| Author | Message | ||
     Pressureangle |
Well...keep in mind that I'm generalizing about an engine with which I have no experience... Dual plugs don't always show up as hp on the dyno; largely, whether they show power gains is a function of combustion chamber efficiency. With reasonably efficient chambers (like I'm ass-u-ming here) dual plugs show up their benefits after the engine is very hot, especially if it has high compression and a significant piston dome. Detonation isn't necessarily heard-it comes in shades of gray, usually between the piston and cylinder above the top ring. The second plug eliminates the highest pressure area of unburned mixture by burning it before it can detonate. One thing to remember about chassis dynos-they cannot reproduce real-world loading cycles. For that, you need a water brake or engine dyno. Heat is the enemy, and even a small bit of detonation makes heat. The 883s would lose 3-5mph top end on a hot day at a track like Daytona or Road America halfway through a race. Richening them up a bit and retarding timing, though reducing initial power reduced the mph loss as well. The main benefit in the long run was exhaust valve life-we changed heads every weekend after practice, to have fresh valves to race with. Careful monitoring of detonation allowed you to get through cooler/shorter tracks without the extra work. Secondarily, it reduced the already enormous heat in the thick 883 cylinder liners, which were prone to piston scuffing. Also, to fully utilize the benefits, compression must be raised to the point of detonation with a single plug; and peak cylinder pressure needs to come at ~20* ATC. Having two flame fronts shortens total burn time, allowing more BTUs near that angle. Total timing needs to reflect this. My apologies for this messy post. | ||
| Ezblast |
So you would say that it helps prevent detonation that performance engines can be prone to when hot by keeping them cooler with a more complete burn? GT - JBOTDS! EZ  | ||
| Pressureangle |
Yes...it's a fine line and precise definitions here. It's not necessarily a more complete burn, rather a complete burn with no explosions in a shorter period of time, or less crankshaft degrees. Multiple flame fronts won't _necessarily_ make a particular engine run cooler but they will always complete the burn sooner and produce higher peak cylinder pressures _at the right time and place_. Back to chamber efficiency-Dual plugging a new Honda 450 won't help (if you could do it at all) but a Shovelhead H-D demands it in any case, even stock. IIRC Ron Wood's big rotax roadracers had 3 plugs. To throw more wrenches in the works, we have to consider octane rating of the fuel-if you're using 100 octane racing fuel, you'll get more hp and less detonation; running anything remotely streetable, dual plugging probably isn't worth the money unless you're adding it in to an already-ongoing process, like porting the head. It's extremely simple, really-poke a hole in the right place, bore the seat and thread it. To make it short (which I'm not prone to do) I'd not consider dual plugging until I'd done all the bolt-on stuff and was ready to port it. | ||
| Pressureangle |
I started a new thread in the knowledge vault/engine/all topics titled I/C Engine Theory, for in-depth discussion of stuff like detonation, camshaft timing, exhaust tuning, etc. | ||
| Ezblast |
Am in it! GT - JBOTDS! EZ | ||
| Gearheaderiko |
Or, in short, with dual plugs you need less timing advance. | ||
| Pressureangle |
I'm still on this. I'm looking for a RaceBlast-anybody got an angle on a wreck/ruined blast? | ||
| Gearheaderiko |
Have you looked everywhere? Cycletrader, salvage yards, insurance auctions, e-bay,etc.I've seen them listed in all. Have you checked with the local Buell dealers (some insurance companies require a dealer estimate). They are out there if you plan to spend at least $1000. | ||
| Mmelvis |
May 29th Moroso racing I was really surprised by the turn out at the track, the hard-core racers were out on this day. The day started at 90 degrees and stayed there all day long. Ran 2 races on this day Am. Ultra Light Superbike (7 is my group) and Am Lightweight F40.(6 in my group). Race tech was a bit of an issue, with my belly pan was looked at more than usual this time. Over the last few race my belly pan has been getting ground down and it has grown a few inches shorter over time and has been patched many times. Tech failed me on my first time through, had to get back to my area and do some quick fixes. Well after some patching to get a rear lip so fluids would not run out they were happy and passed my bike with the following words “ $500 if you oil the track”. I figure OK only seems fair and went on my way to get ready for the practice session. The practice session went well getting used to the bike with a little more power under the belt. Seemed like I was able to get around the track at a quicker pace than I have before in the past. Everything was running like a clock and no major problems to speak of, everything just worked like it was supposed to. Race 1 for me Am. Ultra Light Superbike 2 waves and I start back on row 8 in the back of the pack second wave The first wave are