Ducati Monster Forum

hello folks,

well i've had my S4 Foggy now for just over 2 months or about 6k miles. the foggy came stock with the DP termi/ECU/airbox and the bike feels nice. the only thing lacking (for me) is the low and mid range. i installed a 39t sprocket on the rear and i thought the stock one was 37t. but i read the Foggy's came stock with a 39t and the regular S4 was 37t stock. anyone want to confirm this? that said, i would even go up to a 41t...

i had a PClll on a bmw R1150R (rockster) and it bumped my redline up another 1k rpm's and my top speed from 122 to 130mph. this is "seat of the pants dyno" but the torque felt awesome through the whole range IMHO.

my only experience with changing out cams was on my '97 bmw 328is. i swapped cams from an M3 from the same year and the results were pretty dramatic.

i read through the S4 sections on the moto one site. the conclusions seemed to say that changing out cams would just gain me more top and just a bit more mid range.

just to clarify, i just want a bit more power without sacrificing reliability. is this possible???

my questions:
-how does one get more low end out of the 916 engine?
-any recommendations (or not) on which cam profiles would be suited for more mids. 996 cams? SPS, DP???
-using more aggressive cams: can i use my existing ECU in conjunction with a PClll?
-or maybe i can just get a PClll, fine tune the cam timing and dynotune?
-and what about installing a lightweight flywheel? i would see some improvement there...
-how many worms will reveal them selves if i open the can?  ;)

thanks,

russ

EDIT: i forgot to mention lightweight flywheels... :D

I ride an '01 S4 that's running a full Termi setup, similar to what the Foggy comes with, but I'm also running the SPS cams.

The cams are great and absolutely worth the $$, but you're right, in that they only really buy you increased mid-to-high powerband performance power. At least that's what I've experienced. I also installed a 14T front sprocket which helped out a bit, but anywhere below 4k RPM is pretty much just as it would be stock, with the exception of the bike sounding like a cigarette boat at idle  [evil]. The cams really do make the engine come alive from 5k to redline though, that's for sure!! With an open airbox, Termis, and the cams, the sound the bke emits is downright frightening at wide open throttle in the mid to high revs!!  [evil]

I too would like some incresed low-end grunt, so if anyone else has any ideas, bring'em on!!  ;D

hey johnster,

where did you get your SPS cams and how much? did you dynotune? DP ecu?

i think some lightweight flywheels would make a decent gain, no?

They were dealer-installed along w/the rest of the Termi kit. I am running a DP ECU as well. It's funny you mentioned the Dyno, because this exact conversation took place on the old board, and I got flamed for not having the bike Dyno-tuned!! "He did a half-ass job!! Who the hell doesn't Dyno their bike with that setup?!?! Blahblahblah"  [laugh]

My dealer has extensive experience tuning Ducs w/Termi/airbox/ECU kits, and was able to tune it effectively without the use of a Dyno, believe it or not. I must say that I can't complain, as it runs beautifully. He said to bring it back if I was not happy w/the setup and he'd have it Dyno'ed, but I haven't felt the need as of now.

A Nichols Flywheel would be nice to add though. Maybe I'll put that on my Christmas list!!  [cheeky]

The engine would spool up quicker, which I guess would feel like better low-end in theory, so that might be a good option...

i'm going in for a servicing in 2 weeks so i'm thinking, while the bike's mostly apart, i should go for the flywheels and possibly cams.

what's the advantage of changing to the front sprocket vs the rear sprocket?

Looking to increase low end and midrange ? increase your cylinder bore, you do not need to go to 955 as that would require boring your cases but a 2mm overbore with hi-compression will get you just what you are looking for. Add the cams as well and you are really cooking [moto]

The 916 motor will stay just as revvy as it is now with the bigger bore but the combination of bigger bore and hi compression will fatten up the mid range as well as increase your top end.

fun stuff

if the cam timing is set as we would it might help the bottom end, but what you want is more low rpm torque, and low rpm torque is capacity based more than anything else.  over boring a 916 is a hassle as to go up 2mm (96mm) for 955cc you really need to bore the cases to get the cylinder supplied with most kits to fit.  some people bore the std cylinders to 96mm, but that makes the spigot quite thin.

you can stroke it as well to get 984 with a 900 crank and 955 kit, but it's getting expensive.  find a s/h st4s or s4r motor.

cam timing, tuning, light flywheel and gearing will all help, but it's still only a 916.

the close ratio box may hurt a bit too.  i'd run 15/43 on a wide ratio box (s4r, st4, st4s, etc), but with a close ratio box that'll add 500rpm to your 120km/h cruise comapred to 15/39.

