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 Thinking of full exhaust/programmer? My .02 worth

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PostSubject: Thinking of full exhaust/programmer? My .02 worth   Tue May 01, 2018 10:16 am

I've been considering adding a FMF MegaBomb header and programmer to go with my FMF PowerCore 4 slip on. I've quickly decided otherwise after a recent event... A friend of mine was looking at another of our riding buddies' WRR to purchase and while test riding we made a strange discovery. This may be any of several factors, but I'll detail the bikes first.

Mine: 2017 WRR, 4k miles, stock gearing, FMF PowerCore 4, Flatland skid, Zeta handguards, Pro Taper 7/8 bars, EXUP bypassed, passenger pegs, helmet hanger, and fork reflectors removed, Kenda K270 rear/Kenda 760 front, 2 LED 3" cubes. Weighs in with full fuel on certified scale at 288.

His: 2012 WRR, 7k miles, 13/49 gearing, FMF MegaBomb, FMF Q4, FMF Programmer(setting unknown), Renthal 7/8 bars, Handguards?, EXUP bypassed, AIS?, Passenger pegs, helmet hanger, and fork reflectors removed, Kenda front and rear?(not sure of type but same size as mine), 3 gallon tank. Unsure of weight.

After comparing the two bikes and their differences, we decided a drag race was in order. (closed course/professional riders of course) Both riders are within a couple pounds of each other and we ran the bikes 4 times. Results: My bike won each time!!!
They were dead even coming out of the hole then mine would start pulling away at the top of 3rd to an eventual 2 bike lead by full speed. This result was virtually identical in all 4 races. Remember I have stock gearing and a slip-on only and the other bike has full exhaust, programmer, and gearing. What gives??? Break-in procedures? I broke mine in wringing its little neck from the get go and have continued much the same. It's not a weight difference. Not a tire size difference. Not a rider difference. I rode the other bike and my buddy rode mine.

If you are thinking of laying down a bunch of hard earned cash on an exhaust and programmer, it may not be worth it! I honestly don't think my slip-on made any difference performance wise either. I absolutely love the sound and look though, not to mention the weight savings. (which have been negated by other mods)

I am at a loss as to why the bikes performed like they did. Any insight?? Could it boil down to break-in? I have rode with several other WRRs and mine always seems faster and peppier. One of our regular WRR riders always comments on this. He can't quite figure out how I can wheelie all the way through 2nd AND 3rd! I know that I've mentioned break-in a couple of times, but I wouldn't, nor am I encouraging anyone to just rip it wide open from the showroom. It's just how I've done on this and other bikes. I have the good fortune of having a fast bike and I'm thankful for that. It certainly helps when your riding buddies are on Beta300Rs, KTM 500EXCs, and GasGas 300s. (yep, two 2 strokes being dual sported)
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Tue May 01, 2018 12:38 pm

JoeHop wrote:
I am at a loss as to why the bikes performed like they did. Any insight??

My 4 cents...

  1. My first guess goes to the differences in sprockets.  In 6th gear at 8000 RPM on flat ground your bike will run 10 MPH faster than his.  He'd probably win an uphill race, where your sprocket gearing would struggle for power.

  2. It also might have been been the riders choice of how to ride and when to shift etc.  Did you guys try swapping bikes?

  3. The FMF programmer has known limitations, most notably that it can only add fuel in its mapped RPM range. (It can't subtract it.)  The Power Commander V programmer is more expensive and has more capabilities such as add fuel, subtract fuel, ignition control, and autotune.  The FMF programmer is popular because it's the least expensive, not because it's the best.

  4. A fuel programmer's performance is only as good as the map programmed into it.  Most riders opting for the least expensive programmer are also reluctant to invest in dyno runs to obtain the best map for their particular bikes.  Instead they copy maps from others claiming good results with similarly configured bikes.  When they don't like the results of their borrowed maps they either borrow a different one hoping for different results or start tinkering with the maps themselves hoping to stumble upon better performance.

