Curious how many of you opened up the ball flange when you installed.

Really curious if anyone has performance data from unmodified before to modified after...

 

I really didn't have much chance to open it up. They fitment was questionable, and on the drivers side, the ball flange is so crooked, it is almost imposible to fit right. had I bolted it together off the car, and opened them up, it would not have worked once I got it on the car.

 

Mine just went it like it belonged there.

 

Perhaps I should clarify: I'm talking about the 1.9" or so opening they leave at the collector ball flange.

 

I woosed out and just installed mine. I was too afraid of screwing up my $500 + investment. They said they would not take them back if you modified them and there was a problem.

 

Mine are box stock also

 

i opened mine up. i could not install a header with such a small outlet. it looks like the stock manifold outlet...yuck.

 

I'm going to be opening mine up next time I get on a lift. Too small. Figured it'd be easier with the carbon deposits already there as a template.
By the way, about how wide is the diameter once you opened it up?

 

About 2-1/8" - 2-1/4". The downpipes are 2-1/2" OD, which makes the ID about an 1/8 of an inch less, but I didn't shoot for the max. When it's apart for the 350 shortblock, I'm going to open it up to the carbon marks. I'll measure then.

 

five7 i dont know if you recall, but i also opened the ball flange up... hell might as well while everythings new and easy to work with, but i had mine on a lift so that made it easier.. opened it up as much as possible before we put on the ypipe, fit checked first of course and stenciled lines with a pencil for the cuts.

more flow = better

 

More flow doesn't always equal better. Since exhaust comes out in pulses, you can over-do it. I don't think that's the case here, but we need to be sure we understand the conditions before we assume things such as that.

Without any performance data, for all I know Hooker could have done the right thing. I don't think so, and their response to my inquiry about that small opening talked about better sealing and gas speed having dropped by the time it gets to the collector. If they had said the small opening works better than a large one, that would have been a different story.