A smaller diameter exhaust header would help a bit.
Though I think it'd be a tall order to talk you out of that Termi 'spaghetti' system you've got.

More compression would help throughout the rpm range, not sure how far is reasonable on our pump gas.
Claimed CR is 11:1, 12:1 seems to be reasonable from what I've seen.

I've got an M1k crank waiting patiently for my S4... it'll bump displacement to 992cc... but it's not a proven thing, and certainly not a bolt-in.

oops! brad is correct the 2mm is for the 955 you don't want. 1mm will be a bolt on kit with out boring. this should bring the displacement to around 935 with hi compression as well.
When I worked at BCM we used to sell 95mm big bore kits so you could try there for the parts. 1mm may not sound like much but it was a real improvement. same as 966 on the st2 motors .

another option would be to find a wrecked st4s and grab the 996 motor and electrics from it.

Depends on how much money you want to spend. 

By having the cams dialed, squish set and dyno tuned (PCIII), your bike should be more responsive. 

Beware a 14T sprocket, I've broke 2 chains and one could have been caused by a smaller front sprocket.  Go big in back but you'll need a new chain.

Cams can add mid to top end and will run you some $$$ to get installed.  Hi comps could help but tuning will be more critical.

Lw engine parts with make bike more responsive as will lw wheels. 

Best mod to my Foggy has been hands down BSTs followed by suspension, slipper, heads, brakes, gearing, billet. 

Regular S4 came with 37t on the rear, ducati.com clicky (http://www.ducati.com/my2002/ducatiModel.jhtml?part=engine&modelName=S4Fogarty) says Foggys came with 39t.

Lighter wheels are a nice upgrade, though I wouldn't rank them ahead of suspension.
But I've never ridden a bike with BST's, so there you go.

thanks for all the input guys! i really appreciate the advice

most of my modding experience has been my '73 harley. it's been an on/off project since around '93. it started off as a 1000cc sporty. right now it's bored/stroked to 1200cc, 12:1 pistons, S&S carbs, 2 into 1 header/exhaust, complete racing drivetrain, dyna ignition/coils, etc, etc...

but as everyone knows... a hog is not a duc  [cheeky]


ducvet, i'm not sure i want to get into a big bore kit with this bike. i don't have the time or the money like i did with the harley to do trial and error tuning. i went through a few different carbs, carb settings, exhausts, ignition, etc to get everything to work where it was halfway reliable. but then again it IS a harley [laugh]
haven't dyno'd it but that bike's got torque for days and i can get the front wheel off the ground with minimum effort. but she don't turn for shit  [bang]




hey brad, yes, this is what i figured...expensive and i don't want to go switching motors. right now i'm at an indicated 5k rpm's at 80mph (180kh). i'll try a 41t...

hey foggy123,
i think you nailed it by saying "more responsive", thanks for the input. i don't want to get into too much trouble with displacement. rather i'd like to get a few things to compliment what i have. i'm thinking about another duc in their superbike range but that won't happen for a few years.

yes, penske's will come in another month. thanks for the heads up on the 14t sprocket. i think i'd leave that alone and go for the larger rear. LW wheels are awesome judging by the LW wheels (almost have the weight over stock) i put on my bmw 328is. i couldn't believe how much better it handled. but that will have to wait until i can get a bonus or something...

you should post your foggy on the foggy thread i started. i'd love to see your bike. magnus and monstermash posted theirs...
http://ducatimonsterforum.org/index.php?topic=1331.0

hey nick,

no i'll keep the termi's and thanks for confirming the rear sprocket.
i think i'd like to install some lightweight parts when i see you next week and get the timing dialed in as well. do you have recommendations on LW parts? and what about some cams? i've been searching and i can't find any for the 916...

PM sent.  ;)

I have access to sps as well as R cams. they will need to be degreed after installing them.  You can use either offset  keyways or adjustable pulleys. I usually use the keyways since I dont change them  after setting them and they are less $$$.
I also stock the keys. If your bike has the adjustable pulleys from the factory those will work but i am pretty sure they did not on the last foggy I put cams in.

ducvet, that's great...now what's the pricing  ;D
send me a PM if you want