A more efficient exhaust system will allow the air out of the cylinder faster, and also allow more to get out when it blows. This will allow more space for air to get in when it sucks. If you have more air getting in but only the same amount of fuel then it will be running lean, and therefore hotter when it bangs. This will lose you power and could also burn valves and other bits in the engine. This is not good. Therefore you need to bike tuned differently to get the A/F mixture correct.
If the air can get into the cylinder more efficiently because of a better intake system then you will have the same issues.
If the air can get into the cylinder more efficiently because of a better intake system then you will have the same issues.
RKTNMYPKT
Village Idiot
A more efficient exhaust system will allow the air out of the cylinder faster, and also allow more to get out when it blows. This will allow more space for air to get in when it sucks. If you have more air getting in but only the same amount of fuel then it will be running lean, and therefore hotter when it bangs. This will lose you power and could also burn valves and other bits in the engine. This is not good. Therefore you need to bike tuned differently to get the A/F mixture correct.
If the air can get into the cylinder more efficiently because of a better intake system then you will have the same issues.[/
**** is it getting hot in here? Or is it just me....
HansO
Not Taking Life Too Seriously
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Jim have you got a bigger outlet fitted or is just your one track mind
RocketandRollit
Can't be accurately measured
Should retune with any mods (intake, exhaust, or both).
HansO
Not Taking Life Too Seriously
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Simple rule
You let more out you gotta put more in especially if not running any baffles to create back pressure.
End of story
You let more out you gotta put more in especially if not running any baffles to create back pressure.
End of story
R3R Torque
.060 Over
Even with a tune, you won't get great results with staight pipes (if that's what you mean) due to a lack of backpressure and volumetric efficiency.
Yes. If you open up / modify your exhaust, you'll need a tune.
Think of it this way. The stock tune makes A/F adjustments based on certain predefined parameters. When modifications are made that are outside those parameters, the stock map / tune can't compensate and you'll run lean. The opposite is true if you installed more restrictive exhaust you'll run rich.
Running too lean causes severe problems due to two things, heat and detonation and one feeds into the other. Heat and Detonation damages valves, valve seats, pistong rings, pistons etc... pistons can literally melt down. Even Triumph's website says a tune is required when off-road silencers (TORs) are installed.
Look into tuneecu and power commander.
Power-Tripp
Turbocharged
First and foremost, you need to understand that factory engine management calibrations are done to meet criteria for sound and exhaust gas emissions. As well as liability issues from bike owners that can't ride all that well - so calibrations are restricted in stock form. They also must allow for the variances in mass produced parts. For instance, injectors may only vary 2% at 100% duty-cycle, but the ECU can only handle a maximum of 86% DC, where variances are larger. And at low duty cycles used at lower engine speeds and loads, injectors commonly vary 14+%, with 40+% not being uncommon. This is the dirty little secret of emissions and the injector industries.
As a result, stock "tuning" must allow for these variances. Especially at lower engine speeds and loads.
Now, once you allow the engine to flow more air into, and out of, the engine with aftermarket exhaust systems, and intake or filter changes, you must give the engine what it wants for best mileage, response, and output. This means that fueling must change for these increases in air flow and pulse tuning.
I hope this helps.
-Wayne
As a result, stock "tuning" must allow for these variances. Especially at lower engine speeds and loads.
Now, once you allow the engine to flow more air into, and out of, the engine with aftermarket exhaust systems, and intake or filter changes, you must give the engine what it wants for best mileage, response, and output. This means that fueling must change for these increases in air flow and pulse tuning.
I hope this helps.
-Wayne
Power-Tripp
Turbocharged
First, "backpressure is a myth. This old-wives-tale needs to die an horrible death. Those who spout and spread this myth have never tested it. And the internet has allowed it to spread like a virus.
Second, "Volumetric Efficiency" is mostly misunderstood and incorrectly calculated. Actual measurement of air and fuel mass trapped in the cylinder(s) needs to account for cross-flow out of the cylinder. As well as intake and exhaust reversion. Most do not do so. Thus most VE numbers quoted are WRONG.
TEST, test again, and then test some more.
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