or maybe you can answer this

hence my asking for them to chime in.

 

dig > roll.

i race in D just because i don't want my car shifting into OD at the end of the track when i let off the gas. the engine brake effect does not apply to me as i have a 4k stall and letting off the gas at the top end of the track in D is like slapping it into N...the stall lets the rpms fall to an idle, so i rely on my brakes to stop.

on the rare occasion that i do choose to roll race, i won't start from anywhere over 45, as the stalling effect diminishes the closer i get to 60. my 4k stalled auto is f'n mean from a 35 roll in 2nd...with DRs i am gone. with my goodyear gscs i leave ~20' of rubber. knowing the limits of your gears helps to choose what gear for what speed.

oh yes, and...for $ - dig or no gig.

 

I've been racing this year starting out in D. Once i hit the shifter off the line to 2nd because i used to race a car with a manual valve body and it bogged because it was in 2nd. Don't do that! I also tuned my shift points both MPH and RPM per different posts on this site.

 

2nd gear start (shifter in 2nd, starts out in 2nd) in F-bodies started with the 2000 MY.

 

Either shift it all through the gears 1-2-3, or leave it in OD. If you leave it in D, it will bring on the overrun clutches on the 2-3 shift. This is where a lot of the 4L60E's have problems (engine flares) is on the 2-3 WOT shift. You are robbing from the 3rd gear apply oil when you bring on the overrun clutches. There is a bigger pressure drop when the overrun clutches come on the 2-3 shift, compared to a 2-3 shift without the apply of the overrun clutches. The 2-3 shift needs all the oil possible at WOT. If you shift it manually 1-2-3, the overrun clutches stay on on all of the shifts, so there is no robbing of the 3rd gear apply oil.

 

When you move the selector valve to a position such as low the selector valve will supply pressured oil to 1-2 shift clutch, block out the 1-2 shift solenoid, and send a pressure signal to the pressure regular for boosted line pressure. Maybe if you are not slipping it doesn't help you though. Maybe the increased pressure means it will take longer for the clutch to disengage and yield a larger overlap before the next one kicks in. That would mean power flow is more consisent, less flare, faster times. But, I have never designed a trans so I don't know.

If I am not mistaken if you let the trans go into 4th you have two members in overrun instead of one. If wear is actually increased in 4th over 3rd despite I doubt it.

 

Thanks PBA! This was the type of answer I was looking for. I now have an idea of what's actually happening inside the tranny.

 

As said before, if you're trapping fast enough (around 120) then leave it in D because it'll shift into OD before the traps.

 

what the hell difference is there between the two?

 

From what I have gathered over the many months of being on this forum, here are the changes I am going to make with tuning. These changes will help with both driveability and racing. Also remember this is on a Pontiac, so when I say "D" it would be "OD" on a Chevy.

-Disable TCC Lockup at 0% throttle - Will take care of the annoying "shock" of the TCC locking back up when I am off the brake and gas (I have no PWM and a strong TCC)
-Disable TCC lockup in "3" selection only (not sure if you can do this, may not need to with the other changes here to accomplish what I want)
-Enable TCC lockup in 3rd gear in "D" selection at 30mph - Car normally would not lock up until 38mph and only in 4th gear. Basically I am trying to combine what the car does in "3" (which is, lock at 30mph) and "D" to do it both when in "D" so I don't have to change the shifter selection. Part of the reason being the next item down.
-Bump 4th gear to 45mph at part throttle - Will keep the car out of overdrive when in "D" selection until 45 - ideal for roll racing. Locked TCC in overdrive is often times too much for 40mph leaving me with very little power also.
-Edit shift points at WOT - To pull all the way through the powerband and stay off the limiter
-Enable downshifting to 1st up to 35mph - Much better than being locked out of 1st gear over 30mph

These changes will allow me to race from a stop OR a roll (up to 35mph for best results, or faster if you like how slow your car is when shifting 3-2) and leave the shifter in "D" where you want it for racing (or so I have gathered from the builders' posts on here)

Now I haven't tried any of this out yet so don't come complaining to if you have problems. However I do think i'll like the car a lot better when it's done

 

The 35mph extension will only be of benefit if you're running a stock cam. My car will downshift into 1st if I'm rolling up to 40-42mph, this is with a 6500rpm shift point/3.23's.

Speed Inc took all the guesswork out of my tuning

 

Very intresting stuff. I hope the pro's chime in as well.

 

what i have always done...

the few passes i've made at a track i've put it in 3 (Drive) and continued until the race is over, the i've always put it in D (overdrive) afterwards so i'd cruise locked up instead of using the engine break.

in roll racing, i've always downshifted to 3 (drive) because one thing i DO KNOW is it's very bad for the automatic tranny to downshift more than one gear (i.e. rolling at 40mph, then smashing it in overdrive will send you from 4th gear to 2nd gear - not good). downshifting from 3rd to 2nd isn't bad though.

i've just heard a lot of people burning out their overdrive racing in overdrive. that's why i race in third until i'm off the throttle, then shift into overdrive to gently coast to a stop.

 

OK I got my WS-6 a week ago, and you guys all have me confused. From what I understand the Chevy's have a shifter that reads OD, D, 2, 1 and the Pontiacs shifter reads D, 3, 2, 1... correct? So that would mean that on my car D=OD and 3=D ? If that's true does that mean if I leave the shifter selected at 3 it will shift up and down through the gears normally as it would in D but not go into 4th gear(overdrive)? Thanks for the clarification, GM does some wierd things with their cars I don't see why the shifters wouldn't just read the same.

 

yes, this is correct - about the gears and GM.

 

It is beneficial to manually shift if you havea shift kit? (And the tranny is built)

 

No, there isn't. All the things I need to manually pick a gear for, I could do when it was stock also. These are picking the starting gear (getting car out of overdrive), holding in 1st for a burnout, or starting in 2nd on a slippery road, which I don't drive on anyway.

 

no, if the car is tuned properly the computer will always act quicker than you can. leave it be.