You may want to check out a good book on two strokes. Exhaust pulses can affect exhaust scavenging as well as intake charge. A lot of modern cars use this effect on both intake and exhaust to improve volumetric efficiency.
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You may want to check out a good book on two strokes. Exhaust pulses can affect exhaust scavenging as well as intake charge. A lot of modern cars use this effect on both intake and exhaust to improve volumetric efficiency.
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"Volumetric efficiency" Now there is a term I have not heard in a long time. Last time I read those words were when I was studying for my commercial pilots exam and studying power plants. Have to dig out my textbooks and read some basic engine theory again.
Sorry got a bit sidetracked. You know I have been reading this thread a lot and at the end of the day it would not matter which exhaust I had on my S it would not have made todays ride any better.
I have a std sys by the way and always use earplugs to protect my hearing and not get tinnitus in my other ear. So don,t need any pipe is louder unless maybe if I was racing.
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- Brisbane, QLD Australia
sifubs your just looking to argue for arguments sake. In the quote you used I start by saying you learn something new every day.
I have only ever had genuine questions which have been very hard to get answers for. Individuals like you who have taken the personal approach just don't seem to get it!
If I have a view and choose to express it I do so without any malicious intent. When someone then explains that I am wrong and I can see their point I am more than willing to accept it. Thats life and a healthy forum community.
Take a chill pill. Better still if you have something constructive to add or ask that would be even better!
I have only ever had genuine questions which have been very hard to get answers for. Individuals like you who have taken the personal approach just don't seem to get it!
If I have a view and choose to express it I do so without any malicious intent. When someone then explains that I am wrong and I can see their point I am more than willing to accept it. Thats life and a healthy forum community.
Take a chill pill. Better still if you have something constructive to add or ask that would be even better!
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This thread has gone 650 post too long . Was it about the heat again ? Just chuck on a 41 tooth rear everything will be sweet .
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OK, time to finally post on this thread:
First off, I have the Termi full system and I'm not a fan of AR's system, though I appreciate Rich for developing it and bringing it to market. Competition is the only thing keeping Termi and Akrapovic in check. Lets face it, if Termi was the only system available, a lot of us would pay an extra $k or two just to have it.
Rich's main fault in this is publishing his comparison numbers, both in peak power and noise. As we said nearly a year ago, that's just bad form. Publish your own graphs showing your curves, AFR and an expected average gains. By not doing so, Rich as left himself open for this discontent.
Any turner worth their salt will admit that Peak Power result from a given dyno are worthless if compared to other Peak Power result from another given dyno. You will find that results from different Dynos and taken under different conditions even on the same dyno will differ. Even though CF attempts to correct for temperature and pressure, the environment will vary your results by +/- ~2% or more.
As well as factors in the DYNO machine and environment, the selected Correction Factor (CF) can play a part in the numbers game -
DIN uses 1013mBar and 20 degrees Celsius as the nominal conditions, whereas the SAE uses 990mBar and 25 degrees Celsius as the nominal conditions. DIN also uses absolute air pressure SAE uses dry. Difference being that dry doesn't account for relative humidity.
The formula for CF is too difficult to type in the text area, but the important thing to remember is that CF DIN is usually ~1.16% higher than SAE.
In short, unless every run is under the exact same conditions, the peak numbers mean little. The only true thing to take from a dyno run is the shape of the torque and power curves and the Air/Fuel Ratio.
Gavin D - Subtraction of back pressure without remapping will decrease the fuel to air mixture ratio (Lean out). Running lean will give you more top end power and higher engine running temperature. In tuning term, lean is mean, but you don't want to go too lean least bad things will happen. But that will never be the case for the Termi slip-on our race exhaust mapping.. they'll always be on the safe side. (usually richer than the Stock map)
Addition of Back Pressure without remapping will increase the fuel to air mixture ratio (richen). In moderation, this can add more torque and response down but less top end power. The engine will also run slightly "cooler" due to unburnt fuel. Going too rich will bog down the engine and make it feel sluggish.
Most manufactures tune a little lean to help pass emissions - Lean = a cleaner burn and less work for the catalytic converter.
Picture this if you will - you have a Stock system which is trying to meet noise regulations so is creating back pressure which will in turn richen the fuel mixture. Now Ducati has to back off the fuel to lean out the mixture to to meet EPA and EU3 emission standards. Now you take away the Stock system back pressure by installing an open system ie Termi Slips or full system, the Up Map will have to enrich the mixture.
From the results thus far, I would speculate the RB unit is setup for the Stock map and not the Termi slip/full system upmap. This would cause the extra rich running with the addition of the RB unit and the AR system.
First off, I have the Termi full system and I'm not a fan of AR's system, though I appreciate Rich for developing it and bringing it to market. Competition is the only thing keeping Termi and Akrapovic in check. Lets face it, if Termi was the only system available, a lot of us would pay an extra $k or two just to have it.
