Torque Please!

[F22B1VTEC]

I have a 95' Accord EX VTEC, and I just needed a few pointers on performance. I needed to know the best way to gain torque through all the RPM's, not just when VTEC starts. I know that Exhaust and CAI will bring down low end torque, so whats the best way to bring it back up?

[Hans]

I'm not thinkin of a specific way that you could bring it back up. I know that getting an aftermarket lightened fly wheel helps out a lot with performance, as it reduces rotational weight in the drive train. I think this might be relevant:

Most of the reason American engines are lower reving is because of typical American driving habits. We don't like the sound and vibrations associated with high revs and we do like torque. Hell, most Americans don't even like to shift gears and thats another reason why we need engines that have more torque, to feed the energy sapping automatic transmission. Torque is created by having a longer stroke and there are limitations on piston speeds and rotational speeds involved with really long strokes having to do with the inertia of the engine components. Americans drive these types of engines because we can. The rest of the world uses smaller higher reving more efficient engines because their gas costs more.
Engines like in your parents van are large displacement engines. They make their power by the tried and true method of having more room in the combustion chamber for the fuel/air package. More package more power. The old saying goes "there ain't no replacement for displacement." These types of engines typicaly have more torque due to a longer stroke required to get that displacement and still get a compact engine size and effiecent fuel burn as well as make American buyers happy. These engines deliver the classic american hot rod experience. Step on the gas and your head snaps back. We like that.
Having said that, the down side of these engines are that they are big and heavy, and generally not as efficient as smaller high reving engines. (all things equal regarding aspiration and construction materials) A smaller 4 cylinder high reving engine is going to produce more HP to it's weight than a comparably equiped V8.
It all comes down to power to weight ratio. Of course you can modify Cameros and Mustangs with even bigger power plants, but you will give up handling. In the case of Nascar you'll notice that while these bigger cars also use V8 engines, and can handle well, those engines are operating at very high RPMs. In general with engineering, if you can operate a system at a higher freqency then you improve efficiency.

:)

[2ndGenGuy]

Most of the reason American engines are lower reving is because of typical American driving habits. We don't like the sound and vibrations associated with high revs and we do like torque. Hell, most Americans don't even like to shift gears and thats another reason why we need engines that have more torque, to feed the energy sapping automatic transmission. Torque is created by having a longer stroke and there are limitations on piston speeds and rotational speeds involved with really long strokes having to do with the inertia of the engine components. Americans drive these types of engines because we can. The rest of the world uses smaller higher reving more efficient engines because their gas costs more.

Engines like in your parents van are large displacement engines. They make their power by the tried and true method of having more room in the combustion chamber for the fuel/air package. More package more power. The old saying goes "there ain't no replacement for displacement." These types of engines typicaly have more torque due to a longer stroke required to get that displacement and still get a compact engine size and effiecent fuel burn as well as make American buyers happy. These engines deliver the classic american hot rod experience. Step on the gas and your head snaps back. We like that.

Having said that, the down side of these engines are that they are big and heavy, and generally not as efficient as smaller high reving engines. (all things equal regarding aspiration and construction materials) A smaller 4 cylinder high reving engine is going to produce more HP to it's weight than a comparably equiped V8.

It all comes down to power to weight ratio. Of course you can modify Cameros and Mustangs with even bigger power plants, but you will give up handling. In the case of Nascar you'll notice that while these bigger cars also use V8 engines, and can handle well, those engines are operating at very high RPMs. In general with engineering, if you can operate a system at a higher freqency then you improve efficiency.
:)

I don't know how true that is. How do you define efficent? Is it HP per liter? HP per liter is a mechanical/technological measurement, not an overall car performance trait. What relevancy does that have when it comes to performance of a car? Overall power to weight isn't going to be affected as much with an engine block as other weight reduction methods in a car...

Take a look at the Corvette. The car has gobs of toruqe, 500hp, and still gets 28mpg. Sounds pretty damn efficent to me. One cam, and pushrod-driven valves...

Also, the C6R has gobs of torque compared to most LeMans cars and tends to be a race winner. Also, look at the turbo diesel Audi R10 LeMans car. It also is a huge race winner. Torque seems to be the biggest factor. Waiting for your engine to wind up before you get power can be a killer.

Wanting more torque out of a Honda engine isn't necessairly a bad thing. It's what gives the Accord an edge over the Civic if you ask me. You're not going to change the charactersistics of the engine significantly without building the block differently, or adding forced induction. A cam might shift your power around, but it isn't going to magically create power from nowhere.

[diegoaccord]

I have a 95' Accord EX VTEC, and I just needed a few pointers on performance. I needed to know the best way to gain torque through all the RPM's, not just when VTEC starts. I know that Exhaust and CAI will bring down low end torque, so whats the best way to bring it back up?

Proud of having VTEC? Remember its a SOHC, VTEC isn't doing shit for you.

Want to keep torque, keep the car stock. Also, I just said this on Honda-tech, its still a 4cyl Honda, you will just not have the pulling power around town that a Taurus/Intrepid/Impala will. As they casually leave the light, see just how much gas/rpm you have to give your car to keep up.

