I want to put headers on my 90 L98. What is the down side if I go with headers without the smog pipes. I live in a state with no smog inspections.

 

There is no downside other than possible future smog illegality The non-smog ones are a cleaner install and easier to work on IMO.

 

its all abought power screwthe state

 

I talked to my muffler shop guy about this yesterday.

He wasn't thrilled about the idea of putting headers on my vette. He's an older guy with plenty of exposure to headers and he said he's seen a lot of engines with headers where they repeatedly need to be removed for a new gasket installation. This includes SMC applications with name-brand headers.

With only 15 HP increase (guaranteed), I'm looking more at redoing the exhaust, but leaving the stock headers on. This might be different if I were going all out with intake and cam work.

Any feedback on this?

 

I can understand the guy's reluctance. There are plenty of cars that are a nightmare to put headers on. The C4 is not one of them. And if you buy a quality header and use the correct gaskets and hardware, future problems should be nil. Perhaps you need to find another installer who may be more familiar with these cars.

 

The downside is you will suffer the wrath of our Kalifornia smog ****!
Upside is you will keep some cash in your wallet!

 

The C4 is really one of the easiest cars to put headers on that I've ever seen. Gasket sealing can be an issue but if you use copper or dead soft aluminum gaskets and make sure that the head mating surface is very clean first you won't have any problems. Gasket technology has come a long way.

You may suffer a little bit of low end torque loss, but the gains in the mid-upper RPM range more than make up for it. I'm an LT1 guy so I tend to recommend 1 3/4" headers because these engines easily rev 6000+ RPM's when modified. For the TPI or CFI engines with otherwise stock intake systems you will likely want to stay with 1 5/8" headers because they will give you more power where you will be able to use it. A power gain at 6000 RPM's doesn't do you a lick of good when the intake is done at 4500.

The brand is a serious consideration and you can pay damn near anything you want for headers. I prefer the hooker 2151 headers for the sole reason that they are the only C4 header maker I am aware of that features a bolt on collector rather than a slip fit. For my purposes the bolt up connection is simply easier to deal with than a slip fit even though it is more prone to leaking. Performance from all of the brands will be virtually the same so long as you're talking about the same size headers.

The coating that you get on the headers will likely be more important than the brand. If you go with Hooker, don't get their coating, it sucks. Mine are hooker headers but they were coated by some company across the street from Speed Demon Motorsports. When it was new it wasn't quite as flashy as some other coatings but it has held up better than any other coating I have ever seen. After 4 years there is light surface rust down near the collector. I've seen several cars with hooker's coating have it completely flake off and rust significantly in the same spot in as little as 6 months. Of course you can go stainless if you're made of money but they will weigh more too so that could be a consideration if you were big into racing.

You do want SOME KIND of coating or stainless. If not they will not only look like crap within a very short period of time you will very likely have underhood heat problems and they won't last very long.

 

Only downside is the headache you'll have after long trips because of the noise.

my website has more information about the install

 

By smog pipe, I assume you mean AIR tubes. AIR is only to help light the cats off and burn off extra gas on start-up. The newer LT1s have an electric AIR pump that shuts off after a max of 240 sec, even sooner if the O2 sensors are warmed up.

The point is, even with a smog test, AIR doesn't figure in (smog tests are run on warmed up, closed loop engines). The only problem is if they inspect. Here in Chicago we have IM240 (the dreaded rollers) and they don't inspect. So you can pass IM240 smog, in Chicago, with long tube headers and no AIR. In fact, since they don't inspect, and OBDII cars don't even go on the rollers (just a scan), I can pass without cats on my 96 Vette (using O2 sims).

Once they inspect, it just depends. Usually an inspection consists of looking for the cat(s). The only real smog ***** seem to be in So Cal, they have manuals on all car's smog system w/pix, they get all twisted up over the smallest points.

 

Installing as others have said is easy. Drivers side can go in from the top no problem, pass. side I had to take off frame extension piece that angles from the crossmember(quite easy 5 bolts). Mnie is a 90 w/2149 hookers. The 2149 allows for 02 sensor and A.I.R. (emmisions) if nessesary, last bolt pass. side is tough an allen bolts make it easier. The only issue I see is available exhaust systems. If you want a true dual there isn't much aftremarket, if you are ok w/y pipe back there is plenty of good choices.

 

The only downside other than the noise and the lighter wallet is once you start doing mods you won't be able to stop. My HTC coated Hedman's are a beautiful header, they fit perfect, and the ball flange collector hooks right up with the rest of the exhaust and has no leaks whatsoever. The gasket plays a huge part in the mating of the surface and I have no leaks and never have with my gaskets. They were a little more than the normal gasket but were well worth the price to not have to play with them all the time. Hooker, Hedman, TPIS, and an assortment of others and I've seen every one of them on different C4's and I've not seen a difference in fit and quality other than what you pay for them. Good luck with your choice!

 

Anything good about shorty headers?

 

What do I do with the EGR Pipr that conects to the Intake manifold? Will there be a conection for this on Headers with no AIR?

 

You can usea block off plate TPIS sells them as others. But I believe you will need to delete it from the programming. If you are not going to use an aftermarket intake why would want to delete the EGR?
If you bought for example 2149 hooker it has egr, air, anf 02 bung, the eger is not drilled through and the air can be blocked. 2151's have nothing on them.

 

Go long, shorties have less horsepower gain!

 

Because it provides a cleaner looking install without all the extra plumbing.

 

All I did was yank off the pipe and the switch and put on a blockoff plate.

No codes.

 

I'd block it off on the manifold and chose a cam w/natural EGR (ex: the stock LT4 cam has enough overlap so no EGR system is needed).

 

I don't think this installer's objection was with the procedure/work. He just doesn't think aftermarket headers stay sealed over time. Also, I'd probably be the installer. I was asking his opinion on the benefit -- when he offered that it wasn't really worth it -- in terms of gains vs. potential headaches!

This was a question I asked in my "HP class (102) thread. But the answer was not so direct. I'm not crazy about installing headers if they MUST be noiser to reap the benefit. I'm all for a hearty growl on acceleration but I don't want resonance drone.

These responses don't answer two important questions....
1) Are there headers that won't have post-installation problems (guaranteed). If so, which brands?
2) Do headers make more noise in the engine bay (due to thinner pipe walls?
3) Are there muffler(s) that could be installed immediately behind the headers and/or in the middle tunnel that would bring noise levels down near factory levels? (For my sidepipe installation, I don't want anything installed behind the rear wheels). If it can be made quiet, would this rob the extra power gained? Cats are optional.
4) Since I don't race (and rarely do WOT driving), are headers really worth it?

I asked a guy I work with this question (he races "entry-level" class). His response was to get coated headers. It would reduces engine bay heat, save on engine part deterioration, improve mileage, reduce heat soak, and help with air intake temps. But I'm guessing the changes would be minimal at best.

What do you think?

 

I recently installed some hooker shorty headers my '95 and I'm pleased with the results.

Why did I go with shortys?

1. No hassles with emissions testing.

2. Easier to install

3. Cost less

4. I not looking for super stroker performance, not yet anyway. But I needed to replace my stock exhaust manilfolds and there is no way I could see myself putting another set of big bulky cast iron manifolds


The end result is my car actually runs QUIETER yet has nice "seat of the pants" increase in mid range torque that kicks in at about 2500 rpm and a slight horsepower increase that's noticable.