Ran a friends 2011 or 12 8090 which had the long feeder house DSP for couple seasons. DSP worked great and much preferred over ASP. Also felt it improved rotor feeding but took some getting used to not seeing header knife or front of feeder house. Never really did get used to it, next combine was 2015 8.9 normal length feeder house DSP much better. Also, the beater on the 8090 completely wore out at about 400-500 hours. Updated beater and replaceable bars much better. CNH should have made it a recall as the original functioned fine but way under built. $6000 I think it was for the updated version.
I would also be shocked if it wasn’t cost prohibitive to ad DSP to an ASP machine.
= Acoustic stone protection which means the noise of a rock going over a sound board, stops the feeder and you spend the next 2 minutes or so reversing trying to clear it, lifting header and resetting the trap - a real waste of time when you see what a rock does to the rotor, concaves and chopper if it misses it.
= Dynamic stone protection refers to the addition of a beater at the top end of the feeder house. On a 2012 model, made the overall length of the feeder longer by the additional length of the beater apparatus. The drawback on my 2012 model is that it is run off the separator and not off the header drive. There is no slip clutch. You plug it with kochia or slugs and the belt smokes until you hit the separator switch off.
I wouldn't be without it! Noise? I can't tell the difference. In fact, I updated to the new beater as Mags said and it will feed the rotors much smoother than the original design. The staggered replacable wear bear/teeth on it do a much better job to even out the slugs and it makes a huge difference to how much kochia you can chew through!
Yes, there certainly is a limited visibility issue with a longer feeder house but I have gotten used to it. Running Macdon fronts, I don't have any issues.
I also toyed with the idea of modifying our other combine (9080) but I would imagine it would be cost prohibitive. You would need longer and larger lift cylinders, kit to install the beater and likely drive modifications to drive it as it would be driven from the RHS off the separator drive. I have never really looked at the newer models to see how and if they have in fact shortened the feeder house, and or drive it from the feeder drive clutch to give it slip clutch protection.
In our rock conditions, doing lentils and kochia, a DSP is a must. After 3 years in these conditions with an ASP system, the concaves need replacement and look "rough" from stone damage and they are not cheap!
I always wanted to try a Claas to see how they perform in these conditions. However, much more expensive and I am not sure they handle kochia any better than what I have now. 1/2 our time is spent doing lentils and kochia and so the throughput of the combines are not based on barley or wheat and straw load, rather based on coverage by header width and how well you can cut it off and feed it in. Twice the combine in my case, has no effect on my overall capacity.
Out of interest, I would like to see how small diameter inline drums would handle green kochia weed. Would the light shafts bend and the belts slip, would they grunt and groan or just purr like a kitten?