OBX header

[9/18/2011] Reviewed by: Dexter Jerome

Applicable to: '90 - '97 1.8 liter

OBX 4-2-1 header.

Couldn't get this header to go in. In order to make it squeeze through I would have to disconnect the steering linkage and that ain't about to happen. The problem is with the two collectors going sideways instead of vertical (one over the other). Maybe if I took off the valve cover I would be able to get it in, because the portion of the header that mates to the engine kept hitting the valve cover scratching the thing up good. I paid $120 for this from a fellow member on, but I plan to give it away at the next Miata meet I go to. Next time I buy a header it will be a Maruha or the Maxim Works for fitment and performance gains. DON'T waste your money on OBX.

Under 30 minutes to remove completely

OBX 4-2-1 99 header

[11/28/2009] Reviewed by: Mighty Miata

Applicable to: '99-'05 1.8 liter

OBX 4-2-1 99 header

Not that Good ... Took me around 5 Hrs, first by trying to remove the Stock one, the 3 bolts after the cats are a Pain to remove and also when you try to hook the EGR... Boy, what a nightmare !!! and not only that, not it touches the body of the car and I get a lot of Vibration from that and also leaks were it meets with the Cat... Save yourself some troubles and get something PROVED to be Good !!!


Over 30 minutes to remove completely

OBX ceramic headers

[8/17/2007] Reviewed by: Frank R -

Applicable to: '90 - '97 1.6 liter

This was the last of the three exhaust mods I have done (Borla cat-back and Racing Beat CAI are the others) and I can say with certainty that all three work together very well. These are $200 knock-offs of a better name product that is twice the price. If they work, why spend double? According to my mechanic they install very easily and the sure seem like they are well made. I've had them on for a week and I can feel a difference above 5000RPM, which is where you should always be shifting your Miata anyway.

Under 30 minutes to remove completely

OBX 4-2-1 99 header

[7/16/2007] Reviewed by: Dave

Applicable to: '99-'05 1.8 liter

OBX 4-2-1 99-00 header

The header did not fit. It hit against the transmission tunnel, and could not torque down the bolts at the head. However at least this one included the correct 99-00 egr bung.

Do yourself a favor and buy a racing beat.

Over 30 minutes to remove completely

OBX 4-2-1 stainless header

[7/3/2007] Reviewed by: Kevin -

Applicable to: '99-'05 1.8 liter

OBX stainless steel header, 4-2-1. Looks very good & comes with gaskets.

This went on a calf model 2000.The old cast iron manifold & cat was difficult to remove due to the bolts in the down pipe would not come out (sawzall took care of that problem)Once out the drivers side engine mount bolt had to be removed and the engine jacked up about an inch to drop the header in. The O2 sensors had to be relocated to the 2nd cat (extended wires). The gasket from the hader to the mid-pipe had to be replaced with a donut type to seal.

I am very pleased with the header. The orig cross over tube can be used unlike other brands and it fit perfect.The price was also good at $155 + $35 shipping. The performace is greatly improved and I like the deeper tone of the exhaust.

Over 30 minutes to remove completely

OBX Exhaust Header

[3/12/2007] Reviewed by: Jean Robert Roy -

Applicable to: '90 - '97 1.6 liter

OBX Exhaust Header installed March 3-07 1993 Black 1.6

The Header is well made and looks very good. It did fit well however I had to grind an edge of the engine transmission mounting flange. The first time I installed it, the down pipe rested against the flange. I removed it and ground the buldge where a bolt goes from the transmission to the motor. It was quite easy access from the top side. Once this was done there was sufficient clearance to install the header. It was necessary to lenghten the Oxygen Sensor cable because the bung for the sensor is about 12 inches from the original header position. I have as yet to try out the car since there is still snow in this area and I will not drive the Miata until the roads dry up. Removing the old header was difficult because I did not have the correct tools to dismantle the unit and I had to remove in all one piece. I had been soaking the bolts for a few days with penetrating oil. They came away quite easily however the bracket mounted to the engine had its own idea and was very difficult to remove. The removal of the old unit took me about 1.5 hours. I will also install a high flow Cat in the next few days. This shoud produce a few more horses. I had installed Cold Air intake last year and it sounded and ran better.

