I have a stock 396 in 58 Chev pickup. I am looking to change out to headers and 3" gl***packs, most likely the Cherry Bomb 12". My question is, which would be better, an X or H style crossover pipe. Plus, is there difference between the two.
The only real issue will be: Do you want to drop the x-pipe everytime you need to do something with the ******? If the answer is, "why not" - then I say X-pipe for sure!! Advantages, while the H-pipe offers a sort of equal pressure state to both sides of the exhaust, the x-pipe offers scavenging via the vacuum created as the exhaust crosses and velocity increases. Increased scavenging equals more efficient use of the combustion chamber because a fresh mix can be drawn into that combustion chamber due to the fact that all spent fumes are now completely gone. X-pipes also offer that mellower Nascar tone because both sides are working in tandem... so you also lose harsh exhaust tones. On a typical 350 hp set-up you can expect to gain 15 to 25 hp....sooo x-pipes all the way. And BTW: IMO H-pipes are a waste of money when given the choice between the two...
X-pipe makes power and reduces noise 3-5db, but gives your ride a different sound (read: non-traditional). H-pipe picks up the torque a bit, but I don't think they're worth installing. Packaging is an issue on lowered vehicles.
Poltax, I'm in the same boat as you with my '56 chevy pickup. My plan is to have flanges at both ends of the x-pipe so I can drop it out when I need to do a clutch or swap the ******...
Maybe this isn't a consideration, but a freind and I have the same basic engine combo with the same cam. His has an X, mine has an H and mine sounds much more radical than his. I'll take that 3 hp loss to get a better sound, but if you need every last pony on the street, I suppose thje X is the way to go.
I KNOW these help with performance, but IMO, V-8s sound A LOT better without them. I won't use one again, I will find the 15 to 25 HP somewhere else if I need them. About an hour ago I finished putting new Smitty's and exhaust on the Lincoln, no X or H, it SOUNDS freakin *****in... Oh yea, if you end up running an H or X, I have heard that the PLACEMENT is way important if you want it to do any good. There is some formula that shoud be used and/or look for the "hot spot" on the pipes (yea I read somewhere that the best way to place the H or X is to run the exhaust first so the "hot spot" shows on the pipes, and then install the H or X) for proper placement.
I have a x pipe and I love it, cruising RPM is so much better sound level wise. If your worried about sound don't bother with it, because if quieted mine down. I don't care though, if I want more sound I'll build a stronger motor.
I've heard that too. I remember something about spraying the exhaust pipe with rattle can paint, then running the engine. Where the paint bakes off to, is around where you should place the H. Of course ****** clearance factors in to it as well. Not 100% sure this is the best way to do it, but thats what I remember hearing...
I can remember the first X pipe I saw. I just can't remember the exact date. I thought then and still think now that it is a gimmick when compared to an H pipe. It looked cool and different and it became a winner. Someone could look at it and see that you had the latest in new ideas. Performance wise, I think it would hurt more than help when compared to an H pipe. If you look closely at the intersection, the cross section of the pipes is reduced in that area in most of the ones that I have seen. At least with the H pipe there is no reduction in the pipe cross section. The first ones I saw were done by muffler shops to be different and not the result of extensive testing for performance. The balance tube in an H pipe is exactly that...it balances the pulsating pressures on both sides. Usually 1 7/8" in diameter. I'm sure that the manufacturers of the X pipes have do***entation that they paid for to refute my ideas but I tend to take what a salesman says with a grain of salt. The new must have gimmick (IMHO) is the stainless flex pipes that are showing up in the high dollar show cars. What for?? We've been putting dual exhaust on front engine rear wheel drive V8 hot rods for over 50 years...now all of a sudden we need flex pipes??? "Build it and they will come"...tell them that they need it and they will eat it up. I doubt that either is much better than the other. I myself want the sounds and don't run either even though it wouldn't cost me anything. JMHO
I agree with all of this,,,, while it may be "best" to install an X or H, but I like the sound of "true duals". I am not talking about how loud a car is, but for me, the use of an H or X pipe changes the SOUND of a V-8 exhaust, and this change is NOT something I prefer. Funny how all of these "must have" improvements are seldom cheap. My 07 Chevy used one of those "flex pipes" from the factory. I became aware of it when I installed my new Borla exhaust, I had never seen anything like it before. Anyway, it went away when the new exhaust was installed. For me these flex pipes were a curiosity, but not something I would put on a "show car", I don't think that they are that atractive...
so i got this 54 and i wanna slam it,, would an x pipe behind the rearend (ie: after the mufflers),, what would placement There do?
