Air Cooled/Dry Clutch Questions

[krbreton]

Hi Guys-

I tried asking these questions in my "intro" thread but didn't get any responses. Hopefully in the more motarded group, someone will have some thoughts.

All of my past bikes have been typical water cooled, wet clutch sportbikes. My hyper is the first bike I've had that is air cooled and dry clutch.

My question is in traffic, how hot can I let the bike get? I saw ~260F the other day before I decided to fold in the mirrors and split to get some air over the engine. It took a long time to cool back down to its usual ~225.

Second, how sensitive is the dry clutch? Especially since the engine is kind of bumply and gurgly below about 20mph, I end up having to slip the clutch a bit in traffic. I realize dry clutches don't really like being slipped, so how do you guys deal with this (especially non-CA folks who can't split)? (P.O. put a 48T Yoyodyne Slipper on, if it makes a difference in your responses).

Thanks,

-Kyle

[fireman1251]

Take a tooth off your countershaft and slow speed traffic will be a lot easier and will need way less clutch work. 260°F should not be a problem, it's oil temp, not water.
As far as cluch durability is concerned, I've been running street and track for 20,000km without sign of excessive wear.

[Hazzbin]

Cure the fueling issues and you'll cure not only slow speed drivability but you may find the bike running cooler as well. If it's DS1100 a fatduc will do it nicely. I have a LV slipon with cat eliminator along with a race ECU and even in the 100 degree head we've had recently I've yet to see anything higher than 226F. I can also idle the bike at 1300 rpm in 1st, vibrating along but running just fine.

[krbreton]

Good info, guys, thanks. Seems like I shouldn't worry too much about it, and if I spend any real time in traffic (I don't usually, I was just escorting my father in law who's a newer rider), I could lessen these issues by richening the low rpm mixture.

For $80, the fatduc seems a little expensive, since it's not tunable but I'll keep my eye out for a used PC3 or maybe even just suck it up and buy one, and try out increasing the mixture at low RPMs...

-Kyle

[minusone]

+1 for the Fatduc.
Summer temperatures here in Australia can get very high and I was concerned too as the temperature rises gear changes become notchy as the oil thins. I installed a larger oil cooler and never need to worry about it, in fact I keep hoping it gets over 100C to ensure any water vapour in the oil is boiled off. If you have severe winters, and worry about too much cooling, you can always obscure part of the cooler.

Another thing the Fatduc richens up the mixture low down and that in itself helps to cool an engine.

[Hazzbin]

Originally Posted by krbreton

Good info, guys, thanks. Seems like I shouldn't worry too much about it, and if I spend any real time in traffic (I don't usually, I was just escorting my father in law who's a newer rider), I could lessen these issues by richening the low rpm mixture.

For $80, the fatduc seems a little expensive, since it's not tunable but I'll keep my eye out for a used PC3 or maybe even just suck it up and buy one, and try out increasing the mixture at low RPMs...

-Kyle

While the fatduc isn't "tunable" it is adjustable.

[krbreton]

Originally Posted by Hazzbin

While the fatduc isn't "tunable" it is adjustable.

Ahhh. Thanks, I missed that in my initial read-over. Am I also correct in understanding that Ducs don't use closed loop fueling above about 4k rpms, so the fatduc really only affects idle/very low rpm performance (which is where the unevenness is)?

Thanks,

-Kyle