the 125 GP bikes, with Expert group next, then AM group (me) and the vintage classes in the back The race starts of great and I am keeping up with pack in to the first turn, I am surprised by this normally I start to see all the folks just pull away. Well by lap 2 I was at the back of my group and slowly loosing ground. Going into one of the switchbacks I cut the turn a little to close and hear the belly pan grid very loudly, still on the bike only missing a little more paint. Next thing I see yellow flags and I think great I am now dropping parts, turns out one of the motards missed the switchback and went down in the grass, he did not look happy as I went by. The rest of the race went well and I ended up sixth place out of seven riders in my group, mr motard came in seventh. This is the first race where the vintage group did not blow by me, things are really looking better. Going back to my pit area had one racer run into me not looking where he was going, he was waving his hands all over the place and pointing at his front brake. He drove off to his race and I just thought glad I am not racing in that group. Race 2 for me Am Lightweight F40, started in wave two row thirteen, wave one is the experts. Go to get on my bike to head out to the track and notice my right peg feels funny, look down and it looks like someone ran over it with a truck. The person who hit me earlier is the person who must have done this, to late to change the peg now. This race started off much quicker and the group was bunched up into turn one. Had to dodge one poor guy who stalled his bike, things were looking good again. Lap three I had a scare came into turn one to fast and by the time I was going for turn two I was running out of pavement. Stood the bike up on the rumble strip and head straight for the grass and the first switch back. I ended up take a short cut through the in field at this point. After that small excursion I had no chance of even seeing the group again, so I ran the best I could and brought up the back of the pack and finished dead last. I getting sort of used to this at this point in my race experience. Need to put a thank you out to Pressureangle for the advice on the track, he has ridden Moroso many times and gave me some great advice on some of my problem areas with the track. Will post pictures if any track photographer happen to get me in a picture. | ||
| Ezblast |
Sounds like your having fun! Nice way to start the season - how did the motor feel - where do you think the improvements helped you the most - in the straights or curves? GT - JBOTDS! EZ (Message edited by ezblast on June 01, 2006) | ||
| Naustin |
Wow, Great! Sounds like the added power will really pay off! I wonder if the peg got Fubar during the accident? Maybe the peg destroyed the other guy's front brake? Or - you don't mean to say you think he sabotaged your bike later - after the incident?? Anyway, if not for the screwed up peg, and that hot corner field trip, maybe you wouldn't have finished last... I love to read these episodes - Thanks! nick | ||
| Mmelvis |
Ez - The improvement helped in both the straights and the curves. I am not bouncing of the rev limiter all the time. I turned the rev limiter up to 6800, I know I can go higher but do not want to do this until I get the dyno tune done by Wes. Right now I am having to much fun to take into the shop.The engine pulled all the way up to 6800 rev limit in all the gears, I just need to get my new shift points down now. What I really found great was on the starts actually pulling ahead of some folks in the first race, usually I end up just watching them slowly pull away. Still need to get better with my corner speeds but that comes with time. Naustin - I did not make myself clear on the peg, I think the peg got messed up when his bike ran into my bike. I just did not notice it when he ran into me. I was just to pumped up after the race to notice. Wish I could blame my poor finish on the peg I think I would have to put my placing so poorly up to my riding skills. Still get that "Oh no feeling" going into a turn at 80, but it is one heck of a rush that is great. | ||
| Ezblast |
Cool! | ||
| Naustin |
Sweet! As far as that "oh, no" feeling - it is very, very closely related to the "hell yes" feeling. In fact, it is the exact same feeling, you just have to get your brain to label it differently. I'm no racer like you though... So, I can't really talk....  | ||
| Pressureangle |
Going back to my pit area had one racer run into me not looking where he was going, he was waving his hands all over the place and pointing at his front brake. He drove off to his race and I just thought glad I am not racing in that group. I know that scenario-been on both sides of it. The guy (or his help) just put in new brake pads, and forgot to pump them up.  Glad I could help, hope my ramblings eventually became coherent. Sorry I couldn't make it down there again. | ||
| Pressureangle |
I was going to send these direct to mmelvis-but since this _is_ the racing forum, I figgered I'd post them up here. The images were plucked from Terraserver.microsoft.com Turns 1-3  Turns 7-9  Turn 10  (Message edited by pressureangle on June 02, 2006) | ||
