Bad ass pipes

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Stochiometric ratios don't tell you what the mixture should be to reliably get the best power output. In the end, I cannot see any way to avoid fine tuning on practice runs on the day. Can you do that at Bonneville ?
When we dyno, we can now see what A/F gave us peak HP at specific rpm. On the dyno last week, we saw that at 7500 rpm, with .300 mains, we where making 92 hp at 13.3:1. We switched jets our to .290s, and at 7500rpm we made 95hp at 14.0:1 (or something like that; I'd have to go back and look at the data to be accurate). Anyway, we found it easier to tune using the WEGO than just guessing what the motor wanted. We also use a Relative Air Density gauge for initial setup, then fine tune with the data acquasition, based on what our dyno session data showed vs what it shows "day of" event. There are no practice runs at Speedweek, just get in line and try again.
 
Aldo

with an A/F ratio of 14:1 you made good power on the dyno, but the dyno cannot and does not replicate on track conditions.
Many have found this out to their cost !
I have no experience at all of what is needed to run sucessfully at Bonneville, but based on my experience of racing at many circuits around the world, I would seriously recommend you start significantly richer than your dyno tests indicated.
If you have RAD data to compare to Bonneville conditions, at least you will have a base line to work from.
 
Isn’t Bonneville quite high, with less oxygen than at sea level?

I though that jetting for Bonneville was a science (or art) in itself?
 
Aldo

with an A/F ratio of 14:1 you made good power on the dyno, but the dyno cannot and does not replicate on track conditions.
Many have found this out to their cost !
I have no experience at all of what is needed to run sucessfully at Bonneville, but based on my experience of racing at many circuits around the world, I would seriously recommend you start significantly richer than your dyno tests indicated.
If you have RAD data to compare to Bonneville conditions, at least you will have a base line to work from.
In no way do I believe the dyno to be replicating "on track" conditions. It is simply a point of reference. Most Bonneville veterans I have spoken to with data systems (and worked with at Bonneville; we actually dyno'd a friends "A" class Triumph on the salt with portable Dynojet with exhaust sniffers last year at Speedweek) aim for about 13:1 A/F when running on the salt. We did some runs at the local dragstrip last weekend, and found we had to richen up a bit, moving from .290 mains to .300s, and ending up with .310s (which put us at 12:1 @ WOT). I'm sure the salt will prove to be a steep learning curve for us, but hopefully with a week to make runs, we can get a setup that works for us. I am treating this trip as a learning experience, and will consider the trip a success if we can get ourselves and our gear to Utah, set up, pass tech and make a run. Anything else will be "gravy" on this trip.
 
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Good attitude to take with you I think Eldo.

Best of luck sir. Hopefully plenty gravy !!
 
In no way do I believe the dyno to be replicating "on track" conditions. It is simply a point of reference. Most Bonneville veterans I have spoken to with data systems (and worked with at Bonneville; we actually dyno'd a friends "A" class Triumph on the salt with portable Dynojet with exhaust sniffers last year at Speedweek) aim for about 13:1 A/F when running on the salt. We did some runs at the local dragstrip last weekend, and found we had to richen up a bit, moving from .290 mains to .300s, and ending up with .310s (which put us at 12:1 @ WOT). I'm sure the salt will prove to be a steep learning curve for us, but hopefully with a week to make runs, we can get a setup that works for us. I am treating this trip as a learning experience, and will consider the trip a success if we can get ourselves and our gear to Utah, set up, pass tech and make a run. Anything else will be "gravy" on this trip.
I should also add "Have a beer at Carmen's Black & White" bar to the list of requirements for a successful week...
 
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If you are doing plug checks between runs, it might be better to cut the motor dead as soon as you finish each run before looking at the plugs. If you are lean enough on the main jets to get the best speed, there will probably be little margin for error before you start burning things or getting detonation.
 
I should also add "Have a beer at Carmen's Black & White" bar to the list of requirements for a successful week...


Amen brother! You will be fine with what you have on your on bike A/F mixture data in plain sight. Start a little Fat and keep leaning her out. Your system is far seperior to 90% of us reading plugs! See you at the Salt and Carmen’s! Mellor runs the same as sea level but he has air induction into a huge air box. Ken Canaga can help with his starting point.
 
We are running M/PG-1000/4 (modified production, Pushrod, Gasoline, 1000cc, 4 stroke.
Nope, we are pushing for a Norton sweep in all classes. Sir Eddy’s Rocket has the record in the 500 M/PG and the 500 MPS/PG classes in the AMA event. Push on Andy!
 
Andy, Time to get this back up to the Top of the forum, 18 days away to Speed Week!
We are all pulling for you, I looked up the M-PG 1000 Record set back in 09-2009 by a Moto Guzzi @ two way average of 157.980 MPH.
Looking forward to seeing you push it up!
 
Just learned that Tyler Malinky of Twisted Throttle is headed for Speed Week, planning to run what he calls a ".. 1950 Triumph I built in my garage, with a stroker crankshaft"
Must be quite the garage!
 

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