Objective full exhaust system comparaison

Important decision must be made in life and I am now challenged with a big one: full exhaust system. Here's what I've got so far:

-lost of info on the FMF Q4+ powerbomb header. I must say that it's not all clear. I'd like to clear up a few things:

a)Power of Q4 vs PowerCore muffler
b)Power of powerbomb header vs megabomb header
c)PowerCore + powerbomb vs PowerCore + megabomb

all the subtle differences in low en torque, mid range and high end. (Please keep in mind I'm trying to turn my newly purchase WR250R into a mean MX machine barely legal for the road...just enough to get to the trails and back.

-I only caught a glimpse of other brands out there... not sure why no one is talking about them(?). Maybe I haven't been looking in the right places. So what's the deal on:

a)DUBACH full system
b)Delta 4 full system
c)Yoshi (does a full system even exist?)
d)Leovince (does a full system even exist?)
e)Pro Cicuit T-4 GP low boy full system

What are your thoughts on these. Most importantly what are teh Dyno results showing? Butt dynos? Sound? Where to buy? IO trust that we will find at least one rider per full exhaust system on this forum. Please speak up and tell you tale. I'm feeling impulsive and think I'm going to purchase on Monday or Tuesday off the net somewhere (the cheapest place would work just fine!). Got few websites lined up and good prices too but I want need to check with you guys and see what the full story is...

Cheers

Only general input from me. I'm new to the bike and have stock exhaust with an FMF programmer. My other dirt bag is a YZ250 smoker where there is a difference in low vs high end power depending on the shape and extraction characteristics of the pipes. But I've always scratched my head on the "power bomb" thing and kind of think its a gimmick.

Facts;

Ever see any flow analysis data or anything scientific on any of the maker's web sites? Me neither. And sorry, but I just don't put much faith in most vendors Dyno charts.

Ever see a "power bomb" for sale for a sport bike? Nope.

Ever see a "power bomb" on an SBK or MotoGP bike? No again.

Only place I see them are on the MX pro bikes where the sponsors are paying.

Fact is, these things in identical sizes are being bolted to all kinds of different displacement bikes with different bore to stroke ratios which basically tells me they're snake oil.

I would love to be proven wrong because I'm an addicted farkeler.

This site is a great read on the subject;
http://www.epi-eng.com/piston_engine_technology/exhaust_system_technology.htm

And this one too;
http://www.rbracing-rsr.com/exhausttech.htm

You're on your own dude.

I know of nobody who has owned multiple systems and parts and been able to "test" them all and provide input.

YOU COULD BE THE FIRST!!!


You'll get every possible answer under the sun here, and in the end still have nothing concrete to base your opinion on.

What's the best ice cream?
What's the best beer?
What's the best religion?


Generally speaking most people are happy with the mods they make over stock. It's up to you to decide based on price, looks, and noise.
Nobody wants to admit that the $300-$1000 they spent on farkles was mis-spent on the wrong stuff.

It's almost like questioning which color makes your bike faster. (white of course)


The objective of skirting the laws of road-legal may not be the wisest choice.

Stealth is never a bad thing.

But that's just my opinion.

I lied. I do have an opinion and its all about cutting weight. Full titanium all the way with carbon fiber heat shields. Oh yeah!

Also - Graves makes killer looking full system.

HMF makes a cannister at least.

I know some of the aftermarket cans will fit on the FmF header.

Then there's the custom built under-tail systems people have built and the single into dual exhaust systems people have fabricated....


Also - the debate over fuel programmers. PCV, PCIII, FmF, AI, Auto-tune, and others....

Airbox mods.......

The guy I ride with has the Delta Barrel 4 setup. All I can say about it is that it's LOUD. I rode his bike briefly, but I have different mods than him so I can't make a direct comparison. He has retained his airbox door and uses a PCV with a set map.
I've got a PCV with Autotune and the Graves full exhaust. It's not quite as loud as the Delta, but when you crack that throttle (especially with no airbox door), whoa. It's got some bark. I may actually be able to get some video today on our ride. I'll report back.

pbnut wrote:

I've got a PCV with Autotune and the Graves full exhaust.

It would be interesting to compare your set-up to stock. Send me these parts and I'll let you use my original stuff to try.

I can comment on the difference between the headers given that I just swapped them last weekend. I bought a used bike that had the Powerbomb, and had some return credits and a few coupons to get a Megabomb for a good price, so I made the switch.

Megabomb: slightly softer sound, slightly firmer low-end and mid power, top end not much different as far as I can tell, possibly a little less aggressive. The noise difference is most noticeable at high rpm. When I say firmer low-end, its still no 400+ cc torque, but you can be just a little bit lazier about down shifting to stay in the meat of the power.

Powerbomb: More top-end focused, a little sharper pitched sound, but $90 cheaper.

