DEm

I was wondering, if you could turn your stock mazda 3 into a "pseudo - mazdaspeed 3"
I know they have different suspension and body kit, but...
Are they using the same engine?
Can i use the turbo from the mazda speed and bolt-it-on my mazda 3 and get the "same" performance?
what turbo is it?
what about the ecu? just reprogramming it will do?


I ask because i dont know the tech specs for the mazdaspeed,

_Kansei_

It wouldn't be exactly the same.. it's the same engine block as any other Mazda3/5/6 with the 2.3, but it has direct injection so the fueling system is very different. You also couldn't just swap the ECU from the Mazdaspeed3 if you turboed your 3 for this exact same reason.

If you have the 2.0, I'd see if HiBoost has a turbo kit for your car. I think Juan (hiboost) is based in puerto rico somewhere but I know he builds some craaazy fast mazdas

http://hiboost.com/KITMAZDA3.htm

_Kansei_

and to learn more about direct injection (cool tech), check this out: http://en.wikipedia.org/wiki/Gasoline_direct_injection

and a quick blurb about diesel direct fuel injection (where the tech was taken from):

"ne big difference between a diesel engine and a gas engine is in the injection process. Most car engines use port injection or a carburetor rather than direct injection. In a car engine, therefore, all of the fuel is loaded into the cylinder during the intake stroke and then compressed. The compression of the fuel/air mixture limits the compression ratio of the engine -- if it compresses the air too much, the fuel/air mixture spontaneously ignites and causes knocking. A diesel compresses only air, so the compression ratio can be much higher. The higher the compression ratio, the more power is generated."

DEm

Since I have the 2.0 AUTOMATIC, damn i hate this transmission, in the future ($$$) will be leaning towards a supercharger instead of a turbocharger.

Is actually the transmission or the slow launch is ecu related? cause if I press the brakes, rev to 1500, then hit the gas, I have way better launch that launching from idle

_Kansei_

I don't try to understand automatic transmissions, they are a big magical mystery.

jzoomer

^^ya you think mazdas auto tranny is complicated try mitsubishi auto tranny

lokalmotive

Why go with a supercharger? IMO a turbo is a more useable. I've had this discussion with a few friends and we came to the conclusion that the only time a supercharger would be a better mod would be on a V8. But then again Chevy did supercharge the Cobalt SS so there's gotta be a reason for it. Do some research on what would benefit you and what you wanna use the car for before just buying one or the other. It seems to me that a turbo would be a better option.

As far as the AT question goes. A friend of mine has a turbo AWD Eagle Talon with an AT. He always launches from a rev because it gives him the opportunity to begin the spool before launching. Although your car is NA I'm sure that it works basically the same way. It is allowing the motor to build torque that is trying to transfer to the wheels giving a harder launch and letting you shoot out the hole with some power hitting the pavement instead of having to build up from a dead stand still.

_Kansei_

^^ most modern autotragics don't let you 'neutral drop' like that. As soon as you shift from neutral to drive it drops the revs to idle before it actually shifts to drive.

MunkiRench

I'm not sure how many of the questions above were meant to be answered, but I got nothing else to do at work, so here goes...

The engine in the mazda3 (from my own experience with it), has very low response/torque at anything below 2K rpm, even less so than most small engines. Without a clutch to allow some slip, when starting from 0, you will experience very slow starting acceleration. Powerbraking (when you hold the brake while revving prior to launch) allows a better launch because you start from a higher RPM. This all has to do with power curves rising with RPM, and slip in the torque converter. Let me know if you need me to expand on this.

Launching by revving then dropping from neutral to manual mode allows an even higher starting RPM, but has some serious drawbacks. Because you end up hitting the drivetrain with high power instead of allowing it to build from a manageable start, such as with powerbraking, the wheels will slip when you launch. Depending on how high of a rev you launch from, this can either be very bad, or just a little bad.

From a low start, such as 3K rpm, the slip will be minimal, and you might end up with a slightly better time thanks to the higher intial power. If you drop from anywhere above 3.5K, you will experience slip probably all the way up the spectrum, until you shift into 2nd, in which case the wheels will re-grip when power drops during the shift. This will result in a much lower acceleration because, kinetic friction is not as strong as static friction. Also, slamming all that power is very very bad for the transmission.

