Drive or Overdrive???

[billsgn]

I'll get right to the point.....

When running the 1/4 mile, is there any performance advantage to leaving the shifter in drive vs overdrive? The reason I ask is because with my car, I need to shift into overdrive before the traps. I "heard" that the transmission would perform better in first and second gear if the shifter is left in drive. If this is not true, then I would prefer to leave the shifter in overdrive and not have to worry about consistant shift into OD....

Thanks, Bill

 

[turbot2112]

i just leave it in drive. i guess you have lower gears than 342s?

 

[billsgn]

No, my car still has the stock 3.42 gears in it. I cannot leave it in drive unless I want to buzz my engine over 6000 rpms. This usually happens at speeds over 125 mph....

I have to shift into overdrive and so my question is...."Is there any performance gains in leaving the shifter in Drive and manually shifting into overdrive or can I simply leave shifter in overdrive at the line"?

 

[turbot2112]

well i guess leave it in drive and then hit overdrive. not sure cause my car is probably a slug compared to yours. nice mile per hour.

 

[tonka]

Seems to me this is the point when most go to a 28 inch tall tire to keep the rpm down at the top of 3rd. From everything I've read, OD and racing do not seem to be a good mix.

 

[UNGN]

If you leave it in Overdrive, it will likely shift to 4th too early.

When it starts nosing over put it in OD. If it shifts itself, it might go into OD at only 95 mph (vs. 114-120 manually)

Also, you should be running 28" tires.

 

[billsgn]

I run 27" tall tires now....next set will be 28's, however I plan to notch the frame rails and run a wider wheel.

Thanks for the replies guys. I think I will try a pass with shifter in OD and see where it shifts. I have been running in Drive and manually shifting into OD just before the traps...maybe I'm getting lazy!

 

[87LtdT]

Bill, I only run 115 range but during test blasts I've accidentally left the car in OD and when it shifted it was in the 100MPH range....(stock 3.42 rear end). And the acceleration really dropped off....

The point is, I'd leave it in D and shift as late as possible.

Good luck, Bob

 

[billsgn]

I actually tried leaving it in OD and letting it shift on its own. I guess my tranny is working good because it didn't shift too early. In fact, the car ran 10.90's.

I wore the 27" tall tires out and decided to go with 26x11.50's. The car still ran a 10.88 @ 124 mph. I am going to a BOP race this sunday and plan to turn it up a notch and go for a 10.70.

 

[Slow91z]

I asked the same question a couple of weeks ago and Bruce told me that the tranny would rather be in OD...He said he leaves his in OD al the time...That was good enough for me.

 

[wistleofdeath]

I don't run the crazy MPH like you guys run and I have the same problem. I need overdrive to get down the track. I have the stock 3.42 gears and if im not in overdrive my motor wants to hit 6000 at the track.