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Discussion Starter #1
i was thinking i should get a 2 brothers racing slip on for the trx because it did good in the dirtwheels pipe shootout for the yfz. it gave 6.3 horses and was 91DB which was the quietest out of all the pipes.

should i get this pipe
if not tell me another quiet pipe i should get.
 

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Lord of Combustion
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This is a totally biased opinion, but since no one else is going to bring it up for me :
There are only 2 types of high performance pipes available:
1) www.viciouscycleperformance.com main man, a medical physicist and lifelong speed junkie has developed The Pulse Charger exhaust with one patent awarded and one pending
2) All the other gussied up glasspacks with BIG pricetags
...............mixxer thanks for the help guys!
 

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wow...I was reading about those vicious exhausts......Im impressed....I think I might be sold. :D
 

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Discussion Starter #4
those r the ugliest things ever but thats ur opinion but i want to know which pipe is good and quiet for me
 

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My girlfriend bought an E2 White Brothers that looks good. Dirt Wheels said that on the Yamaha 450 it put out around 97.7 on there sound level. I personley don't like the E2 becouse they don't offer a head pipe, but I didn't buy it she did.
 

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Discussion Starter #6
thanks for that
 

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Lord of Combustion
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Unless you change your cam NO pipe will give you ANY more power, or be quieter than the stock exhaust. That's a fact. You will gain 3HP by cutting your airbox lid and rejetting with your well designed, and quiet , stock exhaust in place.

check this thread http://www.quadzoneforums.com/forums/showt...72&page=1&pp=10

...........mixxer
 

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Discussion Starter #8
then why do you have to rejet when you get a new exhaust hmmmmmmmmmmmmm.......
maybe cus there is more air flow coming out of the motor!!!
 

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Originally posted by trx450Rrider@Jul 7 2004, 08:02 PM
then why do you have to rejet when you get a new exhaust hmmmmmmmmmmmmm.......
maybe cus there is more air flow coming out of the motor!!!
the same reason you have to rejet when you open the stock exhaust up...and you dont always have to rejet...sometimes you can add a pipe and not have to rejet...it just give you a better option of re-jetting....I agree...most of these exhausts are hopped up glass packs...and all glass packs work the exact same...the only difference is the length and shape of different exhaust types...all this does is move your power curve around...but dont really give you more power....the longer your exhaust, the curve switches towards the higher RPM range....the shorter your exhaust, the more the curve switches to low rpm power.....or that might be the other way around...but you get the point.
 

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Radiation therapy (cancer treatment) uses a physics group to do all the things that physicians aren't trained in such as the calibration of the linear accelerators, and the actual generation of the treatment parameters, including fabrication of the attending beam modifiers and attenuators.
Thanks for adding trx450r lude! Shorter= higher rev
Many motors instantly benefit from a different exhaust without other engine mods, the 450r is not one of them. The gains you see with everyones postings (void of other engine mods) are from the unrestricting of the intake tract. The OEM snorkle has a smaller cross section than the does the carburetors bore, hence the large change in main jet requirement upon lid removal. The largest of any atv thus far. The change required upon adding an exhaust (again void of other engine mods) is nil.
Big changes in peak power come from an exhaust working in unison with the overlap period of camshaft timing in aprocess known as scavenging. Think of it like this: you wish to let some fresh air into your home (your home is the combustion chamber, the doors are the valves) first you open the front door and decide you are not getting enough air exchange. Next you open the front door and back door simultaneously (this is the overlap portion of cam timing, scavenging made possible by flow through the combustion chamber , intake to exhaust, removing remnant exhaust and subsequent dilution of the fresh charge). You decide that both doors open creates much better cross flow since you have broken the vacuum in a closed chamber.
The next surprise comes when you have both doors open and a strong breeze (vacuum created by an efficient exhaust system) blows past (not through, (bernoullis' principle , this is how your carburetor or a paint gun works) )the front door (exhaust valve) and you notice a sharp insurgence of air through the back door (intake valve). This is scavenging aided by negative pressure (vacuum) generated by the exhaust system. Not only do you effectively scavenge the remnant burnt exhaust particles , you give a good "yank" to initiate momentum to the fresh charge waiting in the intake port even before the piston begins it's movement downward.
Imagine only opening both doors only for the short time events allowed during actual high rpm engine operation. the effectiveness of the flow through become more and more dependant on the suction present at the front door and on the length of time both doors are open simultaneously. If you only open one door at a time there is no flow through and no scavenging takes place.
The honda camshaft has practically no overlap in it's profile and this makes it profoundly insensitive to exhaust system changes. Honda did this deliberately to limit their liability , still feeling the sting of the 3-wheeler lawsuits.
No overlap= No scavenging=Insensitivity to exhaust systems. The stock Honda exhaust is VERY well designed. Nobody can make anywhere near the power of the oem exhaust at those db levels! Why would anyone think that the company with enough engineering to create the entire machine, and capture so many motorsport championships, would remain in the dark on proper exhaust system design?
Pulse Charger exhausts work with 2 megaphones to create negative pressure and a high surface area annular flow section to control sound.
By the time the Pulse Chargers are in production (hopefully late August) My patent app. will be complete for our headpipes, at that time I can discuss them. They are as different functionally from current headpipes as our Patented Pulse Chargers are from conventional systems...........mixxer