The difference between superchargers and turbochargers can vary a lot depending on implementation. Superchargers will offer boost all the way up the rev-spectrum, from 0 to redline. Therefore, the power curve will basically have the same shape, but will be proportionally larger, depending on your boost. This means that the car will handle similarly, just with more power output. the drawback is that superchargers sap power from the engine, because it is powered directly by the engine. Therefore, the supercharger has a very high power overhead. On a small engine, This means that even if the power is substantially boosted, much of that power will be sapped away. This is why the cobalt SS only puts out ~200hp, and the mazdaspeed3 puts out around ~260hp, even though both have boosted engines (assuming that they are both running similar boost, which is probably true, +/- 20%).

turbochargers are powered by the exhaust of the engine, meaning that they have very little overhead on the engine's performance. The only power-reducing character of the charger is the fact that the engine has to operate against a higher back-pressure. this has an effect, but not as drastic an effect as a supercharger. Turbochargers, however, require time to spool up, because they are not mechanically linked to the engine's output. While a supercharger will supply precise, constant boost, because it is mechanically linked to the engine output, a turbo will vary, because of the fluid link in the exhaust. This is similar to the way that a the engine of a manual car is directly linked to the transmission through the clutch, whereas the automatic transmission offers a fluid link through the torque converter. the turbo requires some start-up power, so, depending on the size of the turbo, it will require a higher start-up RPM. This is good for manual cars, because it allows a proper high-rpm launch. the engine may be revved to whatever RPM the turbo needs to spool, then the clutch can be released, and a maximum-power launch is acheived.

Conclusion:
the basic difference between super chargers and turbo chargers is that the super charger is constantly supplying boost, and the turbo will only be on after the engine reaches a certain RPM needed to spool the turbo. this also means that for a non-race car, the turbo will only be on when the driver revs the engine to a race-level RPM, allowing the car to operate with normal characteristics in lower-rpm ranges, saving gas when the extra power of the turbo is not needed, and putting less wear on the engine during normal, everyday operation. Superchargers will also offer a little less power at a given boost than a turbo. On a larger engine, such as a V8, the engine puts out so much power while naturally aspirated, that the overhead required to power the supercharger is only a small fraction of the engine's output, so it is much more plausible than a small engine, such as a straight-4, where a substantial portion of the output must be used for the supercharger.

There's a lot more to say about turbochargers, supercharges, and manual vs. automatic transmissions, but I don't know how comprehensive of an answer you were looking for... maybe you already knew all this stuff. oh well.

Let me know if you have any more questions, or if you want me to expand on any one of these topics.

_Kansei_

^^ turbos don't spool based on engine RPM directly, it's related more to load than just RPM.

for example, cruising on the highway I can be in vacuum at 80mph even though I'm at 3500 rpm. If I so choose, by 2300RPM I can be at full boost.. it depends a whole lot on throttle input.

glad to see I'm not the only one who does long writeups while at work haha

K-Zoom

Hey ... get back to work ya slackers ... aw crap, that remark applies to me too

Tennpenn83

i agree and i don't

the gm LSJ which is the engine in the cobalt ss and the ion redline is a 2.0 liter block as the MS3's is a 2.3 turbo. the mazda's is pushing what, 263hp at 15.6 psi, and the GM's pushing 205 at only 12 psi.

with the supercharger running off a belt directly connected to the engine, it does sap some power, but you can usually estimate around a 8-10% loss. however, contrary to this fact, people who have dyno'd their completely stock ion's and cobalts usally see 210-220 at the wheels.

gas mileage was another point, and i agree that you will see a slight decrease in gas mileage as there is more rotational mass, however, i am currently running a stage 2 setup with intake and exhaust and getting 34~ish on the freeway at around 65 mph, so if there is an advantage, it is minimal, and i am happy with 34 mpg in the prices of today's gasoline

(btw stage 2 consists of a smaller supercharger pulley pushing boost to about 15, bigger fuel injectors and a different ecu tune, all of which is still covered under warranty by GM! Power is increased from 205 hp and 200 tq to 241 hp and 220 tq)

tojones

The 2.3 would be a better engine because the compression rate is lower and has more torque.