Tuesday, March 15, 2016
Doing the supermoto post calculations of bore and stroke on that little 350 DSES got my brain boiling. It was not too long ago (alright a couple of years) in a blog entry I referenced this chart and made allusions to how much power I might be able to get out of the mighty 494 cc ATK.
So rather than sit and dream I did a little research on ways to get the most out of your Rotax. I wish that there was a more organized way to present this information, but since I kind of use this blog more for my own reference back to things I have seen, Ill just have to deal with the way I present it...
I will start with determining the power that I have. For the most part it has been subjective. The only other bikes I have ridden in the past 5 years have been a Ducati Hypermotard and a BMW GS1200. Those are bad baselines for comparison. I ride with a guy that has a 650 KLR and a Vstrom, and while I don't feel he can really get away from me in the twisties, his comfort at a sustained 75 is a lot higher than mine. Granted, I have a weight and vibrational disadvantage. I already CHANGED THE GEARING
Where are gains to be made? Some Harris Matchless G80 devotees pointus in the direction on Page 3 of a Jampot PDF. This gives a few pointers, but no how-to's:
CCM MAD Forum 604 rebuild and tune
INCREASING COMPRESSION RATIOS:
Dynamic vs static
Compression Decking- AKA Milling the cylinder head or using no head gasket, or even a thinner head gasket (copper)
CAMS Jampot pdf on why to fit a softer cam, and instructions on how to change the cam
HEAD WORK / VALVES
Porting and Flowing head: CCM MAD has good pics comparing heads pre and post porting / flowing here.
Engine Dynamics in Petaluma works on heads
Valves: Please see Ron Wood
FUEL AND AIR FLOW
This is an internal combustion engine right?
CARBURETOR / EXHAUST
Mikuni VM44 vs Del Orto- Lee loves the delorto
NO REPLACEMENT FOR DISPLACEMENT:
Ron woods 676 Cylinder Ron Woods 100 cc Piston kit
Sportax in UK 640 kit.
Here is a write up about their 348 to 405 conversion.
Downside is reliability and needing to use race fuel. Bones describe this problem on the ATK rider Website in this thread.
Exercise and Diet-Just lose some weight fat ass, riding on the road and not just a dyno is all about power to weight ratio and not just power.
Shorai Battery: Mild weight difference, but some say is noticable compared to the Yuasa.
Rewound stator: Rex's speed shop claims 2-3 hp gains using a rewound race stator on the MT 350 and MT 500s.
CDI Box: The CCM folks claim that the programmable ignition delivers more consistent power across the rev range.
I really just need to get the 490 on the dyno, but for now I just bought 3 boxes worth of a 605 that I am putting together to do a side by side comparison of power... But that post is for another day.