Difference between revisions of "Category:Performance Tuning"

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=Better, Faster, Stronger=
 
=Better, Faster, Stronger=
 
+
You'll get noticeable power improvement on most mopeds by the following mods:
 
 
You'll get noticeable power improvement on most mopeds by the following
 
mods:
 
  
 
==Bigger Carburetor==
 
==Bigger Carburetor==
 +
Installing a bigger [[carburetor]] will increase the amount of fuel leading to more power.  The hard part is getting the air to gas ratio correct so that you don't cause a seizure or foul plugs.  Controlling the gas flow can be done by changing the size of the [[jet]].  Controlling the air flow can be through the use of special [[air filter|air filters]] or by drilling holes in your air box.
  
Installing a bigger [[carburetor]] will increase the amount of fuel leading to more power. The hard part is getting the air to gas ratio correct so that you don't cause a seizure or foul plugs. Controlling the gas flow can be done by changing the size of the [[jet]]. Controlling the air flow can be through the use of special [[air filter|air filters]] or by drilling holes in your air box.
+
You can also try over-boring your carburetor.  The process isn't very hard and saves a lot of money.  
 
+
:Click here for more info [[Over Boring Carburetors 101]]
You can also try over-boring your carburetor.  The process isn't very hard and saves a lot of money.
 
Click here for more info [[Over Boring Carburetors 101]]
 
  
 
==Performance Exhaust==
 
==Performance Exhaust==
 +
For most mopeds, this will be the best performance improvement, and the easiest for the average person to do in an afternoon.
  
For most mopeds, this will be the best performance improvement,
+
Many mopeds of 1970-1985 vintage had exhausts tuned to deliver the most power at approx 25mph. As the engine goes faster, it's cycle rate moves out of the power band of the exhaust, and the exhaust begins to restrict the amount of fuel available for combustion, which self-limits the top speed.
and the easiest for the average person to do in an afternoon.
 
 
 
Many mopeds of 1970-1985 vintage had exhausts tuned to
 
deliver the most power at approx 25mph. As the engine
 
goes faster, it's cycle rate moves out of the power band of the exhaust,
 
and the exhaust begins to restrict the amount of fuel available
 
for combustion, which self-limits the top speed.
 
 
 
However, if you replace the stock muffler with one with a power
 
band that is higher, your top-end speed will increase, but at a
 
cost of the low end power. For most moped riders under 200lbs,
 
this really isn't an issue.
 
  
For example, on a [[Honda]] Hobbit, you can get up to an ''8mph'' improvement,
+
However, if you replace the stock muffler with one with a power band that is higher, your top-end speed will increase, but at a cost of the low end power. For most moped riders under 200lbs, this really isn't an issue.
just by swapping out the stock muffler with a [[Proma Circuit]] exhaust.
 
  
Of course, every model of bike is different, and you'll need to use the
+
For example, on a [[Honda Hobbit]], you can get up to an ''8mph'' improvement, just by swapping out the stock muffler with a [[Proma Circuit]] exhaust.
forum search function on the 'Performance Tuning' forum to find
 
what people recommend for ''your'' model.
 
  
 +
Of course, every model of bike is different, and you'll need to use the forum search function on the 'Performance Tuning' forum to find what people recommend for ''your'' model.
  
 
== High Flow Air Filter ==
 
== High Flow Air Filter ==
 
 
A high flow air filter will increase the amount of air flow capable of flowing through your intake.  Most of these filters are made out of foam or another similar material.  You must up-jet if you install a high flow filter in order to match your increased air with an increased amount of fuel.   
 
A high flow air filter will increase the amount of air flow capable of flowing through your intake.  Most of these filters are made out of foam or another similar material.  You must up-jet if you install a high flow filter in order to match your increased air with an increased amount of fuel.   
  
 
==High-Compression Head==
 
==High-Compression Head==
 
 
Cylinder heads can be obtained that increase the compression in the [[combustion chamber]] leading to faster strokes leading to increased speeds.
 
Cylinder heads can be obtained that increase the compression in the [[combustion chamber]] leading to faster strokes leading to increased speeds.
  
 
==Performance Crank==
 
==Performance Crank==
 +
Installing a performance crank alone does not increase your speed. A performance crank can however influence the carter flow and the combustion chamber size.
  
