Eric Buddrius

Amanda Bolland

Ian Lootens

Greg Hilbert

STEALTH CAT’S

SPECIFICATIONS

GENERAL REQUIREMENTS

SPECIFIC REQUIREMENTS

ACCEPTABLE PERFORMANCE

QUIETReduces the sound emissions of the sled

78 dBA or less in J-192 Sound test (goal of 73 dBA)

SIMPLE MAINTENANCECatalyst must be replaceable, no other maintenance needed

Cat. replacement takes less than 15 Minutes

PERFORMANCEDoesn't increase backpressure

Less than 110% of stock backpressure

COMPACT DESIGNFits in sled without modification

9" Deep, 18" Tall, 13" Wide

LIGHT WEIGHT Doesn't increase weightLess than 16.76lb (110% of stock muffler weight)

CATALYST• Aristo Contact is Bob McDowell

• Goal: to meet National Park Standards

• Focus: Carbon Monoxide and Unburned Hydrocarbons emissions

Emissions Data

2010 Results

CSC Limit NPS BAT

CO 209.94 < 275 < 120HC 41.6 - < 15NOX 5.8 - -HC+NOX 47.36 < 90 -E-Score 125.9 > 100 -Units: g/kW-hr

MUFFLER BASICS• Two Main Functions

• Reflection

• Most Effective

• Destructive Interference

• High Back Pressure

• Restriction

• Most Common

• Cheapest

• Absorption

• Simple with Low Back Pressure

• Low Damping

HUSHPOWER TECHNOLOGY

A. Entry Cone

B. Laminar Flow Area

C. Thermal Barrier

D. Exit Cone

DESIGN EVALUATION• Flow Bench

• Ricardo Wave

• J 192 Testing Procedure

• Timeline

FLOW BENCH

Test Stand

Settling Chamber

Mass Flow Meter

Vacuum Supply

FLOW BENCH• Active Flow Bench

• Vacuum source

• Test Part

• Multiple uses

• Cylinders

• Porting

• Mufflers

• Air filters

• Measures

• Pressure differential with respect to mass flow

WHAT IS RICARDO WAVE?

MUFFLERS IN RICARDO WAVE

RICARDO WNOISE

RICARDO WNOISE OUTPUT

J 192 SOUND TEST

SOUND TESTING• Existing Muffler

• Laminar Flow Muffler

• Hushpower Muffler

• Affect of Packing

• Small vs. Large Cone Perforation

• Series

• Parallel

TIMELINE• November 29th – Start J192 Sound Testing of Existing Mufflers

• December 10th – Complete Flow Bench

• December 15th – Flow Test Existing Mufflers

• December 17th – Final Muffler Designed

• January 15th – Receive Final CAT

• January 21st – Final Muffler Built

• January 22nd – Begin Testing Final Muffler on Sled

• March 4th – Leave for Competition

QUESTIONS?