Downpipe is 3" to a 2.5 " reducer into the resonator which comes out 2.25" on to the Split T which goes down to 1 3/4 for each muffler . :(

Adding "backpressure" (atleast the automotive term) KILLS power. If his exhaust is too big, adding the correct size shouldn't add backpressure, but increase flow rates.

Headers don't necessarily kill low end power either, but they remove restrictions to top end power, and make the entire powerband smoother. This is of course, if they're properly sized in both primaries and collectors.

Thanks for the analysis..

Club experience and my own personal was the basis for my post. With both of us having S2 L67'* with headers..I thought my experience would be relevant..


Adding headers w/o flow dropped some low end torque and allowed the top end to flow. Being in NYC....he'* probably not seeing much top end driving.

E... I was thinking.. you didn't change or regap your plugs. What are they?

NGK TR55s gapped at .055 or .054 IIRC.

O2 readings at WOT?

DOH! We forgot to check 02 readings at WOT last night. But I am getting misfires . Time to get new plugs.

Do you need plugs?
Do you need better fuel pressure? (did you find the vise grips I put on your fuel line?)
Need to find out what is causing the KR.

Update: Captians Log Stardate 08090.7

I had the car on lift today and discovered that car is leaking exhaust from the clamps on the Y-pipe and from the downpipe gasket. Going to put car on lift tomarrow to try to remedy the situation.


End log

You didn't fix it while it was in the air?

Didn't have the material on hand. Today I may try to copper RTV the heck ot of it.