We had Lexus SC430 bought in to us, to have the exhaust modified so it would be quieter as the current exhaust system was far too loud for the vehicles owner.
When we put the car up on the exhaust ramp, we noticed something strange with the exhaust. The old exhaust was a ‘dual exit exhaust’ with 2 single boxes, which means the exhaust at the rear comes out at both ends of the vehicle. The exhaust’s pipework, just before the exhaust splits at the rear, was squashed (as can be seen via the pictures). We asked the customer about this who was told by the previous exhaust garage that this was necessary in order to clear the axle and for ground clearance. However, we just couldn’t figure out why something like this was carried out when there was no need for it.
Having exhaust pipe work squashed isn’t abnormal, we have come across this before. Many do this either for structural purposes or to make the exhaust sound raspier. Have you heard of the term ‘Screamer pipe’? it’s similar to that, to achieve a louder sound. We would strongly advise to only get this done by professionals in the field as it can cause issues, such as back pressure if it’s not done or fabricated properly.
Moving back to the Lexus, upon further inspection we became aware that the exhaust had been modified with a bigger bore. This, as well as the dented pipe work would have been contributing to the loud sound that the customer wanted to change. After discussing various ways to quiet the exhaust we concluded in getting a special rear exhaust box made. We call this kind of box a chambered/baffled box that helps in quietening the noise dB level. The exhaust box was made in stainless steel with a twin inlet in the middle and had twin exits from the side (refer to images).
The customer chose to have single oval tips fitting on at the rear which ended the look of the exhaust nicely.