Pulley Test Nytro Stage 1

[full tilt viper]

Just working with a new sled and a new set up . Running MPI supercharger 27t x28b making 5-5.5 lbs boost @800'. I also have a 29b, any idea how much more boost 1 tooth on the bottom would make ?Running stock fuel system ,cold air kit with intercooler. Based on the afr's is getting lots of fuel. Could I go to 6-7 Lbs on the stock fuel pump ?

 

[ShafeNytro]

Just working with a new sled and a new set up . Running MPI supercharger 27t x28b making 5-5.5 lbs boost @800'. I also have a 29b, any idea how much more boost 1 tooth on the bottom would make ?Running stock fuel system ,cold air kit with intercooler. Based on the afr's is getting lots of fuel. Could I go to 6-7 Lbs on the stock fuel pump ?

I'll have to look tomorrow at what pulleys I am running on mine. I'm at 1000 feet running 9.5 lbs of boost. I have the upgraded fuel system that I don't think is needed. You could easily run 6-7 lbs. I'll chime in tomorrow with my pulley set up.

 

[Agman 57]

I have the upgraded pump also, I run between 9-12# at about 850-1000 ft. I think it would be safer to run the automotive pump, just to be safe, they are inexpensive. I would call Matt at MPI and ask him what you should do for sure. He would know best.

 

[full tilt viper]

Will do thanks !

 

[mpi xtx]

We are doing a MPI stage 1 with 25t and 29B, an idea what the boost will be at sea level? Trying to get around 12#.

 

[Agman 57]

That sounds like what mine is, but I would have to check and see. I'll try and check tomorrow and get back to you.

 

[full tilt viper]

25 x 29 will give 8-9 lbs. Ran that last year with ecu reflash

 

[NeverEnuf]

I run 31b 25t @ 9000 to get 12psi on mine at 800' elevation.

Agman, how are you getting such a wide range of boost with your pulley setup? Rpm's? If so how low are you spinning to make 9psi?

 

[Agman 57]

Sorry for getting back to you so late, have been under the weather the last few days and didn't get out to the shop to check this out. I am running 25 top and 29 bottom. My range on boost is just by changing my BOV. If I set it all the way in, it will run 12#. I also have MPI's cold air intake. I usually only run that high when we go out west. For trail riding in the U.P. I will back it down to 8-10# and just let it blow the excess off. It will run around 6-6.5# when I am around 60 MPH.
Some people say this is a waste of HP to make extra boost and just blow it off. To get the best mileage you would want to slow the SC down some and only make your target boost at your full RPM's. I really don't think it hurts your mileage that much and so I just run it this way and not bother changing pulleys.
If I only used it to trail ride, then I would slow it down to the lower levels. Have never had any troubles running it this way now for over 4,000 miles on 93 pump gas. But I don't get crazy with it on high boost at low alt. Just short burst now and then. I also keep a couple cans of Torco with me and if I get somewhere that does not have 93, I just dump a can of it in.

 

[NeverEnuf]

Sorry for getting back to you so late, have been under the weather the last few days and didn't get out to the shop to check this out. I am running 25 top and 29 bottom. My range on boost is just by changing my BOV. If I set it all the way in, it will run 12#. I also have MPI's cold air intake. I usually only run that high when we go out west. For trail riding in the U.P. I will back it down to 8-10# and just let it blow the excess off. It will run around 6-6.5# when I am around 60 MPH.
Some people say this is a waste of HP to make extra boost and just blow it off. To get the best mileage you would want to slow the SC down some and only make your target boost at your full RPM's. I really don't think it hurts your mileage that much and so I just run it this way and not bother changing pulleys.
If I only used it to trail ride, then I would slow it down to the lower levels. Have never had any troubles running it this way now for over 4,000 miles on 93 pump gas. But I don't get crazy with it on high boost at low alt. Just short burst now and then. I also keep a couple cans of Torco with me and if I get somewhere that does not have 93, I just dump a can of it in.

Thanks for the reply, your doing the same thing I will be with the stage 2, I'll be doing it with a boost limiter valve instead of the bov but same concept. I'm sure it's not the most efficient way to do it but I'll be spinning the stage 2 in its efficiency zone this way.