Unlike some others, I will answer with "I don't know" if I don't know. I have always thought there should be less consequences for leaving a blank than filling with BS. You can't fill in enough misinformation to build a correct answer!
 

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Discussion Starter #11
ok this sucks cus all i wanted to know is what pipe should i get that is quiet and i really want a 2 bros pipe cus i heard it was quiet and wanted to know if this was true. i dont want a jet engine for an exhaust. i just want to know what is a good QUIET PIPE that doesnt COST MUCH???
 

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Discussion Starter #12
alright thanks man now we r on my topic :D
 

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Discussion Starter #13
ive checked it out and it sounds really good. it was in a pipe shootout for the yfz in dirtwheels and was one of the best. it gave at most 6.3 horses throughout the powerband and was the quietest of the bunch at only 91db (the E2 was 97db but they also said the E2 was very quiet when riding). so i am not sure but i am leaning twards those two and i also heard the lrd was i think 94db which is pretty quiet.
 

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Originally posted by trx450Rrider@Jul 8 2004, 11:08 AM
alright thanks man now we r on my topic :D
another very good exhaust to look at that is quiet is the CHM full system....you might check on it to...
 

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I just wanted to reply to some of the exhaust system/engine discussions that have been posted lately. On the TRX 450 in stock form the engine is designed as a total package. Honda designed the air box, cam, and exhaust to meet noise,emisions, durabilty, and satisify their legal department. They did all quite well but there is room for improvement. As we all know an engine is basically an air pump(thermodynamics aside) and more air means more power up to a point. When you only add a properly designed exhaust system without increasing the available intake supply, power will usually go up mainly do to less pumping loss (less backpressure) but the full gains of the exhaust will not be realized until the engine is allowed to take in more air. This is true on every quad I have tested not just the TRX 450. Cam timing in the TRX 450 is typical Honda, very mild. When you add the HRC cam to the mix, power goes up due to fact that the cylinder is filling and emptying more efficently. but B.M.E.P.( torque) may not increase much due to the lower cylinder pressures caused by the longer than stock intake closing. This is why it is a great benifit to raise the static compression when going to a cam with delayed intake closing. One thing to keep in mind is that static compression and dynamic compression are two different things. Unless the engine is 100% volummetric efficent the static ratio will actually be less, but if it exceeds 100 % it wiil be higher than static. This is why Nascar engines with restrictor plates used 16+-1 compression ratios Their engines weren't getting enough air and even with the super high compression ratio were running at around a true 14-1 ratio. if you remove the restrictor plate the engine would have entirely too much compression.

