Street avenger carb
 

Has anyone used one of these carbs on their small block? I plan on getting the 670cfm version. Was it hard to tune? did the engine run good with the carb? I found a place that will sell one to me for 400 bucks for the electric choke version and 370 for the manual choke CND. Which would you go for and why? Thanks

I have an Avenger on my 1930 Chevy. It runs like a raped ape. :D Haven't had any problems whatsoever.

Ive had 2 570 Street Avengers on mild 305s & my 454 has a 770.. I love em.
What are you putting it on? what kind of RPM do you plan to run it to ?

spend a little more money & get a lot more carb by getting a Demon. I cannot stress how much better a Demon is. JMO

A 350 Sbc with vortec heads and performer rpm intake crane cams 272 454 lift. Im thinking around 5500 rpm. I plan on adding a 100 shot of nitrous in a year or so. Why is a demon so much better?

Hate to diagree here ;) the Demon is a good piece but unless he is getting into tuning air bleeds and emultion bleeds that the higher end Demons offer, the street avenger is a fantastic carb money for money.

Just my opinion, the Holley is a better buy.

I have 2....Truck Avenger that is a door stop and a Street Avenger that is on my truck now. Have a hesitation at about 1000 rpm that can't get rid of. Have had 2 different guys work on it that know their stuff. Gonna get rid of the air gap and go back to a performer intake. See if that gets rid of it. Too much more crap with these carbs and it'll get TPI.

I'm curious also, what is so much better about a Demon. To me it looks just like a Holley knock off with a smoother outer body.

From willow72's post the other day, it sound's like he's not having much luck with a "Crate" Demon on a "crate" engine, and the Demon support isn't of much help.

the main reason Demon is so much better is casting. no porosity. if you were to take a holley & cut the metering blocks with a bandsaw you will see holes all over the place. thesew holes let air & fuel in at the wrong place & time. holleys also have the venturi boosters installed out of alignment. main bodies not square or flat. the list goes on & on. Barry Grant used to buy holley castings & rework the hel7 out of them & sell them as modified holleys. patent infringement laws were imposed & he decided to go even better. it is a long story. he just built a better mousetrap.
as far as demons requiring more tuning with the small stuff than is done on an average joe scale, that is untrue actually. (no offense, not trying to be a jerk here or stir up the water). the demons have the same basic design as holley has had for the past 50 years or so. they just need less of it due to construction accuracy. when most ppl tune a holley right out of box it is for 2 reasons. 1: bought wrong size or type. 2: trying to tune AROUND flaws in constructions.
demons are now availabe for more than the professional racer. I had a customer with a 85 olds cutlass with a 403. he had a holley that he could not keep in tune. I looked at it, tried to tune it & would change tune at will. bought a demon 650 vac. sec. which was right on the money straight out of box. set idle mix & speed & everything else was 85 % right.
now keep in mind that any carb you buy will be PERFECTLY tuned for your app. way to many variables. carb tuning is a science where every case is different. 2 identical cars will require different tuning. driver habits is one important issue.
whoa, I better stop here. this instructional is getting out of hand. just to much to get in to at this time.
in short a holley is like a Hyundai & demon is like Mercedes Benz. they will both get you to work :D
thanks Todd

Canadian, a 350 that runs to 5500 doesnt need that much carb really anyway. If your stayin within 5500 RPMs you wont even need 600 CFM, I personally think a 570 Holley would be great, although a 1" open spacer might be nice with it...or a 600 CFM of your choice. If you plan to spray it, might want to consider a little more like the Demon 625.

well thx to u all i was gonna buy a avenger and now i am going down tonight to pick it up thx

Well I think ive decided on the road demon 625 or 725. I might go 725 just for later upgrades I might just have some idle problems but I dont plan on doing much idling. Thanks for all your comments!

I read an article regarding Demon Carb's, and it stated that they are significantly under-rated to their flow capacity. For example, a 750 will flow almost 900 cfm. So I would err on being slightly undersize when buying one. I hear the Road Demon 625 vacuum is an excellent carb which would work good for a 350 ci. mild combo.

When I dynoed my 500 hp 406, I used a 750 street Demon mechanical. The dyno guy said to try is custom 950 cfm Holley to see if it would make a difference. It actually made less power, even up high.

go for the 625. trust me. I know these things. see one of my previous replies to a guy with off idle problems due to an oversized carb. with or without NOS you need a carb for whatever rpm expected. be coservative.

Amen. A 650 cfm Holley carb should be good to about 7000 rpm for a 350 cid engine. If more cfm is needed, then go with the Demon.