experience with 'performance' headers

[Barjavel]

Hi all,


I am hoping to get some collective sense on 'performance' exhaust headers. I recently installed a new muffler (the ANSI muffler from AR) and deleted the cat, but my mechanic left the muffler cockeyed and it protrudes too much, and so I am planning to take the car to a "custom exhaust" shop run by some very skilled folks from south of the border to straighten and shorten things.

I am wondering if, while I am at it, I should also have them install one of the stainless steel headers and down-pipes from the main suppliers; AR and Vick's seems to be the main options, but both shops are a bit vague on whether there's much of an evidence-based performance gain. I am not expecting massive improvements in HP, but was wondering if there might be noticeable gains in engine liveliness. The engine is stock otherwise, except for a K&N exhaust and tubular-aluminum intake. I am also wondering if a custom-muffler shop is equipped to install a new header on these cars, i.e. how hard is it?

I'd appreciate any thoughts. While in my dreams I will someday install a performance head/valve set-up and put in some high-compression pistons, realistically I'm not in a position to do that for a while, and it may never happen.

[18Fiatsandcounting]

...but both shops are a bit vague on whether there's much of an evidence-based performance gain.

That's because there isn't much evidence for a performance gain, and the reason for that is that the stock header/exhaust on the spiders was pretty good. Many muffler performance shops can customize a system for a really crappy 1980s Chevy and get 5% more horsepower, but it's not as easy with a spider. Are there shops that can squeeze a few more HP out? Yes, but likely very expensive.

The other issue is that there are very little options in souping up a FI spider unless you get into the internals of the engine (cams, head flow, pistons, lightened parts, etc). The cheapest bang for your buck is to make sure your ignition advance is spot on, and then advance it a couple degrees more. 10 minutes of time and zero cost.

I'm not negative on performance, and much can be done with the impressive Fiat twin cam, but it starts getting into $$$.

-Bryan

[calvinconrad]

I have the Allison automotive Header and the whole straight pipe system. included catalytic converter and one muffler. on a 1.8 liter with weber 32/36 carb. with the stock cams i felt the engine was more powerful and responsive. don't have dyno numbers but felt there was a great improvement over stock. since then I have had larger valves and street performance cams installed.