Right now I turn Over Drive off when I run. With my 26" slicks I'm way in the red going through the traps in 3rd gear(~5600 rpm, I think). Makes me wonder if I ever go faster and max 3rd out what will happen if I have to shift to OD. Is it bad for the tranny? Will it hurt my time? I guess if I do go faster I should invest in 28" slicks, just curious about OD though.

 

69Roadster
I think turning the OD back on will slow you down... JR

 

Have you considered going back to 3:55 gears?

 

3.73's w/ 28" slicks work well...

 

If your truck is mean enought to wanna shift into overdrive when going down the 1/4 then i would say yes. Some of us like me, for example, do not have the luxury of that problem!

 

wtf 2 posts? freebie for me!

 

That's one that doesn't come up very often, I've always told people to leave the OD on because in a 1/4 mile you never get there anyhow, but if you top out at 5600 in third, you may want ot try it both ways and see if you get an improvement, we don't really know where it would shift if you let it, may hurt the time or help it, hard to tell. I don't think it will hurt the transmission to let it shift if it wants to, I'd say give it a try and see what it does to the ET.

G

 

If for no other reason, the truck will behave more normal as you get out of the gas at the other end. It is hard on the rods go 5000 rpm ithe no load on the piston tops as you back out of the power. The truck does not get weight all transfered forward when you least need it to pull a huge downshift like move. If for some reason you need the brakes at 105 MPH you are in huge trouble if you are locked in 3rd at 5000

Andy

 

Thanks for the replies.

I'm closing in on 114 mph. The truck definitely shifts into overdrive if I don't turn it off. Now that I know it is safe the next time I go to the track I will make runs with OD off and on and compare ets. Will make a good experiment.

 

keep us posted on the results with the OD on and off......JR