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

[BLK2012GT]

Is there a difference as far as performance goes between the two sizes of headers?

[Grandpa]

Depends on the amount of air being flowed.

[Phuck Phace]

Go 1-7/8.

[Grandpa]

Go 1-7/8.

That makes sense for a boosted car, not so much for N/A. On motor his car might be a little lazy until he hits the panic button.

[Midnight11]

hes got nawsssss though lol

[Phuck Phace]

That makes sense for a boosted car, not so much for N/A. On motor his car might be a little lazy until he hits the panic button.

Futureproofing, better to put them in now than to change them out later.

[BLK2012GT]

Just got off the phone with Tim and he explained everything.

[Midnight11]

explain what he said lol

[Phuck Phace]

Check this...
http://www.svtperformance.com/forums/exhaust-215/819599-everyone-wondering-about-1-3-4-vs-1-7-8-headers.html

[Grandpa]

Just got off the phone with Tim and he explained everything.

Oh lord... lol.

[TrueStreetTim]

Oh lord... lol.

:Nonono:

As we know; any engine will make its best overall power when treated as a complete system. Let me nerd out for a moment....

As engine speed increases, so does flow rate. As restrictions (collector, converter, muffler, bends etc) increase, velocity reduces power accordingly. Smaller diameter pipes flow less volume than larger ones, but the exhaust in the smaller pipe flows faster. Until you reach the RPM where the sheer volume of exhaust gases require bigger primary tubes. This is the basis for the OP's question.

Essentially; Each header size creates a certain "torque boost". The size of the header determines at what RPM. If you plan to drive the car around all day at say, 3-4.5 RPM, a 1" 5/8 header is your man! Any bigger and you'll lose a noticeable amount of low end torque. 1" 7/8 header lives above 5k where most of you have your fun. Not to mention the Coyote's spin to the 7's. There is no reason not to go for the 1" 7/8 with the Coyote in our opinion....no matter the combo.

[Grandpa]

Depends on the amount of air being flowed.

That makes sense for a boosted car, not so much for N/A. On motor his car might be a little lazy until he hits the panic button.

:Nonono:

As we know; any engine will make its best overall power when treated as a complete system. Let me nerd out for a moment....

As engine speed increases, so does flow rate. As restrictions (collector, converter, muffler, bends etc) increase, velocity reduces power accordingly. Smaller diameter pipes flow less volume than larger ones, but the exhaust in the smaller pipe flows faster. Until you reach the RPM where the sheer volume of exhaust gases require bigger primary tubes. This is the basis for the OP's question.

Essentially; Each header size creates a certain "torque boost". The size of the header determines at what RPM. If you plan to drive the car around all day at say, 3-4.5 RPM, a 1" 5/8 header is your man! Any bigger and you'll lose a noticeable amount of low end torque. 1" 7/8 header lives above 5k where most of you have your fun. Not to mention the Coyote's spin to the 7's. There is no reason not to go for the 1" 7/8 with the Coyote in our opinion....no matter the combo.

That's what I said. lol. :favorites37:

[BLK2012GT]

That's what I said. lol. :favorites37:

Is not

[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.

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!

[Grandpa]

Are you guys seeing any issues with the 02's with the longtubes on these Coyote motors?

[TrueStreetTim]

Are you guys seeing any issues with the 02's with the longtubes on these Coyote motors?

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.

[Toby]

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]

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?

[Phuck Phace]

I have longtube.

[BLK2012GT]

I have longtube.

In your ass:win::chewie:

[Courtesy Flush]

Are you guys seeing any issues with the 02's with the longtubes on these Coyote motors?

Funny you ask, http://dfw50s.com/showthread.php?t=454

been a nightmare and $300 to get this mess fixed.

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.

see link above,

OEM parts have their fair share of problems too, as ive never seen a car with 7k miles(my own)throw an 02 so early with simlpe bolt ons. Given the conditions of my situation i understand the cause, but upon purchase of another OEM replacement 02, it was faulty. :disgust:

From this experience ive began to think its not the absence of cats causing the problem, but the placement of the 02's with LT's being further downstream. My issue was post cat so regardless of if cats were installed, i doubt it would have changed the issue.

