I know the 4.6 needs some back pressure. Does anyone race the 1320 with open headers on a 4.6? I was going to run my car that way this year but I had heard of someone that did it but actually ran slower E.T.'s because of it. Any info would be helpful. Thank you.

 

you are going to run leaner if not tuned for open headers. thus not tuned for open headers, yes you will go slower

 

I have a tune made to run open headers already.

 

I heard that running open headers is pretty bad for the car unless it's like longtubes

 

already have them.

 

running open headers wont hurt anything, and it really shouldnt even effect how the car runs, as far as the computer is concerned (turning the rear 02s off, which I think only indicate if the cats are there and and working). It will certainly have less back pressure, and probably drop some torque, but it make up for that on the big end. I ran open for a long time, the biggest thing is that is sounds NASTY.

 

what about electric cut outs? that way you can drive it to the track... then open the headers

 

I thought about cut outsand i made my x pipe so that in the future I could put them in if I decided to but I dont drive it to the track. I trailer it there. The nearest track is an hour and a half away and I dont want to be stranded incase something decides to break. I have watched that sort of thing happen to many times before.

 

I think what I will do on opening day is try a few runs both ways (with open and without) and see what the outcome is.

 

The 4.6L engine is like any other engine and does NOT need backpressure.

Running open headers will move your powerband up and unless your engine is built to rev high it's pointless. Once I get the cash together I will be installing electric cutouts that will work on a rpm switch and open at 3000rpms. That will keep my low end torque and add power when I'm up around 7000rpms.