Edelbrock 1406 - (Running 11:1 AFR cant get desired 14.7:1) next step? - Third Generation F-Body Message Boards

FueledSoul · 09-01-2009, 03:50 PM

I have a Edelbrock 1406 (600cfm) carb on a modded 305, mild cam, long tubes etc. by the way im runing a wide band, i adjusted the idle screws and tryed other adjustments on the carb and timing but i can only get the carb to run a 10.9:1 to 11:1 at idle its running way to rich i want to get it down to the 14.7:1 ratio. what is the next step. rods? springs? jets? etc any help would be greatly appreached

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//<86TA>\\ · 09-01-2009, 05:07 PM

Pickup a tuning kit from edelbrock for the carb and tune the primary jets and rods leaner. Then try again

stroker_SS · 09-01-2009, 05:07 PM

14.7 even though it's stoichiometric is too lean for idle, 14 is too lean. Id set idle for around 12.5-13. How is the mixture during cruising and wot.

EvilCartman · 09-02-2009, 01:47 AM

Even my car idles fine at 14:1, driving around seems fine as well. 12.5:1 through 13:1 should be a goal for WOT, whatever makes the engine happy. FueledSoul, check out www.innovatemotorsports.com in the forum, lots of info in there under the general tuning. They mostly talk about Holley or Demon carbs but should still be able find info about Edelbrock ones too.

5678TA · 09-02-2009, 05:00 AM

i lost 0.4 sec and 2mph in the 1/4 going from low 13:1 to 14.7:1.

12.8:1 is the average ratio for power.

FueledSoul · 09-02-2009, 11:34 AM

Quote:

Originally Posted by EvilCartman

Even my car idles fine at 14:1, driving around seems fine as well. 12.5:1 through 13:1 should be a goal for WOT, whatever makes the engine happy. FueledSoul, check out www.innovatemotorsports.com in the forum, lots of info in there under the general tuning. They mostly talk about Holley or Demon carbs but should still be able find info about Edelbrock ones too.

hmmm didnt even know they had that. thanks man

FueledSoul · 09-02-2009, 11:41 AM

thanks for all the help and input. i ened up buying a rod, jet and spring assortment kit. I aslo bought a few diffrent sized jets from edelbrocks website too. we'll see what happens. hopefuly i will get these before the weekend, other wise i will post any other qustions i might have here. agin thanks guys

FueledSoul · 09-05-2009, 12:10 AM

I got my kit today but i didnt even use it i thoght id mess around with timing and the carb more before i start tearing into it. i hooked up a vacumm gage as well, no matter what i did it (SITTING IN A IDLE) would not go over over 18" hg just under. The wideband was runing at 10:9 - 11:1 consecutively, But today it was here and there frist runing the 10 to 11 then it bonced all over from 9:1 to 13:1 then i played with timing and the idle screws i got it to run 12.5:1 13:1 but it still was boncy with hints of 9's and 10's. the throttle is perfect no dead spots smooth even a fast or slow rev comes right back to idle with out missing or skipping a beat. when i held / left the thottle open till it was sitting at 2,500rpms to see what it was reading, i was about a 9:1 to 11:1 but when it returns to idle from sitting at that speed it then has a reading of 13:5 to 15:1 for about half a minute. then goes back into its boncy goofy state AFR.
two things i noted today

1.) It's a very high pitched whistle hard to hear when your around the engine but very very audible away from the car. its hard to pin point but it's not the carb sucking in air. is there something i could do to detect where it's coming from? a spray or whatever? the vacum and tach hardly moved from where they where sitting could be a vacume leak

2.) insignificant power - alternator not charging battery properly not sure whats going on here. i think the pulley is simply spinning to slow but im posting a question in another thread regarding this issue since it might be pully related. but im runing a electric water pump, MSD. wide band, and two electric fans. dont know what the deal is but if anyone is good in this area. i have a 140 amp alt. the volts where at 14 when it frist started but half an hour later the gage was siting in at around 8 or 10 volts and keep droping slowy. whats weird is when you rev it the volts go up. pull the fuse for the alt and the engine bogs a bit and you hear the alt switch off. but when you pull the main power off the battery the car simpley dies. the alternator should still be keeping the car runing. the batterys newer and it keeped its charge. is it possbile the wideband could be boncy because of whats going on above? it really doesnt seem like it since its been working fine but im sure this and high pitched whistle might be eiether affecting the wideband gauge or the real AFR

so this is whats going on with the car now

one92rs · 09-05-2009, 08:15 AM

14.7 is perfect idle fuel ratio. it is also the perfect cruise ratio. the only time you want it iff that or richer is when you are getting into it or racing it. under a load in the neighborhood of 12.8 to 13.1 is good.