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Hp vs. lb-ft

Okay, I just got my most recent issue of “Honda Tuning” magazine, and this month’s “Wrenchin’” article is about this dude at Arizona Performance Imports who dropped a J35A4 V6 engine swap into a Honda Civic.



Normally, I’m not a fan of V6s because they output very little horsepower compared to their mass and they’re dismally balanced (come on, they need huge counterweights on the crankshaft because of the cylinder firing order) whereas the I4, if done right, can easily belt out close to or over 200hp with stock parts.



However, this article I read says they’re brutal monsters when it comes to outputting torque, and that the I4 isn’t that good at torque, even though I can vouch for my dad’s I4 powered Toyota having monstrous torque in first gear–enough to lift the front bumper an inch or two at full throttle (which is quite a bit considering how old and heavy his truck is). So, here is a question that I must ask.



What is the better rating to look at in an engine? Horsepower or torque?

They’re both sides of the same thing. HP is torque multiplied by RPMs (with a constant thrown in). You’ll get more torque with a v6 because of the displacement. Driving around town you’ll notice torque more. As revs rise, HP becomes more apparent.

Torque is real,horsepower is a rate at which torque is produced. Torque is a force that tends to rotate things. Power in watts,or horsepower is a figure that has its beginnings in torque.

Are you asking what data will tell me if this engine meets my needs?

For me the engine that produces the most torque the earliest in its rpm band and keeps producing this torque for the widest rpm band fits my most demanding need,towing.

If my need is getting myself and my books to school at the least cost (personal transportation) I don’t need high torque.

The question is what are your needs dominated

There is so much incompatibility between the racing or performance world and the get me from point A to point B world.

depends on its use…I like a long flat torque curve increasing with rpm rather than a spiky one…but you may have different use and need for engine performance.the amount of HP and Torque are exactly the same a one rpm (math issue). so if you want a strong easy puller look at that torque curve, torque is what you feel when you step on the gas

Right now, my needs are perfectly satisfied by the current engine I have in my ‘90 Civic LX. It’s a 92hp D15, outputs about 97lb-ft max. Right now, my car functions as an A-to-B econobox on fancy wheels (I blame the previous owner for buying the nice-lookin’ alloys :stuck_out_tongue: ).

However, I do have performance-based dreams for this car. My ultimate goal is to achieve 400hp OR outdo this ungodly epic Corvette that a friend of my dad’s has (he claims it can do 110mph by the top of downtown Cookeville’s shortest interstate access ramp, which is probably only 200-250ft long I think, but don’t quote me on that distance).

So, for now, my car as-is with its 200K miles on its current engine perfectly suits my needs. It drives, and it’s peppy enough to make the occasional joyride through the countryside chock full of fun.

But, when more years get put on it and I’m out of college and in the working world, I want it to be more than just an A-to-B. I want it to be A-to-B with a little bit of “HOT DAMN!!” along the way. I’m not really looking to race. I’m just looking to take my current old car and considerably extend its useful life, and make it faster, stronger, better along the way, and I want to take it as far as I can without getting out of control with it. Although I do have something small to prove to my dad who won’t stop bragging about that damned Corvette. I sorta want to prove that Japanese pep can outdo American muscle.

So, with that in mind, which, in your opinion, would be the numbers to look at? Or would it be a combination of both? If it’s a bit of both, what are some good ratios to consider?

Why don’t you just leave the Corvette idea alone. If the Corvette is indeed fast (not 80s or 90s vintage), you’ll need to put a turbo/supercharger or two on it. If you do that, you will need to rebuild the engine to make the parts strong enough to accommodate the power. Next, you’ll need a transmission, differential, and suspension that can handle the power. And don’t forget the tires. This will be quite expensive, and there will be periods when the car is in pieces. It will not be your commuter car. Is that what you want?

Well, you didn’t really get any answers did you?

Your dad’s 4 banger Toyota didn’t have much torque. It just had really short gearing. Furthermore, your dad’s truck wasn’t that heavy by truck standards. Small displacement I4s (2.5L or less) don’t produce much torque without some sort of forced induction. BTW most 90 degree V6’s will run much smoother than a typical 4 cylinder. If your normally aspirated I4 makes 200 HP it’s not making much torque. There is no free lunch in camshaft design, if you want 200 HP it’s going to come at high RPMs, there will a corresponding lack of torque at low RPMS. Tricks like varibile valve timing can help somewhat.

