Can someone tell me what the outlet size ( where the flange is ) is for the SS Headers. Is the pipe diameter 2 1/2 or 2 1/4 ?? I already istalled mine. Thanks.

 

2.50" but this is not to suggest that the outlet pipe size be that size. More than one car is running strong on stock 50mm (1.97") piping and some with 2.50 (against recommendation) are not getting as good of low end torque. The suggested size is still 2.25" although 2.125" may be even crisper but obviously not a common pipe size. S&S does carry 2.125"

So you have installed yours? Impressions? What did you do for the rest of the exhaust system?

 

Thanks, is the hole in the end of the header 2.5 ? I'm a little confused about the statement about outlet pipe.

PS check you PM . Thanks

 

do yo mean this distance?

 

Yes, the hole in the flange as you show is 2.50". Outlet pipe size refers to the size pipe from the catalyst outlet. For people not using cats or relocating the cats (early LS and SC cars) the recommendation is for the downpipe size to be 2.25" with 2.00" and 2.125" being acceptable sizes. Going too large will not make more power and will reduce velocity in the low to mid RPM range and this is where people complain of a loss of low speed torque/power.

 

The very few who have complained dont really depict an accurate result of the piping differences IMO.

 

OK I am having a problem mating the Pipe off the end of the header. It's not at all a header problem. Now I think I should have gotten those optional flanges for my 97 Sc400 but did not know I needed them at the time.
A few questions ? :

1. Is the flange a 3 inch BOLT partten collector flange with a 2 1/2 inch hole, or a 2 1/2 inch bolt patten flange with a 2 1/2 inch hole ?

2. How are people necking down the 2 1/2 inch header outlet hole down to 2 1/4 and 2 inch ? Are they using a short expansion of 2 1/4 pipe expandered at the flange to match 2 1/2 ?

Anybody got pics of the joint of the headers outlet end to a CAT or straight pipe ?