Any experience w/ Jetting on the Dyno?

[Oilsmoke]

It's Power output and the level it raises is pretty smooth. Passionre Ported you Jugs?

[Big Blue]

yes jim ported my cylinders.

[Ducman]

Big Blue

 

So am I reading the dyno right, it shows your A/F was about between 11 to 13 above 7K rpm and then the next run it was between 13 and 14 and it made about 7 more HP? Did they change the jetting a lot or do you know how many jet sizes, needle clips they changed? That looks like a pretty sucessful dyno tune. Making almost 70 HP at 93 to 95 degrees, thats impressive. Could you feel the difference and did it run better afterwards. Did it seem to make a lot of color difference on your plugs from going leaner?

 

Sorry for all the questions but I'm curious and it is all good info to know. Thanks Bro!

[00BANSHEE]

yep lonnie sure did, super nice and a pretty cool guy to talk to. i was pleased except for the dip in the 9500 range but ill have to deal with that he said it was from my stock ignition.

99% of the dyno readings I have seen of banshees have that same dip. I too was told it had to do with the stock ignition. Although the dip looks drastic I really never felt it when riding mine.

[Banchetta]

Timing doesn't create that dip, its port timing that caused it, not ignition timing....as far as jetting on the dyno, its always worked for me, but I do all the testing. no one touches my shee...I wouldn't trust anyone to jet in my shee. Most tuners in these shops don't know shit. Just keep that in mind. They might give you another 1-2 hp and just give up and collect your $120 when you have another 5hp still there to be released....You can't jet in a shee in a half hour on a dyno. I've always had to change my jets at least 3 times, one for a base, one size leaner and see if it likes it or hates it, then you either go leaner or richer, but you'll have to make several runs to find out. The tuner will have over an hour or two just changing jets...Just be careful, and watch em.

[Banchetta]

I have no dip...

[Banchetta]

This is w/ the stroker.

[Oilsmoke]

Banchetta You are right you have no dip. you also have no peak power after about 8700 rpm and it just falls off. where big blue Passion 12 port dips alittle at 8900 to 9700 and than it start to climb to max peak that is at 10400. So can you still say that a Stock ignition not to blame if your motor don't even get to that RPM level?

at leased that is what i see.

[Big Blue]

Big Blue

 

So am I reading the dyno right, it shows your A/F was about between 11 to 13 above 7K rpm and then the next run it was between 13 and 14 and it made about 7 more HP?  Did they change the jetting a lot or do you know how many jet sizes, needle clips they changed?  That looks like a pretty sucessful dyno tune.  Making almost 70 HP at 93 to 95 degrees, thats impressive.  Could you feel the difference and did it run better afterwards.  Did it seem to make a lot of color difference on your plugs from going leaner?

 

Sorry for all the questions but I'm curious and it is all good info to know.  Thanks Bro!

The bottom line on the a/f is where it was when we started the top line is where it ended up after making several runs and all the changeds, on the jetting change we went from a 170 to a 145 on the main, and 4th clip leaner on the needle i will need to check and make sure. as for how it ran i really couldnt notice alot on the top end but lower-mid range it felt like a totaly different bike. Banchetta this was done over a period of about a hour and a half, running it making changes, running it making more changes. I let him do the changes since that is what he was being paid for i just watched and it is aslo jetted on the safe side for those temps im sure it has a few more ponies it is somewhere but id rather be on the safe side. lonnie is a builder as well it is pretty much a one man operation at his shop.

Edited November 2, 2004 by Big Blue

[Ducman]

Wow! I feel stupid. I think I figured out my problem. I checked my compression today, I haven't checked it since I got the motor back

[Oilsmoke]

And?

[Ducman]

He He He, didn't mean to post mid way through sentence, spilled some clam chowder on the keybord and had to let the dog help me clean up the mess and I think the enter key got licked?

