IRL adds mufflers to reduce obnoxious engine noise

IndyCar Series officials heard the comments. Now the cars whipping past fans in grandstands at 220 mph will be easier on their ears. A slight modification to the exhaust manifolds of the 3.5-liter Honda Indy V-8 engines has resulted in about a 4-5 decibel noise reduction, essentially taking the edge off the shrillness of the cars at speed.

“We’ve reduced the decibel level by about 4 percent and taken the harshness and shrillness out of the exhaust notes along with the tone, which makes it gentler on the ears," IndyCar Series senior technical director Les Mactaggart said. “So we’ve had a reduction in pitch and reduction in noise level. It will be noticeable."

Baffles have been installed in the exhaust manifolds (contained in canisters) just past the collector. There hasn’t been an adverse impact on the 100 percent fuel-grade ethanol-powered engine’s performance, and it’s a spec system.

“The first thing we did when it was designed was take it to Honda, which ran it on the dyno," Mactaggart said. “There was no change in back pressure in the system, which would have affected performance.

“Having everyone use the same parts eliminates the subjective arguments that they have played around with it." More at IndyCar.com

[Editor's Note: No doubt this move was made to eliminate the obnoxious noise put out by the Honda IRL engine for the street circuits. This has been a problem with the IRL's inferior cars from day 1 with fans complaining they could not bear the noise. It's good to see they finally put this band-aide on the problem. Previously they added diapers when the engines would blow up every few laps and they added butt pads to the back of the transmission after they broke umpteen driver backs….though as Bruno Junqueira proved, you can still sustain a broken back even with the butt pads.]