[rob]

I have a budget, Holley Brawler 750dp with choke. Drive ability, cold start, etc... is great. It’s in my Fairmont wagon with a boss 363 z headed crate engine. Nothing spectacular, I run shorty headers through2 1/2” h pipe and exhaust. Also had a mildly ported victor jr intake. Through a garbage c4 (my mvb aod will be going in soon) it ran [email protected] in good weather which calculates to 1[email protected] 60ft is only 1.67 with not so good converter.

carb is out the box other than adjusting idle. I think there is at least 11.2 or 3 once I fine tune wot air fuel and timing on the dyno and improve my 60. I’m underachieving compared to most, but would be happy with a high 10. I think I could do it easily with a better head and a smaller than 63cc combustion chamber, but would like to do it with the heads I have.

how much if any benefit would a choke less “race” carb be worth?

what I have now; https://www.holley.com/products/fuel_systems/carburetors/brawler/diecast/parts/BR-67257

what I’m thinking about getting; https://www.holley.com/products/fuel_systems/carburetors/brawler/race/parts/BR-67331

opinions?

 

[b--rad]

depends on your future plans..... if you are going to race it any... get a race carb.... if your going to drive your granny around and try to get a few mpg better than a race car... then stick with what you got.

 

[bluemp301]

Buy a 2nd one. Tune one for racing and one for street driving. Interchage as needed

 

[rob]

before I buy a carb for racing, i'm trying to figure out if the gains (if any) are worth the expense.

i'm not worried about gas mileage on the street.

 

[bluemp301]

In all seriousness I'm sure you could find some power with the right carb but not enough to warrant the expense given the other areas you mentioned that could be improved.

 

[Killer95Stang]

So what are the "defined" differences between a so-called race carb and a street carb? I one of Holley's 4150 based HP "street" 750dp carbs with no choke, on a 347 stroked 63 1/2 Falcon Sprint. Holley sell this carb as either a street version or race version. I do live in sunny socal, so the cold starts is less of an issue for me, but overall, I don't see a diffence between the two? I did take the car to a local carb tuner / builder who tuned the carb to my engine size / camshaft specs, which helped a lot with driveability.

 

[Cutlass327]

The choke tower and plate can be a restriction of smooth airflow. That is about the only difference.

Back in the 90s I read of the effects of an air cleaner system on an engine, and I thought I'd experiment one day I was at the track. I ran a basic open element air cleaner on my Chevy 350 powered 85 Cutlass Supreme. A couple passes were with the full setup. A couple were without the assembly, and the final was with just the base of the cleaner assembly. That last run was my best. I ran slower without the assembly than with the full setup. I was only able to run one pass with just the base as I ran out of time (it was test and tune/grudge match night, so had to wait my turn). Unfortunately, that was also the last run I ever made, as I lost oil pressure (it was my daily driver) and never got it fixed as life reared up on me.

All of that to help show the purpose of no choke tower.

You say you do not care about MPG, but you didn't say your primary use of the vehicle. If you use it more as a driver, with a few passes a month for fun, run what you have. you have it, it's tuned, and it works fine. If it is a competitive runner with a few weekend cruises for fun, go race-built.