Over 30 minutes to remove completely

OBX 4-2-1 Stainless Steel Header for 1.6L

[2/13/2007] Reviewed by: Benjamin Fields

Applicable to: '90 - '97 1.6 liter

4-2-1 knockoff of a more popular and expensive product. Purchased it from a local Miata enthusiast who was restoring a 91 back to stock (including header). For those who are not buying it from a buddy, it will ship gleaming and with the required gaskets, however over time it will discolor due to heating and cooling. I suppose you could polish it back, but I'm not going to bother. The O2 sensor is located further down the pipe than the OEM location, so you may need to lengthen the wire.

Flawless installation. Unbolted the OEM header from the downpipe, the downpipe from the catalytic converter and removed both bits. OBX slid in without a hitch and bolted up fine. While the difference is not amazingly huge, the engine feels smoother along the RPM range with more pull in the middle of the tachometer. Very enjoyable.

Yes this is a knockoff, but it does what I want for a price I can handle.

Over 30 minutes to remove completely

OBX Header

[9/10/2006] Reviewed by: Pat Walker -

Applicable to: '99-'05 1.8 liter

OBX Exhaust header

After reading mostly positive comments re: this product I decided to give it a try. I mean it is really affordable, but E-bay only. This header was everything I could possibly want. Beautiful, easy to install with absolutly none of the issues I had heard about. Fits like a glove. Haven't had a chance to get to the dyno yet, but my SOTP dyno says the revs rise more easily and the car is snappier. Added to a Goodwin midpipe and a Power Pulse muffler it is as loud and deep as I would ever want to go.

This has to be a "Best Buy". For less than 1/2 of the cost of most name brand units I would do it again without hesitation.

Over 30 minutes to remove completely

OBX Racing Ceramic Coated Header for 99+

[7/25/2003] Reviewed by: Jonathan Morrison -

Applicable to: '99 + 1.8 liter

Ceramic coated 4-2-1 header for 1.8L 99+

Header comes with absolutely no instructions,I used other peoples experiences from the internet as a guide. Welds seem to be pretty good, like others who have reviewed it I had trouble with the fit. I heated up the second(2 to 1) Y and bent both sides closer together, I also had to bend the EGR fitting. I took the EGR tube off the engine installed the header end first then installed it back on the engine. I am tight on the bell housing side and have about 3/8" between one tube and the firewall. No hitting against the frame under any driving conditions (hard accel/decel). I also rerouted the O2 sensor to hook it up and added some self adhesive wire ties to keep the wire up away from the EGR, header and heater hoses. It took about 6hrs. total with putting the header in, taking it back out and heating,bending.

I have not done a dyno so I can't say how much power has been added. The car accelerates better through the rev's. Seems to have several more hp in the upper rev. range.For $135 vs. $400+ I would do it again. A torch to heat the pipe up and some fabrication experience are a big help. Maybe OBX will read some of the reviews and try changing the EGR fitting and the second Y angle to fit right from the beginning.

Over 30 minutes to remove completely

OBX "Ceramic" 4-2-1 Header

[7/18/2003] Reviewed by: Cliff Knight -

Applicable to: '90 - '97 1.6 liter

This is a mild steel, ceramic coated, 4-2-1 header for the '90 to '93 1.6L engines. It is of surprisingly good quality, the welds are sound, and the flange is quite substantial at 3/8" thick or so. It comes with a metal/asbestos/metal gasket. The ceramic coating is a high-temp ceramic spray-on product, like that sold in some of the auto specialty stores. The design is identical to the Racing Beat and Moss Motors' 4-2-1 headers.

I bought it on eBay, from SSAutoChrome (despite some of the bad feedback), for $185 delivered to my door. I paid for it via PayPal at 7:30 on a Monday night, and received it at 12:30 pm on Thursday! Installation was a snap--it fit perfectly and nearly fell into place. I had none of the problems others have related with removing the manifold nuts, and when I removed the catalytic converter some time back I used SS bolts to install the "test pipe"--so that just popped apart too. The stock header and downpipe came right out (in one piece) and after cleaning things up a bit the OBX header just slid right down into place. I used a new O2 sensor ($17 at Autozone), not wanting to play around with the old one. Total installation time was about 1-1/2 hours.