Just keep in mind that the engine must remain a balanced "package" for best performance. There are many other factors that will effect performance. port velocity,combustion chamber design, and many other things that could fill a book. Just try to shoot for a flat torque curve over a broad R.P.M. range. As an old timer once said" torque wins races,horsepower sell engines" if you make good torque you will also make good horsepower. Stick to basics they have been proven to work time and time again, you won't go wrong. :)
 

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Originally posted by pipes@Jul 9 2004, 01:02 PM
This is why it is a great benifit to raise the static compression when going to a cam with delayed intake closing.  One thing to keep in mind is that static compression and dynamic compression are two different things. Unless the engine is 100% volummetric efficent the static ratio will  actually be less, but if it exceeds 100 % it wiil be higher than static. This is why Nascar engines with restrictor plates used 16+-1 compression ratios Their engines weren't getting enough air and even with the super high compression ratio were running at around a true 14-1 ratio. if you remove the restrictor plate the engine would have entirely too much compression.
my ADD kicked into overdrive right about here. :huh: i got the rest of it. maybe in simpler terms for those of us(or just me) w/o a PhD in 4 stroke theory. or... how about a list of does and don'ts as far as engine mods for the R based on this info. that would be good. :D

in another thread though, because we don't want to upset "trx450Rrider" again. LMAO... that was funny. :lol:
 

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Sorry about being too tech. another way of veiwing compression ratios is that a 12.5-1 piston is based on the cylinder volume of lets say 449cc, but if the engine doesn't breath enough to completely fill the cylinder you will actually have a lower ratio, and on the other hand, if the engine is super efficent and benifits from wave and ram tuning you can "overfill" the cylinder, thus this will increase the dynamic ratio above the static (it's like adding displacement) only to a small degree though
 

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Discussion Starter #18
i read about that chm pipe and i think it is the one for me . for a full or slip on how much does it cost guys.
 

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Well, we have been doing alot of testing lately and of course many more parts are becoming available. I know that there are bore/stroke kits soon to be able to exceed 500ccs from these engines, but as you know that starts getting pricey. What i would recommend in 3 stages would be the following:

stage 1

Install a good aftermarket exhaust system (CHM, Sparks, etc..)
Use a Dyno jet stage 2 jet kit designed to be used with the lid off
Get a high flowing quality air filter assembly that doesn't use a flame arrestor.
Install a high rev ignition box. and a 13 tooth counter sprocket.

Stage 2

Everything in stage 1 but add:

J-E 13-1 std. bore piston, (oversize when available) stock rings work best as far as ring packs go. Mill the cylinder to achieve .038" min squish on the flat part of the piston.
The HRC cam isn't bad but could be better on low end. The WEB 613/729 grind will work well as will the mega cycle x2 both should be degreed in. (milling cylinders/heads changes cam timing) you could run 92 octane but not when outside temps are over 90 degs run a 50/50 mix of prem and race gas.

Clean up the ports but do not make them bigger, the exhaust ports need the valve guide bosses thined and widened. un shroud the intake valve out to the bore size.


Stage 3


In this stage if you are not racing in a class that requires certain displacement then go with the most displacement you can afford. The crankworks in AZ is building strokers as is Falicon in FL. kits will be available soon, that will come with a crank, replated/resleeved cylinder and piston, some case machining will be nessesary to clear the stroker. The head would benifit from installing bigger valves and oversize seats, and the chamber opened up as no to shroud them. (let a pro do your head) RHC in michigan does wonders with these heads (989) 463-1267. as do some other shops.


For a cam use Web 208/729+5 with the Matching springs. set the intake lobe center at 107 degrees.

Carburation: use the 40mm f/s from the CRF 450 bored out to 41.5 mm you could convert to alky but that requires entirely different jetting and more timing(offset key) Sparks does make some alky carb kits. If you run Gas, VP ultimate 4 is great but double the cost of most race fuels. you will also need a good clutch and spring kit the stocker will not last. As you can see this last engine is "max effort" and I am sure there are other combo's that will work good this is one example so you get the idea of whats required. The first two are proven combos that have worked well for us. the last one is a current project we are now working on. B)
 

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Originally posted by pipes@Jul 10 2004, 03:59 PM
The crankworks in AZ is building strokers as is Falicon in FL.
pipes, does falicon have a web site?
 
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