My Radical came with a pair of large resonators sitting behind the transmission. It’s my understanding these are the quiet resonators.
They're not quiet. I was measured at 101 dB at the track this past weekend.
Being that the track has a limit of 96 dB I have to figure out a way to quiet my car down.
Here’s my first attempt. I’ve installed a set of small bodied resonators into the system.
Next is adding 90 degree elbows to point the sound away from the booths.
I checked the packing in the big cans and it was perfect.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
A "Laguna" muffler is made by Radical if I am not mistaken. Laguna has something really low like 92db all but a handful of days per year. Mufflers are quieter than resonators. Resonators tend to be tubes with packing inside. Mufflers tend to have packing plus passageways where the gas bounces around before it exits.
A "Laguna" muffler is made by Radical if I am not mistaken. Laguna has something really low like 92db all but a handful of days per year. Mufflers are quieter than resonators. Resonators tend to be tubes with packing inside. Mufflers tend to have packing plus passageways where the gas bounces around before it exits.
Agreed on all accounts. Both of these are resonators. I'm already thinking about making a different system that takes both headers and merges into one muffler across the back with dual outlets.Just takes a few mandrel bends, tubing and welding - and I need to make a full exhaust system for another vehicle so it would be good practice. I'm scared as to what the "Laguna" system would cost from Radical. Heck, I wish FMF made a Q-pipe for the Busa, I'd stick two of them on and be done.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
Looking at the other SR8's in the Registry most have an exhaust like your car. Radical does make silencer that mixes the exhaust for both sides, but it is ~$1k.
Looking at the other SR8's in the Registry most have an exhaust like your car. Radical does make silencer that mixes the exhaust for both sides, but it is ~$1k.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
A query on this muffler has been place with Spring Mountain. I'm supposed to hear back this coming week on price and availability.
I'm signed up for another HPDE day at AMP this coming Saturday (Dec 15). I'll stay off the fun pedal around the sound checks as much as possible until the final session and then I'll go ahead and seed how badly I blow the level. I'll be talking with the sound tech through the day too, just to see where levels fall.
It'll be interesting as I have a base line of 101 dB from the last time I was there and with the addition of the smaller resonators (and 90 degree elbows pointing away from the check areas) I'm curious to see how much they cut from the overall loudness.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
I was talking with Anthony at Radical Northwest the other day and he told me that he believes he has one of these mufflers in stock. Also, as I mentioned before, the guys from Radical North America and One Motorsports did some sound testing and found that putting fuel cell foam into the inlet reduced the sound by 2 db, so it is an easy way to get a little quieter. I'm sure the 90 degree elbows will help a lot also. Be sure to think about what geography is in the area that will impact the sound. For example, at Laguna Seca the elbows are pointed an an upward angle because the track is slightly banked and there is a sand berm on the left side of the track that reflects the sound. By pointing them up a bit the sound gets less reflection off of the sand berm.
Thanks - just sent Anthony a note asking for details.
I've been thinking about what direction to point the elbows. The place is pool table flat so I'm thinking upwards 45 degrees and away from the sound booths, so to the right. I have them and slip fits on order from Summit Racing. I expect I'll see them Wednesday.
Fuel foam - hmmm..... had some laying around - guess I need to see what I can shake up.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
Got the elbows installed today. Both are 18" long, hence the offset. Got to keep the exhaust lengths the same, after all.
I don't think the point upwards towards the wing will be an issue. There's enough airflow going over the bodywork that any of the heat from the exhaust gasses should just head on back behind the car.
I cheated for now and just pop riveted them in place. I'd be much more wise to cut four slots in each of the slip on pieces and then use a quality clamp around them. First I want to see if this work was worth the effort. I'll find out Saturday. - plan on getting very friendly with the sound tech guy, especially after he came and talked to me about the exhaust last time I was at AMP.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
A (mostly) successful day of driving a Radical was had today!
The exhaust system didn't get me flagged. I was careful to always be up in 6th and a bit off the throttle as I'd go by the sound booths until the last session and then I was going past in 5th, pedal to the floor, so it would appear that I've met my goal of under 96dB.
I also discovered just how quiet a Radical can become when you run out of fuel too. Oops.
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
I know you were trying to get it as quiet as possible... but not using fuel is going a bit too far ?
But it did allow me to get past the sound check point without even a side glance from the officials! ?
"Life is not a journey to the grave with the intention of arriving safely in a pretty and well preserved body, but rather to skid in broadside, thoroughly used up, totally worn out, and loudly proclaiming 'WOW-What a Ride!'"
