I'm always one to root for the underdog. I want companies to try to find more efficient ways to do what other companies do expensively. I'll say that most of the time, that works out great. For example, I just bought a Coolster 125cc pit bike to get around the pits at hillclimb races, and couldn't be more impressed. It's definitely cheap Chinese manufacturing, but that's exactly what's called for in a pit bike.
Unfortunately I struck out with CXRacing, and wanted to share my experience with others. I've been encouraged by a couple of inexpensive aluminum radiators that treated me well in past cars, and decided to count on them for my most recent purchase of an exhaust header. I ordered https://www.cxracing.com/header-manifold/header-manifold-mazda/HD-MIATA18-1-1 from their eBay store because eBay has additional buyer protections built-in. It looked like a good design, but when it arrived, I quickly realized that it wasn't equal length at all. The front runner is a foot longer than the rear two runners, and now my Miata sounds like a Subaru.
Anyway, before I could install it, I took a good look at where the exhaust gases would be going. The only obvious flow problem was at the header flange itself, so I spent some quality time with a die grinder and smoothed that out a bit. I'm not going for perfection here, just breaking those hard angles that would cause big pressure pockets in the exhaust.
Despite the vast differences between runner lengths on this "equal length" runner, I had a race event to prep for and I was committed. I got it on, made a blockoff plate for the EGR valve, and re-routed a few hoses. I definitely didn't gain any power from this, but it allowed me to finish making my new exhaust, which allowed me to move my seat further inboard.
I tried to explain that they had made a mistake (or lied?) about what they had sold me, with photographic evidence.
Hi, the photo you sent to us show the received item is same as our listing.
Your previous message
My issue is that it's sold as an "equal length" manifold, and wasn't even close to being equal length. There is almost a foot difference between the front and rear runners.
unfortunately we do not have much feedback as to what kind of power gains are typically expected using this header, many of the cars that we have seen this being used on seem to run just fine and have decent power curves but again being that we do not have the ability to fully test any gains/loses we cannot specify exactly what is to be expected with the header especially since many engines are built differently so comparing dyno numbers from one engine build to another may not always show the same results.
Your previous message
It looks just like the photo for the listing, but based on the title/description, I had really expected equal-length runners. I don't think I have the shipping label, but the order number is attached to this message.
Can you please take some pictures of the item that you received with the shipping lable and attach them on ebay message?
Your previous message
After installing and hearing the exhaust note on this header, I measured each of the runners. They aren't even close to being equal length (especially the front runner), which was one of the main selling points for me. After a dyno tuning session yesterday, I found that I've lost 4 ft/lbs toward the top end (but gained around 5 ft/lbs between 2000-3000rpm). That's the opposite of what I'd like on a race car, so I'm pretty disappointed overall. Before I leave feedback, is there anything I might be missing here?
During that time, I had one race event. At the second event, I found that the welds were insufficiently penetrated and were coming apart at the seams. This was a clear manufacturing defect, and the only dignified way I could see around it would be to return/replace it (even if I'm not excited about the design, a company should at least stand behind the quality of their work).
I'm completely checked-out trying to deal with their eBay support. In a last-ditch effort to let them get out of this in a dignified manner, but even if they do step up and provide reasonable support this is much more work than it should have been.