| Author | Message | ||
     Jonnyz |
Nobody makes a turbo for the Blast for a number of reasons. 1. cost a turbo kit would run between $2000 - $3000 thats 1/2 - 3/4 cost of the bike itself. 2. Smaller displacement engines, under 900cc, can't handle the stress of a turbo without serious mods. Engines 900 and above can get away with it because you won't be on the boost long enough to blow the motor. For more info on motorcycle turbocharging I highly recomend "Motorcycle turbocharging, supercharging, and nitrous oxide" by Joe Haile ISBN # 1-884313-07-8 Hope this helps | ||
| Xgecko |
Honestly speaking I can't see how one could get the RPM's up high enough on a single to use a turbo but that's just me. As much as I would like to have 50hp in my blast I can't get around the $1k that Mr Wilson's mods will cost. I keep rolling the cost differance between Stage 1 and Stage 2 porting (from Brian Nallin) around in my head. I wonder what a Stage two will give me if I do only that. As I see it a Stage 1 is all I need. decisions, decisions. | ||
| Phillyblast |
Tony, stage 2 still gives you bigger valves, and better springs to handle the additional revs if you can find a rev limiter to allow it without completetly disabling it. You don't neccesarily need to cam the bike if you don't plan on getting rid of the limiter, either. The increased displacement and airflow with proper tuning should still give you a healthy boost without being peaky. And figure it this way - sure it's a grand, but what's the msrp on a firebolt? Close to 50 hp on this bike? How much does it weigh again? Wouldn't you love to beat a couple of sportsters at the next dyno shootout? Sure, it means some other guy gets the 200 bucks of goodies, but . . . :-) david | ||
| Xgecko |
I have a feeling that just porting it would let me beat a few of them (it the straight pipes) Mind you if I had had my V&H pipe at the time I'd not have "won" 50hp would be tough to keep from spining the tire all the time I'd rather keep the Blast and get a Firebolt. Anyway that's the plan for 2 years down the road. BTW I paid off my Blast on Friday!!!!!!! sorry I had to get that out of my system. | ||
| Mother_Big |
That's my plan also. Keep Blast, acquire Firebolt. Can I ask about this weight-balancing feature of the Firebolt, 51% front-wheel, etc. I haven't thought about that much. What is more typical? What is it on the Blast? Any idea? That would be with a rider of course, right? Any thoughts welcome. Congrats on being free and clear on the Blast! | ||
| Aaron |
Just to clarify one little detail ... Brian doesn't *quite* have his 3-9/16 bore Blast piston available yet. When he does, it will yield 10.5:1 compression as a bolt-in. On the LSR Blast, I used the 3-9/16 bore piston from his 1250 kit. Although this piston gives 10.5:1 compression with the 3-13/16 stroke of the 1200, you only get about 9.7:1 with the 3-1/8 stroke of the Blast. We did some milling and brought that up to about 10.7:1. Milling it beyond that would have been real problematic. Also, the dome angle is very slightly different on the 1250 piston, it's designed for a t-storm chamber and apparently the Blast head's squish band is a little different. I had to hand-fit the squish band in the chamber to the piston, which is something of a PITA and a little time consuming. His Blast piston will have a dome angle that more closely matches the Blast head. Since we were limited in compression to 10.7:1, I used a fairly mild set of cams, else my cylinder pressure would've dropped too much. Essentially, I ended up with a 46hp package that, except for the straight pipe, was very streetable and pump-gas friendly. I think with his new piston, 50hp should be an easy target. BTW, with respect to a rev limiter, keep in mind that the single window on your timing cup makes the module think the motor is spinning half the rpm it really is. The important thing is to look for a limiter that will go low enough in rpm, since your actual rev limit will be 2X the setting. Also keep in mind that your curve will be effectively half as aggressive as whatever you have the module set for, i.e. if you set it to have all the advance in by say 1500rpm, that'll actually be 3000rpm. You may want to ground the VOES wire to get the curve aggressive enough. I've fitted a Crane HI4E, which allows rev limits down to 500rpm (1000rpm on a Blast) in 100rpm (200rpm on a Blast) increments. AW | ||
| Xgecko |
Keith Code had some interesting things to say about Weight balancing but as I'm at work I don't have accesss to my books. I think I have two scales if I do I'll measure it | ||
| Xgecko |
Aaron you are just trying to tempt me aren't you???? | ||
| Aaron |
Tony, adding 20 more hp really does make the little bike more fun to ride. It always frustrated me before, I was constantly winding it up into the rev limiter trying to make it go. Now it just zips, loads more fun. AW | ||
| Killa_Spot |
Aaron, How much cash have you put into the bike? | ||
| Aaron |
I make it a point not to keep track  | ||
| Xgecko |
very smart Aaron, that way the Boss (she who rules the house) will never know. Mine only has a vague idea (however she gets her own bike this Xmas...ninja 250). 20hp would be nice but I could live with 6-10. | ||
| Xgecko |
