[size=20pt]NA Power Stage 2[/size]
(designed primarily for the Mz3)


Modifications
1. Throttle Body Coolant Bypass
2. Ignition Timing Advance ("Monzta's Timing Mod&quot
3. SRI/CAI
4. Rear Muffler / Cat Back
5. High-Flow Cat or
6. Race pipe/Cat delete
7. Rear Engine Mount


The mods in this stage will yield a decent increase in gas mileage and a really good gain in both horsepower and torque once completed- around gains of 16whp/18wtq peak- and that’s not counting the intake!! The installs are relatively easy, which anyone can do with the right tools, but you might have to have a shop install your exhaust modifications as it requires 1 or 2 cuts into the stock system and possibly some welding involved.


1. Throttle Body Coolant Bypass
Price: $6
Install: 20-40min (http://www.mazda3forums.com/index.php?topic=44789.0)
Pros: Colder throttle body (less TB heat soak)
Cons: Possible sticking of throttle plate (no reported issues yet)
Peak Power Gains: N/A
The coolant bypass is a very easy modification that I would suggest for spring/summer driving. An engine operating at normal temperature will have hot coolant circulating (~117°C {242°F}) therefore you end up with a very warm throttle body because there's a coolant line that goes through it. While it's normal for modern cars to have them as a standard feature to keep the throttle plate from sticking during very cold mornings (think freezing and below freezing temps), it serves no purpose to a 3 owner in who lives in a place that’s relatively warm.

If you live in a cool weather place, and still want to do this mod, as a precaution after you're finished, occasionally remove your intake tubing and use a clean rag to wipe the throttle body of any debris and sludge close to the throttle plate, which could cause the plate to stick. You can also push in the plate slowly with your finger to clean up the crevices.

You’ll probably gain back 1-2hp (possibly more) when driving in hot summer conditions (think 90-100+° weather), especially while the A/C is on. Gains are probably 0-1hp during winter season. Touch the TB before and after the mod- big difference in temperature. The TB after the mod is cool to the touch as only air is going through it. What better way to complement your CAI!

SCI Water bypass kit: http://sportcompactindustries.com


2. Ignition Timing Advance (Monzta's Timing Mod)
Price: $0
Install: 20-40min (http://www.mazda3forums.com/index.ph...5573#msg585573)
Further Reading: http://www.miata.net/garage/KnowYourCar/S10_Timing.html
Pros: Take advantage of higher octane, smoother acceleration, more hp/tq, ECU pulls back when engine knocking is detected
Cons: 1.6L has the sensor in a fixed position, Cost of using higher octane, Possible knocking from 87
Peak Power Gains: +6whp/3wtq (using 89 octane and timing vs. 87; your mileage may vary)
What you're basically doing is igniting the fuel mixture a little sooner by moving the slotted crank position sensor to advance the ignition timing. It will still be within factory specs (8° BTDC set at factory according to Service Manual, 10° BTDC according to Service Highlights- that info alone could be why some stock 3s are putting out slightly higher #s than others). This modification only deals with the ignition; the cam is not affected- therefore, the VVT operations/changes will still engage at the same rpms. While 87 octane works with this modification, those who have experienced knocking/pinging use 89 octane to compensate.

I advise you to reset the ECU so the timing curves/maps can be learned quicker. It will most likely stall just once while trying to find the new idle speed (it won’t stall again while it’s idle hunting the next time you reset the ECU). Some users report a slightly lower idle speed after doing this mod, so don't be surprised if it drops lower than you're used to. You might also want to add some fuel injector cleaner every few tanks if you’re using 89 or higher.

My observations on different octane after this mod:
I've tried running 87 and it didn't seem to accelerate as fast on the freeway (ECU possibly retarding back the timing to a "safer" level). Burned through 2 gallons pretty fast though. I feel almost no difference between 89 and 91 for my 3, but both allow me to get better performance and smoother/quicker acceleration at the cost of lower gas mileage compared to the 87.

From Monzsta, the mod's originator:
Factory timing is highly conservative, plus the ever-present knock sensor will protect the engine. Worst case scenario is the mod won't show any gains, meaning that the engine is utilizing all the advance it had previous, and the ecm is pulling out the added timing due to spark knock. Being users of this mod ARE reporting gains, it would seem the engine can use more timing. My car hasn't shown any improvement in stock form with 87 vs. 93 octane and it seems to now after advancing the timing, indicating the ecm is finally using the knock sensor to determine what grade of fuel I'm running and adapting it's timing maps to compensate. (as it should if the engine were in a max effort tune from the factory, like a 'Vette's.)

