Brooking850 2:1 fitting

pommie john · Mar 30, 2018

oldmikew said:
Just a thought , had anyone expereince of using silencers other than peashooters on 2 into 2 systems?

I use Supertrapps. They were great on the racetrack but when I gave up racing it and put it on the road I went from using open end caps to closed. This caused all sorts of problems. The plugs went black in no time and adjusting jetting leaner made it run worse but still with black plugs. Going back to open end caps fixed everything.... except it's very noisy.

Hobot · Mar 30, 2018

I've been though supertrap installation to say its useless stupid heavy load of steel advertising crap. Adding enough plates to get some decent flow weights too much for factory muffler support cushions to take very long and closed end plate definitely resists back pressure power relief. I suggest ya try removing all vent plates and just use the end cap plate with ~1 3/4 - 2" hole cut out or better 12 ga slug blasted flaired hole which muffles nicely deep soft throbs at low throttle yet roars authoritatively w/o pain - jetting flames out a few inches w/o damaging ears on WOT. Seriously Ms Peel was about to be sold off as sluggish obsolete til doing above then enjoyed embarrassing any size modern to the ton and didn't get left behind way over the ton. Of course if exhaust system sizing not up to the power plant may not notice much no matter what's on the end. May need to re diddle carbs leaner after wards for best spunk of better exhaust exiting. Its was the most shocking thing I did to Ms Peel and the cheapest simplest.
http://i184.photobucket.com/albums/x93/hoboter/Norton Commando items/2586806140037141179iQRXeT_fs_zps7d5991b3.jpg

http://i184.photobucket.com/albums/...ando items/160770433DVzapV_ph_zpsaa88f8c1.jpg

Fast Eddie · Mar 31, 2018

Ladies,

How does the plate stacking work with a super trap, is it more plates = less noise or vice versa?

Does plate quantity effect power?

It’s common to fit a super trap style fitting on the end of a Maney system these days (Maney system was designed in an age of kinder race noise rules). Are they really any good in this application, or would a length of large diameter per tube silencing be better?

oldmikew · Mar 31, 2018

pommie john said:
I use Supertrapps. They were great on the racetrack but when I gave up racing it and put it on the road I went from using open end caps to closed. This caused all sorts of problems. The plugs went black in no time and adjusting jetting leaner made it run worse but still with black plugs. Going back to open end caps fixed everything.... except it's very noisy.

Thanks for posting , am not familiar but have looked at their website. Seems good. Sounds as though one might need a dyno to set up for road use.

oldmikew · Mar 31, 2018

Fast Eddie said:
Ladies,

How does the plate stacking work with a super trap, is it more plates = less noise or vice versa?

Does plate quantity effect power?

It’s common to fit a super trap style fitting on the end of a Maney system these days (Maney system was designed in an age of kinder race noise rules). Are they really any good in this application, or would a length of large diameter per tube silencing be better?

They have a very good website... The problem for me is finding somewhere to do plug chops .. the A20 going out of London used to be excellent .. 90mph then pull the clutch and switch off. coast into the Macdonalds have a coffee and a smoke by which time you could get the plugs out without needing asbestos gloves.

pommie john · Apr 1, 2018

Fast Eddie said:
Ladies,

How does the plate stacking work with a super trap, is it more plates = less noise or vice versa?

Does plate quantity effect power?

It’s common to fit a super trap style fitting on the end of a Maney system these days (Maney system was designed in an age of kinder race noise rules). Are they really any good in this application, or would a length of large diameter per tube silencing be better?

More plates give a greater area for gas to exit so in theory , yes more power. In general terms. more plates give more power and need leaner carburation. Closed end caps restrict them even more which was my problem. I ended up drilling a 13mm hole in the closed end cap and adding some washers between the plates to give more exit area for the exhaust gas. It's a bi ton the noisy side, but now carburates cleanly.

I have seen Supertrapp plates on Maney ( and on Triumph Triple ) pipes, but I have no experience of how well they work.