This should help the aftermarket parts department Race Series for the Blast -------------------------------------------------------------------------------- AHRMA ANNOUNCES PRODUCTION SINGLES ROADRACE CLASS With the demise of the Skorpion Cup contingency class in 2002, the American Historic Racing Motorcycle Association has created a new class for the MuZ Skorpion machines that have run with AHRMA for the past five years, as well as other production-based four-stroke singles such as the BMW F650, KTM Duke and Buell Blast. The new Production Singles class is open to any four-stroke single-cylinder motorcycle available for sale to the general public and intended for street use in the U.S. and Canada. The machines must meet AHRMA's SuperStock standard, which stipulates: . No engine or chassis modifications. . Stock wheels and forks. Fork springs may be changed. Modern DOT race tires must be used. . The original carburetor and airbox must be used. Jetting changes are allowed. . Allowable changes include brake master cylinder, brake lines, pads, rotors, shocks, handlebars, control cables, fuel and oil lines, exhaust system, and chain and sprockets. . Replacement fairings and bodywork must be a cosmetic duplicate of the original and made of fiberglass or plastic (no carbon fiber). The Production Singles class will debut at AHRMA's 2002 Florida Bike Week events, March 1, at the DeLand Airport, and March 4-5 at Daytona International Speedway. For information, call 615-851-3674, 913-268-4401 or visit www.ahrma.org. | ||
| Hoser |
Pic's of a C & J racing , dirt track frame for Blast engines.   Expensive ?? , .......Yup , but it's a work of art!! | ||
| Spooky |
I want one!!!! How much? | ||
| Hoser |
Spook: 2G's ( US $ ) | ||
| Rockbiter1 |
Ok, just did a web search for C J Racing, the site was hosted on a Netscape Webpage service, which apparently has been closed down. Anyone got a good url for C J Racing?? I already looked through the links section. | ||
| Aaron |
Last dyno sheet I'm likely to share on this project:  I'm not nearly done with development, I anticipate getting some more, but I kinda need to keep it under wraps from here. This is achievable with Nallin stage 2 work, 515cc big bore kit, some decent cams and a Mikuni. It's kinda peaky, it's using a drag pipe. If you put a muffler on it I suspect you could smooth it out quite a bit and probably make it streetable. You'd lose some on top, I don't know exactly how much. This particular combo has a streetable corrected compression, too. It has a lot of compression but it also has a lot of cam, and that bleeds off much of the pressure. The compression tester shows only slightly more cranking compression than my M2. AW | ||
| Jonnyz |
Aaron, Are you really running the Blast all the way to 7800 RPM? Is there anything you can share about the valvetrain mods? I know this is an all out race bike, but what do you think of the relilablity of your current setup? I take it your not building a grenade. Thanks. Jon | ||
| Aaron |
Yes, 7800 is no problem, but as you can see, it's power peak is more like 7400. I don't want to share what I've done as far as cams go, let's just say I've tried multiple sets, and may try some more, but honestly, cams aren't the hard part. There are many sets that'll take this little motor well into the 7's, assuming you have good head work. A set of cams that are considered hot street cams for a 600cc cylinder are essentially race cams for a 500cc cylinder, so they're easy to come by. The short stroke kinda changes how you want the cam grind to look, though, in terms of lift and timing. The stock valve springs will float right around 7000rpm, depending on the cam grind that'll be plus or minus a little. 185lbs or so seat pressure will get you into this upper 7,000 range safely, again, that'll vary some depending on the aggresiveness of the ramps. Use good heat treated chrome moly pushrods IMO. Ti retainers. I'm using Ferrea (sp) stainless valves. I tried Ti valves but they have pros and cons and basically the cons were outwieghing the pros. Stainless valves will certainly last longer. Part of their longevity/durability has to do with how much margin you choose to take out of them. Brian can help you make that call depending on the intended usage of the engine. Cam profile and springs play a role of course. One of the things I'm really working on understanding is the whole valve sizes versus overlap versus sinking trade-off. That's a sticky area and it's important. I learn a little more with every experiment. Maybe someday I'll feel like I've really got a handle on it. There's lots of ways to skin the cat, exactly which approach works best under what conditions is something I'd like to get my arms around. Good Luck! AW | ||
| S2no1 |
Aaron, Is there a computer program to help you model these curve and intake overlaps, etc.? Curious minds want to know. Arvel Dang, that bike has almost as much poop as my S2, at less than half the CC's. Course, you might have trouble ideling around the park. | ||
| Aaron |
Damn, Arvel, I know I responded to your question but I don't see it there. Probably over on the classifieds page or something. Yes, there's software. "Dynomation" or some such thing is the one I keep hearing about. I don't know anything about it, someday I'd like to mess with it though. I would presonally be surprised if it could get down to the level necessary to really answer that question properly, though, I think that's a cut and try deal. There's fancier software, too. A fella who works at a motorcycle company told me they have a $100K engine simulation package that runs on a workstation that's really slick. Obviously I don't have a copy of that AW | ||
