Mild steel painted headers. About $230.00. No instructions (the only bad news on this product).
Excellent. They installed easily, in about 1.5 hours, and I am not a very accomplished mechanic at all. Lots of WD-40 was left overnight on the exhaust manifold bolts, and reapplied a couple hours before the installation, and the same for the nuts securing the header to the catalytic converter. These nuts all came off pretty easily, without any of the problems I'd heard about before. Unfortunately, I received absolutely NO instructions with the product. I'd advise anyone else in the same boat to realize that the coolant pipe whose tab is secured by one of the manifold bolts can be gently rotated enough to allow the old header to be removed and the new one to be installed, without any further monkeying around with that pipe (i.e., don't need to remove it!). Immediately after installing the headers, I noticed a very nice "header" sound, like more obvious combustion impulses felt upon acceleration, though pleasingly so and not annoying. Sound is comparable to my old stock mainfold without its heat shield (long since removed the shield due to repeated cracking) in volume, but more visceral in sound. I also already had the Jackson CAI and the Genie cat-back exhaust system on mine, and these headers really livened the whole system up, complementing them very nicely. I had never thought my Miata was short of breath at high rpms, but the headers made it even easier to hit redline, as the engine doesn't run oout of breath up there. The midrange was a nice surprise, as it feels beefier throughout. It may be my imagine, butI believe the ignition can be advanced a bit more without detonating, though I backed it back down to probably 14-16 degrees where the top end retained some guts lost at max advancement. I shift a little less than with the stock set-up now during normal driving, as the engine just pulls more eagerly. Best of all, I never, ever, have to mess around with the factory heat shields again!! Unlike a previous reviewer, I feel the quality to be excellent, especially for the price.
Overall, about $200-250 less than Jackson's product. In my humble opinion, if the Jackson's (an obviously excellent executed product) are worth about $500.00, these are a bargain at $200-230.00. They are not stainless steel, but my understanding is that stainless steel is inferior to mild steel for headers, as mild steel better survives more heating/coiling cycles of the magnitude a header is subjected to. Stainless steel makes sense after the cat, where the water output pretty much necessitates it. Also not ceramic coated, but I didn't care. I'd read that even on a 750hp racing Chevy V8, a ceramic coating on the headers prodcued only a max of 3-4 additional hp. Aesthetically, speaking, the Jackson's are much more attractive, but then again, I couldn't justify the additional couple hundred dollars just to impress the Unocal station mechanics who change my oil. So, I highly recommend these Genie headers, made by a company with apparently enough experience in this area to produce a quality product. Thanks.
Mild steel exhaust headers with a Tri-Y (4-2-1) design.
Headers came painted and with a chrome logo attached so to be visible when installed. Cost me $70 and about 3 hours to get them installed. Only problem came when the old downpipe had to be separated from the cat. Bolts were very stubborn and had to be cut off. These headers don't have means to attach factory heatshield, so temp under hood is a little higher now. As soon as started the car after installation, the paint on the headers started to crack. Paint is still slowly cracking to this day.
I had the timing bumped to 14 degrees right after installation, so I am a little sketchy on the performance benefits. I drove the car for a few minutes before timing jump and didn't feel much difference in power. Timing made a much better improvement (of course my timing was originally 8 degrees!?!). Headers are supposed to also improve/increase exhaust sound...another loser here. They actually made the sound from my Borla quieter! When the car is cold it actually sounds closer to a stock Miata now...deep growl is almost gone. I've been told that the sound muffling due to the fact that these headers have thin walls and actually resonate, cancelling out some of the exhaust noise. Bottom line: if you absolutely need cheap headers get these ($200), but I would recommend stainless thick walled headers (like JR) instead.
| Back to Product Reviews | 15 February, 1998 |