McXpress RX-1 - Max boost question

[martini]

I have been running my Mcxpress rear mount on my RX-1 for 3 years with no problems. I am running 9 pounds of boost on pump gas and I am wondering,

- what is the max boost on pump?


-max boost on AV Gas?



thanks for any info,

 

[rxrider]

If you are running a stock motor (CR=11.8:1), 9 lbs would be about max running on 93 premium pump.

If you have installed 3 stock head gaskets stacked (CR=9.6:1), 14 lbs is max, but you better have a wideband to verify your jetting, you're close to the edge, wouldn't run it wot for more than a 1/4 mile on pump.

If you install low compression pistons 10:1 and stack 2 stock head gaskets stacked (CR=9.13:1) you can run 16 lbs on 93 octane pump, again having you jetting in order is a must. Then again you have to be sure that the pump gas you get is of good quality.

Take a look at the boost calculator at the top of this forum, they will give you guidelines as to how much octane fuel to run on a given boostlevel. What I have said here is only theorethical. My engine have survived for 2 seasons at sealevel running those boost levels on pump fuel, but our pumpfuel is of high quality, and my jetting is on the rich side of max power.

 

[martini]

thanks for the info.

- what is the horsepower gain from 9 to 14 pounds of boost?

-how many jet sizes would you increase with this change in boost,

thanks for any info you can supply,

thanks

 

[lakercr]

thanks for the info.

- what is the horsepower gain from 9 to 14 pounds of boost?

-how many jet sizes would you increase with this change in boost,

thanks for any info you can supply,

thanks

A rough estimate is about 10hp for every pound of boost (this is a bit optomistic in my experience). 9 - 14lbs might need one jet size, depends on what a/f you are at at WOT right now at 9lbs.