Forcing myself to take a shower first, I went for a ride (1:00 in the morning, 78*, top-down). The first thing I noticed was a significant improvement from 2500 to 4000 RPM--much smoother and noticeably more tug. From 4K up the improvement continues, pulling strong right up to the rev limiter. Cruising at 65-70 seemed to require less throttle than before, it will be interesting to see what happens to my gas mileage. Overall, well worth the money--highly recommended if you're on a tight budget!

Not an installed item

OBX 4-2-1 99+ header

[3/29/2003] Reviewed by: Roger Dick -

Applicable to: '90 - '97 1.8 liter

OBX Racing Stainless Header 1996 1.8L

I'd read everthing bad on about OBX and but thought what the heck, for half the price I'll take a chance. I was high bidder on Ebay for 2 separate bids of a header and catback. I wrote the guys at ssautochrome and asked if they'd make me a deal on shipping and they did. I got everything shipped to the door for $400.00 flat, not bad. See my writeup on the cat back. Got everthing shipped promply and safely. For this good of a deal has my vote. The header had good welds, and came with a great metal gasket. I had to clean out some of the excess in the head end with a die grinder, but I'm pretty picky, there was just a little bit of a lip. The EGR tube and the fitting are maybe 15 deg. off. Look at it before you put the header in and you can bend a little on the tube in the car and a little on the fitting on the header and get a pretty good match. Also you'll need to extend the back oxygen sensor cable about 12". Solder and heat shrink.

The two transmission bolts came out easy with a breaker bar. The front cat bolts were a Xz?!X getting out and not because they weren't soaked. After getting them off I realised the last 1/4" of the bolt had no threads. I had to grind the tip down a little on one and chase it with a die. The header went in fairly easy, but I did have to gently use a BFH to get the manifold past the head. Also the header when bolted down does touch the bellhousing and is about 1/4-3/8" away from the side of the floorboard. There's no noise from anything banging around and I gave it a good thrashing. The floorboard doesn't feel excessively hot, but we'll see. I changed the catback at the same time so I'm not sure which made the biggest effect. From everything I read I wasn't expecting to much, but everything helps if you don't plan on going forced induction. Maybe 5-7 hp more. You do feel the difference. All in all I'd do it again. For twice the price I doubt the na! me brands are twice the header.

Over 30 minutes to remove completely

[2/20/2003] Reviewed by: Hollister Siegmund -

Applicable to: '90 - '97 1.8 liter

Stainless steel headers, 4 into 1 design with threaded O2 sensor fitting. Installed on 96M w/ RB Intake, 15 deg advance

The headers are substantial and come with a good, thick gasket that does not impede flow and needed no trimming to fit. I ground down a few high spots around the interior of the manifold flange, but nothing major. Initial fitment was easy as the header bolts came off without a hassle after a good soaking, there were no clearance issues and the O2 sensor fit. However, it was excruciatingly difficult to try and line up both ends of the EGR tube as the header end needed to be bent in 2 directions to mate. Finally, after much coaxing and cursing, we were able to finish the installation. Once I put the rest of the exhaust system back on and started the car, I noticed the exhaust note was significantly quieter and felt smoother and like it revved quicker. On the road I noticed a solid high-end HP increase measured SOP (seat of pants) of around 7 Hp. Not bad for the money and the 2-3 hrs if took to completely install.

It will be interesting to see what a good cat-back exhaust will do for the power and sound. For the money ($175 plus shipping), my experience with the OBX headers was positive EXCEPT for the EGR fitting. If you plan on installing them, get ready to be creative to mate the 2 ends fit.

Under 30 minutes to remove completely

[2/7/2003] Reviewed by: Topless Autoxer -

Applicable to: '99 +

Cheaper header that hints to be a copy of the RB 4-2-1 header on ebay.

Terrible. Bad fitment, never fit properly despite hours of manipulation of the piping. It would take a professional welder to take it apart and reweld it so it would fit. The header touches both the bellhousing AND the chassis. Even after I was able to bend it by getting it very hot I could never get it to stop touching the chassis which provided terrible vibrations.

Do not buy this. Save your money and get another header such as the BSP, RB, or JR.

Over 30 minutes to remove completely

Back to Intake/Exhaust

2 October, 2011

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