Installing a performance crank alone does not increase your speed. A performance crank can however influence the carter flow and the combustionchamber size.
+
A performance crank with full "cheeks" can improve the carter flow. Sometimes there are holes in the cheeks, filled out with nylon or cork. This is done to reduce the weight of the crank, increasing gas reaction but reducing low end torque. This is mostly done on high-rpm machines, since they don't need a lot of low end torque.
  
A performance crank with full "cheeks" can improve the carter flow. Sometimes there are holes in the cheeks, filled out with nylon or cork. This is done to reduce the weight of the crank, increasing gasreaction but reducing low end torque. This is mostly done on high-rpm machines, since they don't need a lot of low end torque.
+
Some performance cranks have a shorter shaft that allows for greater or less displacement. Shorter or longer shafts are also used to fit cylinders that are not meant to go onto a specific engine. Although it does not fix the timing-problems, it does fix the piston coming above or too much below the cylinder.  
 
 
Some performance cranks have a shorter shaft that allows for greater or less displacement. Shorter or longer shafts are also used to fit cilinders that are not meant to go onto a specific engine. Although it does not fix the timing-problems, it does fix the piston coming above or too much below the cilinder.  
 
  
 
A common mistake is that a shorter or longer shaft would influence the length of the stroke. This is not true. The stroke is determined by where the shaft is connected to the crank, how far it is off centre. The further off centre, the longer the stroke.
 
A common mistake is that a shorter or longer shaft would influence the length of the stroke. This is not true. The stroke is determined by where the shaft is connected to the crank, how far it is off centre. The further off centre, the longer the stroke.
  
 
==Piston Kits==
 
==Piston Kits==
 
+
These kits replace your cylinder and piston with a larger bore. Generally, you will also need to re-jet your carburetor to allow a greater volume of fuel/air mix to enter your engine.
These kits replace your cylinder and piston with a larger bore.
 
Generally, you will also need to re-jet your carburetor to allow a
 
greater volume of fuel/air mix to enter your engine.
 
  
 
They can be done in weekend, and generally give good performance.
 
They can be done in weekend, and generally give good performance.
  
However, most kits recommend a 300 to 800 mile break-in period
+
However, most kits recommend a 300 to 800 mile break-in period after installation, to allow the rings on the piston to use the fine scratches (call the honing) in the cylinder to gently polish into a smooth, well seated finish.
after installation, to allow the rings on the piston to use the fine
 
scratches (call the honing) in the cylinder to gently polish into
 
a smooth, well seated finish.
 
  
Overrevving the engine, and showing off your new kit to your friends
+
Over-revving the engine, and showing off your new kit to your friends by throttling all the way up is a sure way to destroy your new kit if it's not properly broken in.
by throttling all the way up is a sure way to destroy your new kit if
 
it's not properly broken in.
 
  
Note that some kits can increase your engine combustion area above 50CC,
+
Note that some kits can increase your engine combustion area above 50CC, which may change your moped to a motorcycle due to your [[Moped laws|state's laws]]. Make sure to check with your DMV before you spend the money on a kit!
which may change your moped to a motorcycle due to your [[Moped laws|state's laws]].
 
Make sure to check with your DMV before you spend the money on a kit!
 
  
 
==Cylinder Porting==
 
==Cylinder Porting==
 +
Cylinder porting is one of two arts - the white art of [[Port Matching]], and the black art of [[Port Reshaping]].
  
Cylinder porting is one of two arts - the white art of [[Port Matching]],
+
See [[Smitty|Smitty's]] full [[Smitty's Cylinder Porting Guide|article]], as transcribed from the forums, for a guide to cylinder porting from the guy who does it for a living.
and the black art of [[Port Reshaping]].
 
 
 
See [[Smitty|Smitty's]] full [[Smitty's Cylinder Porting Guide|article]], as transcribed from the forums, for a
 
guide to cylinder porting from the guy who does it for a living.
 
  
 
==Gearing==
 
==Gearing==
 
 
By changing the front and/or rear [[sprocket]] you can redistribute speed to top or low end depending on your needs. Usually increasing top end with this method decreases low end, and vice versa.
 
