Hi,
So the state of Arizona has decieded to pass new strict laws for atv/ohv's that includes a 96db requirement. (GRRRRRRR) So right now I have an FMF Ti with an open core. I also have a big gun and a tip insert to make it quiet but kills power a lot. How ddo I go about doing this with out killing my hp?
Thanks
God bless...
Mark
Best way to get down to 96db???
Is this going to coincide with the new sticker law on Jan 1st? Or is this something new? Does it apply to all riding areas? I hadn't heard anything about it yet.
The only thing I can think of is to insert a quiet core (if possible) canister. Although it will possibly take away a little power. Good news is everyone else should be running stricter exhausts also.
The only thing I can think of is to insert a quiet core (if possible) canister. Although it will possibly take away a little power. Good news is everyone else should be running stricter exhausts also.
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cannondale27
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- Joined: Wed Mar 10, 2021 10:41 pm
The Toaster exhaust is a very good way of producing power but being under DB limit.Have you seen my Silent But Deadly post?The only thing you have to do to make the toaster last is put a reinforcing pad or washer around the stub which mounts to frame and a few more welds on dividers inside.Not only will you make 93DB but it is stock,Spark arrested and doesnt call attention like a aftermarket silencer would even if it were quiet.Most of all they are cheap and plentiful and never need packing.
Other options are the dual toaster exhaust Wistech made.His toasters were punctured but I think are very close to passing DB and must have even more performance than single would.
Next most expensive is the Weapon MX system.UPSMAN runs it.It looks real nice but headpipe I believe hurts power.Untested dyno wise but as far as durability it is top notch.UPSMAN went through 3 or 4 HMF quiet exhausts in one season and didnt have a single failure on his Weapon MX.
We are in same boat as you here in WI.I believe every ride we went on here we got stopped and checked for sound.They are testing correctly so if your over DB there is no fighting it.The more stock looking your exhaust is the less they will be inclined to actually test it.Wistech dual Ti system really freaked them out even though it came within 1 DB of passing and was probably quietest of all of us.Be prepared to lose some low end power or snap.But dont worry we will find plenty to make up for it.Glad your doing the right thing.I still dont believe being quiet will satisfy the FUN Haters but it helps if they dont know your there.
http://www.cannondaleriders.com/forums/ind...showtopic=22266
Other options are the dual toaster exhaust Wistech made.His toasters were punctured but I think are very close to passing DB and must have even more performance than single would.
Next most expensive is the Weapon MX system.UPSMAN runs it.It looks real nice but headpipe I believe hurts power.Untested dyno wise but as far as durability it is top notch.UPSMAN went through 3 or 4 HMF quiet exhausts in one season and didnt have a single failure on his Weapon MX.
We are in same boat as you here in WI.I believe every ride we went on here we got stopped and checked for sound.They are testing correctly so if your over DB there is no fighting it.The more stock looking your exhaust is the less they will be inclined to actually test it.Wistech dual Ti system really freaked them out even though it came within 1 DB of passing and was probably quietest of all of us.Be prepared to lose some low end power or snap.But dont worry we will find plenty to make up for it.Glad your doing the right thing.I still dont believe being quiet will satisfy the FUN Haters but it helps if they dont know your there.
http://www.cannondaleriders.com/forums/ind...showtopic=22266
The early fx400 muffler made by fmf was 1 hp less than the open core full TI system on darkknights 448 stroker. It lost a lot on the bottom but at 52hp corked up it had no power issues. I think backing cam timing down will help a lot to gain low end losses. Running cam timing above 113 degrees gave huge power on the open duals but lost nearly 8 when switched over to quiet cores. Id run cam timing 1 degree less than stock for a stock exhaust. The trick is just to build a very powerful engine and stifle it to be legal so at least you still will have great power . The duals with the big cores are the way to go to keep losses to a minimum.
I tested an FMF ti with a quiet core and it was still just over 97dbs. If I put my leg next to the engine or used the coating on the clutch cover it did drop it down 2 db. The one thing I was checked for is having a stock exhaust and spark arrestor. The problem with every aftermarket system is they end up being a glass pack with a restrictor in them . Both stock dale exhausts were probably the only ones that had at least some effort go into making them quiet and retain as much power as possible. . The dyno doesnt lie .
I tested an FMF ti with a quiet core and it was still just over 97dbs. If I put my leg next to the engine or used the coating on the clutch cover it did drop it down 2 db. The one thing I was checked for is having a stock exhaust and spark arrestor. The problem with every aftermarket system is they end up being a glass pack with a restrictor in them . Both stock dale exhausts were probably the only ones that had at least some effort go into making them quiet and retain as much power as possible. . The dyno doesnt lie .
QUOTE (Kuma @ Dec 11 2008, 02:09 PM) <{POST_SNAPBACK}>
How do they measure the dbs, what I mean is do they check at full throttle in neutral from 5 ft just behind the pipe or do they just setup on a straight section of the track?
Around here they have a very exact method to be standardized. You would have to look up every states requiremnets. The meter has to be zero set to ambient noise,an exact angle and distance from the outlet,1/2 engine rpm ect. Everytime I got checked it took them forever to set it up. I have not had my latest cores checked in my duals but I would bet they are quieter than any stock exhaust .
QUOTE (Wistech @ Dec 11 2008, 01:18 PM) <{POST_SNAPBACK}>
Around here they have a very exact method to be standardized. You would have to look up every states requiremnets. The meter has to be zero set to ambient noise,an exact angle and distance from the outlet,1/2 engine rpm ect. Everytime I got checked it took them forever to set it up. I have not had my latest cores checked in my duals but I would bet they are quieter than any stock exhaust .
How do they get 1/2 engine rpm? that seems like it would not be very exact and +/- 100 RPM could be the difference of pass or fail.
So far at Glamis there has been no enforcement of noise or spark arrestors.
QUOTE (Kuma @ Dec 11 2008, 03:18 PM) <{POST_SNAPBACK}>
How do they get 1/2 engine rpm? that seems like it would not be very exact and +/- 100 RPM could be the difference of pass or fail.
So far at Glamis there has been no enforcement of noise or spark arrestors.
So far at Glamis there has been no enforcement of noise or spark arrestors.
They had a book with all the atvs listed in it.(except cannondales) so they used a yfz instead. They have very accurate vibration sensing tachs . Pretty soon Im sure the dnr will be at the racetracks handing out fines for racers as well around here. They have been holding back enforcment until all the officers got the test equiptment but all I can say is beware .Its coming . You trail ride with a loud exhaust in WI and better have a large amount of cash to pay the fines. Several local guys have already been fined . A couple hundred bucks a ticket.
QUOTE (Wistech @ Dec 11 2008, 02:42 PM) <{POST_SNAPBACK}>
They had a book with all the atvs listed in it.(except cannondales) so they used a yfz instead. They have very accurate vibration sensing tachs . Pretty soon Im sure the dnr will be at the racetracks handing out fines for racers as well around here. They have been holding back enforcment until all the officers got the test equiptment but all I can say is beware .Its coming . You trail ride with a loud exhaust in WI and better have a large amount of cash to pay the fines. Several local guys have already been fined . A couple hundred bucks a ticket.
Sounds like someone needs to invent some sort of iris like in a camera, you know the old fashioned ones that use film. make it so you can flip a lever and choke off the exaust.