Or get a H23 or F23. In a rare occurance I dont fall under this rule, my motor was made to lug Preludes and JDM Accords around swiftly, so this light Teg moves...

[B18Civic]

it kinda depends on what you want to do to the motor.do you want to keep a daily driver or do you want to go all out? do you want to go all motor or do you want to go with forced induction?

[AccordEpicenter]

get a header

[F22B1VTEC]

Proud of having VTEC? Remember its a SOHC, VTEC isn't doing shit for you.
Want to keep torque, keep the car stock. Also, I just said this on Honda-tech, its still a 4cyl Honda, you will just not have the pulling power around town that a Taurus/Intrepid/Impala will. As they casually leave the light, see just how much gas/rpm you have to give your car to keep up.
Or get a H23 or F23. In a rare occurance I dont fall under this rule, my motor was made to lug Preludes and JDM Accords around swiftly, so this light Teg moves...

Just because its a SOHC does mean VTEC doesnt do anything. When I hit 4.5k rpms, the torque kicks the car in the ass. Im just wanting more torque than the car has. And the Taurus/Intrepid/Impala thing, i take off from the light just fine, and keep with traffic just fine without having to hot rod my engine to keep up.
Now I want the car to be a daily driver pretty much, just a fast one lol. I dont want a full out race car. Im willing to do Flywheel, Headers, that kinda stuff, I just wanna avoid extensive surgery if possible. If it has to be done though, it has to be done.
If I were to go the route of forced induction, i would probably wanna go super charger though. Also I wanna go with a new Intake and Exhaust manifold.

[Hans]

Sounds good to me. Point is that you may feel torque gain and loss with each part, but once all the mods are on there and working together, that's when it'll really matter. With one mod you might loose torque, but after you get another mod to work in conjunction with the first, that first mod might end up giving you torque rather than taking it away. IMO

[diegoaccord]

Okay, if the car is NA, the better it breathes, the more the balance of bottom end/top end is going to lean towards top end. Thats always a given.

Major thing you can do is get a 4-2-1 header, instead of a 4-1.

Light flywheel, they rob torque. It doesn't actually take the torque away that the motor is producing, but from a stop, the amount of torque getting to the ground is less, and you will have to rev higher on a normal basis, city driving.

[Ls1-Inside]

Light flywheel, they rob torque. It doesn't actually take the torque away that the motor is producing, but from a stop, the amount of torque getting to the ground is less, and you will have to rev higher on a normal basis, city driving.

That's not really accurate...

With a lightened flywheel you will have less parasitic loss, and it will reflect on a Dyno by producing more Wheel TQ and Wheel HP. (Like you said it doesn't actually take TQ away)

The reason you have to rev higher, and can't launch as hard is because w/o the stored energy of the flywheel your engine has less rotating momentum and is easier to stop. So when you dump the clutch, the weight of your drivetrain may actually stall your engine.

An engine with very little parasitic loss and light rotational mass will rev very quickly, and it will rev down quickly too. That means, you have to compensate for an engine with less momentum getting the tires rolling... but once the clutch is fully engaged and the tires are rolling, your engine will be reving faster, and accelerating more quickly.

The difference between the lightened flywheel and OEM flywheel may or may not be noticeable... depending on the car...

I would guess it's more noticeable on Larger Engines w/ Larger stock flywheels. Simply because on a small underpowered low torque engine, you already have to bring RPMs to like 2k when starting off... just to get the car rolling a little clutch slipping is common.

On a car like mine (5.7L 380HP v8) i don't even have to give it gas and i can let the clutch out, (Really Big Flywheel) with the RPMs somewhere under 1,000 and get rolling easy enough... If i lightened my flywheel and let the clutch out like that, my drive-train would most certainly try to stall my engine. And I would probably notice the need to make sure i keep the RPMs up when getting started... So for some cars you notice the difference, some you don't.

I think 2ndGenGuy stated he hasn't noticed any real difference going to a 9lb flywheel...

-Dan

[2ndGenGuy]

Well, I noticed that the clutch grabs better, and the engine spends more time sending power straight to the wheels. But then again, I couldn't set my timing because my old flywheel was SO caked in grease I couldn't see timing marks. Turns out the timing was WAY advanced before, and I had no power. Like it was advanced PAST the vacuum advance mark when it was sitting at idle... Plus, I have a better clutch now, so that could be it too. I just change too many variables with one upgrade to know for sure.

If the flywheel did anything, it makes rev-matching your downshifts easier. :D

[Hans]

If the flywheel did anything, it makes rev-matching your downshifts easier. :D
My dad never told me about downshifting when I was learning how to drive. I picked up a Car and Driver mag, found out about downshifting, and then taught myself how to. lol

[guaynabo89]

so whats the best way to bring it back up?

cam

[MessyHonda]

My dad never told me about downshifting when I was learning how to drive. I picked up a Car and Driver mag, found out about downshifting, and then taught myself how to. lol



yeah i had to learn too.....makes stoping so much better...but it wastes more gas.

[Hans]

yeah i had to learn too.....makes stoping so much better...but it wastes more gas.
yeah that's the bad part :(

[MessyHonda]

yeah that's the bad part :(



the exhaust sounds good when i stop like that. so props for that.