I feel almost bad for asking this question, but I guess that's what this forum is for. Here's the background:
In November I built a completely custom exhaust for my 2.8 M20 from scratch. All 2.5" SS304 mandrel tubing, magnaflow cat, and Vibrant resonator and muffler. Stainless Vibrant v-bands and stainless hangers. Parts cost me nearly $1k and you'll laugh, but although I wanted BavAuto or Stahl headers, I just couldn't afford them new and I couldn't find a used set.
So... I took a gamble on a set of eBay OBX headers. I figured since I was building the system from scratch, fitment would be less of an issue. Well, it wasn't and they're CRAP. Their x-pipe is total trash, the header outlet pipes collide with each other at almost a 45* angle under the car plus they're jammed against the floopan, they're jammed against the motor mount bracket, and I had to bend the oil cooler lines out of the way. And once I got them to actually fit (kind of) they still leak where they mate to the cylinder head. BADLY. And I can't stand the noise anymore.
So. I was set against ever buying eBay headers again. But then these (http://www.ebay.com/itm/BMW-E30-325i...#ht_1121wt_831) came along and appear to be direct copies of the BavAuto units. And at least they have real flanges at the cylinder head (even if they need to be planed flat)! And they're true long tubes w/o that crappy x-pipe too! And at this price, I'm very tempted to take another gamble, although it would include a lot of work and I'd be upset if they were a waste of time like the OBX units.
I'm hoping somebody has used them and can provide some insight on fit and quality of construction. I searched like mad hoping someone would have experience, but didn't find anyone that tried this particular type/brand.
Thoughts?
Thanks.
UPDATE 1/15/12:
The new headers (brand:Top Speed) arrived yesterday and here are my thoughts. I'm going to do a lot of comparison to the OBX units that are currently on the car because they're my only point of reference.
First, the build quality seems like a toss-up for the most part, though if I had to choose, I might give a slight edge to the OBX units which does not speak poorly of the new headers simply because I believe the OBX units are constructed pretty well. They just lack badly in design and fitment.
The mounting flanges on the Top Speed headers are mild steel and 7/16" thick which is quite thick. I checked the flatness of the flanges with a nice Westcott ruler and they're close to flat, no more than 2-3 thousandths out.
The TIG welds are also very nice, though again, I might actually give the nod here to the OBX units. This comes down to appearance alone, I'm sure they give up nothing in strength.
The tubing itself seems of nicer quality on the OBX units and the mandrel bending seems to have been slightly nicer too. The diameter of the primaries is slightly smaller on the Top Speed headers, though this isn't necessarily bad.
Inside the header flanges, the welds were cleaned up on both headers, but again, slightly more nicely on the OBX units.
I am no expert on collectors and the quality seems equal in this regard between the OBX and Top Speed headers. I'm sure, however, in the grand scheme of things, that neither is great.
Outlet diameter is 2" and the Stainless Works 2" SS304 tubing I'm going to be using to mate to the collectors will neither slide over nor inside the header outlets.
The polished finish on the Top Speed units isn't quite as nice as the OBX units either, but not a big deal in my mind, as the OBX units are quite discolored after 2 months of using them anyway.
The big remaining question is fitment and this is where it seems the Top Speed units already have an advantage over the OBX headers. Just looking and guessing at how they'll lay in the engine bay, I foresee them having fewer interference issues with other components and it doesn't seem as though the collector outlets will collide with each other at a 45" angle when bolted up.
It may be a little while before I get more 2" tubing, figure out how I'm going to mate these to the rest of the system, and order new exhaust gaskets, but when I get down to installing these, I'll be sure to update.
UPDATE 2/24/12:
I've delayed updating this so long, I'm sorry! I installed the headers almost a month ago at this point and been daily driving the car ever since. My thoughts so far:
Here's the additional parts I bought to complete the installation onto the rest of the system (listed above). Stainless band clamps, 2" diameter SS304 u-bend, and new gaskets
The old OBX headers removed:
Direct comparison between the rear OBX and TopSpeed header sections. Pretty obvious here which has longer tubes... lol. And which one exits at a 'normal' angle/location.
Really terrible picture in the dark, but they sure look TERRIFIC in the engine bay:
Here's the one fitment flaw. But I don't know if others will have this problem or not, maybe I need new motor mounts or something (they aren't that old, though)? But the number 5 primary interfered tremendously with the strut tower, I had to heat it and flatten it many, many times to get it to fit and even now, it's still jammed against the tower. Luckily it doesn't rattle! The number 6 primary rubs a bit too I think, but I didn't modify the tubing at all.
These do sit VERY low! My car is also a little on the low side and I have only 3 inches of clearance between the ground and header outlets! I have scraped the exhaust a few times already even though I'm very careful. I'm hoping when I take off the 14" winter wheels, it will sit a bit higher. Also, the nice stainless band clamps I bought don't work in this instance because there isn't enough straight pipe at the exit of the collector... meaning the clamps ride up the collector a bit and can't be tightened all the way. It leaks there, of course, and I'm afraid I'm just going to have to use a u-bolt clamp to make it seal. I'm not welding it b/c I want the system to be easily removed from the headers. And ignore my temporary O2 wiring...
Next up, tomorrow I hope, is to get some video footage of the sound of the car with the headers and complete system. I have to say the exhaust sounds very different with the TopSpeed headers compared to the OBX headers. It sounds meaner and louder, without a doubt. In fact, the sound difference really surprised me b/c the rest of the system hasn't changed. I also feel it has a bit more torque than before, but that's just the butt dyno. Either way, the car sounds terrific, I get looks and stares everywhere. In fact, the other day I had a guy in a Miata behind me in town who would break out laughing each time I got on the gas. It's quite loud, to be honest, but the sound is addicting.
