NASCAR314

It appears that some of us with LT1 automatics that MUST maintain emmissions compliance are restricted to "Shorty" style headers.

My question is: Is there any performance gain from using shorty headers, over stock iron exhaust manifolds?

I understand the tube lengths, and the scavenging effects of long tube style headers, but, I'm stuck in the emmissions nightmare of cat. convertors and all related parts.

There appears to be some well constructed shorty's out there. Anybody running them? Any Improvement?

Thanks,

ittlfly

I'm running JBA's shortys; (ones shown on "Crank and Chrome" ),street legal. They are ceramic coated inside and out which I highly recommend for under the hood heat control. They look good and they did deepen the sound of my Borla mufflers. Makes it sound meaner than it is. At the higher RPM's I can feel the car come on and I'm sure it's in part to the headers. At normal highway speed, there doesn't appear to be much of an advantage.

Nathan Plemons

A friend of mine put hooker shorty headers and a hooker aero chamber cat back on his 93 Z-28. Oh, he also doesn't have the cat anymore. He dyno'd something like 280 hp and 320 torque.

Now my completely stock 92 vette dyno'd 270 hp and 301 pounds of torque, that's full emissions still intact.

Another friend has a 95 Z-28 that has over 100,000 miles on it he dyno'd 270 and 317, with a quickly falling torque curve due to badly worn out valve springs.

So basically what I'm trying to say is that they are pretty much useless. So on my friend's 93, how much was gained just from removing the cat and installing the cat-back? All of this work netted him basically 10 hp and possibly a few pounds of torque. Also, if you have ever looked at the F-body manifolds you can see that they have a lot more to gain than the Corvette manifolds, their design is terrible while the Corvette design is fairly decent.

I wouldn't put much stock in them, you probably won't be happy with the results. You know you could get a set of hooker 2149 long tubes, they are essentially the emissions version of my 2151's. They have all the AIR connections and such. If you added a set of bullet cats you can still maintain full emissions and actually have a power difference you can feel. The headers themselves probably won't cost that much, the cats are where the money comes in, but it will be money well spent. I'd hate to see you waste a lot of money on a set of shorties that you won't be happy with.

Just another option and my $.02

BlueDemon

I agree with nathan, shorties suck. Get some emissions legal long tubes like he was talking about, i'm sure you can find them in several brands, hooker will
probably be the best though.

NASCAR314

I'm not trying to make masive gains in power or anything, Just happened to run across a set of used JBA's for a very reasonable cost. (cheap)
Just wondering if it's worth my time installing them on my 96. There are a few minor bracket issues I need to work out, but not a big deal.

Heck, The weight savings alone, might just be worth the switch!

Tom,

95BLKVette

Also think about changing your plugs down the line :rolleyes:

With shorties installed, #'s 6 & 8 are damned near impossible to get to :cry

Didn't think about that when I installed them :eek:

AquaMetallic94LT1

Don't forget that the shorties have no heat sheilds so everything around them gets a lot hotter. The AC evaporator cover tends to toast a bit. Plug access is poorer. JBA headers change the way one of the brackets on the driver side bolts on and their solution looks like it reduces the effectiveness of the bracket. Finally, not much hp gained if any.

Z28 use completely different exhuast manifolds that are more restrictive than the LT1 vette ones so the comparison is not really valid.

Nathan Plemons

Not really. Think about it, the Z-28 has a much more restrictive design to begin with, so it would seem to reason that they would have more to gain from shorty headers over the vette. How given shorties, no cat, and a cat back, you only got 10? That's a whole lot of work for not much gain. A gain that is likely to be far less on the vette.

92TripleBlack

I've never heard of anyone saying the shorties did anything for an LT1-4 vette. Long headers on the other hand may but they are a pain in the tail. There are alot of other easier and more cost effective mods for the amount of additional power you get than the shorty route.

mackeyred96

:nonod: :nonod: :nonod:

Nathan Plemons

:confused: Maybe from an emissions standpoint, but as far as ease of installation and being able to work around them, there is no better. I can get to ALL of the plugs and plug wires on the passenger side easy. The driver's side is a different story, not because of the headers but because of the brake booster, ASR, alternator and A/C compressor. Still way easier than the stock manifolds.