Just wanted to confirm this. Are firmer shifts normally programmed on the 89octane side of a flip chip? Finally got my chip in this weekend and took the Expi for a spin. I didn't immediately notice any diff in shifting, but I'm on 35's w/ the stock tranny/ gears so I figured this may be why.

thanks,
ronb.

 

Hi Ron,

Yes, unless a customer specifically requests a different transmission setup on one "side" (program) of the Flip Chip, we normally do the same transmission mods to both programs in the Flip Chip, so that you have all those benefits no matter which program you're running on.

It's definately the 35" tires affecting that, they will make the shifts seem softer, as it takes much more line pressure to effect a firm upshifts with those much larger tires, for a couple of reasons. First, you have effectively changed your gear ratio to a much lower numerical number, so you have lost a good bit of torque multiplication. Then the added load of the tires themselves, which is all unsprung weight, also needs more line pressure for a firm shift.

With 35" tires, if you want a really "firm" shift characterstic, your best bet is to install a line valve mod or a complete shift kit.

We carry the line mod valves here, but keep in mind they are only for the 4R100 automatics, not for the 4R70W's.

If you'd like to perhaps give us a call, we'd be happy to go over all of this with you.