What’s crackin my fellow brethren? I pose 2 question for all you tech heads…we all know our integras peak torque at 5k rpm and peak power at 6k rpm…my first question is what would I have to do to make my integra peak torque at let’s say 3,000 rpm, and how would that affect my peak power, or is that even possible? Second, wouldn’t popping in cams with the same lift and duration as VTEC cams theoretically bump our power to match that of a VTEC car or is their power attributed to an overrall more effecient head design? Just something to think about. Thanks.
I dont know the answer to your 1st question but for the 2nd one, VTEC heads flow better.
Ben
Re: Tech Questions
Originally posted by phatsamury
What’s crackin my fellow brethren? I pose 2 question for all you tech heads…we all know our integras peak torque at 5k rpm and peak power at 6k rpm…my first question is what would I have to do to make my integra peak torque at let’s say 3,000 rpm, and how would that affect my peak power, or is that even possible? Second, wouldn’t popping in cams with the same lift and duration as VTEC cams theoretically bump our power to match that of a VTEC car or is their power attributed to an overrall more effecient head design? Just something to think about. Thanks.
where the motor makes its torque and hp is going to be dictated by the overall build of the engine, not just one specific characteristic. typically small displacement motors like ours make their power up in the top and end. which isn’t a problem because they are built to do so.
basically, who cares where the power is, as long as you have it. Our motors are very strong and don’t mind being revved up, in fact they LOVE it. Now yes having some low end torque may be useful in some situations, and some people like that more than having screaming 8k redlines. If you’re looking for low end torque go for a bigger motor. The b20b/z for example. Its gonna make more torque than any other b series motor and i beleive it may make it a bit lower than the b18a does.
Doing most mods will slightly increase your torque (however most increase high end hp more than low end torque, some even sacrifice low end torque for high end hp). The only real way you’re gonna get any really substantial amount of extra torque is to bump up your displacement. But still, its not going to be a huge jump in torque (unless maybe you’re comparing a b16a vs a b20). And even increasing displacement isn’t going to lower where you get the peak torque (maybe by a couple hundred rpm, but nothing like down to 3k).
i say don’t worry about moving the power band. if you want a motor that makes power down there go get a big V8. Oh, and you may also want to look into turbo. I know turbo motors make a good deal more torque than all motor engines. I’m just not sure how a turbo affects where the peak torque is and so on… as you can see i’m not too well versed in FI so i’ll leave that to someone else.
as for the cams, the answer is yes, and no.
Yes:
1)the answer is yes because if the cams have the same profile then the motor should be able to pull in the same air right? (this is true only if you ignore all differences in flow characteristics of the different motors).
No:
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Like i mentioned above, the two motors have very different flow characteristics. The vtec heads are designed to be more of a “high performance” head. stock vtec intake manifolds are better flowing, and even some stock vtec exhaust manifolds are better flowing.
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Rpm. Like i talked about in answering your first question… honda motors make their power in the high rpms. And this is even more true with vtec motors. For example, stock redline on the b17a is 8k, and you’ll make power all the way to that point. Stock redline on a b18a is 6.5k. Reving the stock b18a to 8k is going to be worthless, the cams just don’t make power up there anymore. However performance cams are going to require that you rev a bit higher to take full advantage of them. But to do that you have to upgrade all your valvetrain and if you’re smart your bottom end to. rememer, honda built the motor to rev to 6.5k without any problems, it wasn’t designed for 8k redlines, so if you plan on taking it there you need to build it to handle that kind of strain.
one thing that i think i remember hearing is that rpms put more strain on the motor than hp does. So, you may not think that 1500 rpm could make that much of a difference in how much strain is put on the motor…but it does. stress related to rpm is not linear it goes up exponentially.
to summarize that. yes you can make your b18a as fast and even faster than non vtec motors. It just depends on how they are built. for example, a healthy b18a w/ crower 403’s (along with all the valetrain), i/h/e, fpr, and an ecu should probably be able to take G3 gsr’s without too much trouble.
Wow…thanks alot for the reply, I didn’t think anyone would take that much time and effort to reply…I greatly appreciate it man. You’ve been more than helpful.
Originally posted by phatsamury
Wow…thanks alot for the reply, I didn’t think anyone would take that much time and effort to reply…I greatly appreciate it man. You’ve been more than helpful.
no problem, just glad its of some use to you. good luck with whatever setup you decide on.
91integGS, you da man. 
Ben
Originally posted by Ben Ogle
[B]91integGS, you da man.
Ben [/B]
nah, no big deal. now if we’re talking about who is the man…it be you my friend! those bars you make are sick. hopefully i’ll actually get a couple someday.