Exhaust Clips:
In November I built a completely custom exhaust for my 2.8 M20 from scratch. All 2.5" SS304 mandrel tubing, magnaflow cat, and Vibrant resonator and muffler. Stainless Vibrant v-bands and stainless hangers. Parts cost me nearly $1k and you'll laugh, but although I wanted BavAuto or Stahl headers, I just couldn't afford them new and I couldn't find a used set.
So... I took a gamble on a set of eBay OBX headers. I figured since I was building the system from scratch, fitment would be less of an issue. Well, it wasn't and they're CRAP. Their x-pipe is total trash, the header outlet pipes collide with each other at almost a 45* angle under the car plus they're jammed against the floopan, they're jammed against the motor mount bracket, and I had to bend the oil cooler lines out of the way. And once I got them to actually fit (kind of) they still leak where they mate to the cylinder head. BADLY. And I can't stand the noise anymore.
So. I was set against ever buying eBay headers again. But then these (http://www.ebay.com/itm/BMW-E30-325i...#ht_1121wt_831) came along and appear to be direct copies of the BavAuto units. And at least they have real flanges at the cylinder head (even if they need to be planed flat)! And they're true long tubes w/o that crappy x-pipe too! And at this price, I'm very tempted to take another gamble, although it would include a lot of work and I'd be upset if they were a waste of time like the OBX units.
I'm hoping somebody has used them and can provide some insight on fit and quality of construction. I searched like mad hoping someone would have experience, but didn't find anyone that tried this particular type/brand.
Thoughts?
Thanks.
UPDATE 1/15/12:
The new headers (brand:Top Speed) arrived yesterday and here are my thoughts. I'm going to do a lot of comparison to the OBX units that are currently on the car because they're my only point of reference.
First, the build quality seems like a toss-up for the most part, though if I had to choose, I might give a slight edge to the OBX units which does not speak poorly of the new headers simply because I believe the OBX units are constructed pretty well. They just lack badly in design and fitment.
The mounting flanges on the Top Speed headers are mild steel and 7/16" thick which is quite thick. I checked the flatness of the flanges with a nice Westcott ruler and they're close to flat, no more than 2-3 thousandths out.
The TIG welds are also very nice, though again, I might actually give the nod here to the OBX units. This comes down to appearance alone, I'm sure they give up nothing in strength.
The tubing itself seems of nicer quality on the OBX units and the mandrel bending seems to have been slightly nicer too. The diameter of the primaries is slightly smaller on the Top Speed headers, though this isn't necessarily bad.
Inside the header flanges, the welds were cleaned up on both headers, but again, slightly more nicely on the OBX units.
I am no expert on collectors and the quality seems equal in this regard between the OBX and Top Speed headers. I'm sure, however, in the grand scheme of things, that neither is great.
Outlet diameter is 2" and the Stainless Works 2" SS304 tubing I'm going to be using to mate to the collectors will neither slide over nor inside the header outlets.
The polished finish on the Top Speed units isn't quite as nice as the OBX units either, but not a big deal in my mind, as the OBX units are quite discolored after 2 months of using them anyway.
The big remaining question is fitment and this is where it seems the Top Speed units already have an advantage over the OBX headers. Just looking and guessing at how they'll lay in the engine bay, I foresee them having fewer interference issues with other components and it doesn't seem as though the collector outlets will collide with each other at a 45" angle when bolted up.
It may be a little while before I get more 2" tubing, figure out how I'm going to mate these to the rest of the system, and order new exhaust gaskets, but when I get down to installing these, I'll be sure to update.
UPDATE 2/24/12:
I've delayed updating this so long, I'm sorry! I installed the headers almost a month ago at this point and been daily driving the car ever since. My thoughts so far:
Here's the additional parts I bought to complete the installation onto the rest of the system (listed above). Stainless band clamps, 2" diameter SS304 u-bend, and new gaskets
The old OBX headers removed:
Direct comparison between the rear OBX and TopSpeed header sections. Pretty obvious here which has longer tubes... lol. And which one exits at a 'normal' angle/location.
Really terrible picture in the dark, but they sure look TERRIFIC in the engine bay:
Here's the one fitment flaw. But I don't know if others will have this problem or not, maybe I need new motor mounts or something (they aren't that old, though)? But the number 5 primary interfered tremendously with the strut tower, I had to heat it and flatten it many, many times to get it to fit and even now, it's still jammed against the tower. Luckily it doesn't rattle! The number 6 primary rubs a bit too I think, but I didn't modify the tubing at all.
These do sit VERY low! My car is also a little on the low side and I have only 3 inches of clearance between the ground and header outlets! I have scraped the exhaust a few times already even though I'm very careful. I'm hoping when I take off the 14" winter wheels, it will sit a bit higher. Also, the nice stainless band clamps I bought don't work in this instance because there isn't enough straight pipe at the exit of the collector... meaning the clamps ride up the collector a bit and can't be tightened all the way. It leaks there, of course, and I'm afraid I'm just going to have to use a u-bolt clamp to make it seal. I'm not welding it b/c I want the system to be easily removed from the headers. And ignore my temporary O2 wiring...
Next up, tomorrow I hope, is to get some video footage of the sound of the car with the headers and complete system. I have to say the exhaust sounds very different with the TopSpeed headers compared to the OBX headers. It sounds meaner and louder, without a doubt. In fact, the sound difference really surprised me b/c the rest of the system hasn't changed. I also feel it has a bit more torque than before, but that's just the butt dyno. Either way, the car sounds terrific, I get looks and stares everywhere. In fact, the other day I had a guy in a Miata behind me in town who would break out laughing each time I got on the gas. It's quite loud, to be honest, but the sound is addicting.
Exhaust Clips:
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