I have been Tracking my Locost (Honda Blackbird) for a few months now and starting to get used to the car and pushing on more.

I got black flagged on my last track day for breaching the fly-by sound limits.

My exhaust is the re-packable type design so I have opened this up and replaced the packing. The old packing wasn't in too bad shape so I'm apprehensive it will just be the same story for my next track day May 7th.

Looking at buying a dB killer as a backup incase I get flagged again. Reading up on these it sounds like they can cause rich running and issues in that department. Any way to easily remedy this or just brunt it to keep me on track for the rest of the day?

It could also be inlet noise as my air filter protrudes through my bonnet (Honda Blackbird). Any suggestions to quieten this down in the future if needed?

Thanks again all.

I got black flagged at Bedford. It was due to being near another noisy car as we flew past the meter. I kept away from the other car and didn't have anymore issues

On my Roadrunner racing SR1 i had to use something like this as the induction noise was pretty loud on the R1 engine.

If it turns out to be the exhaust then a slightly bigger exhaust may be needed.

Personally i found the db killers too restrictive however depending on what ECU you have maybe get a second map added for in case you have to fit one




[Edited on 9/4/24 by number-1]

Don't underestimate induction noise. Having been on many trackdays BECS seem far noisier from the front then behind.

I enclosed my 4A-GE intake after getting black flagged using a PX600 sausage filter through the bonnet. I didn't do anything with the exhaust, never had a problem again.

I used a Pulsar GTiR plenum and Pipercross Vortex enclosed air filter with custom GRP inlet above the radiator, this was the final result


comp 1

[Edited on 9/4/24 by bi22le]