SuzukiSavage.com - dyno results for performance mods

diamond jim

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Re: dyno results for performance mods
Reply #15 - 06/09/09 at 04:44:16

We did the fuel circuit checks first then the full throttle in 4th check. On my dyno run it showed a mix that stayed between about 13.5 across all the circuits. Rod said that was perfect because it's just a tad on the rich side. He said he likes to keep it between 12 and 14.5. With mine he said that if I ride in a different environment that normally leans out the fuel then it may lean the mix to 14-14.5 and in an environment that makes it rich maybe 13-12.5.

So why do some dynos show torque/HP @ rpm and some show HP @ speed? Do the HP @ speed dyno runs also do the fuel circuit analysis? Seems to me the portable ones at done at bike nights and shows only do the HP @ speed.

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SV og LS

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Re: dyno results for performance mods
Reply #16 - 06/09/09 at 05:25:26

diamond jim wrote on 06/09/09 at 04:44:16:

We did the fuel circuit checks first then the full throttle in 4th check. On my dyno run it showed a mix that stayed between about 13.5 across all the circuits. Rod said that was perfect because it's just a tad on the rich side.

If it was a full throttle run, it was lean. It should be around 12:1 to 13:1, maybe 12.5:1 for best power. If it was a part throttle check, it may be somewhat rich, on smaller throttle openings it could be progressively more lean to over 15:1 on a slow steady cruise for best efficiency. On a 10% throttle in reality it doesn't matter if the engine makes 10.76 hp or 11.29 hp but leaner setting may give you 20% better fuel economy and that's what I would choose.

diamond jim wrote on 06/09/09 at 04:44:16:

So why do some dynos show torque/HP @ rpm and some show HP @ speed? Do the HP @ speed dyno runs also do the fuel circuit analysis? Seems to me the portable ones at done at bike nights and shows only do the HP @ speed.

All dynos these days should be able to show torque to rpm or torque to road speed, you just tell the operator which graph you want to be printed. If operator doesn't bother to connect rpm pickup you only get torque to road speed.
Some dyno shops may not have A/F ratio sensors or software that could support them.

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diamond jim

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Re: dyno results for performance mods
Reply #17 - 06/09/09 at 05:36:45

It did vary some. I pretty sure it never went over 14 or under 12. We spent more time talking about the idle circuit because that was too rich the first time and why we stopped the first run two weeks ago. I don't have a print out of the fuel ratios. Maybe he was talking more about the idle circuit while I was thinking more about all circuits. Don't quite remember. It's funny though- we have all afternoon, shop is empty, he digs the single, wants to see what it can do, I'm there with jets and tools in hand ready to fine tune... we do the runs and he seemed surprised at the result.

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SV og LS Full Member Offline Kawasaki ZZR 1200 Posts: 236	Re: dyno results for performance mods Reply #18 - 06/09/09 at 14:46:56 diamond jim wrote on 06/09/09 at 05:36:45: It did vary some. I pretty sure it never went over 14 or under 12. At least it's reasonable close, you can do some fine tuning if you want and you've a solid base setting you can always return to.
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diamond jim

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Re: dyno results for performance mods
Reply #19 - 06/09/09 at 15:47:00

I checked the mixture screw today to see where he turned it when he tuned it. Two turns out. It's the smoothest idle my bike has ever had. But with that I still get a little bit of between gears and decel popping that was better controlled with the 55 w/bleed holes. I turned it to 2.5 and that maybe helped the popping a bit but noticed it started idling rougher and had to turn the idle up a 1/4 turn for more air.

Which do you think is better for sitting at a lot of stoplights in 90 degree weather?

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Serowbot YaBB Moderator ModSquad Offline OK.... so what's the speed of dark? Posts: 28848 Tucson Az Gender:	Re: dyno results for performance mods Reply #20 - 06/09/09 at 16:38:25 I'd go with a little higher idle speed to increase oil circulation in the heat.
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SV og LS

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Re: dyno results for performance mods
Reply #21 - 06/10/09 at 01:27:13

diamond jim wrote on 06/09/09 at 15:47:00:

It's the smoothest idle my bike has ever had. But with that I still get a little bit of between gears and decel popping that was better controlled with the 55 w/bleed holes. I turned it to 2.5 and that maybe helped the popping a bit but noticed it started idling rougher and had to turn the idle up a 1/4 turn for more air.

Which do you think is better for sitting at a lot of stoplights in 90 degree weather?

In a nutshell, there are two options:
- idle smoother than ever
- idle rougher
I would have no trouble choosing the first one. The richer idle won't get any better sitting at stoplights and it doesn't cool down the engine which will be hot anyway. Plus the whole point of dynoing the engine was to get the jetting sorted and the engine running in a most efficient way.

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LANCER

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Re: dyno results for performance mods
Reply #22 - 06/10/09 at 04:09:13

SV og LS wrote on 06/10/09 at 01:27:13:

diamond jim wrote on 06/09/09 at 15:47:00:

It's the smoothest idle my bike has ever had. But with that I still get a little bit of between gears and decel popping that was better controlled with the 55 w/bleed holes. I turned it to 2.5 and that maybe helped the popping a bit but noticed it started idling rougher and had to turn the idle up a 1/4 turn for more air.

Which do you think is better for sitting at a lot of stoplights in 90 degree weather?

In a nutshell, there are two options:
- idle smoother than ever
- idle rougher
I would have no trouble choosing the first one. The richer idle won't get any better sitting at stoplights and it doesn't cool down the engine which will be hot anyway. Plus the whole point of dynoing the engine was to get the jetting sorted and the engine running in a most efficient way.

Set the pilot screw for the smoothest idle possible, then raise the idle speed for the better oil flow.

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diamond jim Serious Thumper Offline Posts: 1425 North Alabama Gender:	Re: dyno results for performance mods Reply #23 - 06/10/09 at 07:17:14 I'll keep it at 2.
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