[DJ Asthma]

Hey guys,

My second post on the forums, but I have read a ton over here and love it here. I have a 2016 BM Mazda3, Skyactiv-G 165 (no 2.5 here in Namibia), named her The Shadow :laugh2:

I have not done much to her since I bought her back in 2016, put on some 18x8 wheels wrapped in 225/40R18 Bridgestone Potenza RE003 and did a custom Cat-Back (cut from the second cat and did custom piping). Next in the list is cold air intake and the OVTUNE at the end of the year, but before I do that I wanted to know, given that corksport removes the second cat for it's cat-back, I was wondering if removing/replacing it would net any gains in performance (trying to turn her into the 200+ HP NA-MPS we were never given)?


I am also going to ask Matt from OVT before I get the Tune done so that we tune with all the mods in place.

(I attached some pictures of her, coil-overs and aero-kit are in the pipeline so don't mind the wheel gap :laugh2

 

[nostalgichero]

It's hard to say how much gain without a dyno. With the cat deleted you will free up some power but probably not much. On the other hand I've heard that with the gwr long tube header you could see expected gains of 40+hp


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[nostalgichero]

Btw nice ride



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[squelchy451]

Not to stomp all over your dreams or to belittle any efforts from mod suppliers, but squeezing more power out of a NA engine is usually more difficult than tuning a turbo engine. Our Mazda3 was meant to be a responsive compact car with good handling. Keep the revs up and I don't find it terribly slow (unless on the highway). Good luck on your search!

 

[arathol]

On the other hand I've heard that with the gwr long tube header you could see expected gains of 40+hp

On the MX-5 ND yes, but only because that car has a different factory header to start with. The header on the 3 is already a long tube design that works extremely well.

Hey guys,
I have not done much to her since I bought her back in 2016, put on some 18x8 wheels wrapped in 225/40R18 Bridgestone Potenza RE003 and did a custom Cat-Back (cut from the second cat and did custom piping).

What sort of "custom piping"? More often than not this ends with a net torque loss unless the system is carefully tuned to duplicate the flow of the OEM system.

 

[nostalgichero]

On the MX-5 ND yes, but only because that car has a different factory header to start with. The header on the 3 is already a long tube design that works extremely well.

You got a point there this was done on the mx-5 ND. However I can't see why it can't be achieved on the MZ3 with the same motor. Headers + OVT would easily give you 25+hp gain on the 2.0 engine. That's 190hp And I'm certain you can squeeze a tad bit more if you went full on e85 gas. You will certainly notice a nice bump in toque with a catless Header as long as you retain the 4-2-1 design. Now if you add camshaft to that zoom zoom.


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[DJ Asthma]

No no, you are not stomping on my dreams (just seeing Equilibrium now) but thank you for being considerate. I know it is more about handling, and that this motor is not a K20. For me I love the car already and just want to get the most out of it, hence NA MPS (NA Speed3). I doubt I would do a turbo conversion on this, but hey who knows.

 

[DJ Asthma]

On the MX-5 ND yes, but only because that car has a different factory header to start with. The header on the 3 is already a long tube design that works extremely well.



What sort of "custom piping"? More often than not this ends with a net torque loss unless the system is carefully tuned to duplicate the flow of the OEM system.

so what we did at the exhaust shop what basically resonator deletes. We kept the diameter stock, chopped off the entire exhaust from the tip of the second cat, laid the straightest pipe we could all the way to the area of the massive rear box (I am no exhaust guru :laugh2. Had the pipe split into to high flow resonators (one on each side) with their own exit. we tried to emulate the magnaflow and corksport exhaust setup.

 

[DJ Asthma]

You got a point there this was done on the mx-5 ND. However I can't see why it can't be achieved on the MZ3 with the same motor. Headers + OVT would easily give you 25+hp gain on the 2.0 engine. That's 190hp And I'm certain you can squeeze a tad bit more if you went full on e85 gas. You will certainly notice a nice bump in toque with a catless Header as long as you retain the 4-2-1 design. Now if you add camshaft to that zoom zoom.


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There is no e85 here, but considering some fuel additives to boost my octane, but still researching here. This is why I posted the question and shall ask Matt after I place my order (of if he is reading this, you can tell me now :laugh2 as I know the first cat is monitored, and will only consider removing that if the header is tried and tested/approved by the tuner with evidence to support it (so if OVT can bring back the header sweet). Cams, I was looking at the BBR GTI cams, but just need to find out how it is as nobody seems to be running them so little info on them, but yes ZOOOM ZOOOOOMM!!!!

 

[DJ Asthma]

There is no e85 here, but considering some fuel additives to boost my octane, but still researching here. This is why I posted the question and shall ask Matt after I place my order (of if he is reading this, you can tell me now :laugh2 as I know the first cat is monitored, and will only consider removing that if the header is tried and tested/approved by the tuner with evidence to support it (so if OVT can bring back the header sweet). Cams, I was looking at the BBR GTI cams, but just need to find out how it is as nobody seems to be running them so little info on them, but yes ZOOOM ZOOOOOMM!!!!

these are the cams I was referring to

BBR High Performance SkyActiv Camshaft Set | BBR GTi

 

[DJ Asthma]

Btw nice ride



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Thank you

 

[arathol]

You got a point there this was done on the mx-5 ND. However I can't see why it can't be achieved on the MZ3 with the same motor. Headers + OVT would easily give you 25+hp gain on the 2.0 engine. That's 190hp And I'm certain you can squeeze a tad bit more if you went full on e85 gas. You will certainly notice a nice bump in toque with a catless Header as long as you retain the 4-2-1 design. Now if you add camshaft to that zoom zoom.


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The thing is when the GWR long tubes are used you get decent HP gains because they are significantly better than the OEM part on the ND. The 3 already has a factory long tube header thats just a good so you won't see the same gains. Yes, 190 hp is possible but thats mostly from the tune. You won't see much gain from any aftermarket header that is currently available. Catless headers are pointless and illegal for street use here, not to mention they won't pass and sort of emission test or visual equipment inspection.

 

[skyactiver]

It would be interesting to see what OVT can accomplish on the dyno with full e85 on a 3rd gen Mazda 3 with bolt-ons. Many of us have run e85 and pump gas blends, but not many have tried pure e85 which is what allows running top-end MBT ignition timing on skyactiv engines. On the Miata ND, there has now been at least x2 3rd party dyno's showing that an e85 OV tune with GWR LT header, mid-pipe and muffler lead to ~180 whp (~200 bph). Whether the stock Mazda 3 header is as capable has not been shown from my knowledge, but despite some disadvantages compared to the GWR LT (smaller primary, secondary and collector diameter, and factory cat), it should still put out decent gains with full e85. 190 bhp could be possible.

 

[pmarsh22]

It would be interesting to see what OVT can accomplish on the dyno with full e85 on a 3rd gen Mazda 3 with bolt-ons. Many of us have run e85 and pump gas blends, but not many have tried pure e85 which is what allows running top-end MBT ignition timing on skyactiv engines. On the Miata ND, there has now been at least x2 3rd party dyno's showing that an e85 OV tune with GWR LT header, mid-pipe and muffler lead to ~180 whp (~200 bph). Whether the stock Mazda 3 header is as capable has not been shown from my knowledge, but despite some disadvantages compared to the GWR LT (smaller primary, secondary and collector diameter, and factory cat), it should still put out decent gains with full e85. 190 bhp could be possible.

We should instead be focusing on getting the 2.5 above 200 HP :laugh2: