Nice article, so you're saying replacing my stock intake manifold with an LS6 style would be a better improvement vs. Headers if I was going with FI?

 

the mids wont pass as well... i have some pacesetter shorties that were noticably better, hence i had wonderful '99 manifolds

 

Get a turbo set up.

 

I just got some JBA shorties and puttin them on now. Got them used for really cheap so I figured it would be worth it. After seeing the two manifold/headers next to each other it is obvious it has to be somewhat of an improvement. Ill post up when im done if I feel a difference

 

I had JBA's, very high quality, but 0 gain, when I say ZERO I mean ZERO gain on the dyno.

 

I dont know how strict your emissions is but the STL area (where I am) is supposed really strict and I had no problems. Pulled it in to the inspection place, paid the $25, started it, made the whole place smell like gasoline, hooked it up to my OBDII port, and then they told me theyd see me in two years. Longtubes, no cats, !EGR and not a single problem as long as you get the codes cleared and your car runs smooth. State safety inspection is a different story...to this day I still have no idea how I passed with no cats on but hey I'm not complaining!

 

heres a suggestion. move.

 

 

yall just jealous... cant beat having the beach, snow, oh and wow... the ***** aint bad either

 

yeah you can, its called virginia, north carolina, south carolina, georgia, flordia......each are long tube friendly and have a lower concentration of ****. and who wants snow.......so you cant drive your car......lol J/P im sure california is great except for San Francisco and emissions.

 

Sadly that's probably not an accurate description. As they require almost the same amount of work to install as LT's (which is a lot).

Sometimes every little bit doesn't actually help, if it's a floored concept to begin with. But hay it's your car and your choice

Obviosous??? Probably not, fluid dynamics are a complex thing and a quick visual inspection at the outside of them isn't going to tell you much if anything.

As I said it's not so much about flow (although this helps) the biggest thing headers can do is scavenge. This creates a 5th cylcle in the combustion process. Essentially when one cylinder fires a pulse is sent down the exhaust. This pulse can create a vacuum and help draw air into the other cylinder(s) which are on a downstroke. This can contribute upto 80% air the air intake velocity into the combustion chamber.

This is all a matter of timing as the pulse needs to reach the collector to create the vacuum in the other cylinders at the right time. Due to the short length of the primaries on shorties this timing balance won't (can't) occur until very high rpms. Higher than what a push rod V8 operates at.

4 cylinder engines run at higher rpms and make PEAK torque at higher rpms so they generally respond better to shortie style headers as opposed to long tubes. That's why you don't see long tubes for them.

But a V8 makes it's PEAK torque low in the rpms (comparitivly). And as:
HP = torque x rpm / 5252 You need torque in order to make HP.

Shorties on a push rod V8 serve 2 purposed (IMO):
1. Styling, the DO look nicer than stock ones.
2. Bragging rights, so you can say you have done the "headers".

But that's about it. If you haven't installed them yet, sell them.

Why do you think you can always pick shortie headers up cheap 2nd hand???? It's because people buy them, spend money/time installing them and then find out they offered little to nothing over stock so eventually sell them for LT's.

If you plan on going turbo, then 500rwhp should be easy, so what if shortie headers might give you a couple more, it's not really going to make any odds at that performance level.

Just my opinion

 

Actually, shortie headers don't really give that much HP on a 5.0 Mustang either. I've owned both 1989 and 1990 GTs, one with regular shorties and one with equal-length shorties. Changing the H-pipe produced more power than either set of headers. Mustang guys are finally figuring this out and long-tubes are selling like hot-cakes with the 5.0 crowd. FWIW, the MAC mids are a great header for a lowered car, or one that won't be seeing extensive mods. They fit great, are easy to install, don't bang or rub and make plenty of power...

 

I had ceramic coated JBA's and loved them ... though i saw little gains, the coating kept the engine bay cooler and they out-flowed the '99 design stockers. 012-02 stocker headers will flow about as well and would be cheap. The JBA's are nice looking on an LS1, but, just not worth the money ... IMO.

 

Florida = Best of both worlds - snow.

 

I'm from CA too, but I'm still getting LT's and a ORY...I wouldn't get shorties, but its your car so do what you do.

 

How do you expect to pass SMOG? That's my only concern or else I'd buy LT's in a snap. The reason WHY I am even thinking about getting Shorties is that i want something to flow better than my stock manifolds with the BLOWER (ATI Procharger) I will be installing. I see LT installs all the time on newer cars but that's because of some loophole law in CA that 6 years or less cars (2006-2000) would be exempt from the biennial SMOG inspection.

Hell, I'm thinking about just going with the Pacesetter LT's with the catted H-pipe that would supposedly pass a sniffer test. I mean, can you REALLY tell by just looking in the engine bay (visual inspection)?

 

Coming from a California boy I'll tell you how to pass smog with LT's...

1) Make friends with a smog tech
2) Find a really crappy shop that doesn't give a ****
3) Find a somewhat crappy shop that will pass you as long as you run cats
4) Swap back to smog friendly and then back to un-friendly after passing

There are options, just depends on your effort level

 

I would look into the C5 Z06 manifold. That flows very well. Or get a 00-02 and get it extrude honed.

 

Maybe because their stock manifolds are more restrictive to begin with?

 

long tubes with catalytic converters will pass an IM240 inspection. and a clear DTC history in the PCM will pass the plug-in test. BTW, the best shorty header is the one you remove to put on LTs.