Some food for thought for those of you lowered with longtubes, How close is your front 02 bungs to the ground? Connector placement?

Now compare to stock placement and connections. May be a reason for that?

Also i wanted to mention, my 11 SG car had an O/R pipe and stock headers tune and bolted @ 800 miles, never had one issue with the front 02's in 20K miles.

[TrueStreetTim]

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.

[TrueStreetTim]

Funny you ask, http://dfw50s.com/showthread.php?t=454

been a nightmare and $300 to get this mess fixed.



see link above,

OEM parts have their fair share of problems too, as ive never seen a car with 7k miles(my own)throw an 02 so early with simlpe bolt ons. Given the conditions of my situation i understand the cause, but upon purchase of another OEM replacement 02, it was faulty. :disgust:

From this experience ive began to think its not the absence of cats causing the problem, but the placement of the 02's with LT's being further downstream. My issue was post cat so regardless of if cats were installed, i doubt it would have changed the issue.

Some food for thought for those of you lowered with longtubes, How close is your front 02 bungs to the ground? Connector placement?

Now compare to stock placement and connections. May be a reason for that?

Also i wanted to mention, my 11 SG car had an O/R pipe and stock headers tune and bolted @ 800 miles, never had one issue with the front 02's in 20K miles.

I actually talked with my Ford guy this morning to get an O2 shipped. I asked if anything "funny" had been going on with O2's that he knew of. He said no. But then, for the first time, his system asked if the build date was (i think April 2010) or beyond. He said this was new. Perhaps something is developing and we just don't know what....yet.

From this experience ive began to think its not the absence of cats causing the problem, but the placement of the 02's with LT's being further downstream.

Placement is a factor.

Also i wanted to mention, my 11 SG car had an O/R pipe and stock headers tune and bolted @ 800 miles, never had one issue with the front 02's in 20K miles.

Same or different brand?




*Sorry...can't delete my double post.

[Courtesy Flush]

I actually talked with my Ford guy this morning to get an O2 shipped. I asked if anything "funny" had been going on with O2's that he knew of. He said no. But then, for the first time, his system asked if the build date was (i think April 2010) or beyond. He said this was new. Perhaps something is developing and we just don't know what....yet.


Upon ordering i was told there was two 02 part #'s available under my vin #. Both specified as front 02's left and right. One was $120 other was close to $200.
Ill agree, something has developed.
I bought the $120 one it never worked. Took it to shop and they bought another $120 one and it worked. hmm

Same or different brand?

Lethal O/R X on the 11 car

SW LT's and o/r X on the 12.

[Grandpa]

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]

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]

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.

[BLK2012GT]

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

The 5.0s sound different with those then the cobras

[TrueStreetTim]

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]

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 :)

[Grandpa]

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

Hmmm.

[Toby]

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

Simply put, No they will be perfectly fine. Will they clog up faster, sure they will, you are cramming over twice the amount of air through them. The only advantage to swapping just the mid pipe would be to delete the cats. the factory pipe is 3'' as is the aftermarket one you will be buying.

Also installing a set of shorty headers on these cars, is a total waste of material and life! haha The install will be the same as doing a set of longtubes. Spend a little more and actually get some power gains.. my .02

Upon ordering i was told there was two 02 part #'s available under my vin #. Both specified as front 02's left and right. One was $120 other was close to $200.
Ill agree, something has developed.
I bought the $120 one it never worked. Took it to shop and they bought another $120 one and it worked. hmm



Lethal O/R X on the 11 car

SW LT's and o/r X on the 12.

All it takes is a simple rock flying up off the road and hitting the oxygen sensor and it will quit working. The new one you bought could have gotten dropped before you bought it and broke the ''crystal'' inside, i have seen it happen before.

[5PointSlow]

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]

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.

[5PointSlow]

the paxton tune was extremely rich though. If im not mistaken I think our cats might be the same as the 11-12 GT500s