How to increase the torque power?

[AllenRPS13]

do u guys know how to increase the torque power?
also, will the torque decrease if install the cat-back exhaust system?
thanks... :eek3:

[HaLo]

You do know that:

Horsepower = (Torque * RPM)/5252

So if a catback claims to raise HP, it must raise torque.

[90RS13]

So if a catback claims to raise HP, it must raise torque.

Yes, but where? An exhaust system can add 15 hp to your peak, but not raise your peak tq much at all, or even lower it. I think what allen180sx is asking about is more of how a cat-back system will effect his powerband. I see these civics with 3" ehaust systems, and alot of times they raise peak hp in a really good way. But they're raising it in a high place like the 6k to 8k range, while hurting their low end tq and moving their power band up. They just want dyno queens. An engine can make alot of hp and not much torque. Look at the S2000. Really good hp, but not much torque, because it makes it's power in the higher revs. Anywho, to your question, I've not seen any dynos, but everyone here, from what I've searched anyway, has said a 3" cat-back is a good power adder to a K series engine, and doesn't hurt torque. Did that answer your question?

P.S. Didn't mean to sound rude to you HaLo, that just seemed like a really simple minded answer to that question.

[andrave]

goddamn it DIE MYTH DIE
IF you happened to read dyno charts...
man, bigger exhaust are better, generally speaking. yes a bigger exhaust will make more torque, especially on a turbocharged car.

[OptionZero]

...die thread die...

[90RS13]

IF you happened to read dyno charts...
You shouldn't make a comment lke that if you don't know someone personally, and don't know what they have or haven't seen.


What we're talking about here is exhaust gas velocity. You want the most exhaust gas velocity you can get. A bigger diameter pipe, (all other things being equal) will lose more velocity as the gas slows more. That's not a myth, it's physics. Now all engines act differently, and some tend to react alot better to bigger diameters than others. The pipe needs to be a size that keeps exhaust gas velocity up at lower rpms, but is big enough to let the engine fully exhale at high rpms. That's the comprimise. Yes, a bigger exhaust will make more torque at higher rpms. but will lose some at lower rpms. Now turbocharged engines are different all together, cause you're just trying to get rid of the exhaust as quickly as possible after it leaves the turbine.

I wasn't trying to start an argument, just trying to help someone learn more about engines. Isn't that the reason we're all here anyway? ;)

[ledzeppelin240]

Horsepower = (Torque * RPM)/5252 like Halo said...But when horsepower goes up the peak TQ is quite a lot lower in the RPM range, this is because the engine gasps for air the higher it is revved...

[orion::S14]

allen180sx is asking about is more of how a cat-back system will effect his powerband...

...all engines act differently, and some tend to react alot better to bigger diameters than others...

...a bigger exhaust will make more torque at higher rpms. but will lose some at lower rpms.

Here's how it affects the powerband of a typical KA: Gains across the board, and it seems like bigger is not necessarily a bad thing.

Sport Compact Car showed a 16rwhp increase from an 80mm N1 exhaust years ago...with little to no low end loss.

Alex over on FA tested a 5Zigen 80mm exhaust and found the same thing...here's the dyno chart:

http://www.worldwidechang.com/Pics/Cars/MyCar/Dyno/NewDyno/IntakeExhaust1.jpg

Only mods on this car were a AEM intake, then the exhaust was added for the "blue" run.

Just FYI...

- Brian

[kandyflip445]

Corky Bell said something like this, turbo=torque multiplier.

[240Stilo]

From Maeda's sig...

"Turbos make torque, and torque makes fun." - Corky Bell

[90RS13]

Here's how it affects the powerband of a typical KA: Gains across the board, and it seems like bigger is not necessarily a bad thing.
I never said that a bigger exhaust diameter would lose anything on a KA.
Anywho, to your question, I've not seen any dynos, but everyone here, from what I've searched anyway, has said a 3" cat-back is a good power adder to a K series engine, and doesn't hurt torque.
See, I didn't say the KA would lose power anywhere. I had already heard from everyone that gave gains across the board. Like I said, I wan't tryin to start an argument. I hate arguing about engines and cars more than anything. I just like everyone sharing knowledge and some constructive critisism when someone's misinformed. (as we all are from time to time)

At least allen180sx diffenantly knows how a 3" cat-back effects a KA now. ;)

[indy240]

I know that headers increase low end torque, put them on my car and haven't really seen what they do, but from what i've seen in other cars and dyno charts headers increase torque every time. I can tell you more when i get the car broken in (newly built motor), and can really get on it. I've been around american v8's all my life (dad and friends), and headers increased torque, in my old beetle the headers increased torque. I'd say the easiest way to increase torque is headers. I bought obx racing headers off ebay for somewhere around $160. The headers fit perfectly, all sensors hooked up right, the tube running to the head fit perfectly, etc.. If you do headers i do recommend a larger diametor exhaust, or at least a high flow muffler.

[ledzeppelin240]

No headers, exhaust system or any kind of intake will 'gain' HP or TQ, they can only reclaim what was lost. Same as a the Royal Purple oil it has the abilitly to a degree to reduce the frictional horsepower loss. If you want lots of torque you might want to look at the stroke of the piston.

A longer stroke will produce more TQ due to it having more leverage. Another thing to think about is compression ratio, the higher it is the more efficient the engine can be...A little of topic...

[90RS13]

No headers, exhaust system or any kind of intake will 'gain' HP or TQ, they can only reclaim what was lost.
They can do more than reclaim what was lost. It goes back to exhaust gas velocity. The exhaust gas will slow down as the space it's let into gets bigger. If you had a head just spewing exhaust out the ports, there would be an extreme loss in velocity. While this would help the engine ultimatly breath better at high rpms, it would hurt it at low rpms because of the lack of velocity. Also in a good design header, exhaust pulses can help "pull" each other out. Especially in a good 4-2-1 header. Intake restrictions can help at lower rpms too, for a similar velocity reason. That's why many cars have factory butterfly's in the intake manifold. One of the most used design is each cylinder having two runners, one with a butterfly and one with out. At low rpm's the butterfly is closed to get good intake velocity. Then at higher rpm's it opens to let the engine breath. (Then people start to make enough power that at high rpm's, the butterfly, even when open, becomes a large restriction so we take em out.) But for a factory car it's a good way to get good power through out the rev range. Anywho, long story short velocity can be important to an engine.