Mopar Muscle – October 2019

chassis dyno and made a series of three

pulls from 2,800–5,000 rpm with torque

and horsepower within 1 percent of each

other. The results were spectacular. The

increase in peak torque was 16 lb-ft and

peak horsepower was up 17 hp (almost

10 and 13.5 percent, respectively). At

certain points in the curve, the torque

increase was as great as 22 lb-ft, and the

horsepower was up as much as 21 hp.

The engine torque rose to 182 lb-ft at

3,600 rpm, and the horsepower climbed

to 144 at 4,900 rpm. The average torque

of the pulls was up 18 lb-ft with an

increase in average horsepower of 13

hp. The A/F ratio on each pull was briefly

lean at initial WOT, but the ratio quickly

dropped to a range of 12.4–12.7:1

from 3,200–5,000 rpm. When cruising

the Dart at various part-throttle speeds

on the dyno, the A/F ratio was in the

14.8–15.5:1 range.

On the street, the Brawler carbure-

tor performed admirably. The choke oper-

ated properly, and the Brawler idled and

cruised in traffic without loading up or

hesitating. The carburetor operated flaw-

lessly after a hot-soak restart. The sec-

ondaries opened smoothly without provid-

ing any feeling of them actually opening.

“The Little Engine That Could” sounded

much more performance-oriented with

the Brawler, and we were pleased with

the performance and economy (nearly

15 mpg in mixed driving) of the carbu-

retor. If you are looking to upgrade your

4-bbl or considering a 2-bbl to 4-bbl

swap, give the representatives at Brawler

a call, and they will provide you with

a Brawler that has the best “Knock Out

Performance” for your Mopar.

With all the adjustments to the

carburetor to tune it to the tiny 273,

we were able to achieve 19 in-hg

(vacuum) at idle. The needle was solid,

and the engine idled smoothly. The

Brawler has two timed spark vacuum

ports (one used for the distributor

advance) and one full vacuum port

(used for the engine vacuum reading).

When cruising the Dart at various

part-throttle speeds on they dyno, the

A/F ratio fell into the 14.8–15.5:1 range,

which was a great range for fuel econ-

omy. The idle A/F ratio was 14.4:1,

and the WOT A/F ratio was between

12.4–12.7:1 for most of the rpm range

of each pull. The Brawler had so many

adjustable components that we were

able to fine-tune the 570-cfm carb to

our engine.

After all the adjustments, the peak

torque rose 16 lb-ft and the peak

horsepower was up 17 hp. The greatest

torque increase was 22 lb-ft at 5,000

rpm, and the horsepower was up 21 hp

at 4,900–5,000 rpm.

The Brawler carburetor delivered excel-

lent performance, yet the fuel economy

provided by the Brawler was just as

impressive. With the Brawler carburetor,

the 273 knocked down just under 15

mpg, which was an improvement over

the Carter 2-bbl.

The engine

torque jumped

to a peak of

182 lb-ft at 3,600

rpm, and the

peak horse-

power climbed

to 144 at 4,900

rpm. The aver-

age torque of

the pulls was up

18 lb-ft with an

increase in aver-

age horsepower

of 13 hp.

At WOT, the A/F

ratio quickly

dropped into the

E10 max power

range between

the max power

rich (12.0:1) and

max power lean

(12.7:1). The

engine pulled

strong from

3,200–5,000 rpm.

SOURCES

HOLLEY

270-782-2900

HOLLEY.COM

MSD

915-857-5200

HOLLEY.COM/BRANDS/MSD

TECH | FUEL FOR THOUGHT

32 moparmuscle.com