Dyno Charts – Chevy Intake Manifold

Small Block Chevy Cast Iron Intake Manifold Dyno Charts

Can You Use Some Extra Horsepower?

A stock cast iron intake is the most restrictive item on a small-block Chevy racing engine. Let’s face facts: Stock cast iron intake manifolds were designed for passenger cars where the engine never sees 3,500 rpm. In a race application, the engine is never under 3,500 rpm. We have seen lap times reduced a couple tenths of a second with a Brzezinski Racing Products Modified Cast Iron Intake Manifold.

Horsepower Comparison 2 barrel Cast Iron Intakes

2 Barrel Intake Manifold Comparison
TORQUE INFORMATION (ft.-lbs.)

RPM
Stock
Acid Intake
Stage 1
Fully Modified

4000
358
360
363
368

5000
315
326
330
336

6000
257
268
280
286

7000
181
194
204
211

TEST ENGINE: 355, Stock ’492 heads, flat top pistons, flat tappet cam, headers and stock 500 Holley 2 barrel carb. NOTE: The intake manifolds were the only components changed.


“If you are running Hobby Stock, Limited Late Model, or Sportsman, you couldn’t miss hearing about Brzezinski because he is the prime exponent of having the stock cast iron intakes and heads pull more air than ever before.  He has learned all the good part numbers and the ways to make them respond.”

– Alex Walordy, “Cast-Iron Creativity” - Circle Track Magazine.

Horsepower Comparison 4 barrel Q-Jet Cast Iron Intakes

Q-Jet Modified Intake Dyno

Q-Jet 4 Barrel Intake Manifold Comparison
TORQUE INFORMATION (ft.-lbs.)

RPM
Stock Q-Jet
Stage 1 Q-Jet
Fully Modified Q-Jet

4000
375
379
388

5000
344
355
371

6000
285
307
327

7000
221
235
259

TEST ENGINE: 355, Stock ’492 heads, flat top pistons, flat tappet cam, headers and 750 Holley 4 barrel carb. NOTE: The intake manifolds were the only components changed.

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