X-Pipe: Advantage?

[whoops]

Hi,
I'm wondering what the advantage of an x-pipe is? I have one sitting in my garage for my '89 that I'll put on after emissions, but what can I expect to gain?

It's an '89 LX 5.0L with an AOD

Thanks,
Justin

[TwiLighTBluEGT]

If your motor is basically stock on top of an AOD, then the only thing you can really expect is to lose some low-end torque. All it will really do is make your car louder.

[whoops]

Well that sucks. This thing already lacks considerably in low end torque. Taking off the line is agonizing.

Justin

[TwiLighTBluEGT]

Get a set of 4.10's and a 3000 non-lock up converter and you'll never be happier

"the only thing you can really expect is to lose some low-end torque. All it will really do is make your car louder."

WHAT??

You may lost some low end torque, but I'd seriously doubt you'd be able to feel it. The gain in horsepower in the upper RPMs will more than make up for it! You are removing 4 constrictive catalytic converters...you are going to feel an improvement, and definitely hear it!

[TwiLighTBluEGT]

ow, i guess for some stangs, you can feel the increase. But I sure didn't notice any hp increase when taking the cats off my *AOD* stock mustang. After installing my off-road pipe, it was harder to break the tires loose. But gears made up for that :-)

[Dark_5.0]

I knocked off 4 tenths in the 1/4 and picked up 3 mph with mine.

I guess my cats were clogged.

You will definitely pick up some HP and I doubt you will lose any torque.

Go for it,

[jim_howard_pdx]

Man you guys SHOULD LEARN before you speak out. An H pipe and an X pipe accomplish the same thing, they allow the on-fire order cylinders on one bank to scavange the off-fire cylinders on the opposite bank.

This IMPROVES LOW END TORQUE GUYS. ALOT OF IMPROVEMENT.

An H pipe will give most cars about 4-8 HP. An X pipe is more efficient and will give you 10-13 HP.

If you have one USE IT. By the way, the X pipe or H pipe will also make your car 4-8 db QUIETER. By allowing the off-fire cylinders to equalize into the second exhaust pipe, it reduces exhaust pulsations that generate the "beating" you hear with non-equalized exhaust systems.

Now bolt up that X flow system and ENJOY. IT IS FREE HORSEPOWER WITH NO NEGATIVE CONSEQUENCES.

[TwiLighTBluEGT]

ALL I AM SAYING IS THAT I DID FEEL A LOSS IN LOW END TORQUE. AND I KNOW FOR A FACT IT IS BECAUSE OF MY OFFROAD H-PIPE.

[jim_howard_pdx]

You cannot measure a car's performance by how it feels driving it. "I cannot break the tires loose, or not as easily." You either need a chassis dyno, or take it to the track.

Mustangs will typically pick up about .1 to .2 seconds with the X Flow, proper pipes and mufflers. You can pick up .3 by going to a 2,500 RPM stall converter on your AOD. Add a better upper and lower intake, bigger injectors, and set the timing right and you can lower the ET by a full second. Add 3.73 or 3.90 gears and you are in the 13's for sure, and many are running 12 second times with this combo with an E cam and 1.7 roller rocker arms.

If we all set up our cars to break the tires loose, we would have huge monster torque engines efficient from 600 rpm to 2,500 rpm. This is not where races are won or lost.

The reason why your low end torque went away is that CATs are highly restrictive. They showed the engine a lot of backpressure which improves low end torque. You could gain that back by going with a 2" exhaust but then if you add the CAT back in, you will have NO POWER.

My Mustang has 2.5" exhaust tubes, and of course it is pre-CAT. I would have more HP if I went to a 3" exhaust, but it would not be as good coming out of a signal, and it would get poor gas mileage. So there is give and take with any choice you make. Unfortunately in exhuast systems you cannot have your cake and eat it too. You chose the rpm where you want the most torque, and you size the exhaust to tune into that max torque.

