good fuel economy with triple pipes?

[roudyroy1]

I know everyone always says that your fuel economy goes down the crapper one you jump to a set of triple pipes... but the need for more power is growing again lol.


my question, is there any set up on the red head triple that you can still obtain reasonable fuel economy with triple pipes on?

 

[mrviper700]

power inc center dumps were about it, but they didn't gain a bunch of power either,were a low rpm pipe. All the rest require a big pilot jet(you spend a lot of time on this jet and the transistion to the needle) so this is where your mileage goes in the dumper. Have you thought about doing a trail port job on the engine and retaining the single pipe?, they can gain a good 10-12hp and still use the stock pipe. Trail port, either bigger reed blocks or at a minimum reed spacers, boost holes in pistons, lighter wristpins, case porting and depending on what gas you use a small peel of the head gasket and the red head will wake up...a lot. Theres a ton of ways to get more power and not totally ruin the gas mpg or deal with the sound laws. If only big power gains like 20+hp are what you want or have to have youll have no choice but to use the other triple pipes out there, cpr,bender,power inc end dumps,aaen,etc.

 

[roudyroy1]

power inc center dumps were about it, but they didn't gain a bunch of power either,were a low rpm pipe. All the rest require a big pilot jet(you spend a lot of time on this jet and the transistion to the needle) so this is where your mileage goes in the dumper. Have you thought about doing a trail port job on the engine and retaining the single pipe?, they can gain a good 10-12hp and still use the stock pipe. Trail port, either bigger reed blocks or at a minimum reed spacers, boost holes in pistons, lighter wristpins, case porting and depending on what gas you use a small peel of the head gasket and the red head will wake up...a lot. Theres a ton of ways to get more power and not totally ruin the gas mpg or deal with the sound laws. If only big power gains like 20+hp are what you want or have to have youll have no choice but to use the other triple pipes out there, cpr,bender,power inc end dumps,aaen,etc.

Well what I have done now is:
-drilled exhaust
-reed spacers
-1 engagement shim, 3.6 g tip 4.5g heal 8DF-00 weights.
-51/43 dalton helix @ 60 degrees, green spring.
- re geared- 21/ 39, 68 link chain
-stock Jetting running regular gas ( premium when possible)with a fuel stabilizer.

I'm hesitant on a thin head gasket because I ride far north in cold temps and gas is sometimes take what you can get.

For a trail port what fuel is required, do you need a re Jet and re clutch, and how much do they run $ wise? Thanks, RR1.

 

[mrviper700]

the porting doesn't make the engine use a different octane fuel, its the compression gain from either thinning the gasket or machining the head. When you port a cylinder you will open up and raise the exhaust port to a certain spec/degree, while you make this port larger you lower the compression of the cylinder due to the duration the port is open. This is why you most times will either cut a cylinder head or thin a headgasket to gain back and then some compression. You don't have to have big compression but it does make a considerable power increase in a 2 stroke engine. Most times a higher octane fuel is used so the engine can use a leaner jetting set up and make more power while being safe. When lower octane fuel is used it must be jetted richer to remain safe, while it might not make every last oz of horsepower that way its still definitely noticeable.

Since your up in Canada, I understand the fuel issue as I think your premium is only 91 octane right? usually what I suggest is to just lightly dust off the stock head and use stock headgasket. jetting will be needed as with more airflow thru the engine will require more fuel. clutching will need to be tweaked(either more rivet weight, or softer primary shift spring) as with more power youll over rev from stock, most of these engines are very happy to run at 8500rpm when done.

youll have to pm me if your wanting me to do any work. what I am telling you is basic understanding of what will be going on and the same no matter who does work for you.