Disclaimer: Before you carry on reading, everything below is just my opinion and personal observation along with remarks I was given by my mechanic and a friend of mine who specialise in metalcraft. These pics are over a year old and I am recalling events a year ago. I may be wrong or things may have changed since. Take what you want out of it.
--------------------------------------------------Starting with AMS: 
First impression was very good. Nice and shiny, the o2 sensor thread came with a cap which was not included in the SZ one I bought.
Second look I already had some concern over the 5 bolt flange, circled in red.
 The welds are good, flange is thicker than the SZ counterpart. The flange is also welded all the way through unlike the SZ unit which has spot welds. There is 1 less weld on the body of this dp than SZ's one. How big of a difference that makes I do not know. 
When I took this to my welder friend he laughed at me when I pointed out the flange holes. "Cheap china sh*t bro" :/ He then pointed out a few things to me while still laughing with hilarity. 
He pointed out the copper brown colour of the dp to me which I never noticed before, and explained to me that these must have been electroplated (rather badly he added). He then went on saying these are most likely made from a cheaper grade of mild steel, plated to look like stainless steel. He told me he has never seen that done in his 35 years of metalwork. 
The 3 bolt exhaust flange is no better, circle in red again you can see how close the holes are to the edge of the flange. My friend said these must of been drilled manually with a template (so hole distances are the same) but that is about it as far as precision goes. The separator which is held on by 2 studs is pathetic. To accommodate the stud head they drill a smaller hole over the bigger hole. NOT PRECISE AT ALL. I don't have a picture of this but you can easily imagine it, my friend traced the triangle and the 3 circles on paper, and then placed the other dp over it. The triangle/bolt holes are no where near inline. SZ dp:
I have to say I expected top notch quality when I purchased this. Box shot:
 As mentioned before; main difference is the flange not being as thick (not thin by any means), the 5 bolt flange not welded all the way through, O2 sensor cap not included and 1 extra weld on the body. The 5 bolt alignment. Note the irregular size holes and clearance to the edge.
 The two pics below are not from me, first one is SZ and second one is AMS. Note the brown copper plating I talked about. You can tell the two uses different materials. 
My separator did look better than the one on the top pic. It was however still not CNC machined or anything if I recall correctly. Seems like both AMS and SZ separators can be a hit or miss as far as quality is concerned. I am sorry but I forgot to check how the studs are held on the SZ one (not sure if its another case of smaller drill hole over a larger one). No major problem with the 3 bolt exhaust side Summary:
Both DP were had awful 5 bolt flanges which really surprised me. Even here in middle-of-no-where New Zealand we can buy 4 and 5 bolt CNC flanges. This is the main problem I had with the SZ unit. The actual welds on both units look decent. No complaints there. AMS dp do appear to use a lower grade material. Compromise between price and quality is evident. My take:
If these can be laser cut so its more precise that will be fantastic. I ran a price check on CZP just now, at $440 and $328 you are looking at a price difference of just $112. If you are planning to buy a set in the near future I would strongly recommend the SZ one. Quality aside $112 is not much to show that you support innovators not copiers. While I know Vuk said "Once again a copy denotes an identical product which it is not." lets not be a five year old now and use some grey matter here. The AMS ones are knockoffs period. I have no problem if you buy the AMS one, however don't buy the AMS one thinking its another product or its better -IT.IS.A.COPY-. I have nothing against AMS and in fact I have used various AMS products over the past 3 years. It just annoys me when people back Vuk up arguing that they are not copies/replicas. SZ is the genuine stuff, get over it.
___________________________________________________________________________ There was a time where I wasn't sure whether the Z would be the right kinda car for me, that is till I saw this one morning...
...Yup. I drive a Z now. |
SZ 3" expansion vs AMS/Alloy Toyz 3” Split Down-Pipe - 
