BCM Ducati spent a couple of days modifying my '01 ST4 with very good results (first graph).
The second graph (different line colors) compares my stock ST4 (blue line) to a stock ST4S (green line) to my ST4 after modifications (red line).
Modifications include Vee-Two cams: Intake V2-03-607A (18/58), Exhaust V2-03-604S (53/20) which is close to a 748R intake cam and a 996SPS exhaust cam, mildly ported head by Bruce with attention focused on the valve seat area, re-cut valve seats (stock valves and seats), 0.5mm flycut off heads to slightly increase compression and to compensate for material removed from the combustion chamber. Assembled by Jay with squish set to 1mm, opened up airbox lid, and an ITG air filter. Both the before and after runs included ARROW slip-ons, collector modification, and an FIM UM201 chip. Stock 916cc displacement, stock pistons and rings, 89 octane pump gas. The goal was a nice torque curve and a boost in HP while maintaining stock pistons and valves.
50 miles so far, and I'm liking it. It sounds a little different now at idle, almost "angry", and blipping the throttle is oh-so-nice
bruce had told me he liked the 748r inlet/sps exhaust combo, but i was a touch unconvinced (not that i doubted him, but). but, the shape of your curve is very good, holding the torque to the top. altho it peaks at 9, the power holds pretty well to 10. the 748r inlet is the same duration as the std cam, but with nearly 3mm more lift.
the port work and extra comp it has will help too. porting generally helps hold the power at the top end, whereas it's effect is reduced the lower down the rpm range you go. good heads let you run shorter cam timing and still make good power, and comp generaly lifts the whole curve somewhat. an 748-872 bruce built that doug tuned made 120 with 33/29 valves and sps cams, so there's potential in those valve sizes.
i generally feel the 916 engines are under-valved, and am surprised just port work will help so much. but there you go. i tend to run different cam timing that demands more of the inlet ports (to increase the mid range) which exagerates the lack of peak flow.
bruce gets to play with lots more engines and customers who spend more than i do, so he's pretty lucky. and he does nice simple stuff. i've already emailed him to ask some questions.
115 Inlet (lobe center), 107 Exhaust. It pulls very well even down low. And it now does 2nd gear power wheelies (which it had never done before). All with stock gearing.
I should mention that I told Bruce I was more interested in mid to upper mid-range power, not just peak HP.
Bruce took it for a shake-down run and mentioned that he was able to hit the rev limiter (10,500 rpm) in 5th gear (150mph) with stock gearing (15/43). And all the bodywork was at home in my garage! This thing is much faster now.
Tell me about your S4 cam timing. Have you run it on a dyno?
Interesting. Impressive chart. Thanks for posting it.
I moved my intakes to 110, and keep the exhaust at 107 (SPS). I dynoed at 110hp without a baseline run. Not too happy with the dyno operator or the PCIII map he made. The guy that did it is a long time Triumph race mechanic and seemed to have a serious ax to grind against Ducati. He keep holding my chart up as proof to how shitty (his word) my Termi full-system was, because my power started to tail off after 9000 rpm. Mine was only second or third Ducati he had mapped. I added and removed fuel, here and there, and the bike seems to pull better.
That said, I have some 35/30, very lightly ported SBK heads I'm going to try to put on; maybe start playing with them next week. Still not sure what I'm going to do, cam timing wise, with the bigger valves. I was thinking 115 on the intakes too, dunno, may keep them at 110. I'll set the squish then (the more I read about this, the more excited I get). And this summer, I want Dan Kyle to build a new PCIII map for me.
Your chart is quite interesting. The S4 has the same engine as the ST4. Funny how things can end up so differently, with just a few changes. I'd like to see what you get with the heads, different cam timing, 1mm squish, and a new map. Post back when you make changes, and I'll do the same.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DanST4 »</TD></TR><TR><TD CLASS="quote">Your chart is quite interesting. The S4 has the same engine as the ST4. Funny how things can end up so differently, with just a few changes. I'd like to see what you get with the heads, different cam timing, 1mm squish, and a new map. Post back when you make changes, and I'll do the same.
