OD or no OD?

[darkred87T]

I'm going to the track this Sunday. I'm already running mid 12's and I'm hoping for at least low 12's this Sunday. The last couple of runs I made I kept it in third and trapped 108MPH. I have 245/50 Dr's on the back. What do you guys think? Should I let it go into Over Drive? Also, my Extender chip has and option where I can set the SES light as a shift light. Does anyone manualy shift on their runs? If so, what RPM?
Thanks,
Mike

 

[XLR8]

I let the car shift itself. You can try making a run in OD but I bet that you lose 2 mph. Are you locking the TC? If not you may want to do that.

 

[darkred87T]

Thanks for the quick response.
I'm not locking the TC right now. That's another option for the Extender. What MPH would you suggest lockin it up?

 

[pacecarta]

stock converter , 89

 

[darkred87T]

Great thanks and I am running with a stock converter.
One more question, I heard you can use two of the wires on the ALDL plug and hook up a switch for a munaul lock up,. Is this true? If so which wires?

 

[pacecarta]

pin F and ground (pin A)

pin F is top left and pin A is top right

http://gnttype.org/techarea/electrical/switches.html

you can progrm it in chip so no need for switch

 

[darkred87T]

Thanks, I rigged a switch and field tested and it worked. I'm running pretty consistantly @108. I tried the swich on my run twice and got the same MPH but who knows, there could be something else holding me from a higher trap speed.

 

[ITSNOTAGN]

you really really need some taller tires and you would probably pick up a good 2mph, i went from a 235/60 drag radial to a 275/60, same 60' and was faster and quicker everywhere else, picked up an average .18 and 2.3 mph on 3 runs, but i also had the stock valvesprings limiting my powerband to about 4400. but i also was trapping 109 and ended up with about 112 after.
Gary

 

[pacecarta]

i have had similar results , the taller tires will increase MPH but mph doesnt mean a thing if your ets go backwards , and they will with the power you are at and a tall tire

locking at the 1/8 i run the same mph at the top as i do locking at line . My MPH pickup locking at the 1/8th is greater than locking at line but my 1/8 mph is lower
locking at the line my 1/8 mph is up and et are lower and my 1/4 et is lower
if i dont lock i loose about 4mph 1/8 and 1/4 and lose more than 2 tenths