does this dyno look okay?





WuzzaCBXRider

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#7
I actually started and warmed it up today,first time in about 2 months.:super:
I rolled the Busa out today for a 130 mile ride west of Yosemite myself, first time since buying my new Z in November. I don’t like layering up with a textile jacket and overpants though. Rain is expected off and on for the foreseeable future around here.:confused: Snow and sandy wet shady corners are just up the road.
 
#8
Supposed to rain down here(and probably up your way)for about the next week straight so figured I'd at least circulate some fuel through the injectors in case that damned ethanol tried to gum stuff up(am always including ethanol buster when I fill up but never certain if[or how well]that stuff does much good).
 

WuzzaCBXRider

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#11
I kept my CBXs longer than any other bike (decades) one with 106,000 and the other with 66,000 miles, neither one had to have the six carb bank off for cleaning or the tank's removed for cleaning. My Busa will be 13 years old next month and has over 63,000 miles on it. We're probably over thinking things but when it comes to reliability and longevity, I err on the side of caution.:D
 
#15
Yours is hard to interpret. Putting it in a car means you have drivetrain losses that are not the same as the Busa's chassis. I'm betting that although the wheels have less inertia than the bike's big hoop, the friction and stiction of bearings and seals on the axle as well as the tires' large footprint all eat more hp per mph. Still it's an unknown.

The chart being in kph rather than rpm throws us another curve ball - even if it were mph, we surely have a member here who has done such a run. To ad even more pleasure - rather than torque in foot lbs we are dealing with torque in newton meters and the scale doesn't match the hp side of the chart. Whew! Your dyno guy isn't making this easy is he? LOL

I will go look at some plots from a Gen I on my dyno and convert the runs to read like yours: power vs road speed in kph, with torque in newton meters. We'll still have the two different dynos, but the shape of the curves should be similar.

I'll get back to you and see what we can figure out.

Dynotech dyno, yes? That's a performance shop dyno from Dyno Dynamics if I'm not mistaken.
 
#16
Yes, very hard to read and compare. I asked the tuner to focus on max torque, as hp means nothing to me. What a fantastic torque curve the busa has! I honestly expected the tuner to take longer than he did, he was very rushed and didn't put priority on the job. I'm a bit worried that it wasnt done right, I might take it somewhere else and ask them to do a baseline (with AFR's and check knock). I now also have a knock gauge on the block (using the bolt that usually connects to the radiator between 2-3 cylinder).

Yep, it's Dyno Dynamics, you are right on it!

Is there something specific about the busa engine... I have tuned 2jz and LS before. 2JZ likes lean before boost and LS likes to be rich before boost... anything quirky with the busa engine?
 
#17
This as close as I found to your combo. A Gen I with porting, cams and 1363 piston kit. It's an early big bore kit. Before the 1400 was developed.

You gearing results in a compressed curve (80 to 185) compared to 70 to 225. So that's something that throws it off, but the shape of the power is similar. Like wise both engines show the s=round toque curve on this scale - albeit yours looks smoother. Yet upon observation I think you have the same slight peaks and valleys this engine expressed. Note the center bump with a peak before and after? Almost a triple peak.


Busa metric.PNG
 
#18
Thanks mate! That really gives me an insight to the engine! Mine does look almost identical to that dyno. Makes me feel a lot more comfortable with the tune. A lot. Really, thank you.

What do you think about the knock sensor placement between #2 and #3 in the hole where the radiator bolts on?

knock sensor.PNG
 

Boosted Cycle Perf

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#19
I’d question where your cams are set. To have power peak and fall off before peak torque is very unusual specially with “mild cams and porting”.

The Busa engines like it fat. Tuning to near knock is gonna net you in some very disappointing HP and tq numbers. Also, knock sensors on these engines are near useless as unless you have one of the old school HKS knock boxes with the head phones so you can actually hear knock vs engine noise you’ll be even further disappointed with the numbers you’ll get. These engines being solid mounted, and High revving the noise picked up makes knock sensors useless.
 
#20
I am not sure what you have tested, Im also not sure what is and isn't possible. I realise you have a great level of experience with bikes. I'm just transferring my car race experience. Happy to learn though.

I have an Emtron ECU which will listen for knock per cylinder (based on firing order), I'm not using the knock sensor for tuning. Now that the tuner has tuned the engine, I can get logs of what is 'normal knock'.

Then I will ask the tuner to log the noise of the engine and then mildly lean it out at low rpm, VERY low load. It should show up the noise level at knock vs historic graphs of zero knock (the Emtron you can vary the gain and sensitivity).

Thanks for the heads up on fat fueling, I will add 5% fuel (stock injectors) to the map after 4000rpm.
 

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