Dyno charts for my 2

[Mazdamatic]

>2012
>still using fossil fuels

i fill my car with moonshine and civic blood

[magnumP5]

Wrong.

Octane isn't a measurement of knock resistance; I literally have no idea how he got Octane = Knock Resistance! Yes, there is cause and effect where if you run too low of an octane, you wind up with detonation; however, the octane rating refers to how resistant to self-detonation under compress the gasoline is. Octane isn't a measurement of knock resistance, it's a molecular compound.

http://en.wikipedia.org/wiki/Octane_rating - "The higher the octane number, the more compression the fuel can withstand before detonating ..."

In other words, knock resistance...

Stop being a dick. I've seen nothing but condenscending posts from you on these forums. You know damn well I was referring to the rating and not the compound.

Gravity, sorry for cluttering your thread but I'm glad to see a civil response to some criticism I will agree most manufacturers err toward economy and comfort, especially with cars in this segment. Even though I don't have any intention of doing power modifications to my 2 (it's my DD) I do like to check out these threads to see what kind of stock power and gains people are seeing.

[Gravity]

I'm all about civil responses! Well, at least when people aren't a complete waste of time... Like you (and most others it would seem), I've seen little to nothing out of our friend here that hasn't been arrogant, condescending, douchey, and more often than not, wrong or at least excessively pedantic. A waste of time and a waste of skin, and completely destructive to the purpose of these forums in the first place. It's too bad you can't get banned for being a useless troll.

At any rate, back to the productive discussion! I'm pretty much squared away on all the dyno info... The only thing I'm still trying to work out is if I could actually be seeing a loss in power from removing that second cat. My butt certainly feels it, but without a before and after I've got no objective way to be sure!

Gravity, sorry for cluttering your thread but I'm glad to see a civil response to some criticism I will agree most manufacturers err toward economy and comfort, especially with cars in this segment. Even though I don't have any intention of doing power modifications to my 2 (it's my DD) I do like to check out these threads to see what kind of stock power and gains people are seeing.

[magnumP5]

At any rate, back to the productive discussion! I'm pretty much squared away on all the dyno info... The only thing I'm still trying to work out is if I could actually be seeing a loss in power from removing that second cat. My butt certainly feels it, but without a before and after I've got no objective way to be sure!

It's possible you've shifted the power band some. Perhaps losing some power down low to gain it at higher engine speeds? You're right though, without any dyno numbers it'll be hard to say for sure. Is it possible to put the cat back on? You could always do some "street legal" speed tests to see if you're 30-60 mi/hr (sorry, U.S.) acceleration times are any different in any single gear.

[njaremka]

here's my take on it... (and, i'm probably reiterating some thoughts already expressed...)

your car is showing wheel power of 92hp and 103ft-lbs, and that's only with an intake and exhaust? that is some serious gain, especially on a 1.5l engine. stock ratings are 100hp and 98ft-lbs at the engine. figure 15% loss for FWD drive train, and you'd be seeing 85hp and 84ft-lbs. so, for just an intake and exhaust, you're looking at +7-8hp and +18-20ft-lbs!! holy crap! throw some light wheels and a light flywheel on that car, and you'll have a nice little screemer on your hands.

[CRG Racer24]

here's my take on it... (and, i'm probably reiterating some thoughts already expressed...)

your car is showing wheel power of 92hp and 103ft-lbs, and that's only with an intake and exhaust? that is some serious gain, especially on a 1.5l engine. stock ratings are 100hp and 98ft-lbs at the engine. figure 15% loss for FWD drive train, and you'd be seeing 85hp and 84ft-lbs. so, for just an intake and exhaust, you're looking at +7-8hp and +18-20ft-lbs!! holy crap! throw some light wheels and a light flywheel on that car, and you'll have a nice little screemer on your hands.

Exactly what I was thinking ^^.

[Mazdamatic]

here's my take on it... (and, i'm probably reiterating some thoughts already expressed...)

your car is showing wheel power of 92hp and 103ft-lbs, and that's only with an intake and exhaust? that is some serious gain, especially on a 1.5l engine. stock ratings are 100hp and 98ft-lbs at the engine. figure 15% loss for FWD drive train, and you'd be seeing 85hp and 84ft-lbs. so, for just an intake and exhaust, you're looking at +7-8hp and +18-20ft-lbs!! holy crap! throw some light wheels and a light flywheel on that car, and you'll have a nice little screemer on your hands.

im really anxious to dyno mine

i think with the 2.5 in exhaust ill see

20lbs ft (LOL) and over 100hp (or an opposite of what he saw) i know i lost tork but i feel a top gain.

this car is interesting.

