High compression pistons

[pcv57]

I was thinking about buying 11:1 high compression "drop-in" pistons for my s2r1k. The write up said it would be a 7hp gain for the 1000DS motor. I'm wondering if this is true and what the downside is. Anybody do this mod?

[scduc]

I also pondered this, but after talking to my tech, I'm convinced that this is not a really the way to go. If you do the math, it comes out close to $100 per 1hp and you'd be way better off going with the big bore kit. With cutting your sleeves, re-coating  and new gaskets along with the pistons, you will end up spending an extra $350 or so, but you will gain much more all around. torque and high end.

[pcv57]

What did your mechanic quote you for doing the big bore kit? I've been quoted $1700 to do the job.

[scduc]

If I do the tear down and reassemble, around $450 for the pistons, another $450 for boreing and coating the sleeves then around $150(he could not quote me, but this is the extreme) for the gaskets. He said he would fit the rings and pre-assemble. I would remount the sleeves and do the mechanical work. Take the bike back to him and he would do the fine tuning for another $100. My guess is that it will be much less then $1500. I do plan on doing this, just not sure how soon.

[He Man]

i think the gaskets are actually over $100 each last i checked. They are freaking EXPENSIVE.

if your going to strip your bike apart, why not just do the bigbore too? How many miles does ur bike have?

[ducpainter]

i think the gaskets are actually over $100 each last i checked. They are freaking EXPENSIVE.

if your going to strip your bike apart, why not just do the bigbore too? How many miles does ur bike have?

Commoto lists those gaskets at 47.89.

You might be thinking SBK.

[ducatiz]

yeah, once you have the heads, jugs and pistons off it's time to pull the rods and balance them.

well, once you do that, just split the case and get the crank lightened and balanced. 

it's not that much extra.

[scduc]

Its just like every thing. You have to draw a line somewhere. For most of us modding the top half is really not a big deal. However if you start getting into the lower, then mo money and time get involved. Every one has different goals and destinations. Doing alittle at a time gives me the financial benefit and also gives me something to do during the winter. If I were to do it all at once, then I would be finished and half the fun would be gone. Either way, the original post is going to have to pull the sleeves and spending the extra money to bore and recoat will be (IMHO) money well spent.

[Drunken Monkey]

HP, while nice for racing, is not the only thing. There's this other thing called "torque"...

Look at the claimed increases for the torque curve on your bike (preferably an actual dyno chart) before you leap in with both feet.

My high-comp + etc job ran about 1500 and it was well worth it for the massive midrange increase far more than the extra 5 HP peak output.

As always, YMMV. But see if you can't find a before and after dyno chart for this particular mod...

[Buckethead]

There's this other thing called "torque"...

I'm thinking that for a grand and change, you could probably swap in an 1100 motor with a reflashed ECU to make it work.

Dunno, tho. Haven't really priced crashed HM's/MS1100's/Monster 1100 motors.

[ducpainter]

I'm thinking that for a grand and change, you could probably swap in an 1100 motor with a reflashed ECU to make it work.

Dunno, tho. Haven't really priced crashed HM's/MS1100's/Monster 1100 motors.

I think you're low.

Most of the gains from a big bore kit actually come from the compression increase normally associated with the new pistons so drop ins make sense.

We're not talking about a 750 motor here...no need for a motor swap IMO.

[pcv57]

The interesting thing was that their website stated the high comp pistons would give me 7hp gain and the big bore kit 8% more hp. At 85hp, 8% would give me 6.8hp. Hmmm, not the best sales technique.
I talked to Steve at ECS in NY and he thinks I should invest in the TPO Beast R and a PC III instead. Since they don't make a PC for that bike, it would be one for  an M1000 and a custom map. It would still cost around a grand just to do that! 

[ducpainter]

Steve knows his stuff.

[He Man]

You are right dp about the gaskets.


Steve showed me a few of the Hi comp bigbore kits for the DS1000. My bike had 82hp/68tq on their rented dyno. On that same dyno, fully kitted DS1000 were making about 95hp/80tq. I may be off on the torque number though. I think they quoted a little lower than $2500 to do the whole thing with the bike in house. Parts and labor, PCIII + Custom map.


One day, when the bike actually needs it...

[kopfjäger]

Go for the 1123 Pistal kit. 


http://www.ducshop.com/product_view.php?cat=6&pid=303