While a similar question has been asked before, the answers weren't satisfying so I'd like to take another shot.

I noticed that the pricing for Mazda o-ring sets for S4T, S5T, and FD differ greatly, why? I mean it's essentially the same keg. I can't imaging the MOP gasket causing this variation, look:

S4 [N318-10-S60A]: $193.00 list
S5 [N370-10-S60]: $293 list (+50% from S4)
S6 [N3A1-10-S60A]: $425 list (+>100% from S4)

Do the FD sets come with magic water seals or something?
Even Mazda couldn't misprice parts that bad for no reason, right?

(PS: I don't pay list prices, just using them for comparison.)

To the one person who might know the answer, Thanx.

 

I do not know where you are getting the pricing from but it is incorrect.

The FD N3A1-10-S60A is $160 at Mazdatrix & Atkins , even RB who is gouging is at $225.00

All the O-rings are the same. Injector diffusers and grommets are different.

 

The pricing I quoted is list pricing from Mazda and is not 'incorrect' - it's just very high compared to 'actual' pricing.

Now that you mention it, Mazdatrix's pricing is noteworthy: the FD O-ring kits are less than the FC-Turbo kits. This is unusual since if you buy from Mazda, the reverse is true. That suggests that Mazdatrix is selling the Atkins kits for FD's rather than the Mazda OEM kits like RB.

I also just realized that the inner (orange) orings are really expensive @ $21ea from Mazdatrix. Presumably they're hi-temp silicone rubber with teflon inner and outer 'bands'.

Apparently, the answer to why the Mazda OEM O-ring kits are more for the FD than the FC is that the FD kits include two 'FI diffuser' thingamajigs. Still unsure why the S4T kits are less than the S5T kits, but I suspect it's just a pricing anomaly (and may actually relate to the oval oring for the MOP). In conclusion, buy the S4T oring kits from Mazda, they're relatively cheap.

Thanks for steering me in the right direction Banzai-Racing.

 

i usually order the N326-10-S60A kit, as it used to be the cheapest, but i see that in 2015 the N318-10-S60A is cheaper by a few bucks.

no idea why the FD kit is so much more, there is nothing in it that justifies the $100+ price difference. it should actually be the same kit as the N370, but instead of the 8 injector diffuser o rings, it should have the 2 lower seals, and 2 diffusers.