By changing the front and/or rear [[sprocket]] you can redistribute speed to top or low end depending on your needs. Usually increasing top end with this method decreases low end, and vice versa.
  
 
=Really Fast, But Not For Long=
 
=Really Fast, But Not For Long=
 
 
==Nitrous Injection==
 
==Nitrous Injection==
 
 
Makes you go real fast for up to 5 seconds.
 
Makes you go real fast for up to 5 seconds.
  
The problem? You run ''really'' lean for those five seconds, and every time you use the nitrous,
+
The problem? You run ''really'' lean for those five seconds, and every time you use the nitrous, you have a good chance of causing your engine seize from lack of lubrication.
you have a good chance of causing your engine sieze from lack of lubrication.
 
  
 
==JATO Rocket==
 
==JATO Rocket==
 
+
A Jet Assisted Take Off unit will make you go ''really really really'' fast for up to 7 seconds... straight into a tree. And fry everybody behind you.
A Jet Assisted Take Off unit will make you go ''really really really'' fast for up to 7 seconds...
 
 
 
... straight into a tree. And fry everybody behind you.
 
  
 
==Nitro(methanol)==
 
==Nitro(methanol)==
 
Nitromethanol, also known as RC-car fuel is an alcohol based fuel that burns faster and hotter than gasoline. This increases the performance greatly.
 
Nitromethanol, also known as RC-car fuel is an alcohol based fuel that burns faster and hotter than gasoline. This increases the performance greatly.
  
But as most people know, alcohol dissolves oil. And oil is what keeps your 2-stroke going. Also the added heat can cause your piston to over expand and instantly seize. So you will need a good lead-replacer (The type that goes into old cars that run on leaded fuel) to insure a good heat-conduction of the piston and cilinderwall. Also you will need special nitromethane 2-stroke oil, so the oil doesn't dissolve.
+
But as most people know, alcohol dissolves oil. And oil is what keeps your 2-stroke going. Also the added heat can cause your piston to over expand and instantly seize. So you will need a good lead-replacer (The type that goes into old cars that run on leaded fuel) to insure a good heat-conduction of the piston and cylinder wall. Also you will need special nitromethane 2-stroke oil, so the oil doesn't dissolve.
  
 
Don't use more than 15% nitromethane, as it will surely kill your engine. Mix the oil and lead-replacer with the fuel in the right proportions, shake and take for example 850ml's of that mixture and add 150ml's of nitromethane. Start the engine on normal fuel and run it till it is completely warmed up. Then switch to the nitromethane mixture.
 
Don't use more than 15% nitromethane, as it will surely kill your engine. Mix the oil and lead-replacer with the fuel in the right proportions, shake and take for example 850ml's of that mixture and add 150ml's of nitromethane. Start the engine on normal fuel and run it till it is completely warmed up. Then switch to the nitromethane mixture.
  
Beware: You can't kill your engine by stopping the ignition anymore, the nitromethane mixture is self-combustable under pressure. So make sure you can cut the fuel off at any time!
+
Beware: You can't kill your engine by stopping the ignition anymore, the nitromethane mixture is self-combustible under pressure. So make sure you can cut the fuel off at any time!

Revision as of 01:33, 4 October 2007

Better, Faster, Stronger

You'll get noticeable power improvement on most mopeds by the following mods:

Bigger Carburetor

Installing a bigger carburetor will increase the amount of fuel leading to more power. The hard part is getting the air to gas ratio correct so that you don't cause a seizure or foul plugs. Controlling the gas flow can be done by changing the size of the jet. Controlling the air flow can be through the use of special air filters or by drilling holes in your air box.

You can also try over-boring your carburetor. The process isn't very hard and saves a lot of money.

Click here for more info Over Boring Carburetors 101

Performance Exhaust

For most mopeds, this will be the best performance improvement, and the easiest for the average person to do in an afternoon.

Many mopeds of 1970-1985 vintage had exhausts tuned to deliver the most power at approx 25mph. As the engine goes faster, it's cycle rate moves out of the power band of the exhaust, and the exhaust begins to restrict the amount of fuel available for combustion, which self-limits the top speed.