 

Anyway, I got 122 psi on one side and 125 on the other. SOB I told Shorty's I wanted domes suitable for running 100 octane at sea level. Although they recommended and set the timing plate at +6 deg I would think that the compression should still be more like 160+ for a dune port 4 mil stroker on 100 octane. I ran a couple of wot plug checks today and they are looking perfect. The plugs are coming out a very nice looking tan color when I cruise around using 0 to 1/2 throttle for a long time or when I do WOT plug checks. When I threw in a new set of plugs and did a plug chop I got a nice 2mm ring at the base of the plug insulator and it was clean other than that. It was colder out today about 55 deg and it felt like it ran a bit better, the plugs looked slightly lighter today more of a tan instead of brown also.

 

Does anybody think that smaller domes would make a huge difference or would it be only a mildly noticeable. I'm thinking of just saying screw it and getting domes for 110 octance since I can get it for only $4 instead vs $3 for 100 octance. I'll call NOSS tomarrow and order some domes they recommend for 110 but in the mean time anybody care to guess what size I should run?

 

Another crazy thing is I found a guy locally, only 10 miles from my house that is a tuner, has a dyno W/ sniffer. Turns out he has a 4mm stroker banshee himself and is developing portwork and wants to start doing custom banshee porting for customers. He claims he's got 70 HP on his 4mm banshee with a MX port using stock carbs, stock reedcage, pod filter, and Dyna FS. Anyway I talked with this guy on the phone for like an hour about banshees, and YFZ's and he really sounds like he knows his shit. His shop is called Loony Tooners and said he has taken his dyno up to the Oregon doons a few times for events, anyone heard of him?

[roosthrower]

Banchetta

I noticed on your stroker motor, you have a dip right before it comes on the pipe. Were you ever able to get rid of that dip with jetting changes? I can feel the dip on my ported stock stroke motor. If I roll on the throttle, the dip isn't nearly as bad, but when I go wfo on the throttle when I'm off the pipe, it'll hit that dip. It just sorta sputters until the motor revs past the flat spot. Do you know what is causing this or how to get rid of it?

[FireHead]

You generally want to keep the AF between 12.5 and 13.0 across the board. This also tranlates into .88 - .9 Lambda.

 

[Banchetta]

Banchetta

I noticed on your stroker motor, you have a dip right before it comes on the pipe. Were you ever able to get rid of that dip with jetting changes? I can feel the dip on my ported stock stroke motor. If I roll on the throttle, the dip isn't nearly as bad, but when I go wfo on the throttle when I'm off the pipe, it'll hit that dip. It just sorta sputters until the motor revs past the flat spot. Do you know what is causing this or how to get rid of it?

I ended up taking off my stock modified head for the stroker and had Dave at Noss make me some stroker domes. I increased my compression from 158psi to 185psi and had a different shape dome put in for a broader powerband. I haven't put the shee on the dyno since my head change, but it definately made a huge difference. I told Fixitrod about this and he bought a head for his stroker to. Fixed his problem and then some. Not to say thats your problem, my shee only fell on its face at that rpm, if I kept the rpms up, then I had no problem w/ response, but when I let the rpms back down and hit it. It'd fall on its face and piss me off...as you can see w/ my originally graph, I'm not used to dead spots.... A lot of times a lean needle will cause that hesitation before powerband like your saying. Have you tried raising the needles? Also, most high rev pipes or dune porting changes the port timing which will make your power move to the higher rpms causing that dip before the powerband since the port timing is no longer matching the pipe....increasing compression can help get the port timing back in play w/ the pipe. The increased compression accelerates combustion speed and will change the timing of everything....Its the one thing that a lot of builders don't compensate for which in turn should tell you something.... so if you ever want to see how much builder knows then ask him what he needs for info from you to build you a motor....he should be asking you what kind of fuel your running, compression you want to run, compression he suggest, riding style, what kind of pipes your running, carbs, timing, etc..It ALL plays a part. Sorry for the book...