Just as title says. Let me know your thoughts? And plz explain what the difference is? I have 3:23 I'm not gonna run out by end of track in 3rd? Thx

 

Its been covered in detail as here:

https://ls1tech.com/forums/automatic...-drive-od.html

In short, with a stock trans keep it in [OD].
Reason - in [D3] during the 2-3 shift the overrun clutches are also applied, bleeding pressure from the 3/4 clutch at a critical time.
The Sonnax 2-3 HD shift valve is a nice upgrade that strengthens the trans in [D3], but is non-trivial to install.

 

I googled searched it to lol. I must of not worded it right. Thx for the link! So what does all that mean? That link didn't really answer my question lol

 

In short, with a stock 4L60E leave it in [OD].

 

I prefer D myself (always have). My trans builder agrees. I've never had or seen a 4l60e failure personally by someone using D at the track. And no you won't need 4th gear at the track.

 

Anybody else? So I leave it in D or OD lol

 

I've always stayed in D. It's true what you read about the over-run clutches but I had always used it before with no problems, still do.

 

I have noticed my 4l80e drops from around 160psi at WOT to 130psi at WOT for a brief second on the shift. Does this apply to the 4l80e also?

 

In post #4 I mention that my suggestion only applies to the 4L60E. The 4L80E is completely different and I cannot answer that.

OP: You are over-worrying. In "theory" racing in [D3] may cause the 3/4 clutch to slip/wear a tiny bit more than in [OD] with a stock trans. Since zillions of people race in [D3], as 01ssreda4 points out, the difference is negligible. Note that a performance built trans will have higher pressure and faster engagement of the 3/4 clutch, making it a mute point.

 

OD it is! Thx mrvedit

 

I leave mine in OD.

 

It is worth noting if the trans has a lot of miles/wear, racing in 3 instead of OD may begin to allow a slip on the 2-3 shift which will further increase wear and cause the car to hit the rev limit instead of completing the shift. I had this issue until I installed the HD 2-3 shift valve mrvedit mentioned

 

FLT always told me to race in 3rd with my 4L60E and now with my 80E I always make pulls in 3rd.

I am sure Jakeshoe or someone from FLT has some input on this.

 

I posted a similar thread a while ago, my responses IIRC, were mostly put it in D instead of OD, although, I did specify that my trans was tuned (still stock other than converter). But for more reference material....

https://ls1tech.com/forums/drag-raci...ip-newbie.html

and then more street oriented...

https://ls1tech.com/forums/automatic...ting-auto.html

 

For me, I do the burnout in 2nd then race in 3rd. Stock 4L60E.

With 3.23 gears its in high 4/low 5 rpm range. Now with 3.73's holding it in 3rd rpm's at the stripe are between 5 and 6K.

 

So warm up the tires in OD also? My trans has 130k

 

With the shifter in [D2] the trans will start and stay in 2nd gear. This is suitable for an aggressive burnout so that the trans doesn't shift from 1 to 2 during the burnout.

 

When I tried doing the burnout in OD or 3rd the engine would begin to lug since it upshifts, hence automatic trans. Holding it in 2nd allows me to regulate the throttle better.

Stock engine and trans with 100+K and used as my bracket car. At the end of season, if I keep the car, will be contacting Jake's for a proper build.

 

I always start my burnout in 1st and upshift to 2nd during it. Gets the tires spinning faster more quickly with less chance for wheelhop. I've heard people say not to but I've yet to hear a convincing reason why it would be bad for the trans.

I can't see any reason for running in 3rd at the track. The car won't shift into 4th at WOT anyway. Why not have every bit of pressure possible going to the (weak) 3-4 clutch pack?

 

Ditto on the burnout. The Vette has too good of rear brakes to use second only as I don't have a line lock. Well, I have one, just never installed it......

The stupid vette also has electronic throttle and traction control. Of course I turn the TC off, have deleted all the abuse stuff, but something in that system still gets pissed off and takes throttle away on occasion during the burnout.

I have a PB level 2 trans, and have no clue if it has the Sonnex valve in it. So I race in D4 (OD to you Camaro guys)

Well over 150 passes over the last two years searching for that elusive 10.99, and the trans works as well as it did when I put it in.

Ron