| Author | Message | |||
     Tnthumper |
I was mainly looking to richen up the a/f ratio because unless I'm wrong with it above 90 degrees when it was tested and I will ride in the winter with the a/f around 14-14.25 in the colder air it will lean it out more. And as hot as it can get over here in TN I'd rather be closer to dead center of where it should be(13.5) Also it shows rpm under a/f chart and I'm translating same lines to hp/torque. I could be reading that wrong But at bottom of graph it has max power listed. and that is where I got the max figures. John | |||
| Jprovo |
TNT, A bigger main jet shouldn't hurt the engine. You might want to try it and see how performance is. James | |||
| Tnthumper |
James, Just put next size up jet in carb. Will know some more tomorrow. Also will have a second dyno run by next week to cross check first run. As soon as i can get graph scanned I will post it. John | |||
| Swampy |
What I meant to ask was has anyone enlarged the vaccum port on the slide? | |||
| Tnthumper |
Swampy, If that is the hole off center next to needle valve hole then the answer is yes. The dynojet kit came with drill bit for that as well as new slider spring. John | |||
| Tnthumper |
James, Next size up in jets seemed to give it more punch.this thing has really started to come alive. John | |||
| Tnthumper |
 Here's dyno chart I got from dealer. This is with pro-series intake/exhaust and dynojet kit with their recommended 155 jet. I am experimenting with the 160 and 165 and will have second dyno run next week. Will post it when I get it and get it scanned. John | |||
| Xgecko |
that Dyno is screwed up...half the RPM's and twice the HP it should be...given that the Torque is correct I would say that they have it set for a twin; my dealer did the same thing to mine the first run then they figured out that they had it on the wrong setting | |||
| Tnthumper |
50.4 FT-LBS is correct torque and 24.87 is double HP? I can understand the 1/2 rpm reading. I asked at dynojet dealer where I am having 2nd dyno run done and he said figures sound correct. This guy ONLY does Harley and Buell. I'll upload graph when I get it from him. John | |||
| Xgecko |
switch that...dyslexia at it's finest... | |||
| Tnthumper |
Roger that. Like I said I'll have second dyno run next week. I am however gonna have a larger jet in when I get second one though. I don't like being that close to the edge of too lean with the colder weather coming on. The cold air will make it run leaner so I'd rather be a little to rich side. John | |||
| Gearheaderiko |
If the rpm shown is at half what it should be, the A/F mixture is consistant, which says a lot for the Dynojet kit. I'm inclined to believe the graph (not numbers) is right since the torque & hp fall off after peaking. Cant wait to see the new dyno runs. (Message edited by gearheaderiko on October 01, 2005) | |||
| Ezblast |
Dito! | |||
| Tnthumper |
Ok everyone, that dyno run was with the dynojet kit and 155 jet.ran it for a while with the 160 and even tried the 165. kit recommends the 155 but from feel I think 160 is the best bet. I'll see how good my "feeler" is when I get next dyno run. Hopefully power will be good and a/f ratio will be more to centerline. John | |||
| Gearheaderiko |
Here's the new dyno with the old to compare to. The new shows power is down, but thats unlikely as it sure doesnt feel that way!I'm guessing the difference is the first one they spent 2 hours on, the 2nd was done in half an hour (rush job). Changing the jets from 165-155 gave it better low end response though.   (Message edited by ezblast on October 13, 2005) | |||
| Naustin |
Are you talking about the dynojet jets taht are numbered different, or are you talking about the HD jets. I have a 175 HD jet in my bike. How does that compare to the 155 Jet you are using - assuming that your jet is measured on a different scale?? | |||
| Ezblast |
Looks to me like you could use that sportster needle and adjust it further up to lean out that one area a bit - or shim up .03. Nice graph otherwise! My cam doesn't fall like that though - that must be the SE550 - yes? - but that cam is supposed to be good to 7000 rpms then drop - is that the exhaust reversion you think hitting you there at around 6800 - perhaps a Force type would serve you better - Desmotto got a 40/53 on his 600 using his copy of a Force and a stack and tunning the carb - Just a thought. I still don't get your torque numbers - somethings holding you back - I just can't figure what - perhaps you should call Terry Parson at Valejo HD/Buell - their dyno guy - and LSR Blast developer for some ideas - perhaps a secondary or a different carb - still - sounds like your ready to race! GT - JBOTDS! EZ  | |||
| Ezblast |