Basically torque is what gets you up to speed from a stop or low speeds. Most of the time V6’s offer the best combination of power and fuel mileage. As for me, both my cars are V8’s. One is supercharged.

Some days ago I saw on the online news a man who got nabbed doing 137 mph in a Honda Civic on public roads in the US. I assumed that was not a stock Civic.

I have thought the expense through, and I know that there would be times the car would be in pieces. I know I’m going to have to own and drive other cars during the time it takes to beef up the Honda. I’m a very patient person who can wait for years to get what he ultimately wants. Such is the satisfaction of Delayed Gratification. :wink:

And my list of mods actually includes a two-stage turbocharger, which will of course necessitate rebuilding the engine. But the first step would be to at least replace the engine and transmission with something newer from the JDM. 200K miles is routine for a Honda, but even then, six-figure mileages is kind of the time when one needs to start considering either getting another car or refurbishing the one he currently has. I’ve priced the B18A on Password:JDM, and I’m definitely going to be waiting a few years before I can afford even a straight-up $3600 stock engine swap not including the cost of the engine mounts or a LHD harness as opposed to an RHD harness.

Years more before I can afford performance upgrades. But I like the wait as much as being rewarded for the wait. It gives me time to thoroughly think things through so that said things are done the right way the first time instead of money getting wasted on impulsive things that just… don’t work.

I’m not one to go quite that fast on public roads. That’s bloody insanity and ASKING to get killed. But who says you can’t try and go that fast out on the local drag strips and totally smoke your dad’s 105hp '93 Mercury Tracer? :stuck_out_tongue:

IMHO torque AND importantly the RPM it starts becoming strong at.

My wife’s turbo Subaru has 90% of its peak torque of 243 lb-ft at 2200 RPM. It makes it a pleasure to drive around town.

Get into a Honda I-4 at 2200 RPM you don’t have much of anything down low making the vehicle feel gutless except at RPM’s where it really is only usable on a track.

Yeah, I hear you there. Right smack at 2250rpm, all the power just… goes poof. It’s like my car has a rubber band engine between 2000rpm and 2500rpm, and the automatic is sometimes a bit too stupid and doesn’t downshift, even when I floor the accelerator. But when it hits 2500, all the power comes right back into your face.

I’m glad you responded this way. I was going to suggest that the best way to use your highly modified Civic is at the track. It will be a great hobby for you when you can afford it. When you said you wanted to smoke a local Corvette, I assumed you were going to street race. Good luck, and have fun. BTW, you might try looking on line for a racing forum, maybe one dealing specifically with Civics or Hondas in general.

all 92 HP of it? :slight_smile:

I don’t know about all 92hp, but most of it comes back. I’m surprised my car has as much pep as it does for having less than 100 hp OR lb-ft. I’d be interested to see how 200+ hp or lb-ft would propel that little econobox.

Well, another goal I’ve had for my Honda was to soup the engine up enough that it would be able to, in top gear, coast along at 80mph somewhere in the mid-2000 rpms max. Right now, overdrive gear has my engine running almost 4000rpm at 80mph. The slower the crankshaft has to rotate to propel the car, the less fuel the engine uses in the long run.

How do figure that souping up the engine is going to lower the RPMs out on the road?
That’s a result of mostly gear ratio and unless this souping up involves the mother of all stroker modifications the RPM is going to stay the same.

The V-6s do very well (say Buick Grand National for instance) and you should keep in mind that if you beef the engine up to 200 HP the next weakest links in the chain will have even shorter lives; transmission, clutch, halfshafts, etc.

As to torque vs HP I’ll take torque any day of the week. Torque is what makes a vehicle pleasant to drive in almost all situations.

Look at the new diesel VW’s The Jetta with the 2.0 Turbodiesel with only 140 HP but 236 lb/ft of torque can propel the car to 60 MPH in 8.1 seconds. The 2.5L I5 gas engine with 170 HP but 177 lb/ft of torque is slightly slower at 8.5 seconds.

But like I said earlier. You’re not going to get 200 torques of out of a normally aspirated 4 banger without some boost. The only exception to that rule that I know of is the Porsche 968, but it had a very large displacement four banger. 3.0L IIRC.

I know about having to change the gear ratios. I’ll have to get a new transmission and axles anyway. But you can’t make the gear ratios lower without the engine being powerful enough to handle driving the car with the new ratios to begin with. Otherwise, you’ll get very poor and uneconomical operation from the engine (such as when you’re going too slow in a stick-shift and you upshift, and the engine runs really rough), and the added stress on the engine will only serve to shorten its lifespan.