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Bike looks great!!!

As for later ridicule I love how you converted that didgeridoo into a silencer.

nice work!
 

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Discussion Starter #23
played a bit more today. i'm getting an acewell 6554 for christmas - i had no ideas to offer, so i thought of this. will get boxed for the day, but i have early access to allow fitting. i modified a bracket I found in the bits box and welded to the spacer tube mounted between the subframe plates and front fairing mount. i had to offset it so the round tacho part of the 6554 is in the middle of the fairing bulge. will paint and fit and then get into the really fun part - wiring.

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i thought i'd try fitting one of the danmoto baffles to see if it would shut it up a bit. i removed the end cap and machined it out a bit to allow the baffle to slide in and stop about 50mm down. then i machined a groove to fit a circlip too. once i'd done that, i realised i didn't have any 50mm clips, so bent a round one up out of coat hanger wire. not exactly springy, but surprisingly effective for now anyway. the baffle has a central tube with 12 holes drilled in it, all 13mm diameter. combined, that's about equivalent to a 45mm tube, which is the inlet size of the muffler. net effect - sfa. it's a bit different sound, but i made a video i won't bother posting as it's nearly as loud with as it is without. i tried blocking 4 of the 12 holes - no change. still very loud.

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Discussion Starter #24 (Edited)
acewell mount painted and dash on. not wired yet, of course. that's the painful bit. it comes with some nice, but large connectors that i might just cut off. the original ducati dash uses a 11 pin screwloc connector which i was going to use to loom side of, as i like plug and play and dislike cutting original bits. the acewell has connectors for lap timer sensor and controller that i just won't use, so i'll cut them and cover. i did have it all up under the front of the tank on the airbox lid, but maybe moving the screwloc down to behind the steering head or even into the headlight mount bracket will be easier. there's certainly easier acewells (less functions) to wire up.

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i have tried a couple of things to shut it up a bit. i found a showa 41/43 preload tube is just the right size to slide over the danmoto baffle. i tried that, giving only two 10 or 12mm holes for the exhaust to flow through and it still wasn't that quiet. i did take some video with the iphone, but it sounds a bit wacky. i'll try it on road once i get the dash sorted. looking forward to riding it again. rego is due soon, not sure i want to run it again for another year. i'm hoping to have the ss going soon, but then again this is me and that's probably a good candidate for straight onto club plates around 03/18.
 

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Discussion Starter #25
acewell dash is on and working. slight fitment debacle here: http://www.caferacer.net/forum/technical/30986-acewell-dash-fitment-issue-residual-voltage-input-sort-thing.html

their temp sensor thread is 1/8 bspt, not 1/8 not. 1 tpi difference. i guess you could call it a self locking interference fit if you'd cut the thread before realising it.

the inverter is now gone, replaced with old school relay. it seemed like a good idea.

off to the island classic tomorrow, so the low fuel light needed to work.
 

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Liked the fabrication work on the exhaust. You got that lined up nicely. With the way it's pretty much aimed at head high I would think that helps amplify the noise level.
 

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Liked the fabrication work on the exhaust. You got that lined up nicely. With the way it's pretty much aimed at head high I would think that helps amplify the noise level.
pipes that direct engine pulses toward the rider behind have been a consideration since we started racing each other. Nothing better than winding up the guy who is trying to pass you.
 

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Discussion Starter #28
we had a day out at the island today. 270km and no fuel light. which i hope means it's economical, not almost out of fuel without my knowledge.

004s.jpg
 

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Discussion Starter #30
fuel light finally came on riding around today, 13.5 litres, 275km. not too bad, but you'd expect a 400 to do pretty well.

still fun to ride.
 

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Discussion Starter #32 (Edited)
took minnie to the dyno today to see how the 2-1 works. not well - red is the 2-1 curve. pretty much dyno'd how it feels on the road. goes well under 8, no point going over. i was going to set up one of the previously dyno'd muflers to give just the change due to the 2-1 header, but didn't get to it. might do it in future. i never really revved it hard before the 2-1 went on, so really didn't notice the crap (ish) top end in comparison to the previous. maybe i need to make a twin muffler bracket and cut down the other one.

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it was a bit on the rich side, so i thought i'd try it out without an airbox lid.

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a bit better, but the mixture change was pretty extreme. more than i think i've seen before on a 2v motor. bad to worse pretty much.

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i tried it with lid and without the snorkles, which helped a bit, but still too lean on the needle. i have some of the original 400ss carb springs, that are a lot lighter. i might try them, not sure if that'll make it better due to more opening lifting the needle more, or worse because it'll have less vacuum over the jet and the needles aren't tapered enough anyway.

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i rode it back from the dyno with one snorkle in, and without the baffle that i have been running for a little while. it's still loud with the baffle, just a little less offensive. felt a bit stronger without it.

baffle in versus baffle out.

