Dirty 98 Elite- updated thread throughout

[Wheelman-111]

Greetings:

It looks like you need rear brake shoes soon. Malossi upgrade opportunity!

[DirtyE]

Thanks wheelman. Ive got brand new malossi pads in the front and rear. New cables, phongeer levers. Brakes are good! Great even. Suspension sucks but starting and stopping is great. I played a little today with weights and rollers and found that wuth my new torque driver the best settings from before are still the best now. 4.5g rollers and a polini blue spring. Ive got polini yellow clutch springs in but theyre maxxed out. Maybe tomorrow ill try to put in the stiffer set.

[DirtyE]

After shimming the vario the belt now rests high atop the rear pulley. More testing tomorrow. I had to shim my kickstarter cover out from the cases cause of the kicker gear catching after shimming the vario.

[DirtyE]

9-11k is where this setup is happy according to my dirty butt dyno. Fairly wide powerband I guess, but the c16 (at least for me) falls off in power after 11k....maybe a few hundos over. Im a little disappointed, as I tuned the cylinder for a little higher RPM, but what I have is satisfactory. Ending up with a bike thats heavy on torque at a low end mid-race rpm is probably most suitable for my application as a street racer anyways.

[swimmingfree]

what is the max rpm on your scooter??
swimmingfree

[swimmingfree]

i no rpm on a dyno is not the same as the street .. just like to no if his rpm stop after the power band ????
swimmingfree

[DeanP]

Two stroke isn't a linear power curve. So a guy puts his bike on a dyno, and it hits 12k, and it's done. let's say he makes 10hp. Well, he isn't making 10hp at 12k, he is making it at 10.5k. It's a curve, not a straight line. Your going to stop accelerating once you hit your peak of the power curve. I hit 13.5k on my 120cc stroker on the dyno. but I wasn't making power up there.

I'm sure this is common knowledge to a lot of you guys, but just wanted to put it out there.

Here is a graph of the c16 on my unported bolt on corsa. Revs till 11.5k, but makes peak power at 10k.

And this my friends is where you want your variator to max out at;10k for the above graph. We do the same to sleds with the primary clutch;set it to peak hp. Anything over this just causes undo stress on the motor.

[DirtyE]

Looks like we found the max on the pipe. Thats confirmation to my thoughts of things pooping out up there. Im fairly certain my port job would support a higher rpm. After a little tuning today power feels alright up til 11/11.5. Thats with tuning in the new torque driver only. 4.5g weights, polini blue springs all around. Main 130, and a semi rich 45 pilot. Needle all the way lean.
Temps are maxxing out at 330f.

[DirtyE]

Yeah, it could be the cylinder, but length was added to the header portion of the pipe and that should drop its peak rpm right?
Id have to pull the cylinder to get the final exhaust timing but it was approaching 190 by the time I was done. Transfers were left alone at 125. Blowdown was around 30. I dont know how to translate that to rpm with all the other factors involved. I may have something as simple as too large of a main jet in causing lack of power up at high rpm. Ive not seen temps over 368f.

[hothatch85]

yeah, id take the pipe if your interested in selling it. just keep me in the loop gentlemen.

[DirtyE]

Im not ready for that. Im going to play with some things. I haven't had a ton of time to put into tuning. Im enjoying it, I can lift the front wheel with the throttle up to about 15 mph and its torquey. Its a fun ride, and temps are good. Ive never wrapped a pipe before, but hotter gasses move faster making the pipe act shorter so im interested to see the effects of that. I can still play more with my jetting and trans.

It may sound like im complaining but im not. Please offer suggestions if you guys have ideas.

[DirtyE]

why is my stock corsa hitting the same, if not higher rpm than the adjusted fabrizi? I have seen graphs of this pipe revving till 13.8k. I stopped at that RPm above, because no power mwas made higher. Keep in mind this was a stock corsa. I believe it went to 12.7 before it was done on the dyno.

Also I do have access to another MXS pipe that has a dyno graph of making peak power at 12.5-12.7, revved till nearly 14k.. If you're not happy with the pipe's output, I will give you a full refund on it, or trade it straight across for the MXS pipe. THe mxs pipe made 19whp on a vertical mina. You'd just have to make it fit, it might be closer, or further off than the yasuni. I also have no input on the quality, or sound. I'm running a drag style yasuni on my beta, and I'm making peak power around 12.5-13.5k, and revving till 15.5k, but its a TOTAL pig below 9k. Keep it mind you will probably spin your bearings at 12.5-13k sustained. We don't get great bearings for our dio's like the mina/piaggios do. I'd like you to see the figures you were shooting for.

Ive been thinking about this post in response to my statement about finding the peak of the pipe. My timings are set higher, but there seems to be no impact from that.... hence we've tapped the pipe. I've got mega torque til 10.5-11k which is all good. Yes on a mina or piaggio horizontal it may rev higher, but these pipes has been lengthened. Length in the header will reduce peak rpm. I'm going to find a nice wrap and see if that does anything. I don't want to get rid of the pipe. There are so many weird pipes and copies of them, and copies of the copies I don't trust any other. If I didn't think this was the best pipe for our bikes I wouldn't keep it.

[jetlag]

Idk but I've been hitting all types of max rpms due to over revs all with a 1000 malossi center having difficulty holding the rpms in my powerband here's one at 14k shoot way past my powerband. I'm trying to stay away from stiffer centers but it seems I may end up stepping up and lose my daily to a weekend warrior. Sweet spot for my mhr I like to say is 10-11 but keeps climbing. Still haven't passed 70 but I know 80 should be no problem since I get to 65 in no time. One thing for sure tho is that this is my most challenging pipe I had to tune to lol

[DirtyE]

Maybe I jacked up the cylinder when porting it. Its possible.

[DirtyE]

Lets face it, blue is NOT the fastest color