Hello all. I'm removing the fuel injection from my engine, going with a new carb and intake. My Engine is a 540 with AFR 325 heads and Straub 239/246 Hyd. roller. 2" headers 4l80/w 3000 stall. 95% street (fast street) only to the track a couple times a year. The plan is a Edelbrock 454-R intake and either a 950 Ultra XP or a Brawler 1050. I'm capable of tuning either carb, but prefer the one that is closes from the start. I thought about a 4500 intake with a 4150 carb for the extra plenum volume, but at 6,000 rpms or so is it needed? Thanks for any help, Rich
Carburetor choice 950 Ultra XP or Brawler 1050
67 velle
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1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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I cut and put an edge to the plenum divider down about 3/8th of an inch on my oval port eddy rpm ag on my 454 but didn't dyno it but seat of the pants it felt better, that's if the OP is considering a dual plane intake?
1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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15,653 Posts
There's a Pro Systems HP 1000 in the TC classifieds right now for $650 plus $22 shipping
A 1.6 venturi is too large for 540 cubic inches?
And why would anyone buy a quick fuel carburetor when a brawler has everything that a quick fuel has other than a price tag that's about 33 percent higher?
Yep or you can buy em right off the shelf with a cut out too if you want .
And to me with 540 cubic inch that sees the track hardly ever how often is hp @6300 coming into play ?
Give me low torque on the street.
Or at the track really .
Allways more than one way to skin a cat
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346 Posts
Price reduced to $550 now.
1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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15,653 Posts
If I hadn't already bought the AED 1000 from another member for about that price that I'm very happy with I'd be all over that Pro Systems HP 1000, if I was the OP I'd be looking into it
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12,324 Posts
Be careful with carburetor spacers. Spacers are a bandaid for induction system flow. They do not provide the same benefit to all combos. My engine ran better with a 1" spacer compared to the $150 tapered 4 hole spacer. Although we normally saw 8-10 hp gain on the circle track motors with the tapered, it lost 4hp to the 1" open on my 548.
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228 Posts
No pcv port so the calibration is going to be way off, also drilled throttle plates. great carb for the money, I'm just wanting something closer from the start.
1968 Malibu Sport Coupe, 489c.i. 590hp 600tq, TCI 200r4 Freakshow 3,600 stall, 3.73 12 bolt posi
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15,653 Posts
I had to remove the 1" open spacer on my 489 do to hood clearance, race engine/dyno shop owner said I probably lost 20 hp but I like my SS hood 
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7,406 Posts
Here is what I learned with spacers last fall at the track. The dual plane intake did not like any of the tapered spacers at all and the car slowed down 2 tenths but the car went quicker and faster with the 1" open spacer. The Single plane Holley Strip Dominator picked up about .002 with the 1" open spacer. When I put the 2" tapered spacer on the single plane the car picked up 2.5 tenths and 1/2 mph. I learned that both intake styles wanted something different.
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12,324 Posts
I know what you mean about that big tapered spacer. My friend has one and on his 555 it made a bunch of power. I couldn’t fit it under my hood anyway, but he brought it when I dynoed the 548 and it didn’t have the same gain. We were kinda bummed because we thought it was going to really show something. And that was on similar type engines, his 555 made 860 hp and my 548 made 910. So neither engine was a dog.
Its not that the 1.6 inches is too big is that it less of a venturi becomes when the one hole is 1.6 inches and the throttle blade 1.75 inches. That is a 90% ratio 1.60 / 1.75. For a venturi to work really well you want to be the 80%-85% ratio so a 1.75 x 80 to 85% is like a 1.40 to 1.50 inch venturi which is what some of the 950s are. It has to do with signal strength at low speeds. The Dominator have like 2 inch blade so there venturi starts at like 1.60 and up.
Ok I'm trying to get this right so I get it right on my own lol
So if I have this correct it's a ratio of about
80 to 85% venturi / throttle blade diameter that is optimal ?
Venturi is a dimmension from where to where ?
Also the booster factors in to signal strength.
An anular booster has a very strong signal.
How would or how does that effect the
Venturi/ throttle blade ratio your talking about?
Then another question which may help the OP as well as me :
Should I be concerned about too much fuel atomization using anular boosters along with a hotter intake? Eg; anular boosters with an Weiland air gap dual plane intake without plenum cut out
The venturi size they give you in carb specs. Its the measurement when you look down the carb and its the smallest part before it goes down to the blades. David Vizard did a great book on carbs and it explains it all including like you mention different boosters. Your carb ventrui look like a nuclear power plant cooling tower wide on top and bottom and narrow in the middle.
I do have the book . I'll dig deeper.
I'm a big mr controversy fan lol
I've got 4 or 5 of his books
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6,021 Posts
I like AED. Super easy to tune, just give them the specs.
a
a
I tried a tapered and a 1 inch open and a 2 inch open on a dual plane 200cc aluminum heads isky 270 . Stock 350.
No dyno not slip. 2 inch spacer sure did feel like more torque . Pulled harder and pulled longer on the outside
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7,406 Posts
Did you re-jet the carb? as they can go lean with that much spacer.
Yep sure did . I've got an afr gauge right in the car and yes you're right. It did indeed lean it out a fair ammount. I want to say about a point and a half
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