Hello Guys,

i bought a used Kakimoto Regu.92-Z for my FD. It's a 3" piping exhaust. As it arrived at my house, i had to find out it has 2" muffler I.D. ..

The exhaust has 2 Mufflers:
The First is a "absorber" (perforated pipe, steelwool) in 50mm (2inch).
The Second is a reflector (not perforated) in 50mm (2inch).

So the exhaust is a 76mm (3inch) which goes twice into 2inch..

Here some picture of the contruction:



and a painture for better understanding:


I wonder how "restrictive" it would be, compared to a full 3" exhaust.
I would love to run it on a dyno and just find out, but my car is still not ready (going to keep 2-3 months) and i have 3 exhausts sitting in my garage.. so i have to sell at least 2 of them

The Car is a big-streetport, going to run 12-13psi of boost aiming at ~310whp.

Could anybody tell me how this 2" restriction would affect performance / Torque?

thanks for any reply.

 

Well if you do decide to sell it, keep my name handy. I would be interested. I've been looking for something exactly like that for a while.

 

wait, n/m. you're across the pond. thats too bad.

 

haha yea, shipping would be around 250-300$

Well the exhaust note is very screamy and high-pitched, thats why i would love to keep it, even if i should consider approx. 10hp + 10Nm torque, but i am not sure about this.. would be a waste.. working on streetport, boost, optimizing airflow etc. and messing it up with a restrictive exhaust

that's the reason i post it on here.. thought maybe there is somebody out there how could tell me how much performance are going out the window with a 3" -> 2" neck, in a car with around 310whp with a full 3" exhaust.

 

You know, in my last build I had the most ridiculously loud and free flowing exhaust to "maximize power"... but this time around I am trying to make it as quiet as I can. It's a DD, and after a while I got sick of the noise. For the 10-20HP I'll loose because of it for me is not a big deal.

 

Well, mine is not a DD. It already has racingsuspension etc. so loudness will not be a big deal. would be too bad, if all the things made to the engine etc. to free some HP would be just a waste with a restrictive exhaust system