i have short headers and a custom y-pipe made and at the Y(T in my case) it has a 2"OD pipe with a bend in it pressing it down even more. i put a fuel pressure guage in the 02 thing and reved it in park at full throttle for about a second or less. it goes up to about 7-10 psi. how much do you think it hurting as far as horse power? before when i had the log manifolds it had more power because of the bigger 2.5" pipe after the T. all of the shops around here say its not hurting much at all but they don't seem to want to work on it either, one guy even said he wont work on it. the same guy also said its not hurting because the pipe gets bigger as you go back(i have a 3" catback) just wondering what you guys think.

BTW, its a 283 but its pretty powerful for a small engine like that, a LOT faster than a stock 305.

 

also, what is the summit # for the hedman headers that come with the y-pipe?

 

they are 2 diff part numbers... the headers and the y pipe.

the ypipe isnt in the catalog. you will have to call anyway...




as for your backpressure question... i donno....

athough it makes me want to see what my stock exhaust has, before i put headers on it.

 

In my opinion, that's a lot of pressure. I haven't ever hooked up a gague like you did but that sounds like a lot. Forcing everything from a moderate displacement V8 engine through a single 2" (or smaller) pipe is definitely costing you HP.

I would suggest calling the header manufacturer to see if they make a y-pipe that fits those headers as installed in a 3rd gen f-body. It should have at least 2.25" down-pipes transitioning (smoothly- not a "T") into a single 2.75-3" collector pipe on back to the rest of the exhaust. If they don't offer one you might want to find a shop that does good custom exhaust work.

I am fortunate that I have such a shop near my house. They do stuff that is, quite frankly, magical to a hack like me. Pipes passing through crossmembers, around trans linkages, etc. Shoehorn operations that look and flow like a million bucks after they are done.

 

Always remember that the closer the restriction is to your engine the more HP it costs you. In other words, having a strangulated y-pipe will cost you more HP than skinny tailpipes.

 

they are flowtech headers and the y-pipe they make isn't much better. its a T and a 2.5" after the T.

i would have a shop do it but i can't find a shop that will do anything besides put a 2.25" in place of the 2" i already have. they all have excuses like "we can't make a bend off the headers" or "if you use any bigger pipe it will drag on the ground" theres so much of that that i think it would be better to just get the hedmans. but then i hear that they have problems fitting.

if i had a welder i would just cut a bunch of angle peices out of a 3" pipe and weld them together to make a bend. i tried this dry fitting them together and you could make fairly smooth sharp bends. doing this would be a little better than a peice of pipe you can fit your fingers around.

 

Maybe you could start with a 3" y-pipe designed for a different set of headers and then have the shop just replace a short portion of the down-pipes to fit your particular headers. That shouldn't be too difficult a job for a decent shop.

Pick a y-pipe that works with a set of headers that are similar to your flow-techs (shorty-style headers maybe start with a y-pipe from Hooker Super Comps or Edlebrock TES headers, etc.)

It's the Y-junction that seems to make most shops run for the hills.

 

who makes your headers?




i orginally bought headmans without the y pipe when i had my 82...

i tried making a y pipe...... after 3 attempts i realised how hard that acutally was to do RIGHT.....

i evntually bought headmans y pipe and everything went perfectly after that.

 

flowtech makes a y-pipe that is similar to mine exept it has a 2.5" after the T. i'm planning on putting in a 350 with about 300-350hp. how much do you think a y-pipe like a hedman with the 2.5" into 3" would be worth over the 2.5" flowtech. i'm not looking for every ounce of power, just not choking the engine off a ton. if the HP with the hedman Y is less than about 15-20hp than i'm not too woried about it.