Y pipe
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Senior Member
Joined: Dec 1969
Posts: 263
Likes: 2
From: west palm, fl
Y pipe
I am going to try a real y pipe with smooth flowing 2.5 inch pipes into a 3 inch pipe. Has anyone done this? I have headers and a gibson single exh. I have used my g tech to document that there is really no change in the performance of the truck and I am now starting to look for the other restrictions in the system. I know the intake horn on the airfilter is a restrictive part of the intake as it is only 49mm in dia. and the y pipe is a poor design.
what do you guys think?
Chris
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98 SC 4.6L stepside, Gibson headers, Gibson single exhaust, superchip, Intake mods, Piaa's, high end audio stuff.
[This message has been edited by cujet (edited 10-31-1999).]
what do you guys think?
Chris
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98 SC 4.6L stepside, Gibson headers, Gibson single exhaust, superchip, Intake mods, Piaa's, high end audio stuff.
[This message has been edited by cujet (edited 10-31-1999).]
Senior Member
Joined: Mar 1999
Posts: 240
Likes: 0
From: HOUSTON,TEXAS,HARRIS
Chris, I've thought about doing the same thing and flowmaster makes a Y pipe 2.5 in and 3 out, it is about $35.00 but it looks like it will take a lot of cutting, bending and welding to get it in. Also, the book says for off road use only????? several months ago someone else was talking about this but I don't know who it was and I don't recall seeing any posts on results. Do it and let us know.
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98 Nascar Edition, Superchip, Airaid, Flowmaster 70 series, bedliner, in bed tool box, Profile bug deflector and window vents, Class III receiver hitch.
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98 Nascar Edition, Superchip, Airaid, Flowmaster 70 series, bedliner, in bed tool box, Profile bug deflector and window vents, Class III receiver hitch.
Senior Member
Joined: Nov 1998
Posts: 102
Likes: 0
From: Ventura, CA
Hey Chris,
My muffler guy is going to cut into my existing Y when he puts on the Flowmaster 70 and 3" piping for me. The stock Y is all made of 2½" pipe, so he'll leave the 2½" pipes coming out of the cats, cut the Y at it's largest point, and weld in a 3" pipe from there to the muffler (and 3" mandrel bent tubing from the muffer out). I know the inside of the Y might get a little ugly from the weld, but having two 2½" pipes come together into one 3" will not result in any backpressure increase (believe it or not, the flow through two 2½" pipes is the same as the flow through one 3" pipe).
Anyway, sorry for rambling and sorry I don't know of a pre-fabbed Y that will fit your needs. If you can wait, I'll post results when I get it installed.
best regards,
Jim
P.S. I had a modified 3" induction tube for the airbox, but recently took it off and put the stock back on. I may go back, but other than quicker throttle response there was no benefit. I am still trying to figure out why I have a bit of a rough idle and I thought maybe it was from the airbox mod, but it wasn't. Oh well...
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'99 F-250 LD 5.4L SC XLT 2WD 3.73LS in White/Silver (w/ EVERYTHING 'cept leather and engine block heater) -- added: SnugTop Hi-Liner & carpet kit, Donnelly electrochromatic/compass mirror, K&N filter, SuperWhite 9007 bulbs, IAS shocks, Mobil 1, more to come... (Flowmaster 70 cat-back exhaust is on order, Westin side bars, electric fan, Superchip, and silver fender/wheel flares are next)
http://hometown.aol.com/jimorama/myh...ollection.html
[This message has been edited by JHerron (edited 10-29-1999).]
My muffler guy is going to cut into my existing Y when he puts on the Flowmaster 70 and 3" piping for me. The stock Y is all made of 2½" pipe, so he'll leave the 2½" pipes coming out of the cats, cut the Y at it's largest point, and weld in a 3" pipe from there to the muffler (and 3" mandrel bent tubing from the muffer out). I know the inside of the Y might get a little ugly from the weld, but having two 2½" pipes come together into one 3" will not result in any backpressure increase (believe it or not, the flow through two 2½" pipes is the same as the flow through one 3" pipe).
Anyway, sorry for rambling and sorry I don't know of a pre-fabbed Y that will fit your needs. If you can wait, I'll post results when I get it installed.
best regards,
Jim
P.S. I had a modified 3" induction tube for the airbox, but recently took it off and put the stock back on. I may go back, but other than quicker throttle response there was no benefit. I am still trying to figure out why I have a bit of a rough idle and I thought maybe it was from the airbox mod, but it wasn't. Oh well...
------------------
'99 F-250 LD 5.4L SC XLT 2WD 3.73LS in White/Silver (w/ EVERYTHING 'cept leather and engine block heater) -- added: SnugTop Hi-Liner & carpet kit, Donnelly electrochromatic/compass mirror, K&N filter, SuperWhite 9007 bulbs, IAS shocks, Mobil 1, more to come... (Flowmaster 70 cat-back exhaust is on order, Westin side bars, electric fan, Superchip, and silver fender/wheel flares are next)
http://hometown.aol.com/jimorama/myh...ollection.html
[This message has been edited by JHerron (edited 10-29-1999).]
Senior Member
Joined: Jan 1999
Posts: 629
Likes: 0
From: Mesa, AZ USA
cujet,
When I had my 97 F150, 4.6L, I dualed it out by cutting out the "Y". The stock tubing size was 2 1/2". Where the driver's side pipe is welded onto the passenger side is where most of the restriction is. First the tubing was reduced, I'd guess and say to 2 1/4", then, the hole in the passenger side pipe is about 2" in dia. Now, if this doesn't but some backpressure on the left bank I don't know what will.
When I had my 97 F150, 4.6L, I dualed it out by cutting out the "Y". The stock tubing size was 2 1/2". Where the driver's side pipe is welded onto the passenger side is where most of the restriction is. First the tubing was reduced, I'd guess and say to 2 1/4", then, the hole in the passenger side pipe is about 2" in dia. Now, if this doesn't but some backpressure on the left bank I don't know what will.
