Afr's and Rpm's. Turbo's

GoHomeYammi

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Mar 14, 2011
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Location
Central Ontario
Country
Canada
Snowmobile
2015 Yamaha viper RTX LE
This is a pretty small community which is great I have been able to learn a lot from what everybody has to offer. I recently picked up a Viper to replace my Nytro, This time around I went right for the hurricane 240hp turbo. I'm looking for any input on what I should be looking for as far as my Air fuel and RPM's I do about 80 percent lake racing and 20 percent ditch banging. My sled will have the hurricane 240 clutching with an 1.25 track. Air box will stay stock until I mess around with Stingrays option...basically what should this thing be doing stock with a bit of boost. I could ask Dave and not second guess what he has to say but I always like to see what the rest of the consumers in sled gear have to say.

Also: The stock 1.7 track has been changed out for a 1.25 ripsaw with gears to suit to better my lake riding. so I'm hoping for a different outcome than your standard LE
 
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With the turbo there will be no more airbox, that gets replaced. With my turbo I did my best to run as close to 9000 rpm as I could and had afr between 10.8-11.2 on long pulls.
 
10.8-11.0 at wot
11.5-12 3/4 throttle around 7000rpms
12-13 1/2 throttle around 5000rpms
13-14 1/4 and below

That's a good round about numbers. The important one is WOT. 11.2 max on a good cool motor and cool air intake temp is safe. Better fuel, and maybe a degree or 2 timing removed you could creep up to 12.0-12.2 and still be good. But the power lost in timing is probably more then what's gained by the 3/4-1 point a/f. Better off running higher octane and bumping boost up and Keep a/f in safe 10.8-11
 


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