Preparing for baseline dyno on the 22nd. Few Qs on spark/octane.

Dr. Gonzo

Dr. Gonzo

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So a week from tomorrow I have an appointment to get a basline run and see how good/bad things are with my tune. I'm told from the guy I bought the bike from that it's running 14psi boost (we'll see if that's true), so I'm a bit concerned about it blowing up on the dyno. I've been running 93 octane around town and it seems to run ok. I thought to fill it with 110 a couple times between now and the dyno run in hopes that if the tune isn't 100% I'll have a bit more wiggle room. After my first fill the other day I'm guessing I'm somewhere around 105 octane as there was about a gallon and a half of 93 in it yet. It doesn't seem to like the higher octane for low RPM driving, but I'll survive some short term low end funkiness if it saves me from high RPM detonation next week. Does that make sense?

I'm not sure if it matters for the octane question, but currently the plugs are NGK R CR9E gapped at .028 or so. They looked to be in decent shape when I pulled them to check engine compression last week. Is this a good plug/gap for my setup?

Thanks!
G

This is on my 01 w/Hahn Stage 1, BTW.
 
Hmmm... sounds like I'm still at stock gap and stock heat plug. Will drop the gap before dyno I think. Any thoughts on octane? Safer for dyno, bad for bike, makes no diff? If no safer then I'd rather give it a try on regular 91/93.

G
 
You might want to throw all these questions at your tuner. You run a reduced gap on the plug but I don't know the exact measurement for 14 psi. Quenching, :dunno:
 
That gap is WAY too big. .018 is where it needs to be.

The higher the octane, the crappier it will run out of boost. If your bike doesn't an intercooler or at Lester water injection 14psi on pump gas would be ok for A DYNO PULL, but to race or due highway pulls, your gonna melt somthing. 8-10 psi is really the max on a spacer motor with no intercooler or water injection.

My suggestion is tune it at 8 and and 14psi on 93 octane. Then later on anytime you want to run 14psi, put 110 in it and it will be plenty safe.
 
Totaly agree. The plan right now is to get the baseline just to see where I sit. I'm not even 100% sure it's setup for 14psi. That's just what the guy I got it from said. I'm afraid to run it up in the RPMs to find out without the A/F meter on it and a trained ear looking for trouble. So if on the dyno it's confirmed 14psi then I'll go online and get the 8 (or maybe 10 :whistle: ) psi spring. Then back for the actual full on tune. In a perfect world he'll tell me the guy I got it from was mistaken and it's running the stock spring and I have a spot on tune already. Not likely, but can always hope. I'll regap tonight in prep for the run next week.

So regarding gas, what I'm hearing is 110 is probably a good idea for the first run and may give me a slight safety net, but then later tune for lower PSI and pump gas. Right?

As always, thanks for all the great info!
G
 
One thing to remember here, the Hahn kit is notorious for the Boost to creep higher than the bike will be tuned for!

Water Injection is recommended
 
14 PSI on a stock motor is asking for a melt down, and that hahn kit specializes in creeping like a mofo. got to keep the full exhaust on to keep the boost from creeping so bad.
 
Hopefully no issue with boost creep since mine has been modded with an external wastegate. Fingeres crossed though. :please:

G
 
Dr. Gonzo said:
Totaly agree. The plan right now is to get the baseline just to see where I sit. I'm not even 100% sure it's setup for 14psi. That's just what the guy I got it from said. I'm afraid to run it up in the RPMs to find out without the A/F meter on it and a trained ear looking for trouble. So if on the dyno it's confirmed 14psi then I'll go online and get the 8 (or maybe 10 :whistle: ) psi spring. Then back for the actual full on tune. In a perfect world he'll tell me the guy I got it from was mistaken and it's running the stock spring and I have a spot on tune already. Not likely, but can always hope. I'll regap tonight in prep for the run next week.

So regarding gas, what I'm hearing is 110 is probably a good idea for the first run and may give me a slight safety net, but then later tune for lower PSI and pump gas. Right?

As always, thanks for all the great info!
G
Click to expand...
Don't bother with the 110. If your dyno operator has any sense he isn't gonna hold it wide upen till redline as soon as it gets on the dyno. It's alwys best to go in steps. Wide open till 6k; check the tune. Then to 7 or 8k, and check the tune. OR just jump your fuel table 20% then lean it out from there if the dyno guy is lazy, or your nervous.

An tcbusa,
I'm running 14psi on a stock motor with a spacer, head studs and good head gasket. Tuned to 12.0afr on pump gas...with an ultra plenum.
 
Big difference between a ultra and a hahn plenum ;) and the little mitsu turbo will be making more temp at that level

if i was putting your bike on my inertia dyno i would start with c 16 and run in a low gear initially like 3rd or 2nd to get a glimpse of the a/f and boost levels on the logger without too much load or run time
then when you know whats happening you can work from there
 
I'm running similar to you Rob , and 14 psi on my stock piston and rod streetbike , just wanted G to know the difference between what he has and a good intercooled system
 
Just filled again with 110 (not sure where to get c16 around here) so with the 93 that was supposedly in it when I got it...

1st Fill: 1.5 Gal 93 + 4 Gal 110 = 105
2nd Fill: 1.5 Gal 105 + 4 Gal 110 = 108

So will be running roughly 108 Octane for the pull if my math serves me.

OZBooster/Murderedout07, my thoughts exactly on the dyno... will have him run it up progressively to check A/F. Unfortunately he's not actually doing a tune next week. Can't get on the schedule for more than a baseline run. I'm going for the full tune either in the fall or first thing in the spring next year. If I do it in the spring I'll have all winter to get things the way I want them so the tune will be good for a while. :)

G
 
And the verdict is... Lean at 6k on 93 octane. Tuner said go with pump so I drained out the 110.

Chart

I'm not fairly confident that it's a 14lb spring as the tuner saw it hit over 10 on the boost gauge before he backed off. Going to order an 8lb spring and head back to see if I can at least get it safe for the rest of the riding season. I've got all winter to figure out larger injectors, a spacer, and whatever else I might want/need to support a little more boost. Then back for a full tune in the spring.

Thanks for all the input!
G
 
Yup, it leaned out at 6k and the guy backed off. I'll be ordering the Tial 8lb spring today and am hoping to get another run scheduled soon. The 14lb will sit on a shelf waiting for a spacer, higher flowing injectors, etc...

G
 
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