Scientific theory and actual numbers are what I rely on, and so I have to completely disagree. The reason for the "hot spot" is that that is the point at which the fumes are their hottest. Hot air is more compressed than cold. As the air expands it seeks to escape the confinement of the area where space is at it's minimum which is at the X itself. Since the end of the exhaust is open and the engine is pumping air out, the VELOCITY of the airflow is toward the mufflers. As velocity increases it creates a vacuum effect which scavenges the cylinder, which aids in drawing in a new fuel mix creating a perfect environment for total combustion. You guys really shouldn't speak off the cuff unless you KNOW what you're talking about here. Also, NASCAR uses them for a reason...they don't spend extra money for looks or gimmicks. And finally, dyno numbers don't lie. A properly installed x-pipe will be FAR superior to an H-pipe as far as HP is concerned...period. Now, if you don't care for the sound then that's an individual matter of taste...to each his own. But don't go offering unfounded information based solely on an opinion...k?
Behind the rearend the exhaust is already cooling down and it will create to much backpressure. The hot spot as described above is the optimal place. Every exhaust system will have it's own perfect hot spot.
on that truck I'd do an H.... the X gives a higher tone. That BBC would sound better with an H... This comes from 32 years of doing muffler work. THE X or H always goes before the mufflers!!!
Thanks Buzznut, So an x pipe is prolly not gonna work out on slammed vehicle i'm guessing, or could i put it under the drive shaft (or wherever that "hotspot" is at) and still have clearance to slam out?
AD, that is also a concern of mine. Since I really want an X-pipe because I know what they do and how well they do it, I'm going to cross that bridge when I get there. Main rule of thumb on a slammed vehicle is getting everything ABOVE the scrub line - scrub line is where the vehicle would sit if you're tires were completely deflated. Of course, when you take into account approach angle UNDER the vehicle (which is a consideration when on an uneven or undulating surface) as well as speed bumps, etc... My guess is that I'm going to want to be a few inches above the scrub line. There is ONE exception to wether or not this will even be a consideration or potential problem. Some pickups when converted to a V8 used the typical corner bolt/post type engine mounts. These mounts hang the engine (and subsequently also the ******) LOW in the frame. While others used the crossmember style engine mount which actually moves the engine slightly forward and a few inches upward in the frame (depending on which manufacturer crossmember you have installed), If the crossmember style was used then your ****** is ALSO up closer to the floorboard and you have more play room to stick in a crossmember. I personally am considering swapping to the crossmember style. The engine appears to fill the engine bay better, the upper half of the engine is more accessible, you will have MUCH less potential of center punching or bottoming out the oil pan, the distributor is further away from the firewall, and an x-pipe is more apt to fit and clear. How WILL however need to have a longer driveshaft AND you will also likely need to cut a larger hole in the floorboard to make room for linkage. Also, if you have an automatic the kickdown linkage needs to be taken into consideration. Transmission mount will either need to be thicker or ****** crossmember may need to be moved as well. It's not a "quick" fix, but it is a good one... AFTER ALL OF THAT I still say see if it will sit a few inches above the scrubline before you make any radical decisions or write it off completely. Guys shave lbs to add TENTHS of seconds and ad go fast goodies to gain HORSEPOWER. IMO an x-pipe is a HUGE bang for your buck...try finding 15 to 25 hp with ANY other $100 to $150 modification... and if you do, PLEASE tell the rest of us about it. PLUS, I think the exhaust tone sounds awesome! Especially with a good set of Flowmasters or MagnFlows... and Cherry Bobs sound sick!
LOL...that made me laugh. Not at you, just at how it really isn't traditional at all. But still, neither is a new set of forged pistons either, but since you don't see them...no foul...IMO.
we put x pipes on camaros and novas in highschool. they sounded bas ***. it also has the scavenge-ing effect others mentioned. they were too hard to make either. we just used two 3in 90deg bends ands cut them up back to back. never been too into the H pipe...but thats just because we always ran the X pipes. the best thing to do in all reality is to find the sound you like and do what you can to mimic that system.
X-pipes give a more even tone at idle and remove the harmonic dissonance at around 2000 to 3000 RPM (you know, the tone that vibrates your eardrums and makes you feel a little queazy) so if you like the REALLY lopey exhaust tone then x-pipes probably aren't for you...
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