By Abhishek Takle
SHANGHAI (Reuters) - Formula One engine manufacturers believe there is a limit to what they can do to improve the sound of the new power-units, they said ahead of meetings aimed at exploring ways to make the sport louder.
Critics have hit out against the switch to smaller, more efficient turbocharged power-units as these new engines, packed with hybrid energy recovery systems, are quieter than the screaming V8s used until last year.
World champion Sebastian Vettel has attacked the new sound and the governing International Automobile Federation is conducting a study into making the engines louder.
The first meetings that will kick off the process were scheduled to take place on Friday, engine manufacturers said.
Renault Sport F1's deputy managing director Rob White said the complex new hybrid technology introduced this year, which harnesses waste heat and reuses it to power the car, limited what engine manufacturers could do to pump up the volume.
"I think the scope to fundamentally and profoundly alter the noise of the engines is extremely limited by the type of technology we have deployed and therefore I think we need to be realistic about the scope of any action we might take," White told reporters.
"But of course we're sensitive to the subject and we'll certainly participate in any of the studies that might lead to action being taken."
Andy Cowell, who spearheads Mercedes' engine programme, said: "The principal reason why the engine is quieter is the turbine wheel and the muffling effect that you get from that.
"That's one of the key technologies for recycling the waste energy that would normally go down the tailpipe so it's a key aspect of the technology we've got.
"There are other things we can do though with the tailpipe, perhaps, to change the noise," added Cowell ahead of Sunday's Chinese Grand Prix.
(Editing by Tony Jimenez)