| Rebelgtp |
Has anyone seen these drag bars yet? I still think the idea of a Blast with dragbars is a lil goofy. First time I saw one was at the drag strip here. Are the bikes actually getting popular for drags? With that kind of power Aaron is getting I think it would be interesting. Oh yeah and just a quick question the buell has a rev limiter set at 6500 rpm right? Is there an aftermarket module? Or is this something that would have to be cobbled together? | ||
| Sarodude |
Aaron- That's a GLORIOUS looking chart! (don't mind the drool) Should I ask how it is under 5K?  -Saro | ||
| Aaron |
"Is there an aftermarket module?" Any module made for a twin can be made to work, and a standard pickup plate slaps right in. But, since the module's understanding of the engine will be 1/2 of reality, the rev limit needs to be set to half of where you really want it, and your curve will be twice as aggressive as the chart says it is. I currently have a Crane HI-4 in the bike, chosen because it allows the rev limit to be set in 100rpm increments over a very wide range. I made a harness to tie it in to the bike's existing harness, it wasn't hard. For that pull, the rev limiter was set to 3900rpm. Should I ask how it is under 5K? No, you shouldn't! You can see how rapidly the torque and power are falling off below about 5700rpm. It's mostly the pipe, though. Like a lot of bikes with a drag pipe and bunches of overlap, it has the mother of all rich flat spots just before it comes on the pipe. I hear it can be cured, but it requires a "Thunderjet" kit, which is this fancy setup Zipper's sells that adds circuits to the carb. Basically it lets you set up the carb really lean and then these extra circuits kick in more fuel at high rpm where the pipe starts working. | ||
| Xgecko |
Aaron, though I know this isn't your point would the low end be better with a real muffler and pipe? | ||
| Aaron |
Yes and no. A drag pipe is a weird deal, it basically sends one narrow, strong pressure wave generated by the outlet. It goes up and down the pipe, probably several times. The idea is to get it to hit the chamber during overlap (i.e. when both valves are open) with a strong negative wave. The negative wave passes though the chamber and pulls on the carb and gets the next fuel charge moving before the piston even starts downward, helping you get a better cylinder fill. Since the speed at which the wave travels up and down the pipe is a constant, it's only going to hit the chamber during overlap at a specific rpm. You can change the length of the pipe and change the rpm where it hits. The problem is that just a couple thousand rpm away from where it hits with a negative wave, it'll actually hit the chamber with a positive wave instead. This causes a stand-off, where instead of yanking on the carb, it shoves some air out the carb. That picks up more fuel. So when the piston starts down and pulls the charge in, it has air that's passed through the carb 3 times (in, out, back in again), picking up fuel all three times. The result is a huge rich flat spot. That's why my pulls above start at 5200rpm. Just below that, the motor won't hardly run. But, as luck would have it, a few thousand rpm below that, the pipe is working with you again. From idle to 3000rpm, it runs fine. A good muffler basically makes the wave broader and weaker. Look at a Supertrapp cone some time, the idea is to generate a long wave from the expansion, instead of the narrow wave generated by a sudden outlet. So anyway, the muffler can prevent any strong positive waves in the pipe and the motor gets a broader powerband. But it won't get as hard of a yank at specific rpms as a drag pipe will. The problem with mufflers is that they often introduce back pressure, which increases pumping losses. Back pressure is a bad thing. So the answer to your question is that a muffler will even out the power and get rid of the mid range flat spot. You won't get as much power, though. | ||
| S2no1 |
From that I gather it'll even idle around the park. But won't pull in city traffic. Arvel | ||
| Xgecko |
Well Aaron I had expected that the muffler would lower the top end power a bit (but being streetlegal is important to me). My other wondering is/was how much power it will have with a stock revlimiter. Your Dyno run shows 45RWHP which with a muffler probably equate to 40-42hp. However I expect the Torque will come up a bit with a muffler as well. I also realize that your system is a bit differant than the "Nallin Kit" that Sport Twin is selling but it does let us Blastards live Vicariously | ||
| Sarodude |
Tony and Aaron- I'm gonna see if I can find out about the XB's valves, springs, head, and cams if someone doesn't post something first. Other things I'd like to know... Header length on the XB. I know the front & rear lengths are different by design - I just don't know what they are. Also, Aaron, look up TSRSoftware.com. He's a 2 stroke guy with a bunch of cheesey DOS programs but he has one that gives you the design criteria for something he calls a Boost Bottle. The intent of said device is to alleviate the richness associated with the 'Twice Carbureted' air on a 2 stroke. Bet it'll work on a 4 stroke with some modification... Let me know if you guys find anything... -Saro |