No - that is a regular jet the same as I'm running as a matter of fact -but I'm running between 12's and 13's because of my Dial A Jet secondary. The High comp piston is designed for the Blast head and actually needs less gas to perform better - thus the lower jetting - lol. So a high performance Blast actually has the potential to have better gas milage, but that never happens due to the way they are ridden! Reason why an oil cooler may be a good idea! GT - JBOTDS! EZ | |||
| Gearheaderiko |
Realistically I think the last dyno is a 'ballpark' graph for the A/F ratio only.It doesnt feel like less HP & the same torque as the PS exhaust.Revs out faster and hits 95mph a lot easier(sitting up & no fairing). Hits redline easy in 4th but I havent yet in 5th (partly due to ticketophobia, partly due to all the lumber on the freeway last night). Without unlimited access to a dyno or a safe unpatrolled road it makes it difficult to just try small changes and see what works, but I'm at the point where that is necessary. Having a unique exhaust also makes it difficult to rely on others research. Of course this will all be a moot point if it handles like crap on saturday! | |||
| Gearheaderiko |
Cant wait to see Tnt's new dyno with the correct graph & numbers. EZ: Is your dyno posted somewhere? | |||
| Ezblast |
Naw - but I'll hunt it out and post it now that I'm moved in and settled - I'll also send you, James, and Dallas those signed pics by Erik B. - they are sitting on the bookshelf waiting to be sent - lol - sorry - I was thinking of doing another Dyno now that I have everything dialed in, however, here is Desmo's Dyno before he re-did his carb and intake and set the SE Ign. to 9 and ran race gas for the above numbers I mentioned running a full stage 3 600cc kit-
You see what I mean about your torque being low for the motor your wielding. GT - JBOTDS! EZ (Message edited by ezblast on October 13, 2005) | |||
| Ezblast |
A thought - maybe a bit lean? - I know that lean usually means more power, however, I have found that a little rich serves the bike better in power - at least on this thumper - lol GT - JBOTDS! EZ | |||
| Tnthumper |
Well,just talked to shop that was gonna do my free dyno run and he is having problems getting dynojet to reimburse him for the run. Guess it's gonna be a bit longer til I get second run.I can't wait to see it myself. I know that since I went from the dynojet 155 to the 160 it made difference in how it felt. When I tried the 165 it made it feel sluggish. Am off tomorrow morning so I'm gonna call a couple of other dynojet shops close to me and see what I can do. John | |||
| Gearheaderiko |
Is still is only 500cc. As said, I dont think the HP dyno number is correct as they didnt put much time into 'tuning', just get-R-done! This bike jumps when you shift gears. Leaning out the midrange (4k-5k) put some punch in the lower end again, but the top end may be helped by being a little richer. I dont think the Pro Series exhaust was doing me any favors, so there wasnt much point in trying to dial it in with it on. Now I can start tuning. | |||
| Gearheaderiko |
The mods: XB head and matching piston 10.5:1 comp. SE XL'04 cams (XB grind specs-SE 550's?). Jims lifters and adjustable pushrods. SE adjustable ignition. (7500 rpm). 1 3/4" exhaust w/ White Brothers can (very long-no discs/open). 98 octane gas (pump & race gas blend). Splitfire sparkplug. Certainly not radical by any means. The XB9 dyno shows power at 73hp, falling off at 7500. If I can get half that (w/7500rpm) I'll be happy. I'm also gonna look for a new dyno guy (one closer with more time to spend). (Message edited by gearheadErikO on October 14, 2005) | |||
| Naustin |
The 155 jet must work in combination with other modifications to the carb. It isn't actually running leaner --- or actually it is, but only over a certain rpm range where the 175 is too rich. Right? It is just more finely tuned and there must be a compensation to richen the mixture at other points in the RPM range. That must be the "secondary" EZ mentioned. Is this a 3rd jet? I'm confused.... Sorry to jump in... | |||
| Tnthumper |
Naustin, The 155 I mention is from the dynojet kit. The kit also comes with new diffuser,ner slider valve spring, new needle valve, and has you drill out the hole next to needle valve hole in the slider. As for being lean according to my chart it is very consistent across the board. Of course I'm trying to get a second run done with the 160 in the thing to richen it up just a bit. John | |||
| Ezblast |
Is the XB head in stock configuration? Perhaps a Sportster secondary, or a Thunderjet, or Dial A jet is needed? That power goal 35/35 should be easily doable. Hmmm... (note: we are talking about regular Kehin CV40 jets) GT - JBOTDS! EZ | |||
| Bobbyhead |
Gearheaderiko, can I ask what # that Splitfire sparkplug is, that you're using ? And no matter what your dyno prints out, if the seat of your pants is happy, don't fret the numbers. Your Blast is awesome  Bobby | |||
| Naustin |
So with 45/175 jets as recommended for a stock blast with an exhaust, it is safe to say that the A/F plot would be all over the place rather than smooth across the board.  |