If you add HI FLOW CATS back on your H tube exhaust, you will regain some of the torque you lost off idle. For the same money, I would just bump up your stall converter to 2500 RPM and enjoy the extra HP and the half second faster time slips.

[Sonics2042]

Originally posted by jim_howard_pdx
Man you guys SHOULD LEARN before you speak out. An H pipe and an X pipe accomplish the same thing, they allow the on-fire order cylinders on one bank to scavange the off-fire cylinders on the opposite bank.

This IMPROVES LOW END TORQUE GUYS. ALOT OF IMPROVEMENT.

An H pipe will give most cars about 4-8 HP. An X pipe is more efficient and will give you 10-13 HP.

If you have one USE IT. By the way, the X pipe or H pipe will also make your car 4-8 db QUIETER. By allowing the off-fire cylinders to equalize into the second exhaust pipe, it reduces exhaust pulsations that generate the "beating" you hear with non-equalized exhaust systems.

Now bolt up that X flow system and ENJOY. IT IS FREE HORSEPOWER WITH NO NEGATIVE CONSEQUENCES.

If you are telling me a stock car is louder than a car with an O/R h-pipe or x-pipe, then you must be insane! (Please tell me I am misundertanding you).

[TwiLighTBluEGT] I don't know how you would lose power download with the h-pipe...only thing I can thing of is maybe the loss of backpressure, but unless something is wierd with your car, I don't see that being the case.

H-pipe provides a increase in overall performance, but gives power most noticably down low. X-pipe increases overall performance, but gives power most noticably up high.

Both of them make your cars MUCH louder (Only can verify this on V8 engines from 1987-2002). After you do your emissions, throw it on with an exhaust, and if you don't like it you can always go back to stock .

Thanks,
DoranW

[jim_howard_pdx]

Loud is a function of noise cancellation done by the muffler, not by the exhaust tube diameter.

You can go 3" 4" or 5" pipes and still be as quiet as stock. You just have to use a stock/restrictive muffler.

As you add horsepower, you do create MORE exhaust and sometimes the unburned fuel will continue to burn in the headers as the fumes exit the combusion chamber. That happens in all my high overlap engines, and it will make for a really weird exhaust noise if you try to use regular mufflers. They will eventually blow out as they collect fuel and then explode......

We used to run Chrysler Hemi mufflers on our big blocks in the 70's. It would be a little more rumble than a stock exhaust, but it would sound really tame. But the things were made to exhaust a 435 hp engine, so the flow and the backpressure were great for a street ride. I know several muffler shops that highly recommended these before the delta flow style flow tech mufflers came around. Now everyone is back into LOUD.

I am using Edelbrock's RPM stainless mufflers and they are a good mix between loud and soft. The chrysler hemi mufflers are quieter and I feel they flow just fine for a street car.

Again, the X flow or H pipes by themselves do not make the exhaust LOUDER. They just allow it to all flow better. Muffler choice is where the LOUD can be tuned up or down. The quieter you go, the more top end horsepower you lose.

The best of both worlds is an exhaust system cut off, run quiet through the mufflers, or switch to open exhaust when at the track. This is a really fun way to go, but adds about 200 dollars or so to your budget and if you try running the bypass on the street, the ticket can be upwards of $350.00.

[Dark_5.0]

My car is quiet as hell with my X-pipe and I have 2 chamber flow masters.

I have 1 5/8 equal length headers off road x pipe and 2 chamber flow masters, and it is quieter now than it was stock.

[moc]

Don't do it , go with a nice 2 1/4 system

[MEDIK418]

In case anyone is interested! August 2002 issue of 5.0 magezine. There's a test on a X-pipe install complete with dyno figures for before (H-pipe) and after. True to form it lost a substantial amount of power, both torque and horsepower below 2800 rpm. It more than made up for it from there up. Granted this was on a blown 2000 GT but it does show a difference. All total, it increased output by 34 horses and 21 lb.ft. of torque.
Facts is facts (if you believe the article)

[jim_howard_pdx]

I warn everyone not to take too much from a magazine article. Rarely do they do baseline dyno testing, and then change a single item at a time.

