Well Opininions very alot so I said screw it and ordered American Racing Headers w/ catted X-pipe, JLT CAI and a Magnaflowe cat back, I really dont need to piss off my neibors with a crazy loud exhaust at 4:45 in the morning. My local tuner is going to dyno tune it on his Mustang (Brand Name) Dyno. It was a toss up between Kooks and American but I went with American for a few reasons. I will let you know how it turns out. Hopefully I am not Disapoionted.
Good choices. Just be advised that with the ARH headers it's a little tricky tuning the O2 sensors due to their placement. They don't heat up fast enough Your dyno tuner should be able tweak this.
No, the tube length (and diameter) will dictate the rpm range the headers scavenge best at. The diameter of the pipe is a factor in dictating the flow speed. Larger diameter pipes will have a slower flow than smaller diameter pipes. Shorty headers are too short for "effective" scavenging because one exhaust pulse is past the collector before the next exhaust pulse is entering it's tube. (I would guess at some rpm well above our engines redline shortys would start scavenging)
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Equal length shorty headers are by far better than stock. But Long Tube headers are an even better choice.
Question - is an allignment required after a LT header install? A front and rear alignment was recommended, but having read the instructions for the install I am a little suspect both front and rear are required...
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2008 Vista Blue Mustang GT Coupe, FRPP Hot Rod Cams, FRPP 4.10s, Eiback Pro Lowering Kit, Steeda UDP, Steeda CMDP, Steeda CAI with 94 Octane Custom Dyno Tune, Solo Performance Axleback Exhaust, 20" Foose Nitrous Legend wrapped with Falken FK-452.
Question - is an allignment required after a LT header install? A front and rear alignment was recommended, but having read the instructions for the install I am a little suspect both front and rear are required...
why would you need an alignment after changing exhaust? That is pretty funny....
Never even heard of doing a "rear alignment" on an S197. Rear wheels dont steer.
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KB 2.4 IC, KB Stage 2, Level 10 tranny, Kooks 1.75" LT, Powerhouse, FRRP, Moroso, M/T, AFCO, Autometer, Hot Rod Chassis, ST Motorsports, Moroso, Granatelli Motor Sports, Simpson
Well Opininions very alot so I said screw it and ordered American Racing Headers w/ catted X-pipe, JLT CAI and a Magnaflowe cat back, I really dont need to piss off my neibors with a crazy loud exhaust at 4:45 in the morning. My local tuner is going to dyno tune it on his Mustang (Brand Name) Dyno. It was a toss up between Kooks and American but I went with American for a few reasons. I will let you know how it turns out. Hopefully I am not Disapoionted.
If the cats American Racing uses are anything like the ones Kooks uses, your car will still be loud I was very surprised how loud my exhaust got when I installed the Kooks system, even with the cats.
You won't be disappointed.
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2007 GT Convertable
-Steeda CAI
-FRPP Hot Rod Cams
-Kooks Headers & Catted H-Pipe
-Flowmasters
-SCT X3 - Bamachips 93 Race
-American Racing Killer Rims
why would you need an alignment after changing exhaust? That is pretty funny....
Never even heard of doing a "rear alignment" on an S197. Rear wheels dont steer.
Correct... The Mustang doesn't have a 4 wheel alignment.
ARH said that the cats were the highest quality CE approved cats on the market thus the higher price. Two of the individuals worked at Kooks prior to starting this company. They made all sorts of promises on quality of fitment, parts and every thing else. Only time will tell. I havnt heard of anyone else running these headers so those of you out there please chime in. Man I hope im not dissapointed.
Actually the best cats you can get are metallic substrate and they're always an upgrade over ceramic. Not aware of any company that offers metallic cats with their headers.
Long tube headers are okay, on a well modified motor. You'll get just as much, with equal length shorties reason being, they'll scavenge the exhaust gasses better. With a stock motor or mildly modified motor, the longer the tube the slower the flow. Your better off, with equal length shorties and a free flowing catted X Pipe, Mike. SCT Tuner.
The funniest part of this post is how absolutely wrong it is and it’s in BOLD! That’s about as ironic as it gets.
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I get asked why I carry a gun. I tell them its because stabbing people is gross.
explain a lil more?? i would just like to here your explination.
Sure, see below.
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im not saying whos right
You couldn't if you wanted to anyway. You clearly have no idea what you are talking about.
Exhaust flow is fairly irrelevant in the sense that stock manifolds, shorties and long tubes will all flow plenty of exhaust through them. They are by no means a restriction. But with exhaust you are not trying to “flow” exhaust. There is no exhaust flow in the literal sense. There are exhaust pulses (which are little columns of “flow” if you want to get technical) which if timed correctly can be used to increase momentum (scavenging) of the exhaust gases. A simple way of thinking about it is if an exhaust pulse from one tube reaches the collector right as another tubes exhaust valve opens it will create a kind of vacuum in the collector which will help the just created exhaust pulse move faster. Consequently if the timing of the pulse is off a reverse pressure wave can be created that will bounce back against an exhaust pulse and therefore slow down the exhaust gases.