| Mmelvis |
Pictures from Moroso 5-29-06      | ||
| Flrider7 |
Mmelvis is one heck of a rider! I rode with him last Saturday and he was up front with the XBs and Jap sport bikes hangin in there just fine. He's really got that Blast rigged up! | ||
| Gearheaderiko |
Thanks MMelvis for the heads up on the H2 steering stabilizer from Pro-Flo(actually after 6 weeks of waiting, I canceled my order and bought new off ebay for the same price). Thanks again for the pictures. It saved a lot of time trying to figure out how it would fit (like everything else on the front end, it has limited options of placement) especially since I got it the day before the races and had to install it that night. | ||
| Buellistic |
Flrider7: Now we have to get you riding a little closer to the front of to GROUP ... By the way my PRODUCT IMPROVEMENTS are coming along just fine ... Can hardly wait to ride my BLAST with other BLAST RIDERS !!! In BLASTing LaFayette | ||
| Mmelvis |
Eric glad to hear the mounting went good for you. How did the race go ? | ||
| Ezblast |
Hey Erik or James or Melvis - could you give a run down on the Damper vs no damper feel when riding? I'll have the new tires broke in by this weekend - will let you all know how sticky they are then! GT - JBOTDS! EZ | ||
| Gearheaderiko |
I'll let James give a race report and damper feel. (Message edited by gearheaderiko on July 18, 2006) | ||
| Mmelvis |
Damper feel to me is minimal, I never set it above the 2nd click. The only time I set the damper that high is in wet races to slow down my steering inputs. On the lowest setting you do not even notice that the damper is there. As far as does the unit do what it supposed to do I would say yes. I actually got to test the unit not by choice going a bit wide and hitting a rumble strip on a track. I tried to over correct and used a death grip on the bars, wrong thing to do when the front starts to shake. There was one or 2 bad shakes then I let up on the grips and the bike corrected it's self. The damper did slow down bad inputs and kept me from crashing. | ||
| Gearheaderiko |
Steering stabilizer ala MMelvis. I opted to use a fork clamp instead of drilling the bottom of the tree, although it works out to be virtually the same position. There are only a couple of more 'creative' places to put the damper, otherwise this is the easiest location.  } | ||
| Jprovo |
RACE REPORT, WILLOW SPRINGS My loving waife Karen and Erik Oberg came out in July to support me at the track. July was Freaking HOT. It's been over 100 degrees in June and July, and it has not been a picnic at the track. Temperatures like that have not made it condusive to putting on a cowskin and flogging a motorcycle around a track. The past two months have seen me being slow and finishing at the rear of the pack, beating a few guys due to atrition. I think that there is a lot affecting me, mostly personal family stuff that is preventing me from really concentrating on the task at hand. The upside is that some better finishes in previous cooler months, and consistent finishes in the last two months have kept me alive in the points chase. At the end of June I am ranked 48th out of 255 riders, and am 4th in top rookie expert points. I am looking forward to a good race next month, it is double points weekend. I will be putting my head down and going for some good finishes in 500 Singles and Formula Singles. I need to work on hanging off the bike more, and carrying more corner speed in turns 1, 3 and 5 (the three lefts, go figure) Right now Karen and I are debating renting a Toyhauler trailer for the weekend to have a Cool place to stay... It's bound to be hot again. THE BIKE The bike is progressing well. The clip-os help get me lower down on the bike and feel more comfortable leaning off in the high speed stuff. It also keeps me from having it feel like my hands are above my chin in some corners. The steering damper seemed to help with some of the galloping, loose feeling that we were getting in the ultra high-speed 100+MPH turn 8. Right now I have it set on 3, but will try it at settings 4 and 5 if necessary next month. Until next month, James WSMC 763 | ||
| Ezblast |
Great report James! Persistence is always the name of the game in racing and it sounds like its starting to pay off - especially in corner 8;0) - lol - yeah baby the hot days of summer - a lot of racers wear/wore wet scarves for that reason - to cool off - What clip-ons did you go to? GT - JBOTDS! EZ | ||
| Naustin |
Congrats on the Uly - Hope it has the side-stand fix... Will look forward to your thoughts about it when you get some good miles on. Impressed that you're in 4th out of the rookies! Way to go! Lets see some more race pics! Nick | ||
| Jprovo |
EZ, I think Erik bought the Clip on s off Ebay, If I remember correctly, they're Pro-Flo... | ||
| Jprovo |
Nick - Thanks, I'd like to finish the season in the Top 3 for rookies, so far so good. I'll let you know more about the Uly as Karen and I put more miles on her. So far we've got just over 1000 and I'm liking it. Still waiting for the Sidestand Recall notice to come in the mail, and for the dealership to get the parts in to fix it... Hopefully in the next couple of weeks. |
