Gotit4cheap16

iTrader: (3)

I was never really good at roll racing but i am trying to figure out if it is better to leave the car in 3rd instead of D when roll racing? Built 4l60e/3800 PTC converter/cooler w/ fan. Any advice would help..thanks guys.

Mavn

iTrader: (3)

I manually downshift mine into 2. then upshift it as soon as I hit the gas and let the computer upshift

redtan

iTrader: (5)

I leave it in 3rd because it's not as big of a RPM change on the downshift to say 2nd as going from 4-2.

Gotit4cheap16

iTrader: (3)

Leave it in 3rd. Awesome. Thanks guys

clinebarger

Without a modified 2-3 Valve & corresponding Valve Body mod to keep the Overruns ON in 1st, 2nd 3rd while in D3, I would leave the shifter in D4 & not have the Overruns constantly on & off.

Gotit4cheap16

iTrader: (3)

Ok i guess ill just have to do some testing and see

mrvedit

Good point. In [D3] the overrun clutches turn on during the 2-3 shift which reduces the pressure to the 3/4 clutch making it more likely to slip a bit and wear.
On the other hand, 4->2 down shifts are also hard on the trans.
Your "testing" won't show any difference, it is a matter of what is harder on the trans, which might depend upon which parts are more worn that others.

Installing the Sonnax HD 2-3 shift valve solves this. You then do all your racing in [D3]. The overrun clutches stay engaged at all times which also reduces the load on the (failure prone) forward sprag.

Kevin Blown 95 TA

I leave mine in OD, but I have programmed it to never downshift into 2nd at any speed beyond really slow, because I am positive that the double downshift coupled with a rapid upshift kills the 3rd speed clutches, especially if it was built without the little springs that help the down shift. Basically, I disabled the kickdown shifting and just use the regular shift tables to downshift into 3rd. Some of this depends on how much power you are making, but my car killed trannys when I floored it on the interstate because it was trying to shift when it was on the converter and the blower was making a ton of boost. So, while the 70 mph rolling burnouts were awesomly awesome to behold, it was eating the tranny to go 4-3-2-3 in a second or so.

mrvedit

Yes, special tuning can be used to eliminate unwanted downshifts. For example I eliminated downshifting into 1st above 5mph.
I am experimenting with a tune which upshifts as quickly as possible so that I basically have manual control over the trans.

Kevin Blown 95 TA

I did that as well. I made the Man 3rd 1-2 and 2-3 shifts in happen at very low mph so it works normally leaving from from a stop or when stopping; it shifts really soon after I start moving, so basically it stays in 3rd as long as I want it to, and Man 2nd already stays in 2nd. Man 1st would be really easy to keep from shifting to 2nd if you would want it to, I programmed it that way but I never really use it.