Brad The Bike Boy: Dyno chart for hot 1000SS: 1080cc, DP cams, Kaemna head, etc

Thursday, October 4, 2012

Dyno chart for hot 1000SS: 1080cc, DP cams, Kaemna head, etc

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Because the new Dynobike dyno reads lower than the old dyno, I don't have 16 years of reference for most of the dyno work I've done in the last 21 months like I have had in the past. And one that I was quite curious about (and a little disappointed in originally) was a 1000SS race bike I tuned.

I first saw this bike when I fitted a U59 ecu to it back in the Moto One days and tuned it at Broadford on a practice weekend. At that point it was 1080cc with heads by Kaemna in Germany and a full system from Mark at Madaz which had the 45mm header pipes going up through the middle of the swingarm and two mufflers under the seat. Owned by a man named Drew, previously the Bears Formula 2 class national champion on his Vee Two Squalo, the bike had a bit to live up to.

After a couple of seasons as was, Drew brought it back for me to fit some DP cams and 748 throttle bodies modified (well, it's a bit more involved than simply "modified") by Kaemna to fit. The job took the usual twists, and due to a tight valve the horizontal head came off. Which made it quite clear that the compression wasn't that high. I'd almost say it was std-ish.

See some photos of the throttle body set up below. I refitted the std airbox, albeit quite modified as required with the handsaw and die grinder as this was the easiest way to mount the battery and ecu. The original 748/916 trumpets were used, but shortened so overall the inlet tract is quite a bit shorter than your std 1000 motor. It doesn't appear to have affected the shape of the power curve at all.

Once the big throttles were on and the cams in (set to 112 degree inlet centrelines) I took it to the dyno to remap the U59 ecu. I made some guesses based on the changes made for a baseline and as it turned out I was pretty much spot on. Given it's a race bike I've not ridden it, but Drew said the cams and throttles made a noticable difference. I was a bit let down by the power output, but in comparison to the two 748/853 and a 996 I've had on this dyno I'd say it's at least 15hp better than a 1000SS with pipes and air filter mods.

The graph below shows the comparison with the 853 in red and 996 in blue. The 1080SS is as good as or better than the 996 up to 7,500 rpm (which is about what you'd expect in a 2V vs 4V comparison) and as powerful as the 853. And I'm quite sure it carries a compression disadvantage.

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