Ok, so Ive never had an automatic before, but my new car is one, so i guess ill have to learn. I know a little about left foot braking for launches and stuff but I was wondering... Should I use overdrive when racing? street? strip? highway?

 

There are a few threads about this topic in the auto trans section. You might want to do a search there.

Personally, after doing a lot of research and testing, I just stick with leaving the shifter in the "OD" position for a Camaro (shifter goes OD-D-2-1) or "D" position for a Firebird (shifter goes D-3-2-1), for ALL types of driving or racing.

 

When running an 1/8 mile when my car was stock i left it in 2nd. Just bc i could finish at the top of that gear @ 84mph. If your running the 1/4 then you should prob put it in 3rd which is actually drive so that it wont shift into OD at the end and cost you extra time. When i street race from a dig i leave it in D bc the race usually ends at end of 2nd or middle of 3rd so im not worried bout it shifting into OD.

 

i like dropping it down to 2nd. ive learned that from a roll, you launch better from 2nd.(well at least in my car) but everyone has their own opinion. youll get alot of people that will flame you for even thinking about manually shifting an auto. but it wont hurt your tranny if you do. and from a dig, yes leave it in D.

 

The transmission is designed to shift at high RPM's in worst case scenario so I dont see how manually shifting it would hurt it either. Ive manually shifted mine on the strip, dont know if I had any gain/loss due to it.

 

mine is 3 tenths faster in the 1/8th by manually shifting got slips to prove it

 

just leave it in OD and let the computer do its job!!

 

yeah I leave mine in OD all the time

 

You're not going to gain anything by shifting manually except more wear on your transmission. Let the computer automatically shift at redline and you'll be good to go.

 

yea Id let the tranny do its job

 

i leave mine in od on the street and d when im racing at the track.there isnt really much of a difference if you shift it manually or not but the computer wont over rev it.i started off in low2 once at the track and it came out of the hole like ****. i ran 13.65 like that.then left it in drive the next run and went 12.67. some cars may differ.

 

I'm surprised by the amount of people racing with OD. I only use 3rd (D if your in a Camaro) for racing, just to hold 3rd longer. Manually shifting your tranny is fine, UNDER PART THROTTLE, manually shifting at WOT will damage things. Burn out in 1st or 2nd, run the 1/4 in 3rd. If your on the street and going from a roll, bump it down to 3rd before you go WOT. If you run out of gear on the street in 3rd you need to be punched in the mouth for going that fast racing someone on the street.

 

if youre racing from a stop it wont make a difference in performance if youre going WOT. it wont shift into OD until around 120 on a stock trans if i remember correctly.

from a roll unless youre starting over 100mph id leave it in D to keep your RPMs up and keep your car in its power range. manually shifting can help from a roll but i dont feel comfortable shifting a stock a4.

 

Go ahead and rip out the auto and flop in the manual

 

I run mine in D until I hit about 80 mph, and then I stick it into OD.

 

There's a lot of info on this and no real 100% right answer.

What I've found is that WOT shifting 3rd to 4th in 4th/OD can be bad. WOT downkick from 4th/OD can be bad and WOT shift 2nd to 3rd in 3rd/D can be bad.

So from a dig you may be better off leaving it in 4th/OD. This will be safest on the 2nd - 3rd shift, if you use 3rd/D then there is a line pressure drop.

If from a roll then manually shifting in 3rd/D then using kickdown is probably best. You'll also find the tranny much more responsive when in 3rd/D as opposed to 4th/OD.

If you are racing in the twisties or just out for a real blast then 3rd/D will be better as you won't want it shifting into top.

Manually shifting probably won't help much.

Of course this all depends on your final drive ratio. Stock ratios are 2.73 and 3.23

A 2.73 car may work well locking it down in 2nd, this is because it will top over 100mph before shifting. In the twisties it will be very useful, although it's worth noting 2000+ models years when locked in 2nd will prevent kickdown to 1st.

But 2nd may work at the track also. Most stock 2.73 geared LS1's will trap 101-103mph but they will be shifting right at the line. Locking it down in 2nd will allow you to go past the regular shift point and on towards the rpm limiter and maybe gain another mph or so and reduce ET.

Same applies up top, a 2.73 geared car will top the 158mph limiter in 3rd before it reaches the shift rpm, so WOT shifts from 3rd to 4th are not a concern in a 2.73 geared car.

3.23 geared cars are quite different and require a different approach. There's a gear calculator in my sig, you may find it helpful.

For roll racing the biggest thing is to learn where the kickdown points are. The 3.23 geared car may be faster from a dig but is riddled with "dead spots" in the gearing. 35mph is a well known one as you are going too fast to kickdown to 1st but will be really low in the rpms in 2nd hence accelaration will suck and even a sn95 Stang will keep up.

With a 2.73 geared car 35-40mph is a sweet spot and will kickdown to 1st and bring you in right at the 4400rpm PEAK torque.

So learn you up shift and kickdown points

If you want improvements in performance you'll want these:

-Stall, this is an absolute MUST!!!! Personally I'd look for something around 3500rpm
-Tranny cooler
-Trans-go shift kit

Where possible try not to up the rpm's or shift points as it will eat the tranny. If you plan on a wild cam and high rpms bank on having to get a built tranny aswell.

 

I agree. I've read/heard conflicting info from a number of top trans builders, regarding WOT upshifts, WOT downshifts, drag racing from a stop, etc. Can't seem to get to a 100% agreement, so that's why these days I just drive the car the way GM intended, leaving it in OD and letting the PCM do all the shifting.

 

there you have it, straight from the big dogs. i've tried different ways on the track and still run the same times so IMHO leave it in OD or your just wasting time...

 

leaving my car in od i run 8.6 at 82.86mph in 1/8 in 3rd i run the same if i manually shift from first to second and into third at the traps i run 8.3 at 86 mph thats at sea level and all in the same night so no track differrences

 

Were you tracking your shift rpms when you ran in OD/3rd? It's very possibile that the car was short-shifting due to traction loss. That has happened to me many times.

If you get perfect/near perfect traction throughout the run, the PCM will in fact do a better job of shifting than you will.