[magnumP5]

im really anxious to dyno mine

i think with the 2.5 in exhaust ill see

20lbs ft (LOL) and over 100hp (or an opposite of what he saw) i know i lost tork but i feel a top gain.

this car is interesting.

Holy way too big exhaust! I'm willing to bet you will see a net loss in power with that exhaust size. Maybe a little HP gained at the very top end.

[njaremka]

Holy way too big exhaust! I'm willing to bet you will see a net loss in power with that exhaust size. Maybe a little HP gained at the very top end.

not necessarily. if you look at his torque curve, it still looks pretty healthy. a lot of modern engines really like to breath, and i'm sure the Mazda2 is no different.

[magnumP5]

not necessarily. if you look at his torque curve, it still looks pretty healthy. a lot of modern engines really like to breath, and i'm sure the Mazda2 is no different.

No doubt there'll probably be some gains up top but I'm willing to bet they don't offset the loss in the low-mid range. 2.5" just seems so big for a little 1.5L, even if it has relatively high compression. IIRC, redline is like 6200 rev/min, which shouldn't be high enough to require 2.5". All I'm saying is you could probably go smaller and still have the same high-end gains with less low-end loss.

[njaremka]

No doubt there'll probably be some gains up top but I'm willing to bet they don't offset the loss in the low-mid range. 2.5" just seems so big for a little 1.5L, even if it has relatively high compression. IIRC, redline is like 6200 rev/min, which shouldn't be high enough to require 2.5". All I'm saying is you could probably go smaller and still have the same high-end gains with less low-end loss.

i'm going to content that his graph still looks great. but, we will never know without a companion graph showing the stock curve.

[Gravity]

Just remember guys, I don't have the 2.5" exhaust. That's another poster in this thread. My exhaust is a single resonated 2" (well 2.25" non mandrel bend, so roughly 2" equiv).

So my curves are based on that, not 2.5". :-)

i'm going to content that his graph still looks great. but, we will never know without a companion graph showing the stock curve.

[shaowq]

i'm going to content that his graph still looks great. but, we will never know without a companion graph showing the stock curve.

like magnum says, you will have shit for useable torque with an exhaust that wide on a 1.5L. People had shit for useable torque on a 1.8L running a 2.5 inch exhaust and only got better with FI.

Honestly, i think with a 2.5 you'd be moving your torque curve way out of the usable fun range. You will definately see HP increases but it might not be more than you think because of once again...our Rev Limit.

Get a piggyback and raise the rev limiter and I can support you, but i think you'd have to raise it to at least 8k rpm for it to be useable...but then you have to get everything retuned for after our redline where the ecu has no pre-written tune at all.

I'd seriously think about this. I don't think you're going to be too happy with your results. I'm with magnum on this one...maybe 2.25 at the very very most...

[Mazdamatic]

like magnum says, you will have shit for useable torque with an exhaust that wide on a 1.5L. People had shit for useable torque on a 1.8L running a 2.5 inch exhaust and only got better with FI.

Honestly, i think with a 2.5 you'd be moving your torque curve way out of the usable fun range. You will definately see HP increases but it might not be more than you think because of once again...our Rev Limit.

Get a piggyback and raise the rev limiter and I can support you, but i think you'd have to raise it to at least 8k rpm for it to be useable...but then you have to get everything retuned for after our redline where the ecu has no pre-written tune at all.

I'd seriously think about this. I don't think you're going to be too happy with your results. I'm with magnum on this one...maybe 2.25 at the very very most...

so far i love it. since most my daily is freeway the top end is good. i actually didnt notice too much low end (at first i thought i did but that was low tire pressure) car tends to rev to 2500 so i never really see tork but anything over that and its quite nice =] and the sound.....hehehe....

but like i said gotta dyno it soon with my group.

[CRG Racer24]

2.5 I think is too big, but I disagree with the 2.5" being "shit" for 1.8L engines.. Coming from a Honda background, especially on Type R's, 2.5" is the way to go. The more mods you put on it, the more beneficial it get's.

On the other hand, 2.25" is the biggest I'd go on our engine. Unless you're FI, it makes no sense to me.