Performance suggestions for my S4

[fouramdesigns]

Buying Quat D, best to move away from DP ECU? Power Commander, other?

[tonkoshala]

I say no. The DP ECU it bumps up the RMP rev limit. Same with the power commander. I bet someone has posted a base map with a similar setup to work from before you tune the bike on a dyno.

What did you decide on the handlebars?

[Raux]

I say no. The DP ECU it bumps up the RMP rev limit. Same with the power commander. I bet someone has posted a base map with a similar setup to work from before you tune the bike on a dyno.

What did you decide on the handlebars?

the PC doesn't adjust the RPM limiter/fuel cutoff. the DP ECU does.

[tonkoshala]

the PC doesn't adjust the RPM limiter/fuel cutoff. the DP ECU does.

Where I meant same was to not move away from. Can see how it coulda been misleading...

[fouramdesigns]

This may be worthwhile, some high comp pistons
http://cgi.ebay.com/ebaymotors/DUCATI-JE-Pistons-96mm-for-851-888-916-4-valve-engine_W0QQitemZ320490755787QQcmdZViewItemQQptZMotorcycles_Parts_Accessories?hash=item4a9ebcd6cb#ht_500wt_1182

[junior varsity]

If you are thinking about doing it, here's some more ideas:

Ferracci 984cc Kit (big bore/stroker): http://www.ferracci.com/store/cart.php?m=product_detail&p=196

Ferracci 955cc AMA Race Kit: http://www.ferracci.com/store/cart.php?m=product_detail&p=194

Ferracci Hi-Comp / 955 HC Pistons Only: http://www.ferracci.com/store/cart.php?m=product_detail&p=192

[fouramdesigns]

what kind of performance could expect from just the pistons?

[junior varsity]

Certainly a gain from high comp, a bigger gain from big-bore high comp, and something ridiculous from the 984cc.

The 955 is nice, but I'd make sure a competent engine builder does the work on any of the bore/stroke kits. There's been lots of favorable and unfavorable 955 discussions in the past.

Others will certainly be better equipped to discuss this. Also, give Ducshop a call, since they are 'nearby'

[gage]

I've heard mixed review on JE pistons... Pistal seem like the way to go.

The biggest big bore kit you can go to without the expense of boring the cases and the decrease in reliability associated with that is 933cc. You may luck out and already have the cases that can accomodate a bigger bore but there is no way to check other than to break it down.

[gage]

what kind of performance could expect from just the pistons?

I was told that HC pistons would be good for 8-12whp

[junior varsity]

I've heard mixed review on JE pistons... Pistal seem like the way to go.

The biggest big bore kit you can go to without the expense of boring the cases and the decrease in reliability associated with that is 933cc. You may luck out and already have the cases that can accomodate a bigger bore but there is no way to check other than to break it down.

You mean the 936 (ish... 935.8cc)? That's only 1 mm diameter bigger than factory bore. I haven't torn into a 916, but that seems odd.

[foggy123]

Buy a 996 motor it will be cheaper than a big bore upgrade.  St4s/s4r will work.  ~1k and you can still sell your motor.

Keep the bike upright also helps.

[fouramdesigns]

Buy a 996 motor it will be cheaper than a big bore upgrade.  St4s/s4r will work.  ~1k and you can still sell your motor.

Keep the bike upright also helps.

Nice. I've made it through rain,. sleet and snow. Was a dry day, low tread on the front, and some road salt.

[gage]

You mean the 936 (ish... 935.8cc)? That's only 1 mm diameter bigger than factory bore. I haven't torn into a 916, but that seems odd.

No I believe it is a straight 933 - this is a 1mm overbore - perhaps you lose the extra 1.4 cc per cylinder because of the Nikasil coating.

I was told this by several very reliable sources at performance engine shops and boring out the cases is a solution but costs big money

[junior varsity]

Interesting. I've never run across such a small over-bore Duc. Its like the 924 kit for 900cc Monsters and Supersports that was apparently available. (and quite dumb imo.)