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545 stroked 460 with 871 blower now runs here are my settings

okay after reading and running the motor a few times I finally have it where it starts like a new car off  of the lot my AFR is set at 12:5:1 because of the mass amount of air the 871 pushes through and fitech web site say to set supercharged applications between 11 and 12, the pump or prime shot is set to 159 from 259 my IAC steps is between 3 and 9  the idle is at 950 my cam setting is on 2 because at idle I am making 10"hg of vacuum at the blower boost gauge port and blower reference hose to the throttle body  but I have a temp problem I am dealing with so I cant drive it as of yet  there is a video on you tube

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Hi are you running 12:51 AFR at idle ?

Thanks Bobby


yes fitech site recommends actual 11:5:1 to  I believe 12: 8,, rich at idle is okay to a point for better idle control and temperatures normally 13:8 to 14:2 would apply if there is not  a turbo or blower

Thanks for the info I am new to the forum. have a 350 sbc with a  671 weiand with a mild cam. I just installed the fitech dual quad 1200 power adder .I have a problem with cold start I have to hold the peddle down a little to get it started and when it starts it runs for a little while then it pops through the throttle body and stalls. My IAC steps between 0 and 10. I will try the settings you have and see if it helps.

Ok I made some changes this morning . I set the AFR at 12:50 at idle form the 13:70.

And set prime shot from 259 to 159. It made a night and day difference the idle stayed more stable it started right up cold and hot . And did not pop though the throttle body at idle. I left it idle in the garage for 40 min coolant Temp got to 190.  My IAC is 0 to 12. I will see how it runs on the road test later.

Thanks for the info

Boosted applications, as you know, are safest when rich and retarded.  AFR numbers are a guide, not accurate numbers.  Plugs will tell you everything.

Moving this thread to the Power Adder section.

sry didn't know about the power adder section lol remember blower application are all on a different level most what you know of carbureted non blown engines ..forget it blown and blown fuel injected totally different animal you very may well half to live with the slight pedal press because once the engine sets a while there is nothing in the intake system to burn like mine for example first start of the day I need to hit the pedal a slight bit but the rest of the day I don't half to touch the pedal fires right up for that reason and because it is rich it may need the extra bit of air during start

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Ok took it for a test drive went about 10 miles. At about 40 mph at cruise had a flat spot like it was running out of gas never shut off. when it hit the flat spot when I say flat spot it would all most shut off. I  would let off the peddle and it would snap back and run good and do it again. So I thought I would change the AFR 1100 45pa from 14:10 to 13:50. And 3000 45pa cruise from 14:10 to 13:50. I will see if it does any better.

14 to 13.5 I would think is a bit lean for a blower motor

Update  I am still having a popping though the throttle body doing start up cold I have to give it a little throttle then it is ok. I did data log it at idle and at wide open throttle on the road it runs vary strong. it miss fires at around 50 mph some times at cruising The throttle bodies  frosts up and water runs down on the blower. almost like you are running on alcohol. I don't know how to down load the data log to the computer to look at it. Seems like it runs strong at wide open. just cold start popping unless I give it a little throttle. when it miss fired at 50 mph at cruise I noticed the handheld controller froze up and the RPMs froze at 5900 on the hand controller. I had to reset the controller.