3.73 gear swap shift point settings

[silverz28camaro]

well i went from 2.73 to 3.73 and i have a tuner who has tuned my car and also recalibrated my speedo and somewhat set my shift points.

my problem is from 2 to 3 sometimes it will hit the rev limiter for a split second, we set to request for shift at 6000 rpm and the mph at 74, the car is limited to 6500rpm and usually barely passes 75 before the shift

my tuner said something about a 3-4 servo upgrade that is supposed to allow for a quick shift, the tranny is rebuilt so its not slipping,

OR what if i set the mph for 71 maybe that will allow it to shift without hitting the rev limit since the request is being sent sooner,



any feedback would be great.

[mrr23]

increase line pressure. i have the billet 2nd gear servo and 4th servo, it helps.

[tblu92]

Yes you are on the right track--set the shift at vehicle speed lower--(VSS) I would set it down to 68-70 MPH also maybe even the 1-2 shift MPH set lower too----Also you can always set the Rev limiter In Gear a bit higher too--say to about 6600---

Whatever you do in the VSS upshift (WOT) I would do the same in the VSS downshift--If you subtract 6 MPH at upshift--subtract 6 MPH at downshift--
I found it quite normal for the RPM's to overshoot the shift at RPM set points--especiallly in the lower gears---1-2-----2-3

[silverz28camaro]

thanks for the response, 1-2 feels perfect its just the 2-3 i need to tweak, on a bolt on ls1 (headers, intake lid, tune) isn't 6500 kinda out of its power band, since the night i had it at the track with this rev limit problem, it pulled a 12.71 shifting into third at 6500 the one time it didn't hit the limit, now if it were to shift into third at 6100rpm or so wouldn't that keep it more in its powerband to rip off a low 12.60........guess we'll find out when i get the mph set lower

and what exactly does the billet servo do, i know its forged aluminum, but more quicker for quicker shifts?

[tblu92]

The rev limiter that i am speaking of is just the safety back-up rev limiter NOT the shift point limiter---The shift point limiter is what RPM's it will shift at--The "In Gear Rev Limiter" is just the safety rev limit in gear in case the tranny misses a shift or has a failure--There is also a "park/nuetral" rev limiter-again just a safety rev limiter--
In your case with the shift point set at 6100 what happens sometmes is the RPM's will overshoot or miss the shift point so the engine will shhift at the safety limiter of 6500 or 6600 -whatever you set it at--If you set it too close to the shift point RPM then it can't react fast enough to finsh the shift and it will overshoot the shift point and bang the safety limiter---then shift
And yes with stock internals you are well out of the powerband at 6600 but again that point is just used as a safety device and shouldn't be used as a shift point unless you have a failure of some kind