Difference in 1 5/8 and 1 7/8 LT headers

[Courtesy Flush]

The pypes headers are what i wish i went with, even with all their bad rep with fitment and quality. Seen quite a few guys running em and making good power. Stepped header design 1 5/8ths stepped to 1 7/8th into a 3 inch collector.

Best of both worlds? could be.

Wouldn't know as i went with the 1 7/8th SW setup personally, very exotic sound with these headers when you creep into the top of the rpm band.

[TrueStreetTim]

Check this... http://www.svtperformance.com/forums...8-headers.html

Nice, yo. I like how they concluded that no TQ was lost which is to be expected. Shorty's to LT's would show a loss but, again, only up to its volumetric efficiency.

Originally Posted by Courtesy Flush The pypes headers are what i wish i went with, even with all their bad rep with fitment and quality. Seen quite a few guys running em and making good power. Stepped header design 1 5/8ths stepped to 1 7/8th into a 3 inch collector.

If it were a carbureted, open header car 110% yes. The smaller diameter section on a stepped design helps to scavenge the gases out of the motor making the cylinder more efficient. Non-carbureted cars, and especially the Coyote, we are able to tune each cylinder individually (bonus)! Once you bolt on an exhaust (with its added restrictions), no matter the platform, the design fails and negates all advantages. Feel good about your purchase, man!

[Toby]

Originally Posted by Courtesy Flush The pypes headers are what i wish i went with, even with all their bad rep with fitment and quality. Seen quite a few guys running em and making good power. Stepped header design 1 5/8ths stepped to 1 7/8th into a 3 inch collector. Best of both worlds? could be. Wouldn't know as i went with the 1 7/8th SW setup personally, very exotic sound with these headers when you creep into the top of the rpm band.

Pypes are complete and total junk! I have only successfully installed one set that actually fit without modification, and that was today on a 3v mustang. I have tried a set on almost every mustang out and not a single set was even close to fitting correctly.


1 7/8 is the only way to go on the new 5.0's. anything else will be leaving power on the table. With these new 5.0's they make so much power so efficently, that they need all the help getting the air out they can. I highly doubt that on the same day and same conditions if the 1 7/8 lose any hp or tq at any rpm to the 1 5/8. Keep in mind, even though they are only 302 ci, they move a tremendious amount of air!

[Grandpa]

Originally Posted by TrueStreetTim To a degree.....yes. If there is anything in common, maintenance wise, is I get calls about O2 codes. Typically with replaced headers, yes. But also those without. But keep in mind, no cats will kill them especially fast by comparison. If you decide to change your sensors out, make sure they are OEM straight from Ford (not Bosh etc.) Tuning has shown us that the aftermarket sensors heat up and cool down just differently enough than OEM to possibly throw codes.

Knowing it would leave some HP on the table, but do the stock cats overheat if the stock midpipe is left in place?

[TrueStreetTim]

Originally Posted by Steve Knowing it would leave some HP on the table, but do the stock cats overheat if the stock midpipe is left in place?

I like where your going with this.

Not so much the heat as it would also be the added pressure from a higher flowing header. Especially if the car is S/C'd....you'll blow it apart! And without a tune after your header swap, you'll 100% throw codes. The midpiping must be replaced, along with the cats (or none), with a header swap!

ARH is already manufacturing a shorty header for the new Camaro and promise to have the Mustang shorty available early next year. The design meets EPA and will not require a midpipe setup (or tune i believe) to bolt to the factory system. A cheaper option for folks. But if you get anything other.....don't try to use the factory piping & cat's.

[Grandpa]

Originally Posted by TrueStreetTim I like where your going with this. Not so much the heat as it would also be the added pressure from a higher flowing header. Especially if the car is S/C'd....you'll blow it apart! And without a tune after your header swap, you'll 100% throw codes. The midpiping must be replaced, along with the cats (or none), with a header swap!

What about with the stock headers? Will the stock midpipe live a long happy life with a power adder? I'm asking, because I don't want this car to be obnoxiously loud. My little girl rides in this car often and I rather not she be deaf by the time she is five. lol

[Phuck Phace]

Originally Posted by Steve What about with the stock headers? Will the stock midpipe live a long happy life with a power adder? I'm asking, because I don't want this car to be obnoxiously loud. My little girl rides in this car often and I rather not she be deaf by the time she is five. lol

If you want it quiet just get the magnaflow street series mufflers, they are still quiet without cats.

[Grandpa]

Originally Posted by Phuck Phace If you want it quiet just get the magnaflow street series mufflers, they are still quiet without cats.

Not a fan of Magnaflow at all. I had them on my Ferminator and hated the way the exhaust sounded.

[TrueStreetTim]

Originally Posted by Steve What about with the stock headers? Will the stock midpipe live a long happy life with a power adder? I'm asking, because I don't want this car to be obnoxiously loud. My little girl rides in this car often and I rather not she be deaf by the time she is five. lol

I see no reason why the midpipe itself would be an issue. It's the cats that need to be a high flow design with a power adder. Maybe look to an H-pipe with high flows into your soon-to-be GT500's perhaps? Or just high flows alone will suffice. Toby may have a better opinion on that.

[Courtesy Flush]

Originally Posted by TrueStreetTim I see no reason why the midpipe itself would be an issue. It's the cats that need to be a high flow design with a power adder. Maybe look to an H-pipe with high flows into your soon-to-be GT500's perhaps? Or just high flows alone will suffice. Toby may have a better opinion on that.

I have a set of high flow cats for sale Steve. They are shiny like your wheels

[5PointSlow]

Originally Posted by Steve What about with the stock headers? Will the stock midpipe live a long happy life with a power adder? I'm asking, because I don't want this car to be obnoxiously loud. My little girl rides in this car often and I rather not she be deaf by the time she is five. lol

There is a guy on SVTP (ruswolf i think) that melted his stock cats basically after installing the paxton. the tune just tore them up.

[Grandpa]

Originally Posted by 5PointSlow There is a guy on SVTP (ruswolf i think) that melted his stock cats basically after installing the paxton. the tune just tore them up.

I figured as much that would happen at some point.