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i don't have any air/fuel for the original exhaust and mufflers, as the bike killed the dyno on those trips. the rpm and air/fuel were shutting down when we tried to run it. the only change has been resistor spark pugs, which is what you need to run with the ignitech anyway. the ignitech has the same advance as the std boxes. well, maybe i should check that - it should have the same advance. lack of advance hurts the top end, i know that from the previous 750 engine testing.

so maybe it was rich anyway. although i ran these same carbs years ago when it was a std 600, and i would have thought with a smaller engine it should be leaner due to less suck. the 400 and 600 are fitted with the same carb spec. i did shoot some video through the airbox lid without an air filter fitted of the slide, and it did look like it was lifting all the way up. i was wondering if it would, given it's a pretty big carb for a 400.
 

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That's exciting, fascinating to watch a CV carb slide in action like that, too bad you couldn't video both carbs at once.

I really like this trace:

all those dudes running open headers and thinking loud equates to more power should study this one.

Dyno test of a stock bike would still provide your best base line, highly advisable to have one of those done before setting out to modify any motorcycle engine imho.
Thank-you for sharing :cool:
 

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Discussion Starter #35 (Edited)
the two lines in the above graph represent std headers with megacycle (local brand) slip on mufflers that always work very well on any bike i have dynod them on (that's the blue line) and my 2-1 being the red line. the 2-1 is longer overall, and has much less muffler volume. it's louder, again i would say because of the volume and also the muffler body diameter and the outlet position. but the megacycle are open, perf core style mufflers. ie, loud.

also i have concerns that the 2-1 merge may actually allow flow from one cylinder to go back up the pipe toward the other cylinder. not so bad from the vertical as the pipe in is angled, but from the horizontal it can. that's possibly an issue.

also, i fitted my old ignitech unit before these runs, and it's much nicer taking off from idle with the ignitech, but although i did check the timing with it and the oem units to make sure they were the same, i don't know if i did that test up over 9,000 rpm. the choppiness of the curve looks rather similar to what i saw when i was playing with the ignitech back when the 750 engine was fitted. the choppiness can be chain and sprocket related, but that hasn't gone to shit in the 100km since the blue line run. fuelling changes didn't make a big difference either, although it did go from too rich to too lean. the last run i did had the mixture back at 13.5 or so in the crap top end area, so that pretty much rules mixture out.

this old ignitech has a delay, that gets worse as rpm climbs. the newer units (this one I've had since 2005 or so) don't. i thought i had allowed for it in my curve, but maybe not enough. i did have the oem boxes with me at the dyno, but my time was pretty much up there and i had to get back to work anyway so i didn't. one thing i hate about not having my own dyno running is that all the things you think of later when it's too late.

so as it sits at work now (waiting for a nice day and time to go for a ride, it's pretty hot here now) it has one of the megacycle mufflers fitted to rule that change out, and i'll put some oem ignition units in my pocket and fit them on the road. i really can't see the exhaust alone hurting it this much, as nothing i've done exhaust wise in the past has, but i'm often wrong.

anyway, with regard to the "Dyno test of a stock bike would still provide your best base line, highly advisable to have one of those done before setting out to modify any motorcycle engine imho." comment, not sure if you're taking the piss or not, but.

Brad The Bike Boy: Another dyno debacle with Minnie the 400 - Ducati Monster 400 dyno runs
 

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Discussion Starter #37
on this dynojet 250, which reads lower than the older 150 they used to have, it has gone as high as 41 (first time i took it there). the next time (in the link to my blog, see the last graph there for the output wackiness) it made 38 or so max. so i'd say the claim is as good as any of their claims. i ignore any manufacturer claim anyway pretty much, i find them kind of meaningless comparative wise. in the 89 400ss manual they claim 45 at 10,500, in the 1994 ss manual they claim 42 and the 2001 m400 they claim 43. so mine is as on the money as you could expect. it's funny, the way it starts you'd swear it has no comp, but it seems as expected otherwise. i haven''t comped it since i put the new pistons and reco heads on, maybe i should.
 

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Man, that dyno run looks strange. especially that erratic section. like some reversion phenomenon choking the engine right around 7500 to 9000. Over 9000 once you got the A/F values back down a little with the lid on and no snorkel, power came back almost to the stock system.

The system probably doesn't like the angle the exhaust gases merge as you have said. And the unequal lengths of the primaries may plan a role as well.

Kudos to you for finding out, though. Can't wait to get mine on a dyno.
 

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Discussion Starter #39
i rode it today with one of the previously used megacycle mufflers rigged up, and both ignitech and oem kokusan ignition units. i think it's the muffler.

maybe more dyno on friday.
 

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...

also i have concerns that the 2-1 merge may actually allow flow from one cylinder to go back up the pipe toward the other cylinder. not so bad from the vertical as the pipe in is angled, but from the horizontal it can. that's possibly an issue...[/url]
Hi Brad,
It would be interesting to see the effect of a revised merge. I'm making 2 merges at the moment, one out of 1 3/4" and the other out of 1 7/8", both will merge into 2 1/2" tube, ovalized at the junction. I've read somewhere that the headers should merge at 15 degrees, but I've just cut a 90 degree bend in half and started from there.
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