Timing Advance + 89 octane dyno:

@3.5k: +2hp, 4tq
@4.5k: +3hp, 4tq
@5.5k: +4hp, 4tq
@6.0k: +5hp, 4tq
@6.5k: +5hp, 4tq




3. Short Ram Intake / Cold Air Intake
Cost: $180-350
Install: 1-2hrs / 10-30mins if resonator is removed (resonator removal install: http://www.msprotege.com/forum/showthread.php?t=60565)
Pros: More hp, torque, gas mileage
Cons: Concerns of hydrolock
Peak Power Gains: varies (reported gains from 6-8hp)
There will always be a debate whether SRI or CAIs are better for the 3. The easiest way to look at it is that the generally cheaper SRI tubing is short and relies on vehicle speed to provide the engine with cold air while moving. A CAI’s tubing is longer and its filter sits much lower allowing the engine to ingest colder air. CAIs are more expensive because of the R&D involved in finding the right placement of the filter and the right tubing diameter to keep the MAFS (mass air flow sensor) working correctly.

AEM seems to have the optimum position because its filter sits very close to the ducting vents on the wheel well. Other intakes curve up at the bottom to raise the filter little to add a bit of safety during rain. The problem with that additional bend is that any water that passes through the filter can collect in that bend and can cause a CEL if not taken care of, as in the case of sedan owners with Injen intakes.

F2 and Fujita intakes currently have the largest diameter of all the intakes, measuring 3.0" and 2.75" respectively. Will an intake with a wider diameter give more power?

It looks like our MAFS is our bottleneck. The F2 and the Fujita intake tubing, while wider in diameter, needs to have the tubing around the MAF sensor area reduced to almost 2.5” to be metered properly. The F2 intakes use a removable urethane insert (reducer) inside the tubing, while the Fujita’s reduction is part of the tubing itself. A good thing about the F2’s removable reducer is that once there’s an available MAFS to take advantage of the 3” tubing, all you have to do is remove the reducer to make even more power. Power will be further augmented by the ECU/fuel tuning once it’s available as well.

Take a look at the Air/Fuel graph of the F2 vs. AEM dyno (the ECU was reset 6 days prior to the F2 runs). The car runs leaner with the F2 intake which means, at WOT, the ECU is not taking advantage of the greater amount of incoming air by adding even more fuel. It only adds fuel relative to the air that passes through the reducer, which is why it creates as much power as the AEM in 3rd gear WOT. 4th gear picked up a nice ~5hp/4tq bump at the top end. Again, once we get some ECU tuning or a better MAF sensor to take advantage of the larger intake diameter, the F2 should produce a greater amount of hp/tq and we might be also be able to run the intakes without the reducer which makes it a full 3.0” intake.

F2 is currently the best intake for the money. With 3.0” tubing throughout, 2 simple bends, no CEL or rain issues, and a removable reducer, there is very good potential for future NA tuning. Revision for the ATX fitment is almost done.

F2 3.0” vs AEM 2.5” 3rd gear:
@2.5k: 0hp, -1tq
@3.0k: -1hp, -1tq
@3.5k: 1hp, 1tq
@4.5k: 0hp, 1tq
@5.5k: 0hp, 0tq
@6.0k: 1hp, 1tq
@6.5k: 1hp, 1tq



F2 3.0” vs AEM 2.5” 4th gear:
@2.0k: -1hp, -2tq
@3.0k: -1hp, -2tq
@3.5k: 0hp, 1tq
@4.0k: 2hp, 3tq
@4.5k: 1hp, 1tq
@5.5k: 2hp, 3tq
@5.0k: 1hp, 2tq
@6.0k: 5hp, 4tq (!)
@6.3k: 3hp, 3tq (!)


Rain and Hydro locking and CAIs:

Further reading: http://www.prepsparkplugs.com/hydrofact.htm
This is what concerns most buyers who are shopping for an intake. Common sense dictates you shouldn't be driving hard in the rain anyway, right? AEM users will get some water droplets on the filter even during light rain, mostly caused by the tire splashes that pass through the left wheel well vents. It's not a concern if the filter gets wet. The problem arises if you throttle in hard enough that it creates a strong enough vacuum to pull the droplets of water from outside the filter into the tubing. Lots of times, the small droplets evaporate before it reaches the combustion chamber. Sometimes, you'll get a simple CEL and the car becomes sluggish. This can be easily remedied by cleaning the intake tubing with a dry cloth, checking and drying both the filter and the MAF sensor and resetting the ECU or have the CEL code checked for free at a local Autozone before you do the reset. It seems like a lot of work/risk for the cost of using a CAI, but again, you really should be cautious driving in the rain.

If puddles concern you, here are some tips: either accelerate enough before the puddle then let off so the momentum lets you ride through the puddle (TB will still be opened, but the suction won't be as strong as you will be decelerating), or you can cover the wheel well vents with those styrofoam egg crates to resist a lot of the water passing through. The first vent on the left wheel well is about 10in off the ground (~9in. if lowered). To fully submerge the AEM intake filter, the water level would have to be at least 15-16 inches to pass through all the vents or seep in through the bottom grill or the splash shield. 15in is pretty deep!

