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Old 12-02-2009, 01:07 AM   #16
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If you download the pipe homologation pdf(which incidentally I just did and it won't open but I have the 2008 one anyway)EFRA show a diagram of every legal pipe with all it's dimensions.these include both the external dimensions ie length diameter etc but also the internal ones..ALL 2 stroke exhausts are made up of 2 cones ,one that expands from the manifold inlet and one that diminishes to the stinger ,joined by a straight tube..well almost straight ,some pipes are slightly tapered here as well..the length and severity of taper of these cones along with the length of the central tube are what shapes the powerband of the engine.They affect the outward as well as the return pulse of the exhaust gas which in turn affects the intake of your engine.This is why different pipes have such a huge effect on the performance of your motor.EFRA's list all these sizes plus the length and internal diameter of the stinger etc and any pipe with the same homologation number must have the same measurements..that said of course if you buy a cheap knock off pipe the QC will almost certainly mean that there may be small errors in manufacturing..but I doubt you'd notice them on the track..Oh and EFRA doesn't homologate inlet manifolds..only the silencer part which is why you can (a) buy the same number pipe with differing manifolds from different suppliers and (b) buy a pipe and swop around manifolds to get better top or bottom end performance without affecting the legality of the pipe.There you go my 2 cents worth.
ps
If anyone is bored and good at science I'm sure you can look up the math involved in designing a 2 stroke pipe..take it from me it's very high level math.
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Old 12-02-2009, 01:02 PM   #17
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Originally Posted by Gizmatron View Post
Oh and EFRA doesn't homologate inlet manifolds..\
Not entirely true, they do have rules for onroad manifolds now. They have to be non-conical with a max inlet and outlet diameter.
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Old 12-02-2009, 02:18 PM   #18
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Not anymore. Last year we had that rule with the new 30xx pipes but those pipes seemed to be very critical in tuning the engine so for this and next year we switched back to the 20xx pipes with any type of header. For 2011 new pipes are in devellopment with an extra damper in or after the stinger.

The non-conical headers are now sometimes used to reach the 5 minutes.
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Old 12-02-2009, 02:26 PM   #19
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You only no when you have the same pipe is wen the EFRA name is in front off the number no efra in front off the number its not legal and a knock off !! :

Sirio efra 2013 is exactly the same as the RB efra 2013.
Novarossi efra 9853 is the same as the JP/Mega/Top/Rex 9853
Novarossi efra 9886 is the same as JP/Mega/Top/Rex 9886
OSmax efra 2042 (also now as 2060) is the same as the Ninja efra 2042


Company's like Dynamite, Ofna, HongNor have pipes that have just the numbers like 053 or 086 stampt on it.
These are just look a likes off the real Efra approved pipes from Novarossi.
The shape my look the same but the material used is not, also the performance may not even come close to the Novarossi pipes.
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Old 12-02-2009, 02:29 PM   #20
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Originally Posted by Paulus View Post
You only no when you have the same pipe is wen the EFRA name is in front off the number no efra in front off the number its not legal and a knock off !! :

Sirio efra 2013 is exactly the same as the RB efra 2013.
Novarossi efra 9853 is the same as the JP/Mega/Top/Rex 9853
Novarossi efra 9886 is the same as JP/Mega/Top/Rex 9886
OSmax efra 2042 (also now as 2060) is the same as the Ninja efra 2042


Company's like Dynamite, Ofna, HongNor have pipes that have just the numbers like 053 or 086 stampt on it.
These are just look a likes off the real Efra approved pipes from Novarossi.
The shape my look the same but the material used is not, also the performance may not even come close to the Novarossi pipes.
This is true, but by the same token it could even be better.
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Old 12-03-2009, 02:20 AM   #21
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What a load of you know what come on guys .Nothing is a cheap knock off of any pipe.

The 2011 pipe your talking about is for 82-83 db of noise measured from a distance of 10 metres of each side of the buggy .some pipes available today can do this at 82-83db already.

some companies believe and we all know its true that there are more non sactioned events then sanctioned events so they see no need to pay efra the $500 euros they ask for a simple test and number .

