carb tuning

[green67cuda]

I know they come tuned pretty close for most applications, but are there any suggestions on what I may need to do when the new carb comes?
It's a 770 Street Avenger, and comes with 72 primary, 75 secondary, .025 squirter, 65 PV, and silver secondary spring.

this will be on my 400. 8.5:1 CR, .509 purple shaft, torker intake.

i'm just not sure if it'll be close for my application or not. I will get it to the strip to try to tune it, but need some suggestions on probable changes so i can get the right tuning parts.

 

[AdamR]

25 is a pretty small squirter. I run 30s on mine.

 

[rumblefish360]

You can purchase a box of jets, springs and squirters and cams for the squirters for the Holley. Run it as is and try adjustments on the carb as is and then you can go from there.
If you had acess to a air/fuel gauge or shop with monitor, you could dial it in well.

 

[green67cuda]

i thought about welding in a bung for an O2 sensor and using a voltmeter on it....but i may wind up just using strip times/plug readings to tune it.....i dunno

 

[AdamR]

Remeber squirters for 60ft times and jeting for mph.

 

[Guitar Jones]

You may want to check the vacuum at idle in gear and then select a PV that is rated 1 to 1.5 less than the lowest vacuum reading. That's why I took mine out, car is much more consistant. Any way sqirters (or pin drills), jets, float bowl gaskets just in case and I like the plastic bowl screw washers as they can be used over and over and over and over and over and over and over...

BTW I've never seen the value in changing pump arm cams from the factory one or the initial setting.

 

[green67cuda]

with a fairly loose converter, it doesn't pull the engine down at all in gear....do i need to adjust the idle down a hair?

 

[GotDart]

i thought about welding in a bung for an O2 sensor and using a voltmeter on it....but i may wind up just using strip times/plug readings to tune it.....i dunno

Unless you go with a wideband O2, it would not be worth the trouble. A standard narrow band O2 will only read accurately when you are very close to 14.7:1 air/fuel ratio. If you get very far off from that ideal ratio, it will show you rich or lean but not by how much. So at best it might be usefull for tweaking the idle mixture and part throttle cruise. But for power tuning, forget it.