which mugen header 4 to 1 or 4 2 1?

PY 01-0972 · Post by **PY 01-0972** » March 11th, 2004, 12:33 am

just want to add power to my car and like mugen products. which is the best choice? and since its a 2.5 collector is there a conversion from 2.5 down to 2.25 until I can get the cash for a full 2.5? thanks

Champ R · Post by **Champ R** » March 11th, 2004, 3:08 am

What do you mean conversion down to 2.25? Both Mugen 4-1 and 4-2-1 headers come with a 2.5" collector, so you will need an aftermarket cat. The 4-2-1 header makes more power in the midrange, as its designed to be more of a gymkhana or autocross header, but the power dies off at higher rpm's from what ive seen. The 4-1 is a very old design, but is still a nice product, but for the cost, I would personally rather get the Toda manifold.

Justin Klemgold · Post by **Justin Klemgold** » March 11th, 2004, 12:25 pm

Champ R wrote:What do you mean conversion down to 2.25? Both Mugen 4-1 and 4-2-1 headers come with a 2.5" collector, so you will need an aftermarket cat. The 4-2-1 header makes more power in the midrange, as its designed to be more of a gymkhana or autocross header, but the power dies off at higher rpm's from what ive seen. The 4-1 is a very old design, but is still a nice product, but for the cost, I would personally rather get the Toda manifold.

For the cost of a toda, wait a month or two and get SMSP's setup for a bit cheaper.

PY 01-0972 · Post by **PY 01-0972** » March 11th, 2004, 8:39 pm

if the factory exhauxt is 2.25 and I get the mugen 2.5 collector It would not bolt up so I was wondering if I could get a cat with say a 2.5 on one side and then a 2.25 to bolt up to my factory on the other. thanks

Justin Klemgold · Post by **Justin Klemgold** » March 12th, 2004, 2:08 am

PY 01-0972 wrote:if the factory exhauxt is 2.25 and I get the mugen 2.5 collector It would not bolt up so I was wondering if I could get a cat with say a 2.5 on one side and then a 2.25 to bolt up to my factory on the other. thanks

Get a cat from SMSP....that's dave...he will give you a 2.5" cat...with 2.5" flanges on both sides....the only difference will be the ID...the cat will bolt up fine with no problems. This way, if you want to upgrade to a 2.5" catback in the future, you won't have to replace the cat again and you will have a 2.5" exhaust system.

PY 01-0972 · Post by **PY 01-0972** » March 12th, 2004, 2:40 am

sweet thanks justin