If you are riding this bike aggressively, you will be spending all your time at high rpms.....therefore I think either pipe will give you the performance you want. For me, a pretty laid back, slower rider, the softer sound of the Megabomb and the fatter power band is nice.

Q4: My guess is it gives enough flow to take advantage of what the 250 can put out, i.e. the powercore won't make you any faster.

Had my bike come with the stock setup, I would have just gotten a fuel programmer to richen things up and left it at that. I prefer quiet over all else.


I run the Q4 with its standard insert with the Megabomb and like it a lot. I also have a quieter insert that can be used if I'm going somewhere a little more sensitive.

I think its important to remember a few things in all of this:

-its a low-maintenance 250 dual sport and the engine can only put out so much - no matter what, if you crave arm-socket pulling torque, you will be dissappointed
-suspension mods and good gearing/tire choice will make a far bigger difference in how fast you can ride.
-whatever setup you go with, be conscious of noise. obnoxiously loud bikes get trails closed.

I stand corrected on what I said about no "power bomb" devices by Akropovic. Here's a view of Andrew Shorts KTM 350 from this link: http://www.grindtv.com/moto/blog/24864/factory%20bike%20friday%20andrew%20shorts%20ktm%20350%20sx-f/



Or maybe its a soup can warmer...

Monkeynuts wrote:

More pic's at better angles too please.

That thing looks way sweet. How's the sound?

Also - do you have stock Yamaha header and just the Arrow cannister?

MORE PICS MORE PICS


please

I've had just a fmf q4, powercore4 plus megabomb, and powercore4 plus powerbomb on my bike. My favorite combo is the pc4+pb, lightest weight with the cleanest meanest sound without being deafening. Butt dyno impression says its definitely the strongest power producer up top, a little softer right off the bottom than stock or the q4 alone. I never liked the q4 sound, very blattty.

For an off-road bike id stay stock for sound control. Otherwise pc4+pb, sounds so sweet.

skierd wrote:

I've had just a fmf q4, powercore4 plus megabomb, and powercore4 plus powerbomb on my bike. My favorite combo is the pc4+pb, lightest weight with the cleanest meanest sound without being deafening. Butt dyno impression says its definitely the strongest power producer up top, a little softer right off the bottom than stock or the q4 alone. I never liked the q4 sound, very blattty.

For an off-road bike id stay stock for sound control. Otherwise pc4+pb, sounds so sweet.

Great input thanks. I'd like to dig deeper on the PC4+PB VS PC4+MB. Interested in power low end/mid/high. Sound wise the Q4 ain't for me. Thanks for clarifying about the Q4 sound.

looking forward to a follow up.

cheers

New to the site, I'm looking at FMF exhaust and Leo Vince full exhausts. I was wondering if anyone has used the Leo Vince X3 full race Ti exhaust with removing the EXUP valve and installing the eliminator. It will be installed on an 08 X. Thanks for any information. I forgot, noise is not a concern.

As requested more pics.

Is that a full Arrow exhaust? Did you completely remove the EXUP valve and replace with and eliminator? Bike look excellent. javascript:emoticonp('')

195CR wrote:

Is that a full Arrow exhaust? Did you completely remove the EXUP valve and replace with and eliminator? Bike look excellent. javascript:emoticonp('')

The EXUP valve is a welded in feature on the stock Yamaha exhaust. Anybody who replaces stock exhaust with ANY aftermarket exhaust will have removed the EXUP.

Yes it is a full Arrows system, the can is titanium with a SS pipe. This system has a plug already fitted for a O2 sensor !

Thanks for the information. I don't think my X has an O2 sensor unless I've overlooked it. I've ordered the AIS removal kit in preparation full a full exhaust. I like Arrow and Leo Vince Ti race exhaust

195CR wrote:

Thanks for the information. I don't think my X has an O2 sensor unless I've overlooked it. I've ordered the AIS removal kit in preparation full a full exhaust. I like Arrow and Leo Vince Ti race exhaust

USofA models do not have O2 sensors.

European models do.

Aussie models do too!
Go the O2!

Clever guys down there, ridding upside down !

Thanks for setting me straight, I think i will install the Leo Vince X3 Ti exhaust. As far as the flapper valve is it better to remove completely or just tape down? Thanks for your input.

i was referring to the AIS removal. Sorry about that.

Motokid wrote:

It's almost like questioning which color makes your bike faster. (white of course)

Really, the ONLY thing that makes your bike faster is flames, lots of flames. Everyone knows that.

I have a full Delta 4. I love the sound. I like how small the silencer is, tucks in nice and tight. Super easy to work on (although it would be nice to have screws versus rivets for repacking). For me, it was looks and sound not performance that made me get the pipe. However, I looked alot at price and happened to get a steal on the Delta. Now, had the same deal been found on a Yosh, FMF, or any of the others, chances are I would have one of those systems instead. I am happy it was the Delta as that is MY favorite. Power, its got snap it didn't before and that's what I go by.