Modified by DanST4 at 3:28 PM 4/16/2004</TD></TR></TABLE>
true it's essentially the same engine, but the mapping must be fairly different between the two bikes. the st4 comes standard with 45mm headers vs s4's 40mm. also, tom's running the "corse" ecu (right, tom?) appropriate for the hot cams. so settings vary even more.
Yeah, that's right Strati; I am running the "Corsa" cam ECU, not that you can tell from the air/fuel chart. Although, I imagine, the cam timing changes screwed that up pretty good. Not sure if Ducati alters ignition timing, or anything else (other than RPM) with these ECUs.
Sure, they're on the 2nd page of this thread. Anyone care to comment? I haven't had experience with FI.
Recenly I rode 550 miles and had a chance to really get to know the new powerband. At 4k rpm it's little changed: same vibration, same sound, 5% more power, the coolant was maybe 5 degrees F warmer... not bad at 4k rpm (4k is where I usually cruise). But from 4k to 6k it really jumps up in power and has a strong intake sound. It seems as if I could skip a gear when I upshift.
It sounds "angry" at idle (probably the additional compression), and revs up quicker with a blip of the throttle. There's very little "cammy" sound when cruising around the city; duration is very close to stock. Pulling away from a stop is easier; it revs up quicker with the 2 pound lighter flywheel (now 2#, was 4#).
Roll-on is better, and jumping into traffic and passing is much easier now. The intake howl is fine (with foam earplugs).
Tomorrow I'll burn a tank to see how all this has altered my gas mileage. I added some leaded race fuel to get an exhaust outlet color. (I got 52.8mpg)
Looks a little dark but the fuel mileage is fine so no changes needed.
Best to call BCM and discuss your performance needs. I'd rather not talk pricing.
I had the 12k service performed, and some other service done at the same time.
Headwork takes time, time is money, and Bruce will need to talk with you before he can give you a price. You can go crazy on headwork. I chose to stay with stock valve and stock seats. And I avoided the extra cost of pistons and boring and break-in.
This is a sport touring bike that I use to cruise the Blue Ridge or take weekend camping trips.
It's just a sport-touring bike that's a bit quicker now.
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DanST4 »</TD></TR><TR><TD CLASS="quote"> 52.8mpg average over 500 miles, with a low of 50 and a high of 56.
So it makes more torque, more HP, and gets great gas mileage to boot! Way to go BCM...
Modified by DanST4 at 11:12 PM 5/1/2004</TD></TR></TABLE>
Wow! Given the price of gas, Bruce's work should pay for itself in, uh, oh. Never mind
Just kidding...
That is awesome, of course. Thanks for the update. I get around 40-45 right now. I wonder how much your fairing aids your numbers vs. a Monster?
I pulled my old heads today and set the SBK heads on. It looks like there are some small issues, but clearance isn't one of them. Pretty much smooth sailing. I'd like to get some opinions on cam timing though. I would think with the larger diameter valves, I wouldn't have to be so aggressive with the advance.
Stock screen. I'm looking at a taller screen and may go with the Zero Gravity. I really didn't do a lot of performance stuff to this engine. Just cams and some headwork. Oh, and some little things like slip-ons and a chip. But compared to race bikes this ST4 is just a touring bike with a bit (15%) more power.
Yes, I'm happy with the fuel mileage. With a 5.8 gallon tank I don't have to think much about finding the next station. And it runs fine on 87 octane. The more I ride, the more I appreciate the torque curve and additional 15 hp. Ducati should offer an R version of the ST4S, say 25 more HP and about 25 fewer pounds (with c/f wheels and bags perhaps). No radio, no CD player, no GPS, no barn door, no drink holders, just a sport touring (ST) bike that's light and powerful. Offer those things as optional kits or packages if you must; I don't want any of them.
I wonder when Ducati will offer a lightweight sport touring machine with a 135hp testastratta engine? I'd like to see that, not a V4 Luxo Tourer.
But now I hear the 4V ST is going away from the Ducati line up. Too bad.
ST4 modifications at BCM Ducati
Linear Mode