IMHO the moral of the story isn't that programmers are a waste of money.  It's that buying the cheapest programmer and/or not programming it based on a dyno run for your bike can be a waste of money if you don't luck out with a fuel map borrowed from someone else.
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Tue May 01, 2018 12:50 pm

We raced uphill and downhill (2x each way). Our riding styles are pretty close to the same. We ride together every weekend year round. My bike would began pulling away in 3rd. We never completely wound either bike out on top. I do agree with the possibility of the programmer not being properly set up.
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Tue May 01, 2018 1:31 pm

The difference could also be affected by one or more of the following:
- Fuel choice (ethanol, octane level, age, etc.)
- Air filter condition (dirty, over-oiled, etc.)
- Spark plug condition
- Tire choice, size, and tread condition (affects speed, traction, and rolling resistance.)
- Suspension settings (affects hookup and traction.) My WRR is way faster off-road after suspension upgrades than with stock suspension.

Here in Idaho most of our pump gas contains 10% ethanol, but we also have a few stations that offer ethanol-free fuel for a little extra money.  I get noticeably more power and range from ethanol-free than with E10 gas.  So much so that I have to adjust jetting leaner on my two-stroke on the rare occasions when I can't find ethanol-free gas. My Dodge pickup gets 13 MPG on E10 and 17 MPG running ethanol-free gas.

My gut instinct though is that it's mostly the choice of FMF programmer, and the program currently in it.
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Tue May 01, 2018 1:48 pm

I am in total agreement with everything that you've stated. I also trust that you have plenty of knowledge about the WRR(I've read your entire build post). The fuel is the same, we ride together and fuel up at the same place. Both air filters are clean(the '12 was cleaned last week, mine was cleaned 2 weeks ago). The '12 has a brand new plug, mine is the factory one with 4k miles on it. The tires are the same size. The suspension on both bikes is stock with a few adjustments as far as sag, rebound, and compression. I'm going to say this is a non-factor since we were racing on pavement. I think we should go with your gut instinct on this as to it being the programmer. I was just really shocked that with his gearing I didn't get blistered out of the hole. After rereading my initial post, I did say we ran to wide open, when we didn't completely wind either bike out. Fact stands, the '12 should've smoked me and it didn't.
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Thu May 10, 2018 6:16 pm

Here's MY two bits... (.50 cents)

I've been tuning the wr250r with PowerCommander V software and Autotune.

I'm running stock exhaust, airbox lid/door removed. AIS is disable. EXUP is connected.

CO is set to -10

Autotune is pulling fuel off the stock map, all over the place. Mostly at low throttle/rpm and high throttle/rpm. It is adding fuel in the midrange. My AFR is set to 13.1... Not lean by any means. This all suggests that the bike is not infact as lean from factory as many believed, myself included. The AIS and the catalytic converter in the muffler are probably doing enough work to pass emissions. The bike came with the CO set to 0 but taht was giving me AFR levels between 12.3 and 12.8, even with teh airbox door off. You could also change the CO to pass emissions and then bump it down to get power back.. As for up top, I've seen more than a few PCV maps with negative values at high throttle/rpm, even with aftermarket mufflers...

I'm getting 46.6MPG with an AFR of 13.1 I could probably squeeze more power out of it but I like the range as it is.

For those not familiar with the Autotune software, you input a value for throttle %/rpm. If the burn is coming through richer than the value you input, it subtracts fuel. If it's coming through leaner, it adds. It stores these changes for review with a computer, at which point you can accept or deny the changes or "trims" as they are called.

Alot of singles make max power with a rich burn. Usually the plug colour and loss of fuel economy deters long term use. I'd say most recipes for thumper carbs available for "max power" are somewhere between 13.3 and 12.8 AFR... maybe richer :P

The variables listed (spark plug, air filter etc) is exactly why I like the Autotune. All bikes are different and I'm enough of a nerd to want to be maximizing everything...
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Jens Eskildsen

PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Sat May 12, 2018 8:20 am

CC_Rider: Good post. thumb
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PostSubject: Re: Thinking of full exhaust/programmer? My .02 worth   Mon May 14, 2018 6:39 am

This somewhat represents my experience with adding a PCV and spending time on the dyno with an aftermarket exhaust.

Did it make more power - Yes
Better throttle response when cold - Yes
Did it reduce my fuel economy - Yes
IMO was it worth all the money and effort - No

I would have been better off spending the money on the suspension up front.

Of course depending how you are using the bike I can see where some one may cherish that extra hp or throttle response over a proper suspension setup.
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