Custom catalytic converters
 

I had some cats made for my 370Z. It's somewhere between a sport cat and a straight pipe.

It started out as a set of Invidia testpipes. I had some magnaflow cats added, and a bypass with a pneumatic valve. The valve is normally closed, and act as two resonators. Open, and they provide a path of less resistance.

Very nice! What was your line of reasoning in having this done?

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It's part of a whole new exhaust setup. Headers, these custom cats, Armytrix cat-back. Everything is stainless, and also ceramic coated (Cerakote). Since the Armytrix set already had two valves (which I also changed out for normally closed ones), I figured these were an extra bonus, for getting more unrestricted flow. On the dyno, my setup makes 379HP with a stage 2 tune. I thought I showed the cats on this forum, as I never seen something similar.

ah... could i hear some more about your tune???

Can not say much about the tune, other than it was done by BR Performance, one of the bigger tuning shops in Europe. They said, due to the exhaust, they were able to tune this 370Z further than any other NA 370Z. After two days, I got the car back along with these figures. Not bad for running on 98 octane, not even the 102 racing fuel stuff!

With the installation of the 4 valves, I can switch the exhaust from a quad resonated, dual catted and back muffler setup, which keeps my neighbours and local law enforcement happy, to basically straight pipe, which keeps me happy.

What all you have done. CAI, Exhaust, Uprev or something else, cams, etc.

Other than the exhaust, not much. I have some Mishimoto silicone inlet hoses, and K&N airfilters in the stock airboxes. My car was already tuned before I got it, as you can see in the graph. Thanks to the exhaust, the extra 17HP were extended to an extra 48HP over stock. I spent some thought over the exhaust. The performance gain was not my main reason, but I simply did not want to have any rust, ever again!

The pictures in my start post shows the cats at fabrication time, but also part of the "stainless" pipes of the custom exhaust that was fitted when I bought the car. It looks horribly corroded. I did the ceramic coating due to the fact that there were no heat shields on the aftermarket headers, but I decided to coat the whole exhaust after I got a good price for it to be done. Nevertheless, the whole setup costed a pretty penny.

375-380WHP with just bolt ons and a tune? Somethings not right there.

Oh right i remember this chart for somewhere, it's been Photoshop'd.

With what he has. It should be not more then 330 at the most.

Of course you are entitled to any and every opinion you may have, but I did not photoshop any picture. Maybe you interpreted it wrong?

The graph shows a calculated 92% drivetrain efficiency, so the actual measured HP is about 348.

I remembered that Z1 motorsports makes a package with a cat, CAI and other intake and exhaust manifolds that makes 425-ish, my 379 is not even that strange.

The Z1 package isn't whp, it's crank hp. Your number is high for the mods you have - what's a stock Z put down on their dyno?

You're crank HP, not wheel HP. That makes a difference. Most of us here use a DynoJet. Could be the difference in dynos too. From past experience. Your 348 at the wheel is high. Most people with your mods get between 310 to 330 roughly.

:roflpuke2:

:facepalm:

Love the exhaust, thanks for sharing that.

The crank HP and 92% efficiency figures are quite optimistic however.

Chart shows
360Nm & 380pk ~7300RPM
360Nm = 265.5Bftlb
380pk = 374.8BHP

Now since you mentioned these numbers are calculated BHP @92% rather then the actual WHP. Which is why people generally don't use BHP because it's subjective and just inflates numbers. A stock Nismo typically puts down about 290whp with a listed 350bhp which is an 83% efficiency, is it really 83%, or 92%, or some other guess. Anyway the numbers still look very strange no peak torque gain over stock but a big HP gain.

Thank you for explaining! I never paid that much attention, because I'm rarely in the 5500+ rpm range anyways. I'm not THAT kind of a driver! What I do appreciate, is the fact that it's not going to rust again. I have some pictures of the Armytrix set getting the ceramic coating treatment.