need exhaust which is below 99 db
 

hi guys im having a bit of a dilemma. still building my rally car(93 wrx) and need an ehxaust system. need to have a performance cat downpipe or if a decat cannot exceed 99db in noise to enter a rally. anyone know the ideal setup for me or better . . have one for sale?? i dont want jap style as needs to be tucked up out of the way. something like the new shape ppp backbox is ideal or the racebox from scoobyworld. cheers for any help as i am totally stuck. marc

noone?!?!

I fully understand! I do Hillclimbs so noise a real issue.
My Sti v3 ran a Revolution with decat for 3 years @ 97DBa using 2 measuring techniques
1
Sound meter on the end of a 1000mm cane and held @ 45 degs from the tailpipe obviously 1000mmm away.
A second person asked what the red-line of the engine is and demanded (and observed) 2/3 of the red-line, in my case = 5000 rpm.
This level is held for 5 seconds and a measurment taken off the peak hold on the meter.
2
A drive by:
about 60 feet from the start line a meter on a tripod along the track side (hillclimb so track about 15 feet wide).
The meter measures the car off the line through whatever gears it happens to use.

The same system with a sport cat gave the same noise levels.

Should add this system came off a rally car and is also a 3'' right through system which can be bought from Revolution Performance Motorstore

The only other great light racing system is the TSL Group N with sport cat and very nice. This will meet the noise levels too and is very 'sleek' to the underside of the car, esp the back box/diff area.

Hope this helps you.
Graham.

Thanks 911 !!

Marc give me a bell and we will sort you out with out 3" system with 4" tailpipe similar tail pipe style to prodrive

Thanks

Colin@revolution

0191 4770785

Revolution Performance Motorstore