What is the best carb/intake combo for a sbc? How much power can be expected to be gained through a good combo?

 

I've seen over 1000hp from an NA 350ci motor.

good luck actually building it you're gonna have to be a whole lot more specific to get any kind of useful answer.

 

No dought, Nascar motors are a little over 800HP @ 9000rpms with a 358CIN motor, and probably cost over 50 grand.
It's achieved with a Victor series LIKE Intake, and a 830cfm Holley 4150 if that helps. They get maybe 4-5 MPG.

If your seeking high end or low end, the word 'compromise' comes to mind. So like Jester said you’ll need to be more specific.

Ron

 

I have an 84 Z28. I am wondering which intake and carb would get me max hp for my money. I am only 17, so that means im on a budget I can't spend like 4 grand on a combo. Im probably willing to spend 400 for a good combo, but I want to know which is the best bang for the buck combo out there that won't leave me with a pathetic hp gain

 

You already have the best carb and intake available - at this time. Spending $400 on a different setup would be nothing more than disappointment and a complete waste of money. Check the tech articles for what to do with your q-jet.

You need to help your exhaust and air cleaner before you do anything else. Then cam, ignition. After that, heads. Then MAYBE intake. But the carb is still fine for all the power that 305 (or even a 350) can make.

This weekend I pitted next to a '67 Nova that had "LT-1" stickers on the front fender (no, '67 Novas didn't come from the factory with LT-1's). That engine, in case you didn't know, was the highest rated carbed SBC ever from the factory. However, it had been improved: Brodix heads and very tall intake, even more wicked cam, 1-3/4" headers, etc. Oh, had a q-jet on top (LT-1's came with Holleys). It ran 13.5's at our altitude (consistently), which translates to 12.5's at sea level.

If they don't need a different carb, neither do you. With $400 to spend, exhaust is about all you can expect to do at this time. Hedman headers and y-pipe ($200 for non-emissions types, $325 for emissions style), $60 for cat, $250 for cat-back - all of that has to be done before you can expect any other mods to produce anything but pathetic gains.

 

I have a custom flowmaster exahust with a dual cat. So you reccomend hooker headers with my engine. What else would you reccomend? A better intake? A chip? Better cam? Better heads? I am planning to supercharge it but that won't be for another month or two. What else do you reccomend for a higher performance?

 

Hooker doesn't make a header y-pipe for dual cats. As far as I know, only SLP and Edelbrock do.

After that, better cam. Heads next. Then perhaps intake (I did all of them at the same time). I put a chip in, but have no clue if it does any good (will have to do back-to-back comparisons some day).

 

Im planning to do all of this at the same time also. You can't feel the difference since you put all of those mods in? I felt the difference right away since I put the dual cat in.

 

The chip was one of the first things I did, while the LG4 was still stock, and before the weak fuel pump was replaced. Since it wasn't running right before I put the chip in, I don't know if the chip made any difference.

The other mods in the sig, those, without a doubt, made a difference.

 

Ok, good to hear that. I have an L69 :-). I hope that I feel the difference in about a month, then it is on to supercharger-ville.

 

A good intake is the Performer EPS. You can buy reman. Performer carbs from northern auto parts for about $160 for the 600 CFM manual choke.

But I agree with the other guys. Cam, Exhaust, and head work should be first. then intake and carb.




-Terry-

 

First of all, there is no one intake and carb that works best for all SBC motors, considering all the variations of size, hp levels, and purpose.

You can have a stock 267 or a mega 434 and they both are SBC, but one may make 150hp and the other may make 800hp.

The idea is this: will the intake and carb improve the power enough to justify its purchase - unless your motor is highly modified (cam, heads, and size), the answer is most likely no.

Since you didn't mention what size motor/what power level/rpm level you are at, I will asume you don't need a carb (unless the induction you have now is damaged). Those of you on the board who have modified LG4/L69 motors know that there is no problem supporting 300+hp with a carb that came with motors rated at 150-190hp stock. I am at 390hp and have not even come into a problem yet - should be good for about 500hp. So the answer is no carb changed needed.

As for the intake, depending on what rpm range you run in will dictate the available intakes that may work well. For example a performer intake will not work on a 8000rpm 350, or a super victor will not work (well) with a stock 305.

One common mistake made by people who are less informed (than they should be) is the overcarb syndrome - putting a 850cfm carb on a 275hp 350 (or worse); a 600 would make more power, be more driveable, and get better mileage.


Concentrate on:

Exhaust
Air cleaner
Ignition
Gearing & converter

These will give you a lot more gain for the $ than a carb and/or intake will.