what rpm is the 86 tpi lb9 305 suposed to shift into second at? with auto trans.

 

approx 4500 rpms.

 

actually the 1986's were odd. They often shifted at 5500. It was a querk with GM that was fixed in 1987 and up.

Basically they used the govenor from the 305HO.

My brother had a 1986 and I had a 1989. His shifted at 5500, mine was 5200.

I duplicated this shift point in another project by using the Vette govenor ... 5500 RPM.

If your shift point is indeed 5500 and you want to lower it, go to GM and buy a govenor for a 1987 car. It will be one of the 4800 or 5200 versions. They are cheap from GM.

Otherise you can buy a kit from B&M and spend a day swapping the springs and weights until you get what you want.

Mark.

 

what would cause the tranny to shift a approx 4-4200 rpm? how can i raise this to 5500? would that keep the engine in its max powerband?

 

you could manually shift it later,

or you could remove a little weight from the governor.

good luck


[This message has been edited by The ODB (edited February 07, 2001).]

 

It could shift that low if the govenor is calibrated that way. OR the TV cable may not be adjusted correctly ... OR your tach is off (GM tachs are often out ... sometimes by huge amounts).

Double check your tach with test equipment or borrow a buddies tach if it is a remote mount style (autometer, etc.).

Set your TV cable ... procedure outline on thirdgen web page.

If all checks out, then you will have to adjust the govenor.

Keep in mind a stock TPI makes power up to about 4500. So rev'ing to 5500 is a waste. About the only thing it does is take the 1-2 shift and place the rpm back in the torque peak. However you lost so much from over reving first, you will be slower. A bit of a trade off.

Some background. If you start adjusting the govenor, keep in mind part throttle and full throttle shift points will change. Part throttle is effected by the TV cable, but as well by the govenor.

Mark.