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SKU #: GR-VK-5 Grand Rock Quiet Performance Muffler| Dual Stacks Exhaust |Cummins/Mack/Detroit | QP-5LC/6LC/7LC

Purchase Grand Rock Quiet Performance Muffler| Dual Stacks Exhaust |Cummins/Mack/Detroit | QP-5LC/6LC/7LC
    • Peterbilt, KW, Mack, IH, Sterling, White/GMC, Volvo Trucks

Description

These are rock solid internal mufflers that will increase your fuel economy by a minimum of 3%! This muffler also yields in quicker acceleration due to the better air flow design. The QP Internal Muf ... read more

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These are rock solid internal mufflers that will increase your fuel economy by a minimum of 3%! This muffler also yields in quicker acceleration due to the better air flow design. The QP Internal Mufflers will easily replace your stock muffler and does so without increasing exhaust noise. Grand Rock customers have see as much as a 9.4% increase in fuel economy from this simple modification.

IMPORTANT NOTES:
  • Please read the engine application section at the bottom of this page before ordering or call us to make sure you choose the correct muffler for your truck.
  • Price is per muffler
  • This is for only the muffler, not a stack and muffler.
FITMENT:
  • The QP-5LC will fit into any 5" Diameter 45" long Stack.

Single Stack: Grand Rock does not recommend a single stack setup with the quiet Performance Internal mufflers. Customers have tried it, but the results have not been as good as with a dual stack setup, 3% and lower gains. Give us a call if you have any questions.

IMPROVE YOUR COMPANY'S BOTTOM LINE.
  • These results are BEFORE quarterly fuel tax payments.
  • Figure in for ADDITIONAL savings.
Grand Rock Company Testimonials
*All results below were tested and published by Grand Rock Co, Inc.
ENGINE STACK CHOICE STOCK 10" MUFFLER MPG QPM-1051 MILEAGE MPG GAIN % GAIN
12.7L Detroit 60 Series, 360HP 5" Dual 6.41 6.79 .38 5.9
12.7L Detroit 60 Series, 525HP 6" Dual 5.85 6.40 .55 9.4
Cummins N14 Plus, 525HP 7" Dual 5.96 6.35 .3 6.5
N14, 400 HP 5" Single-Not Recommended 5.75 5.92 .17 3
Engine Application
For maximum performance we recommend the following MINIMUM sizes of QP's for your Application.
ENGINE SIZE IN LITRE ENGINE SIZE IN CUBIC INCH HORSEPOWER RANGE RECOMMENDED MINIMUM SIZE QP PART#
5.9L 360 ANY QP-5LC*
7.3L 445 ANY QP-5LC*
8.3L 506 ANY QP-7LC*
10L 610 ANY QP-5LC
11L 672 ANY QP-5LC
11.1L 678 ANY QP-5LC
12L 733 ANY QP-6LC
12.7L 745 ANY QP-6LC
13L 794 ANY QP-6LC
14L 855 ANY QP-6LC
14.6L 892 ANY QP-6LC
14.7L 898 ANY QP-6LC
15L 916 up to 400 QP-6LC
15L 916 400+ QP-7LC
16L 977 ANY QP-7LC

Specifications

  • SkuGR-VK-5
  • ManufacturerGrand Rock
  • MPNVK-5
FEATURES:
  • 3% MINIMUM MPG GAIN.
  • Quiet Performance Muffler
  • 7.28% Fuel Mileage Increase (avg.)
  • Much Quieter then open stacks and as quiet as stock. Engine brakes will still be loud.
  • Meets Federal and California Sound Levels
  • Heavy Gauge, 100% welded construction
  • No Turbo Lag, Faster Acceleration
  • Easily Installed, Bolts in place
  • Patented 2004
  • Easy Install! Two holes in each stack is required.
  • Tax Deductible- Repair/maintenance of a vehicle used in business is tax deductible.

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Grand Rock Quiet Performance Muffler| Dual Stacks Exhaust |Cummins/Mack/Detroit | QP-5LC/6LC/7LC

Grand Rock Quiet Performance Muffler| Dual Stacks Exhaust |Cummins/Mack/Detroit | QP-5LC/6LC/7LC

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