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Is a Injen sp short ram cold air intake worth it on a 2018 Mazda 3 hatchback touring 2.5 L!

12K views 36 replies 10 participants last post by  JoeMini 
#1 ·
Is a Injen sp short ram cold air intake worth it on a 2018 Mazda 3 hatchback touring 2.5 L!
 
#9 ·
It may add 1-2 hp and sound louder ... you need to make your exhaust (headers/cats/down&exhaust) less restrictive in order to gain from a cold air intake which is really warm or hot from the engine bay unless you have air that is directly from outside the engine bay.
 
#11 ·
If you install it and perform an ECU tune directly after, I would get it. Without doing a tune, I would stick to the OEM CAI system (the car comes with a very well designed CAI system btw).

I've tested two different aftermarket SRI/CAI setups (K&N and AEM) and they both made almost no change in performance by themselves. With tuning they were able to add about 6 HP and 7 lb/s torque when testing on a v-dyno compared to the stock unit. I was mainly concerned with IAT and the AEM intake did a good job at keeping IAT closer to ambient. Not as good as the stock intake, but it was pretty close and it did a better job than the K&N Typhoon model. Cooler air is denser and has more oxygen to burn as fuel, which means better engine performance.
CK
 
#13 ·
If you install it and perform an ECU tune directly after, I would get it. Without doing a tune, I would stick to the OEM CAI system (the car comes with a very well designed CAI system btw).

I've tested two different aftermarket SRI/CAI setups (K&N and AEM) and they both made almost no change in performance by themselves. With tuning they were able to add about 6 HP and 7 lb/s torque when testing on a v-dyno compared to the stock unit. I was mainly concerned with IAT and the AEM intake did a good job at keeping IAT closer to ambient. Not as good as the stock intake, but it was pretty close and it did a better job than the K&N Typhoon model. Cooler air is denser and has more oxygen to burn as fuel, which means better engine performance.
CK
What was the power increase with just a tune?
 
#15 ·
With a OV TUNE on 91 octane or higher you can see: 2.0L non skyactiv: 10-14HP gain. 2.3L non skyactiv: 14-19HP gain. 2.5L non skyactiv: 22-30HP gain. 2.0L skyactiv: 16-20HP gain. 2.5L skyactiv: 25-35HP gain: 40+ with certain modifications. (not sure if these stats with or with out CAI & cat back) ...i think without.
 
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#16 ·
Here is a thread with actual dyno test that shows results from a 93 octane tune on a 2.0 motor.


Initial results show a 7 hp increase from the SRI when using an axle back exhaust.
 
#17 ·
#22 ·
2012 Mazda 3 GX MT5 2.0L non sky.
TBH ... unfortunately i cannot say if it would have reduced the bottom end with the oem flywheel/clutch because the flywheel was lightened and with a stage 1 clutch when the mods were added. Bottomline is with this set up is the bottom is better that oem. Personally i think the lighter flywheel /clutch has offset the bottom end loss. These cams do there stuff 4K to 7K and were all the HP is made and keep pulling all the way to redline. Xerolimit uses them in there miata on the track (the MZR 2.0L) and can pull past 8000 with no internal changes except stiffer valve springs.Check out theire website if you are considering Cams. They have a stage 1 from Kelford, a stage 1.5 zerolimit (which are grinded from OEM mazda blanks) and a Stage 4) stage 1 & 1.5 can work on oem springs.
 
#23 ·
Ok... thx. I have a '17 Mazda6 GX 6mt... (Skyactiv-G 2.5) - heavier car, more bottom-end oriented engine... which needs to retain/enhance that bottom-end otherwise it'd be a PITA in city traffic here in Vancouver. Also, whereas the 6at would mask the bottom-end a bit (what-with torque multiplication at converter stall) no such effect is at play with my 6mt.

So I will go with OVT tune for 91 (RM+MM)/2 octane fuel... with added 25% (?) TMap. Will likely add axle-back exh just to actually HEAR the engine, haha, though CS Axleback actually lessens torque a 'wee bit between 2000 and 2900 rpm (which is where I want to richen-up torque). Wish I could have a more throaty exhaust while keeping at least the OEM muffler, without any non-reversable (oxyaccetylene torch-cut) changes. Bolt on /un-bolt is what I want... with no loss in bottom end... in fact, with GAINS in the bottom-end.
 
#24 ·
#26 ·
I would prefer to keep the OEM exh. manifold. It's quite the work-of-art despite being hidden behind heat-shield haha. Seriously, I want to stay emissions compliant. I fully expect, particulary here on the Left coast of Canada in the not too distant future, that a person running a gasoline powered car in an urban setting will be repeatedly keyed by "environmentalists". I'm SERIOUS... and I'm not looking forward to that day. Ah, political correctness, peer pressure, rampant eco-terrorism...
 
#28 ·
Had i know i would have kept the 2012 oem airbox and then add a second cold air source . The one with oem box doesnt seem enough.
So ... saying that ... im modifying a box that will fit Corksport CAI and will incorp the oem cold inlet that is puling air from front top of rad
and a second from the bottom of the box pulling air from the driver side fog light panel. On my GX no fog light , cut a hole in the panel
and voila , intake #2 . Now i just have to do it...lol
 
#36 ·
Thats something I made myself. I got 3 feet of 51mm flexible silicone ducting from ebay, some bits of PVC to attach it to the box (threaded trap adapter w/P nut and a bit of pipe) and a silicone flare (step adapter for an intake tube) from Autozone for the intake end.
Rain isn't an issue. As long as you have a secondary intake source it won't draw in water.
If you have the CS box you need to seal around the intake tube if you haven't already. A length of 4" square weather stripping foam cut lengthwise about half ways through makes a good collar to keep out hot under hood air.



 
#37 ·
Thats something I made myself. I got 3 feet of 51mm flexible silicone ducting from ebay, some bits of PVC to attach it to the box (threaded trap adapter w/P nut and a bit of pipe) and a silicone flare (step adapter for an intake tube) from Autozone for the intake end.
Rain isn't an issue. As long as you have a secondary intake source it won't draw in water.
If you have the CS box you need to seal around the intake tube if you haven't already. A length of 4" square weather stripping foam cut lengthwise about half ways through makes a good collar to keep out hot under hood air.



Nice !!
Mine will look trailer park compared to yours .
As long as it works ..that is all that concerns me !!
 
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