Hello there, here's what I've seen and learned. I'll compare a 2007 9660 STS (what we ran last fall) to a 2008 9670 STS (whats on order for next fall). Okay now the 2007 9660 already had a bullet rotor and the 9.0L engine. (I'm sure you know, both combines are a class 6) The new combines have the following changes (this is specific to the 9670, not 9770 or 9870): Clean grain elevators have an 8% increase due to a faster speed. The cleaning shoe has a more aggressive stroke, shoe drive pulley is heavy and cast acts like a flywheel to run smoother. Same horsepower- 305 with same boost as before. There`s a new chopper design, The outside has dedicated fan blades for more spread, inner blades move the wings closer to the chopper rotor, requires less HP with better spread. New design chopper drive...I don`t know if it is heavier for this size, but you no longer have to loosen the belt to raise the chopper. The cab has some changes, new color monitor on the armrest, settings are supposed to be dialed in using the monitor and a dial, no more holding the button to the correct setting. If you want 900 rotor rpm dial it in and press enter. (as far as I understand it...no experiance with that) I think that is all...if you have heard more or have questions feel free to ask.
Personally, I feel it may have a little more capacity that the 9660. As these combines a likely to be limited (here in Canada) due to horsepower, the savings on the chopper design may give us a little edge on the old ones. I know our 9660`s seemed to gain from the bullet rotor and the tough handling (rice) feed accelerator over previous models we have run. NOTE last year was our first year running 9660`s, however we had demos as well as custom guys running earlier models. Maybe it was just me, but it seems these smaller combines benefit the most when the say something will take less HP to run. Last year, one combine broke both chaffer arms, one on one day another a week later. Other combine had no trouble with this. Hoping new flywheel drive will overcompensate for the more aggressive sieve stroke. Making it easier on the arms.
Now the 9770 and 9870 both get bigger clean grain system I think it is 15%(bigger augers and elevator). They both get more horsepower 9870 is now about the same as the 9860 premium. The 9870 gets dynfloII ICC (translation: Increased Cleaning Capacity) which is a front fixed precleaner extended with some air diversion changes plus more fan rpm. The 9870 also gets an optional multispeed feederhouse. Basically a 5 speed powershift(at the primary countershaft gearbox)-with the same reverser gearbox idea- might be heavier. Gets away from variable speed belt and torque sensor for heavy duty fixed speed belt. Gears can be changed on the go to match ground speed/condition. Sounds like thats meant for new corn headers, as most other headers are limited to 1st or 2nd gear. Any how, the deere website has more details. If you wanna see some other deere combines...check out the european website. 400+ HP CTS 530HP STS