CAI:

AEM: [2.5”] http://aempower.com | http://www.aempower.com/pdf/dyno/21-...Mazda%203s.pdf
F2 [3.0”] http://f2cars.com | http://f2cars.com/ProductImages/Dyno%20Mazda.jpg
Fujita: [2.75”] http://f5air.com
Injen: [2.5”] http://injen.com
K&N: [2.5”] http://knfilters.com
Simota Twin Charger: [N/A] http://www.simota.com

SRI:
Autoexe: http://www.autoexe.co.jp/english/index.html
Cosmo Racing: http://www.cosmoracing.com
SR Motorsports: http://srmotorsports.com
Simota: http://simota.com
Weapon-R: http://www.weapon-r.com
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4. Custom / Full Cat-Back Exhaust
Cost: $400-$800
Install:1-2hrs (http://www.draxas.com/docs/Mazda3Exh...stallation.doc)
Review: Draxas http://www.mazda3forums.com/index.php?topic=30097.0
Video: Stock vs. Draxas Comparison http://media.putfile.com/beanexhaustbeforeafter
Pros: More hp, torque, gas mileage, aggressive exhaust note
Cons: N/A
Peak Power Gains: +3hp/8tq (with my 2.5” Draxas Exhaust; your mileage may vary)
This is where the 3 has a wide variety in aftermarket options- the exhaust. While the 3 sounds fine with the stock system, eventually, you will want to upgrade for better flow and further augment gains from future engine modifications. There are several diameters to chose from ranging from around 2.25"-3.0", from the slightly more aggressive Mazdaspeed kit, to the better flowing kits like the Magnaflow-based kits like the 3.0" TruBendz respectively.

There are also kits like the HKS (2.55&quot and the Corksport kit that eliminate the second catalytic converter. Whether you want to make the commitment of installing a system that already removes the secondary catalytic converter in an emission-controlled state is up to you. Technically, they can still be called “cat-backs” as they would still be installed right behind the primary cat.

2.3L owners who wish to install a cat-back but want to keep both cats to stay legal might want to consider installing the 3" Trubendz to relieve some pressure generated by both cats. The 2nd catalytic converter alone produces a big restriction by itself that removing it alone produces very good gains throughout the power band. If you’re worried about the low end losing power, know that the 2.3L makes peak torque in the midrange and about 90% of the peak torque is already available at 2500 RPM in stock trim, while peak is made around 3900-4500 RPM. I think that you should only worry about exhaust velocity once you've removed both cats; cause then, you no longer have any pressure generated by the both.

Cat-Backs according to size, Muffler used, Info

Trubendz : http://trubendz.com (2.25”, 2.5”, 3.0” Magnaflow, optional 2nd Cat-Delete)
HKS: http://hks.com (2.55” HKS, 2nd Cat-Delete)
Draxas: http://draxas.com 2.5” (Thermal R&D)
http://www.draxas.com/images/Stock_vs_Base_vs_Race.gif
Borla: http://borla.com (2.5” Borla)
Racing Beat: http://racingbeat.com (2.375”)
Corksport : http://corksport.com (2.4”, 2nd Cat-Delete)
Vibrant: http://vibrantperformance.com (2.36, Vibrant)
http://www.vibrantperformance.com/ne...dyno1small.pdf
Ark Performance: http://arkperformance.com (2.5”)
Mazdaspeed: http://mazdaspeed.com (2.25”)
Magnaflow: http://magnaflow.com (2.25” Magnaflow)
http://www.magnaflow.com/02product/dynos/15861.jpg
AutoExe: http://autoexe.com (2.0”)


Many budget-minded enthusiasts have decided to go the custom route by choosing their own muffler and/or having a shop fabricate piping and choose their own. Sometimes, if you have not completely decided on which muffler and model # to use, someone in the shop can suggest one for you- just make sure you get a “straight-through” design. Your options are having the shop:
- replace the muffler with a straight pipe and put a canister-style muffler at the end
- replace the muffler with a higher flowing unit and keep existing piping
- replace the cat and muffler with higher flowing units
- fabricate wider piping (as long as it’s wider than 2”) and replacing cat and muffler

It should be noted that the “crush-bent” method of bending your custom pipes is not recommended for the best top-end exhaust flow as that method just bends the pipes by force creating an uneven surface at the inside of the bend. It’s “ok” for bumper to bumper and low speed cruising, but once you reach high speeds, you’d want the flow provided by mandrel-bent pipes. Mandrel-bends and larger piping costs extra, and before you know it, your custom exhaust cost can go above $300. For a little more, you can have a full cat-back from one of the kits being mass-produced. If you’re keeping your 3 for a very long time and want to spend the least possible, then go the custom route. Once you decide to get rid of your custom exhaust setup, remember that it’s easier to sell a full kit from a well-known manufacturer as they already come in pieces and easily bolt/slip on together. A shop-made kit will have to be cut into pieces by the shop for easier shipping.

