Bonneville 2014

jcmduc

Have been advised to put this on as it may interest some folk, We plan to run our 851 at Bonneville speed week in 2014, Off for a recce this year and get some idea of whats its like, it will be in October after this years event (due to work etc) but should be good. Started to try and get parts together and swotting up on what we can and carnt do as the class regs are very tight..any comments and advice, ideas will be more than welcome...shall update as time goes on..

Mr.R

I would think that one of the problems would be getting the fueling correct at that altitude.
Are you able to remap the fueling yourself?

Steve R

jcmduc

No...any tips

got2dv8

Mr.R wroteI would think that one of the problems would be getting the fueling correct at that altitude. Are you able to remap the fueling yourself? Steve R

I thought an Alpha-N system with an air temp and MAP sensor could compensate for altitude (air density)???

Robert

Mr.R

got2dv8 wroteI thought an Alpha-N system with an air temp and MAP sensor could compensate for altitude (air density)??? Robert

I think the standard ecu etc isn't capable of making big enough adjustments for extreme altitude, big changes etc.

When Duanne Mitchell used to make FIM Ultimap chips, he supplied special maps for bikes used at high altitudes.

Steve R

mikesps

I think the P7 corrects to high altitude, but later P8 maps are limited to a low altitude to prevent the fuelling going very lean if the air pressure sensor fails.

Mike

got2dv8

So theoretically (not for practical purposes) could you run a P8 using Speed Density and add MAP sensor to the vacuum fitting(s) on the intake manifolds?

Robert
Just in theory. Obviously it would require extensive mapping modification.

wgsvintage

Is 4218 feet considered extreme altitude?
Bill

griff851

Fuel pressure reg has a hole in it to correct for altitude on the adjustable early ones. If not drill a little hole in the back so it will. Ambient plus spring equals fuel pressure.

Mr.R

wgsvintage wroteIs 4218 feet considered extreme altitude? Bill

Well Bill,
Living within sight of the sea (sea level) 10 miles away in a straight line, I reckon that in excess of 4,000 ft is quite a climb.
I've ridden over the European Alps a few times on carb'd bikes and have personally felt the difference that climbing too high altitude makes to the way a motor goes.
Recently I've been following a program on the TV about a group of British "Petrolheads" who've made/taken the pilgrimage to Bonneville, 3 or 4 bike teams and some Jocks with a special stream liner car.
What surprised me is how slow the extremely modified motors are at Bonneville, until it dawned on me the altitude factor was coming into play.

Steve R

wgsvintage

For what it's worth, I checked and the computer can compensate for around 8000 feet. When we raced Pueblo (Pikes Peak International Raceway, 5365') and Albuquerque (Sandia Motorsports Park, 5787') in 2005, we chased the 250's jetting but left the 999 alone.
Bill