Log style manifolds have no “timing” in them and they are effectively very short tubes dumping into a big plenum and they don’t have a “collector” to speak of. Stock manifolds if they create any sort of scavenging effect is probably by accident. Stock manifolds are so simple that they can be defined by their “flow”. It’s a good thing they have an abundance of it.
Unequal length shortie headers probably don’t have a flow advantage over a log style stock manifold and if they do have some scavenging effect it is by accident again and minimal. What they do have is a collector. I could go on forever about collector design and why some are good and some are bad but the basics are that a collector should help the individual tubes to merge the gases together in an orderly and smooth fashion and therefore increase exhaust velocity. The collector is about the only measurable advantage that an unequal length header will have over a stock manifold.
An equal length shortie again will “flow” the same amount of exhaust gas as a unequal length shortie and not much more than a stock manifold but by equalizing the tubing lengths there is a slight advantage in scavenging effect because of exhaust pulse timing but the primary tubes are way too short to be able to take full advantage of the timing available. They of course also have a collector which will help a little with exhaust gas velocity. The collector design has everything to do with how well that works though and the only nice equal length shorties with a good collector design I have seen is JBA ones. I’ll bet cash money the JBA shorties will out perform all the others on the market by quite a bit.
Now long tube equal length “tuned” headers are the cats a$$. Now the primary tubes are long enough to start timing exhaust pulses correctly (or most efficiently) and since they are so long the collector design can be very good because a long smooth merging collector is the most efficient. I’m pretty sure the optimum length for a long tube header on a 4.6L is 32” or there a bouts, that’s what I mean by tuned length. The length dictates the timing of the exhaust pulses and when they get to the collector. If everything is perfect every exhaust pulse helps the one behind it and it will actually start to “suck” the following exhaust pulse (scavenging) behind it. Tuned length and the timing of the exhaust pulses is the key to making a header work. There is a lot of Voodoo in the design of a great header. Take a look at some NASCAR headers sometime, they are incredible.
Other factors in exhaust performance are the heat inside the tubing. The hotter the gases inside the tube the faster they will flow. That’s why ceramic headers or heat wrapped headers are an advantage, they keep the heat in. On some motors, and I don’t know if the 4.6L is included will see a massive exhaust gas pulse timing advantage by taking one primary from each side of the motor and running them over to the other sides collector. This is a product of the firing order of the motor. Windsor motors are like this. There is a name for that style of header that escapes me at the moment but you don’t see them much outside of pure race cars because obviously packaging is a nightmare. Strangely enough though the X-pipe design came from someone who was trying to mimic this style of header. X-pipes help with exhaust timing and balance. It can almost be looked at as a third collector. H-pipes help with balance only.
One last factor to consider in exhaust performance is if you have FI. The scavenging effect or the desire for it isn’t nearly as critical as a NA motor. Why you ask? Because the exhaust pulses are being pushed out with a lot more force because the next piston that is getting it’s intake charge is being force fed which actually turns the intake stroke into a sort of mini power stroke in the sense it is helping move gases somewhere else in the motor. Now with a FI car the percentage of actual true exhaust flow goes up in comparison to exhaust pulse timing quite a bit because the size of the tubing can now become a restriction and since the exhaust pulses have something behind them pushing scavenging is not nearly as important. A good example of this is that a stock manifold and a equal length shortie header will probably perform almost identically in a FI car. The advantages of the shortie are not very important to the FI motor. A set of long tubes will help out an FI car over the stock manifolds because firstly the tubing diameters are a lot bigger so they simply flow more, and when it’s FI flow starts to be important. And the exhaust gas pulse timing provided by the longer primary tubes and the nice pretty collectors will help, but not as much as a NA car. I imagine that if you sat down to design a FI full length header you would find that the tubing size, primary tube length and the collector design would need to be different than the NA long tubes to be 100% efficient.
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I get asked why I carry a gun. I tell them its because stabbing people is gross.
You couldn't if you wanted to anyway. You clearly have no idea what you are talking about.
Exhaust flow is fairly irrelevant in the sense that stock manifolds, shorties and long tubes will all flow plenty of exhaust through them. They are by no means a restriction. But with exhaust you are not trying to “flow” exhaust. There is no exhaust flow in the literal sense. There are exhaust pulses (which are little columns of “flow” if you want to get technical) which if timed correctly can be used to increase momentum (scavenging) of the exhaust gases. A simple way of thinking about it is if an exhaust pulse from one tube reaches the collector right as another tubes exhaust valve opens it will create a kind of vacuum in the collector which will help the just created exhaust pulse move faster. Consequently if the timing of the pulse is off a reverse pressure wave can be created that will bounce back against an exhaust pulse and therefore slow down the exhaust gases.
