Hey carb guys!

[flyby84]

Alright...the combo I have in my sig works pretty good but I have noticed the exhaust from my car will choke you out! I have a stock Holley street avenger and was wondering if this is enough carb or should I get something else? Everyone I have talked to say I should pitch it in the trash...

 

[asecretfile]

Alright...the combo I have in my sig works pretty good but I have noticed the exhaust from my car will choke you out! I have a stock Holley street avenger and was wondering if this is enough carb or should I get something else? Everyone I have talked to say I should pitch it in the trash...

what CFM do you have...570 670 770 870?

Might try running your mixture screws all the way in and then a turn and a half out as a starting point

 

[85_SS_302_Coupe]

If this is a 670 Street Avenger then it's not a bad carb for your combo...should run pretty stout. I'd say you just need to tune it a bit. Carb exhaust always smells a little more gamey than an EFI exhaust, especially if you don't have the emissions equipment and cats installed.

 

[Wallzy]

Flyby84,

With that cam i would imagine you are making peak power around 5500-6500 RPM, and with your 306 you will be pulling 576cfm@6500rpm, 620cfm@7000rpm and 664cfm@7500rpm - when do you plan on shifting? Your peak cfm should be how you choose a carb becaue of the velocity to vacuum profile as air is drawn thru the venturi. Just remember in this case, bigger is not always better. Good luck!

Walz

 

[85_SS_302_Coupe]

^^ Keep in mind that just because a carb is labeled as a 650cfm, doesn't mean it actually flows that. What looks good on paper in a math formula doesn't always work out in the real world. I'd personally say a 650 is about perfect for his setup. With a 600 he may have slightly better throttle response (and i mean slightly) and slightly better bottom end (again, slightly) but he'll more than make up for it in the top end.

 

[flyby84]

My stang pulls pretty hard with this combo! I shift at around 6k and I believe this is a 570cfm!
I am looking foward to running at the local 1/8th in a few weeks to see what it will turn.

 

[RsStanG1987]

Id also say the 650 is perfect for your setup. Im running pretty much the same setup and my exauhst smells pig rich..

 

[DrMaxit]

What jets are you running and what altitude are you at? Generally you should go down a jet size per 1700ft or so IIRC. The CFM on a carbs rating is aprox how much air it will flow, not how much fuel.

 

[flyby84]

It has the stock jets in it right now...will be running about sea level at the track and I am about 1000 feet above right now!

 

[93 LX]

why stock headers? Maybe they are killing your performance...

 

[joel5.0]

What do the spark plugs say? LUK

 

[flyby84]

The plugs look just a little bit on the rich side...not much just a little! I just haven`t bought headers yet,they are coming this summer. Looking into getting some longtubes. How much of a performance gain will I pick up with a decent set of LT`s?