If I remove a stock exhaust system that is designed to make maximum torque figures from 1800 to 3600 rpm, and then add a system with larger diameter pipes, no CAT or use a hi-flow-CAT, and then use a hi-flow muffler, then YES YOU CAN EXPECT TO MOVE YOUR TORQUE RANGE UP THE RPM SCALE.

However, if you leave the stock CAT and stock muffler on the car, then the x pipe will deliver about a 10-15 hp difference. It will be at least 2-4 hp more than an H pipe system. It will be quieter than stock, and the HP and torque will be FREE since it is just allowing your engine to pump air at greater volumetric efficiency in its operating range.

You gotta love the magazines. I read one article today that said a fairlane running a 347 stroker and K code cast iron exhaust put out 206 hp on the chassis dyno. A change to Hooker Super Comp headers raised the horsepower to 308 hp.

Now what idiot bolts together a 6,000 dollar free breather, and then chokes it to death with a cast iron exhaust system that cannot deliver even 1 hp per cubic inch. Then they claim the Hooker headers increased the horsepower. THEY DID NOTHING. The K code headers CHOKED OFF 100 HP!!!!!

Now test the Super Comps against FlowTech, Hedman, JBA, or some other good headers and you will see that they add about 8-10 hp more than street style headers. This is good journalism. 100 hp is IDIOCY USING A PEN.

[MEDIK418]

I so sorry. . .I meant not to make assertions that the article did anything but seek a way to improve flow by installing the X-pipe. This was part of the reason for the original query. I cannot imagine adding anything in the way of an exhaust system that didn't flow better than a stock piece. Whether the X-pipe is actually better than an equal size H-pipe is yet to be seen by me. Increasing collector volume would be accomplished either way and in theory I suppose the results would be similar since scavenging shouldn't be affected by the reduced flow restriction the X-pipe might provide. Equalizing exhaust pulse reversion would seem to work better if it didn't have the crossover pipe to contend with and the right angles that go with it but then, I guess I need to go find that turnip wagon and climb back on afore I get myself in trouble. I merely offered the article and the information it provided along with a disclaimer for those who feel threatened by the written word.

[jim_howard_pdx]

No Medic, you are cool!!!

I just hate the magazines because they do not test one item at a time. They just want to sell rags, so they go for the cheap and the simple. The bad thing, is that they rarely help someone make the best decision for their car.

An H pipe like mine is easy to work with. Disconnect the collectors and access to the drive shaft and tranny is excellent. On some X systems, the ground clearance is compromised, the ability to work on something else is compromised, and in the end is the extra 2-6 horsepower on a street driven car worth the hassles and problems down the road.

You should not think of your H pipe as a right angle. Air is almost identical to water in engineering terms. As the fluid (air) moves past the H tube it creates a vacume in that tube that pulls fluid from the other pipe. All this simple H pipe does is show EACH of the two pipes a vacume signal at all RPM ranges. This helps scavange the cylinders better. The improved flow is similar to increasing the diameter of the exhaust tube, but without the effect of raising the torque curve.

An X pipe and an H pipe theoretically should provide the same flow. As the exhaust expands out of the combustion chamber it violently pounds side to side along the pipe as it moves down the length of your exhaust. It literally "Rings" back and forth as it moves down the line. I think it is the reverberation of the exhaust pulses ringing back and forth across the 90 degree H tube that reduces its vacume efficiency. Since the X pipe shows a 45 degree angle to the reverberant energy it is less affected than the 90 degree H tube. I think this accounts for the .5-1.5% improvement in horsepower. To test this, you could have an H tube welded in at a 45 degree angle instead of the 90 degree angle. However I suspect that the exhaust guy would have you committed for insanity before they would weld like that.