Racecar 95db limit

[JT]

AE101 Levin with 3sge
2.5" stainless exhaust with one straight through resonator at back

Car is just over the limit, averaging 96ish according to tester at the track. Canterbury Car Club have been at court over noise levels so they're having to be strict.
Eventually will put a quieter muffler in but wondering if there's a quick way of getting it down 1db.

Have heard a bolt through the tip might help. Has anyone experimented and found something that works?

[atmosports]

90 Degree turn down/turn up/turn left or right?? 2 bolts through the end of the exhaust at 90 degrees to one another. Tried these in the past with varying degrees of success. Don't forget weather condition/cloud cover can play a part in noise readings, also don't forget than induction noise can also play a big factor. Going to thicker wall section exhaust tubing whilst adding weight can also help.

But in all honesty the best thing is to just change muffler/exhaust design & get down under the limit. We went from regularly running over the 95Db limit to running at around 91-92 all the time just be changing mufflers, we even gained power in doing so & compared to no muffler the gain/loss of power wasn't noticeable on the dyno although the drop in noise was, this in on a speedway midget where you are quite limited by the length of the exhaust & size of muffler etc & Western Springs is as hard if not harder on noise

[DRFTIN]

in my experience (as the guy who does the most noise testing at Ruapuna) the bolt thing won't do shit. Nowhere near enough to gain 2+ db

like atmosports said the conditions of the day can change things a few db so really you need to drop 5db to make sure you're safe. plus it probably sounds terrible with only a resonator right now?

[touge_ae101]

Side exit exhaust pointing towards the inside of the track normally does the trick.

Also add a proper muffler resonator it will help heaps
heaps. Get a decent flowmaster etc and you won't notice any drop in performance

[DRFTIN]

Side exit exhaust pointing towards the inside of the track normally does the trick.

Not when one of our permanent noise testing systems has microphones on both sides of the track and takes an average

[touge_ae101]

That's rough! All the NI circuits test noise at the perimeter of the track boundary.. Manfield owns all the land around the circuit so it's always pretty safe. Some classes such as the f5000's won't race if they have to adhere to a noise limit so naturally they do a lot of their meetings at Hampton and Manfield

[d1 mule]

slightly off topic, but $&#$% me people who move next to the race track then take the race track to court about noise need to be shot.

[Flannelman]

Ive got the 4age in my 101 Levin. Rear muffler is removable to reveal a straight 2.5in pipe, no resonators, that exits on the drivers side. Loud? Try being able to be heard at over a kilometer away, or, being able to be heard coming back down the return road at Meremere.

Road is covered by a single muffler. Its a sad old thing, the bum got blown out of it and its been patched up so safe to say there is little in the way of baffling. However, it passes warrants and doesn't attract the police or complaints of noise. Safe to say its around the 85dB with no power loss.

Because the muffler is as far away from the engine as possible, it becomes more effective at reducing noise. It also exists vertical to the road and is even with the bumper, so noise doesn't bounce back under the car.

[Akane]

Can't do anything in terms of having a silencer at the end of the pipe as a quick dirty fix until you get the whole system sorted?

slightly off topic, but $&#$% me people who move next to the race track then take the race track to court about noise need to be shot.

New Zealanders have a high sense of self entitlement. "I paid mega bucks to move here and I'm entitled to peace and quiet, just like everyone else". Sadface.jpg.

[MAC_HATER]

Rings very true

[touge_ae101]

Rings very true

Deserves a repost.

I'm building another ae101 with a blacktop next week. Going to do a 2.5" exhaust with adrenalin R resonator and standard rear resonator with twin 2" tips. Will report back if it is road legal or not. My guesstimate/experience says it will be the perfect sound/noise level.

/I am probably wrong

[1I1]

You may find you'll need another resonator to rid it of the typical 20v rasp. One where the cat was and one just before the rear crossmember.

[touge_ae101]

Yeah I've always thought that too but then again I've always only used crappy coby resonators in the past. Adrenaline R mufflers are supposed to be quite good and even able to quieten rotaries so thought I'd give them a go. The rear tip will still be quite restrictive so I'm hoping it won't be too loud.

Will report back soon if these adrenaline R resonators work well.

[whynot]

I have one of those under my 20v. Can't say how well it works as I also have a turbo to help keep the noise down. The build quality is nice though.

[matt dunn]

I have one of those under my 20v. Can't say how well it works as I also have a turbo to help keep the noise down. The build quality is nice though.

Turbo's, best mufflers ever.

I run nothing at all from the turbo, just a straight 3" from memory,
and never had a noise issue at the track as it's not that loud.