However, if you replace the stock muffler with one with a power band that is higher, your top-end speed will increase, but at a cost of the low end power. For most moped riders under 200lbs, this really isn't an issue.

For example, on a Honda Hobbit, you can get up to an 8mph improvement, just by swapping out the stock muffler with a Proma Circuit exhaust.

Of course, every model of bike is different, and you'll need to use the forum search function on the 'Performance Tuning' forum to find what people recommend for your model.

High Flow Air Filter

A high flow air filter will increase the amount of air flow capable of flowing through your intake. Most of these filters are made out of foam or another similar material. You must up-jet if you install a high flow filter in order to match your increased air with an increased amount of fuel.

High-Compression Head

Cylinder heads can be obtained that increase the compression in the combustion chamber leading to faster strokes leading to increased speeds.

Performance Crank

Installing a performance crank alone does not increase your speed. A performance crank can however influence the carter flow and the combustion chamber size.

A performance crank with full "cheeks" can improve the carter flow. Sometimes there are holes in the cheeks, filled out with nylon or cork. This is done to reduce the weight of the crank, increasing gas reaction but reducing low end torque. This is mostly done on high-rpm machines, since they don't need a lot of low end torque.

Some performance cranks have a shorter shaft that allows for greater or less displacement. Shorter or longer shafts are also used to fit cylinders that are not meant to go onto a specific engine. Although it does not fix the timing-problems, it does fix the piston coming above or too much below the cylinder.

A common mistake is that a shorter or longer shaft would influence the length of the stroke. This is not true. The stroke is determined by where the shaft is connected to the crank, how far it is off centre. The further off centre, the longer the stroke.

Piston Kits

These kits replace your cylinder and piston with a larger bore. Generally, you will also need to re-jet your carburetor to allow a greater volume of fuel/air mix to enter your engine.

They can be done in weekend, and generally give good performance.

However, most kits recommend a 300 to 800 mile break-in period after installation, to allow the rings on the piston to use the fine scratches (call the honing) in the cylinder to gently polish into a smooth, well seated finish.

Over-revving the engine, and showing off your new kit to your friends by throttling all the way up is a sure way to destroy your new kit if it's not properly broken in.

Note that some kits can increase your engine combustion area above 50CC, which may change your moped to a motorcycle due to your state's laws. Make sure to check with your DMV before you spend the money on a kit!

Cylinder Porting

Cylinder porting is one of two arts - the white art of Port Matching, and the black art of Port Reshaping.

See Smitty's full article, as transcribed from the forums, for a guide to cylinder porting from the guy who does it for a living.

Gearing

By changing the front and/or rear sprocket you can redistribute speed to top or low end depending on your needs. Usually increasing top end with this method decreases low end, and vice versa.

Really Fast, But Not For Long

Nitrous Injection

Makes you go real fast for up to 5 seconds.

The problem? You run really lean for those five seconds, and every time you use the nitrous, you have a good chance of causing your engine seize from lack of lubrication.

JATO Rocket

A Jet Assisted Take Off unit will make you go really really really fast for up to 7 seconds... straight into a tree. And fry everybody behind you.

Nitro(methanol)

Nitromethanol, also known as RC-car fuel is an alcohol based fuel that burns faster and hotter than gasoline. This increases the performance greatly.

But as most people know, alcohol dissolves oil. And oil is what keeps your 2-stroke going. Also the added heat can cause your piston to over expand and instantly seize. So you will need a good lead-replacer (The type that goes into old cars that run on leaded fuel) to insure a good heat-conduction of the piston and cylinder wall. Also you will need special nitromethane 2-stroke oil, so the oil doesn't dissolve.

Don't use more than 15% nitromethane, as it will surely kill your engine. Mix the oil and lead-replacer with the fuel in the right proportions, shake and take for example 850ml's of that mixture and add 150ml's of nitromethane. Start the engine on normal fuel and run it till it is completely warmed up. Then switch to the nitromethane mixture.

Beware: You can't kill your engine by stopping the ignition anymore, the nitromethane mixture is self-combustible under pressure. So make sure you can cut the fuel off at any time!

Subcategories

This category has only the following subcategory.

Pages in category "Performance Tuning"

The following 103 pages are in this category, out of 103 total.