I could adjust my shift points WITHOUT a shift kit!!! :grin: My 455 would shift so quick 1-2, 2-3 before 25 miles per hour I couldnt believe it. Today I started tweaking my modulator got it up to about 4700 RPM shift 1-2 now but 2-3 will only do about 4000 before it shifts at WOT but wow --what fun it is!!! :bglasses: :3gears: Pete
See there!?!?!? It's true, you do learn something new everyday! :TU: You can adjust your shift points w/ the modulator which will affect them at WOT in Drive, or you know, you could manually shift the car to get the RPM's you want, too. :Brow: :TU:
Nope, minumum throttle shift points and part throttle shift points, yes, but the adjustment is limited. If his car shortshifted at minumum throttle like he said, the modulator adjustment worked for him, but the WOT shift point is mainly controlled by the governor, and that is the right way to modify the shift points. Shifting yourself will wear out the trans prematurely, and will cost you races as well as consistency.
Larry--I remember you talking about "shifting yourself"---I believe the shifts are MUCH SLOWER this way---which is why I'm glad I have it shifting "itself" FEELS much quicker,plus the WEAR factor you talk about could be real bad. Again the modulator adjustment got me to 4800RPM on the 1-2 and that is OK by me --it is firm and quick. Pete
I don't have a tach in my car, but when the V6 was in the car and I left it in drive, I could hear the engine pumping out high RPM's at WOT, but it seemed like if I would take it down to L1 and shift to L2, then back to drive, I could get much higher RPM's than w/ it in drive. Of course then again, i'm talking about an engine that only had maybe 105 rwhp, so it wouldn't matter how many rpm's it would crank out, it was still slooooow, LOL. :laugh:
It's really hard to shift an automatic on the number, there's always some lag, which compromises consistency, especially since you don't know exactly where it is shifting. When you shift yourself, the shift is accomplished in a different way internally in the transmission(at least the 400 anyway) That is where the wear factor comes in. It wears a specific band out.(low/reverse I believe) You can adjust shift firmness with the modulator, to a degree. Where are your minumum throttle shift points now? As long as you are happy with where it shifts, that's all that counts.
TH-400 wear Larry: In manual low the low/reverse band is applied, in drive/low the band is not applied. The drum is held by the roller clutch. The intermediate band is similar in operation and is applied in manual second (super?) and off in drive/second. The drum held by the intermediate clutch and sprag/roller. So, both bands will experience additional wear in a manually shifted trans, although I have rarely seen damage to the low/reverse band due to this. Hope this helps, guys. :grin: I figured Larry knew this, just didn't have time to explain. :Smarty: Jim :3gears:
Thanks Jim :TU: But I didn't know that :laugh: At least not the specifics :grin: Thanks for the info. I have seen a few guys have problems from manual shifting due to wear though. At least one guy in the N.E GS/GN club. Our resident trans expert Mark DeConti explained it to me, but I forgot the specifics. Thanks again.
The stock modulator was not meant to be adjusted, but you could adjust them. There is a threaded stud extending from the end of the modulator. It was sealed with a silicone sealer after adjustment at the factory. If you turn the adjustment, you break the seal, and you must reseal it or the modulator will not hold vacuum, it will leak where the threads go into the modulator cannister. Turning the adjustment in clockwise will make the shifts occur later, counterclockwise for earlier softer shifts. The range of adjustment is 2-5 MPH, at minumum and part throttle. The aftermarket modulators are much smaller, and brass colored. They have an adjustment screw located inside the vacuum nipple.
