torque (part 2)
 

To answer a question asked "how do you get more torque?"

One big problem is where to begin. The D17 does not respond all that fantastically to mods, so without swapping out the ECU, there are not many gains to be had.

2 questions you need to ask yourself are, first, how much money am I willing to spend. And second, how do I want to go about getting more power.

The biggest power gains you can get will be going with the Forced Induction route. IE, turbo, supercharger, or nitrous. The supercharger is out, because no one makes one for the 2001+ civic. Nitrous is the cheapest of those 3, but the downside is nitrous is much harder on your engine then a lower psi turbo. While your civic could probably run a 50 shot of nitrous (essentially adding 50lb/ft torque) this is not a constant power. Plus, if you abuse it, and use it too often, eventually something will probably go boom.

The other route you could go is to stick with the n/a route. The most expensive mod in this form, would be swapping in the K20 RSX-s engine. 200hp (210hp for the K20Z) and much better torque than what your civic offers. However, if you want to keep your own engine, you could start by swapping out your ECU for something like the AEM EMS. Your ECU is your biggest hinderance in n/a power in the D17. Once you do that, your intake/exhaust/header, and other type mods will be able to do much more for you. I dont know what the maximum n/a power you could get out of the D17 is, but it would probably be expensive to get there.

Lastly, changing your final drive gear would be a cheap and easy option, however I dont think anyone makes one for the 2001+ civic, nor do I know if any of the other cars in the honda line-up have compatable gear and pinion with the 2001+ civic.

To clear it up about the nitrous part, it's not a guarantee that you will gain 50lb/ft of torque. I think a 50 shot is flywheel power, not to the wheels.

I believe there are some all-motor d16s out there, let me find some dyno sheets that will get some idea of how much torque potential the motor has. (even though its not really the same motor)

thanks for the help i appreciate it.

so let me get this right. Is there a "torque nut" that can be replaced to gain more tq or was that b.s.?

I was kidding. I thought it was obvious :shrug:

i thought you where, it sounded to good to be true

yeah as qboi said. it's not gauranteed 50lb/ft to the wheels. many people often are under the misconception that a 50 shot will give them 50 horsepower. that's not the case. it's an estimate, and usually nitrous will add torque at the beginning, but tapers off toward the end falling closer to stock. if tuned correctly, you could realize a 50hp gain fairly evenly throughout the power band.

hey uh...didn't mean to piss you off. actually what exactly pissed you off? just wondering.

hehe, me giving bs replies :lol:

on the AEM EMS, what is the benifit of it and I took a quick look at the AEM site which is the best one the universal one or the one made 4 the civic(which is coming soon it says)

i can't see how an aem ems will do more than say a vafcII that can already give a solid a/f curve. What else is there to change from the ecu aspect of things? Higher revs won't do anything, my car actually makes peak power at 6k rpms. Unless you're talking about after adding all sorts of serious mods like internals, boltons, etc.

here's the problem with the vafc. while the vafc is a piggy back solution, it does only that. piggy backs off of your ECU. part of the problem is your ECU will actually LEARN to work with the VAFC over time in a negative way. let's say you were able to get 10 horsepower out of a VAFC. over time, that gain might be reduced to 6, because your ECU will want to correct it's air/fuel mixture back to the built in mappings. (vafc gets you power by allowing you to lean out the mixture.... since the VAFC is a piggyback, the ECU will learn to counter-correct for this over time)

a stand alone ECU such as the AEM EMS gives you total control. and not just over fuel mappings, but also timing, and other such advanced features. it lets you completely tune your car for the best power you can get using all of those features. that's a lot more than a VAFC can do. to my knowledge, no one has gone too far with this on a civic yet, however, I do know that the ECU is a hinderance on the D17 from obtaining more than a couple measly horsepower from bolt-ons.

using the S2000 as an example, people have gotten as much as 20whp from i/h/e and VAFC tuning. then over time that horsepower falls to like 10 or 12 instead of the 20. also, the S2000 engine has the most potential for peak horsepower of any honda engine, however, the key to that is a stand alone ECU.

another real world example is the K-pro ECU flash from hondata. this essentially reprograms the ECU with preset mappings, timing, etc.

obviously the S2000 and civic are different cars and different purposes, but the civic still falls into that same pitfall, just not as drastically. make sense?? sorry for the long explination.

yea thanks. my numbers actually stayed exactly the same from last year when I got it tuned. But maybe over time the ecu adjusts. Idk, I would think the ecu would like the corrected a/f better because its closer to the 14.7/1 ratio, for emissions. Anyway, yea I didn't think about other stuff like timing and all that. I know civicvtec1ps got some very good gains from hondata and a few boltons with his si, so I don't doubt it.

13.7:1 is stoichmetric. if you're running 14.7:1 that's actually dangerously lean unless you are idling.

that's another thing, is your air/fuel mixture depends on load and RPM. the ECU wants to retain as close to the particular mapping it's using for a given situation.

not to say that a VAFC can't give you some gains, and in your case, fortunately they held. (which is good to hear!) but a stand alone would let you gain even more. :) obviously, though, a stand alone ECU is more money, and more time.

dont get me wrong, I'm not saying a VAFC is useless or bad. i'm just saying if you're going for as much n/a power as you can get, stand alone is the answer. :)

ya my a/f is 13/1 at 3.5k+ rpms but below 3k its 15/1. is that bad?

what the hell does that mean? lol

air/fuel ratio. How many parts air over how many parts fuel. You can change this with a vafcII by adding or subtracting fuel. The results can be seen on a dyno using a wideband 02 sensor. There is a ratio that favors the most efficient combustion and emissions. Too hi and you run lean (too much air), too low and you run rich (too little air).

ok air fuel ratio. i get the rest. thanx. vafcII? i need to brush up on my acronims. i know the rich and lean problems. i'm not dumb its just 130 in the morning.

alright cool. vafcII is the apexi vtec and air/fuel controler. You can add or subtract fuel at certain rpms and also monitor engine functions.

http://www.7thgencivic.com/memberrid...m/8177vtec.jpg

so its a plug and play ecu controller? or is it only for a/f mixture?

its only for air/fuel, and vtec engagement (which I wouldn't change anyway). And no its not plug and play. You need to splice and cut wires to connect it to the stock ecu.

VAFCs merely let you adjust the stock one by + or - in increments. the only way you could know exactly what air/fuel you are running would be on a dyno. did you dyno tune?

majin it's only for air/fuel and it's a piggy back, so it runs off the ecu.

thanx guys. for not flaming and explaining. man i love this site.

yes i just had a new dyno done. the red is from tuning last year and blue is new mods without tuning. They said it would still be okay.

http://www.7thgencivic.com/memberrid...kn-typhoon.jpg

wow. little less hp and little more torque. good for you

ok so red was with the vafc and the tuning right?

and the blue is the most recent one with more mods added?

correct. before with tuning it was a flat 14. Now its lean again in low rpms and around 13 upper rpms.

you don't need vtec to use a VAFC, do you?

If you don't have vtec, get the safcII. It only does air/fuel.