[nacho_nissan]

the title says it all. one of my friends needs help with what size of pipe we need for his homemade intake and exhaust(ka24). i was thinking a 2.5" intake, and 2.5" exhaust? thanx for the help peeps.

nacho

 

[Gsolo]

the title says it all. one of my friends needs help with what size of pipe we need for his homemade intake and exhaust(ka24). i was thinking a 2.5" intake, and 2.5" exhaust? thanx for the help peeps.

nacho

do you want high rpm peak horse or low rpm grunt torque??

 

[nacho_nissan]

eh, can you gimme the combo for each? then i'd let him know which is for high end or low torque. thank you!

 

[Gsolo]

well i can't give you specific...but general rule of thumb small side for both will give good torque...like 2" tailpipe and usually just stock, maybe a tad bigger than stock but with a venturi effect. for high end you need a lot of air in and a lot out....and i can't say for sure what to do for the ka....

 

[KA24Tech]

I think the stock exhaust pipe is 2" so I think that a 2 and 1/4" with a good performance muffler would make the better all around system although a 2 and 1/2" would not be too detrimental to performance since the manifold is still stock. Make sure that you use a resonator if you don't use a high flow cat or else it maybe a bit loud.
The intake can be just about any size, within reason, as long as it is as big as the throttle body or the mass air flow meter.

Troy

 

[Gsolo]

I think the stock exhaust pipe is 2" so I think that a 2 and 1/4" with a good performance muffler would make the better all around system although a 2 and 1/2" would not be too detrimental to performance since the manifold is still stock. Make sure that you use a resonator if you don't use a high flow cat or else it maybe a bit loud.
The intake can be just about any size, within reason, as long as it is as big as the throttle body or the mass air flow meter.

Troy

logic would reason 2 1/4 would be perfect if intake was smoothed out and increased. 2 1/2 exhuast would be just a tad to much... granted great peak horsepower but you have to get there before you can use it.

just my idea...do a nice smooth intake to the throttle body (and same size as throttle body) and a good air filter (none of this foam shit) and have a horn style inlet...i don't know if it's been proven but the horn can smooth intake and deliver smoother torque curve. if you don't have a horn oh well...i don't think it makes a huge difference...but theres a reason for sure why chevy has always used it.