Fast Eddie · Apr 1, 2018

Thanks John. And more plates = more noise I guess?

pommie john · Apr 1, 2018

Fast Eddie said:
Thanks John. And more plates = more noise I guess?

Yep, spot on. I originally started using Supertrapps on my BMW race bike, partly because Jim Cray had good success with them on the dyno, and partly because noise regulations were getting tighter year on year. Supertrapps give you the opportunity to change the noise level without buying new silencers.

WZ507 · Apr 1, 2018

I’ve heard very good things recently about the so-called "auger" or "spiral" style exhaust inserts as a means to tame noisy exhaust. Heard of a 750 Kawa GNC flat tracker that required a boom box to meet the standard at that time (IIRC 105 dB measured 24” from discharge, 45 degrees off discharge angle, at ½ engine rpm). After installation of the boom box the owner tried an alternative means of noise reduction, i.e., a tubular spiral insert placed in his 3” ID muffler. With only the spiral (boom box removed) in the previously noisy exhaust system he got under the noise threshold and found no loss in power via subsequent dyno tests. So in this case it worked extraordinarily well.

The tubular inserts can be made in a variety of formats, e.g., the fractional helix shown below, full spirals made from perforate stock, full spirals made from solid stock, or full spirals with no tubular core.

https://tinyurl.com/y9zlcprj

Hobot · Apr 1, 2018

WaahoOO WZk thats right along the lines of Viktor Schauberger water vortex flows.
https://www.google.com/search?rlz=1...RnJraAhVwmK0KHRi9ARAQBQgmKAA&biw=1242&bih=614

If unclear what supertrapp is, its gizmo screw fastened into the end that holds a series of thin steel big dia. washers stamped out configured to leave slots between them when stacked up for exhaust pulses to turn 90's to exit after piling up on end cap. More washers/weight = more slots = equals more power making noise exit area and visa versa. In my case even a few plate was pretty loud and I kept feeling more power released with more plates added till ridiculous mass on megaphone end plus long fasteners I gave up just put on opened up end cap to get better lower softer sounds w/o much mass. Try it and get back to us please. Play-creep up on end opening and stop if suddenly surprised. Supertrap end cap could be configured fairly straight forward to hold the spiral section silencer so maybe a double softer lighter win win. I tell ya what this also provides a strong sonic compression wave reflection that can wake up an over lapped cam sooner than later.

acotrel · Apr 1, 2018

Usually if you change the cam timing to get the best out of the exhaust, the noise gets louder. When you replace separate pipes with a 2 into 1 pipe the back-pressure is greater, so advancing the exhaust cam can help. The bit the inlet cam also moves doesn't really matter. If you don't do this you often lose top-end. With my bike, it will go straight through the roof, if I let it.

Fast Eddie · Apr 2, 2018

Just to prove the old saying “there’s nothing new under the sun”... The standard OEM silencer fitted to Vincent’s was a ‘spiral baffle’ affair just like this.

But... they weren’t very quiet, they had a proper ‘crack’ to ‘em !

The fashionable phrase for such things these days is ‘DB killers’ (much more macho than ‘baffle’)!

I’m on the lookout for some good DB killers that I can adapt to fit into the short open pipes on my 961, I’m also looking for similar ways to silence the Brooking supplied Maney copy exhaust system. Both are too loud for modern track day noise limits in the U.K.

Deets55 · Apr 2, 2018

Fast Eddie said:
Just to prove the old saying “there’s nothing new under the sun”... The standard OEM silencer fitted to Vincent’s was a ‘spiral baffle’ affair just like this.

But... they weren’t very quiet, they had a proper ‘crack’ to ‘em !

The fashionable phrase for such things these days is ‘DB killers’ (much more macho than ‘baffle’)!

I’m on the lookout for some good DB killers that I can adapt to fit into the short open pipes on my 961, I’m also looking for similar ways to silence the Brooking supplied Maney copy exhaust system. Both are too loud for modern track day noise limits in the U.K.

http://www.coneeng.com/motorcycle_components.html

These guys are suppose to be pretty good.
Pete