Here’s dyno of the Stock vs. 2.5” Draxas base kit

5. High Flow Cat:

Cost: $50+ plus install
Install: Shop: 30min-1 hour
Pros: Higher flowing than stock
Cons: Emission testing legality still unknown
This is a short section as not many enthusiasts are running with high-flow cats. They’ve either stuck with their stock cats to keep their exhaust decibels low, or went straight to test/race pipe setups to have the most gains. The exhaust flow of an aftermarket catalytic convert will almost always exceed that of a stock depending the number of cells it has. The more cells, the more efficient, but it becomes more restrictive. The better ones can cost more than a full exhaust system, but will nowhere reach the power gains of a straight pipe, as it's still a cat.

Vibrant adds a high flow cat; whether it is enough for you to pass the emission's sniffer test, is unknown for now.

If you wish to use a HFC (high flow cat), someone in a muffler shop can help you choose the right one. The highest flowing ones will be the cheapest/lowest quality as they are built with the least number of cells and precious metals. There should be many brands to choose from, good or bad, as they are universal. A suggestion is find a cat closest to the design of the stock. That style offers the least turbulence.

If you’re going to get one, find the most narrow HFC that has the inlet and outlet matching your exhaust piping, not wide like a muffler, to reduce some exhaust turbulence during high RPM driving.


6. Race pipe/Test Pipe/Cat delete

Cost: $30-100
Install: 30min-1 hour
Review : Draxas Race http://www.mazda3forums.com/index.php?topic=33051.0
Pros: More power and torque
Cons: Loud depending on muffler, illegal in emission-controlled states
Peak Power Gains: +9whp/5wtq (with my 2.5” Draxas Race Pipe; your mileage may vary)

Upgrading your existing cat-back exhaust system by bypassing your secondary catalytic converter yields very good gains. Bypassing it on a stock exhaust however won't yield as much because of the small piping and the restrictive OEM muffler. The stock 2nd cat is there to further reduce emissions processed by the first cat [which is built in the exhaust manifold]. Once removed, the exhaust will just have the primary cat left. It's better to have the most restriction in the beginning of the exhaust system than to have it in the middle or the end.

The upside in upgrading to a race pipe is the option to remove it for emissions testing. Exhaust kits that already delete the 2nd cat (HKS, Corksport) still have to be modified to pass emissions, so choose accordingly.

Draxas Base Kit 2.5” + Race Pipe 2.5” vs. Draxas Base kit dyno

@3.0k: +2hp, 3tq
@3.5k: +2hp, 3tq
@4.5k: +4hp, 5tq
@5.5k: +8hp, 8tq (!)
@6.0k: +7hp, 6tq (!)
@6.5k: +9hp, 8tq (that’s 9.84hp!)




7. Rear Engine Mount
Install: 30-50min (http://www.mazda3forums.com/gallery/...tGuideRev1.pdf)
Pros: Better shift feel, reduced engine movement and wheel hop for better acceleration
Cons: Lots of cabin vibrations during the first weeks of break-in, some small vibrations felt after break-in
A stiffer rear engine mount can be installed in place of the much softer stock mount. This reduces wheel hop and the bucking from the engine during shifts and hard acceleration. You can easily see the engine buck hard during a simple up shift during a dyno session. The play looks to be almost 3 inches. With a stiffer rear engine mount, you'll have to pay close attention or else you'll miss seeing your engine just nudge during the break-in period. I’ve installed mine on 3/16/06, dyno was on the 3/21.

The cabin can vibrate strongly during the mount's beak-in period, but only at around 1K rpm. The dash, seats, shifter, floor, steering wheel will be vibrating. Over or under that, the vibration subsides. After a few weeks, you only get very little, if any. I get mine at idle speed (at a stop light) when the A/C is on, or when I just start moving from a stop.

At the moment, only the AWR mount is available for purchase in 70 and 88 durometer (higher = stiffer). AWR has designed the 88 for track and 70 for daily drivers.

After about 2 months of using the D70 in my 3, I have concluded that while the shifting had less of a jerk during the break-in period, it will eventually feel like the engine’s on the stock mount after the mount’s completely broken in. I’ve verified this during a dyno session on 5/04/06. Anyone could easily see the engine’s movement.

Bottom line, even after it’s broken in and the engine moves again, it’s still better than the stock rear mount.

AWR Racing http://awrracing.com

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