Rich's main fault in this is publishing his comparison numbers, both in peak power and noise. As we said nearly a year ago, that's just bad form. Publish your own graphs showing your curves, AFR and an expected average gains. By not doing so, Rich as left himself open for this discontent.
Any turner worth their salt will admit that Peak Power result from a given dyno are worthless if compared to other Peak Power result from another given dyno. You will find that results from different Dynos and taken under different conditions even on the same dyno will differ. Even though CF attempts to correct for temperature and pressure, the environment will vary your results by +/- ~2% or more.
As well as factors in the DYNO machine and environment, the selected Correction Factor (CF) can play a part in the numbers game -
DIN uses 1013mBar and 20 degrees Celsius as the nominal conditions, whereas the SAE uses 990mBar and 25 degrees Celsius as the nominal conditions. DIN also uses absolute air pressure SAE uses dry. Difference being that dry doesn't account for relative humidity.
The formula for CF is too difficult to type in the text area, but the important thing to remember is that CF DIN is usually ~1.16% higher than SAE.
In short, unless every run is under the exact same conditions, the peak numbers mean little. The only true thing to take from a dyno run is the shape of the torque and power curves and the Air/Fuel Ratio.
Gavin D - Subtraction of back pressure without remapping will decrease the fuel to air mixture ratio (Lean out). Running lean will give you more top end power and higher engine running temperature. In tuning term, lean is mean, but you don't want to go too lean least bad things will happen. But that will never be the case for the Termi slip-on our race exhaust mapping.. they'll always be on the safe side. (usually richer than the Stock map)
Addition of Back Pressure without remapping will increase the fuel to air mixture ratio (richen). In moderation, this can add more torque and response down but less top end power. The engine will also run slightly "cooler" due to unburnt fuel. Going too rich will bog down the engine and make it feel sluggish.
Most manufactures tune a little lean to help pass emissions - Lean = a cleaner burn and less work for the catalytic converter.
Picture this if you will - you have a Stock system which is trying to meet noise regulations so is creating back pressure which will in turn richen the fuel mixture. Now Ducati has to back off the fuel to lean out the mixture to to meet EPA and EU3 emission standards. Now you take away the Stock system back pressure by installing an open system ie Termi Slips or full system, the Up Map will have to enrich the mixture.
From the results thus far, I would speculate the RB unit is setup for the Stock map and not the Termi slip/full system upmap. This would cause the extra rich running with the addition of the RB unit and the AR system.
Not trying to argue , just pointing you in a direction to get some facts and understanding of how an engine works unless you're satisfied with relying on someone's say so. Lets not forget a few posts ago you responded incorrectly and at the same time ridiculed my pertinent and valid question to wmcdonal.
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Hey Woot...
Ok just so I am clear on this ...You bought the AR system and the RB Evo loaded with the AR specific tune... and the bike ran like crap and melted your fairing?? This cost around $4200 and you got 5.5 hrs of work done at your dealer (retail value approx $550) for free and yet you still have a bike that doesn't run well and you are now going to have to buy the TB Ecu tuner to try to get this all sorted?? (cost approx $600)
Do I have this right???
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Ouch.... Well what can I say.... AR appears to be 0-2 on here.... what could possibly be wrong here??
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AR has a new money back policy posted yesterday. You don't live in the UK, but its worth a try?
Honestly, the exhaust worked great out of the box minus the RB Evo unit. I can't really fault him for the RB unit. For all I know it could be bad. Was informed that Evo's would have issues with not running it's settings properly. But I think the nicer route is with getting an ECU tune. I came in with an open mind that I would more than likely need a tune. Not trying to sugar coat my situation though.
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Its supposed to work great without a tune... I quote from AR website..
NO REMAPPING IS REQUIRED ALTHOUGH ADDING A RAPIDBIKE MODULE PRE MAPPED FROM US OFFERS SUPER SMOOTH THROTTLE RESPONSE WITH LARGE POWER GAINS
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Glad you're happy with the exhaust...but I don't understand the RB issue. Who told you it would have issues? I would think any company would take back a product that doesn't work for a full refund?
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Woot - Did you have the Slip-ons prior or did the AR system replace a fully Stock system?
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This thread is painful if you have not followed it from the beginning....as I have not. It would be nice if the OP would update the first post if anything good happened. I only got through about the first 18 pages. Has anything happened since then worth reading?
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- Michigan
Products don't seem to be living up to hype, few people getting sued. Other than that, not really.
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Never ridiculed you just corrected a very wrong statement you made about fuel and I followed that up with a clear explanation. Ron ratings are a world standard while names may change 98 Ron in Aus is the same as 98 Ron in the UK is the same as 98 Ron in the US.
If it makes you feel vindicated to be condescending and pious good for you. But without explaining the wrong statement that your correcting it just sounds like sour grapes.
As a Fanboy please explain the claims from Rich and AR that the system without tune or additional modules and flashes out side of the Termi up map will produce 180+ hp and better torque compared to multiple real life accounts mentioned within this thread that show otherwise because that is after all is said and done what this thread was about.
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