Exhaust piping size

[Donedreamin]

Hey guys, my exhaust is violently leaking on my 71' 521 with a L16. Just want what I/D you guys would recommend?

[metalmonkey47]

2'' should be perfect. 

[Ratwagon1600]

2" maximum.

 

Ensure you have at least one good quality muffler at the rear of the vehicle and a hot dog muffler/resonator shortly after the Y piece in your exhaust header.

 

 

 

(Disclaimer, my descriptions of the parts are Aussie English and may translate differntly for you :D)

[DISLEXICDIME]

17/8"

[datzenmike]

For an L16 I wouldn't go that big. Measure what you have an increase by say 1/4"

 

 

Say your exhaust pipe is 1 3/4" the cross sectional area of that pipe is 2.75". If you increase the diameter to 2" it becomes 3.24 square inches or an increase of just over 14%. Bigger is ok but what happens is a larger pipe causes the exhaust to slow down. You want the exhaust to flow fast as possible short of being restrictive. Too big and it will affect low and mid range power where you drive all the time and on an unmodified motor does very little at the top end for this. Remember, doubling the pipe diameter increases the cross sectional area by 4 times!!! so go easy. I would increase your pipe size by 1/8" to 1/4" and run a low restriction turbo muffler.

[Dawa]

got 2" on my L16 and it was a noticed improvement,

most notably at higher rpms, of course.

 

if i was staying L16 i wouldntve gone 2" though,

i did it because of plans to go bigger motor. (was gonna go L20, now goin Z22(23)

 

whatever you do, i suggest you have them increase the size all the way to the Y,

so theres no bottle neck there.