Log style manifolds have no “timing” in them and they are effectively very short tubes dumping into a big plenum and they don’t have a “collector” to speak of. Stock manifolds if they create any sort of scavenging effect is probably by accident. Stock manifolds are so simple that they can be defined by their “flow”. It’s a good thing they have an abundance of it.
Unequal length shortie headers probably don’t have a flow advantage over a log style stock manifold and if they do have some scavenging effect it is by accident again and minimal. What they do have is a collector. I could go on forever about collector design and why some are good and some are bad but the basics are that a collector should help the individual tubes to merge the gases together in an orderly and smooth fashion and therefore increase exhaust velocity. The collector is about the only measurable advantage that an unequal length header will have over a stock manifold.
An equal length shortie again will “flow” the same amount of exhaust gas as a unequal length shortie and not much more than a stock manifold but by equalizing the tubing lengths there is a slight advantage in scavenging effect because of exhaust pulse timing but the primary tubes are way too short to be able to take full advantage of the timing available. They of course also have a collector which will help a little with exhaust gas velocity. The collector design has everything to do with how well that works though and the only nice equal length shorties with a good collector design I have seen is JBA ones. I’ll bet cash money the JBA shorties will out perform all the others on the market by quite a bit.
Now long tube equal length “tuned” headers are the cats a$$. Now the primary tubes are long enough to start timing exhaust pulses correctly (or most efficiently) and since they are so long the collector design can be very good because a long smooth merging collector is the most efficient. I’m pretty sure the optimum length for a long tube header on a 4.6L is 32” or there a bouts, that’s what I mean by tuned length. The length dictates the timing of the exhaust pulses and when they get to the collector. If everything is perfect every exhaust pulse helps the one behind it and it will actually start to “suck” the following exhaust pulse (scavenging) behind it. Tuned length and the timing of the exhaust pulses is the key to making a header work. There is a lot of Voodoo in the design of a great header. Take a look at some NASCAR headers sometime, they are incredible.
Other factors in exhaust performance are the heat inside the tubing. The hotter the gases inside the tube the faster they will flow. That’s why ceramic headers or heat wrapped headers are an advantage, they keep the heat in. On some motors, and I don’t know if the 4.6L is included will see a massive exhaust gas pulse timing advantage by taking one primary from each side of the motor and running them over to the other sides collector. This is a product of the firing order of the motor. Windsor motors are like this. There is a name for that style of header that escapes me at the moment but you don’t see them much outside of pure race cars because obviously packaging is a nightmare. Strangely enough though the X-pipe design came from someone who was trying to mimic this style of header. X-pipes help with exhaust timing and balance. It can almost be looked at as a third collector. H-pipes help with balance only.
One last factor to consider in exhaust performance is if you have FI. The scavenging effect or the desire for it isn’t nearly as critical as a NA motor. Why you ask? Because the exhaust pulses are being pushed out with a lot more force because the next piston that is getting it’s intake charge is being force fed which actually turns the intake stroke into a sort of mini power stroke in the sense it is helping move gases somewhere else in the motor. Now with a FI car the percentage of actual true exhaust flow goes up in comparison to exhaust pulse timing quite a bit because the size of the tubing can now become a restriction and since the exhaust pulses have something behind them pushing scavenging is not nearly as important. A good example of this is that a stock manifold and a equal length shortie header will probably perform almost identically in a FI car. The advantages of the shortie are not very important to the FI motor. A set of long tubes will help out an FI car over the stock manifolds because firstly the tubing diameters are a lot bigger so they simply flow more, and when it’s FI flow starts to be important. And the exhaust gas pulse timing provided by the longer primary tubes and the nice pretty collectors will help, but not as much as a NA car. I imagine that if you sat down to design a FI full length header you would find that the tubing size, primary tube length and the collector design would need to be different than the NA long tubes to be 100% efficient.
Squidd you are like a Mad Scientist.I read this like 3 times, and only understand 3/4 of it maybe a bit more. It is just the most technical write up on headers I have ever seen. This is a compliment so do not take it wrong. I will read it again in the morning , I am worn out from getting my car ready for a car show tomorrow. Oh yea shorty or shortie who knows. good night!
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Airraid CAI/BAMA tune,moto blue pullies,3:73`s,LPW girdle;Powerhouse DS,CHE safety loop,CHE LCA`S & Adjustable UCA,Kooks LT`S & O/R X Pipe,prothane MM`s,Steeda CMDP`S,Eibach springs,Tokico D specs,Polished TB(by Me),Steeda radiator support,MT DR`S,Zex kit 100 shot. Taylor Relocation batter kit and cut off switch
11:933 ET, 1.674 60`,111.877 MPH
I fail to see any relationship.
I was very surprised how loud my exhaust got when I installed the Kooks system, even with the cats.