It does not mean they are cheap knock offs because they dont have a efra number .They do these tests and give out efra numbers and make changes to the rules for money nothing else .Efra needs to survive like everyone else .
Femca is just as powerful as it is the Asia pacific region were 90% of pipes and r/c is produced but efra wont except femca approval what does that tell you ?
IT'S ABOUT THE CASH BOYS NOTHING ELSE .

Can anyone tell me were the Nova pipes are made ?
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Old 12-03-2009, 11:07 AM   #22
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I think you'll find cobra that we weren't suggesting that pipes without an efra number were knock offs or poor quality simply because they weren't homologated..we were suggesting that some pipes with the same EFRA number on them but made by different companies, whilst technically the same pipe performance wise, may well be made of lower grade materials and/or of a lower quality control etc..these are usually cheaper so it's a buyers choice.same performance maybe but almost certainly the cheaper pipe will break sooner.I know some good manufacturers offer the same pipe in several finishes..jp to name but one use chrome or their "hard coated "finish..I've never used one so can't comment on which is better..

regarding EFRA rules I quite agree it's about the money..would love to buy a GO 0801 for my MG66 to try but as it's only FEMCA rated I can't race with it in europe..shame..but if you race in unsanctioned races sure use whatever pipe you like.I don't know how you find out which pipe without an EFRA number matches one with..use the forums I guess...

EFRA's best ruse yet has been pending here for 2 years now..they want to issue new noise regs for all pipes to pass which will mean re-testing all current homologated pipes (at I'm sure NO discount price to the manufacturers)and adding some kind of new noise pass stamp to the pipe.If you already own a pipe that passes the proposed regs it won't have the new stamp engraved on it..Naturally they won't allow you engrave said stamp retroactively,and to be fair the manufacturers will want to recoup the costs involved, so racers will find themselves having to buy the exact same pipe a second time just to have either the same EFRA number with a second tiny stamp or more likely they will simply issue every pipe a new number beginning with a 3 or a 4 or something else..our federation has advised us not to buy any new pipes unless we have to until what is actually going to happen (or not) is made clear..what a rip off....naturally various european groups are fighting this.
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Old 12-03-2009, 12:36 PM   #23
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Quote:
Originally Posted by COBRARACING View Post
What a load of you know what come on guys .Nothing is a cheap knock off of any pipe.

The 2011 pipe your talking about is for 82-83 db of noise measured from a distance of 10 metres of each side of the buggy .some pipes available today can do this at 82-83db already.

some companies believe and we all know its true that there are more non sactioned events then sanctioned events so they see no need to pay efra the $500 euros they ask for a simple test and number .

It does not mean they are cheap knock offs because they dont have a efra number .They do these tests and give out efra numbers and make changes to the rules for money nothing else .Efra needs to survive like everyone else .
Femca is just as powerful as it is the Asia pacific region were 90% of pipes and r/c is produced but efra wont except femca approval what does that tell you ?
IT'S ABOUT THE CASH BOYS NOTHING ELSE .

Can anyone tell me were the Nova pipes are made ?
What i ment was that some company's want to ride on the aother brands efra homligation with there (thats why i call it a "knock off") pipes.
Dynamite sells a 053, HN/Ofna sells a 053 and from the outside they look like the Novarossi's Efra 9853/053 pipe, the same goes for the 086 pipes from those company's.
They fool people with that, we hat people here that bougth a dynamite pipe only to get the answer your are not aloud to drive it, the guy said why ?
It's not efra legal, he says but 053 is on it.
See what i mean, why call those pipes 053 or 086 and let them look like they are Efra homligated.
And yes mayby the will even perform better then the orginal pipe, could be

I understand Novarossi makes no pipes ho makes them for them i dont no, but from the last i heard off (few years back) that it was a oather Italien company witch also made the pipes for SVM crono but i have to inform on that.
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