the right size!

[legion1capone]

I want to get magnaflow mufflers for my 1990 lexus LS400 but I don't know what size to order. Should I order 5x8...or what?

What piping should I run for the exhaust on a N/A motor? I am thinking 2.25" to 2.5".

 

[cjsupra90]

2.25 is the better choice for pipe size for a N/A engine.

As for the mufflers, what ever size you can fit. keep in mind, typically speeking, the larger the muffler case, the more noise suppression it is capable of. There is not much differance between a 5x8 or a 4x9, other then space requirements.

 

[feztallica]

i'm thinking a twin screw s/c in the far future, but i'd still like to know: what is the proper piping size?

 

[cjsupra90]

With an S/C, 2.5" would probably be a better choice as long as you are using some form of headers. The stock exh. manifolds are a major restriction especially when using a S/C and in this case, the exhaust will not make that much of a differance.

You can run 2.5" on an N/A, but it will lower you low end power by a small amount. So as long as you can live with the slight lose for now, doing a 2.5" system now would keep you from doing the exhaust twice.