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Boost Questions regarding a MPI Stage 1 Nytro at Sea Level

snowmaaan

Lifetime Member
Joined
Sep 7, 2005
Messages
226
Location
Fairmont, MN
Country
USA
Snowmobile
Yamaha Sidewinder, Viper XTX Turbo, Apex SE, Vmax 4, SRX 700
LOCATION
Farimont MN
Hey guys, I am trying to determine what a decent pump gas setup for sea level with a Nytro XTX would consist of. I have an MPI Stage 1 kit with a BOV, A/F gauge and stock engine. I would like to spin it around 8800rpm and I want to RUN PUMP GAS. Again, this is a trail sled.

I have not had great luck dealing with MPI directly (dont even get me started!!) so I thought I start here...

I believe the following to be true;
28 bottom/ 27 top = 6lbs
29 bottom/ 27 top = 8.5 lbs
28 bottom/ 26 top = 3.5lbs

Can anyone verify if my data is correct. Sadly enough I have more than enough pulleys to run all of these configurations and then some.

Thanks in advance!
 

On my wifes sled with 28 top and 27 bottom it runs 5.5lbs of boost at sea level.

Run pump gas no pronlem with safe afr readings.
I have the upgraded fuel pump though an cold air intake.The intake adds about a lb of boost.
 
Cool! Thanks for the insight. I have since spoken with MPI and I believe I will run a 28 bottom and 27 top...should be ok for about 6-7lbs at 8800 rpm.

Your wife must be a fun gal! Yikes!!
 
What pulleys provided 7lbs at sea level?
 
Thanks! Interesting that your 29 bottom / 27 top made 6-7lbs. Do you know what RPM this was at?

I was told by MPI that a 28 bottom / 27 top would make 7lbs at 8800rpms. I really need a boost gauge!!

Thanks again!!
 


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