlocked) and you are running an RPM below the stall speed for extended period. In which case you are promoting slip of converter and causing excess heat.
Some time motor co. do not want you to LUG the enging because sometime it has been thought to show premeture bearing wear.
But in the case of the TPI engine that makes peak torque very low in the RPM band, you are kinda hard presses to lug the engine.
Which is also where the skip shift came into play, If GM thought it caused excessive wear on the bearing the never would have incorperated the first to fourth skip shift. (which is very annoying if you have ever driven a 4th gen 6 speed without it disabled)

 

You are right about it locking in lower gears to I was wrong in thinking it only locks in OD. So much BS gets thrown at you everyday it is nice that you can get all things straightened on here

 

thanks for all the info guys. i was gonna run a big tranny cooler to combat heat. i just dont want the converter locking on me arond town stoplight to stoplight under cruising conditions. i also am running a vigilante converter, i put the tranny back in this weekend but i havent driven the car yet, but i am told this converter will stall at advertised speed but is tight enough not to slip alot at part throttle. maybe i am wrong about this i guess i will find out when spring gets here

 

2600 will be no problem at all.