raverx3m

iTrader: (1)

just buy a b20 it seems like thats exactly what youre after. low end torque and no power on top... honda already made engine for you it seems like

ill rather stay with my gsr motor. if i need to pass someone i know what to do instead of blindly smashing on gas pedal and detonating the sht out of it in low rpm i can just downshift and go... not that hard and more fun when your rpm just seem to go on forever and people start to turn heads because your sht just keeps revving up...

no im not a ricer i just enjoy driving.


before i built my gsr thats exactly what i thought because i didnt know ****. i asked a very silly question.

i wanted a car that feels like a v6 and has torque on the low end and power on top.. i got laughed at and didnt understand why. untill i finished my build and tuned it then i got a much better idea about the numbers


i red post 21 and you still make no sense bro.

thats a 2.2-2.3? lliter engine? thats liek saying my 2.5L mazda 3 makes tonns of torque compared to my 1.8 whats goin on.
i donno have you even notice the increase in displacement?
most of us here are talking about a b series engine thats the most popular engine still besides maybe k series starting to gain momentum cuz its getting cheaper and more available...


1.5-1.8l is not gonna give you same torque as 2.3-2.4 liter
its like a lil kid punching you in the face you probably wont feel anything try that with a pro boxer whose hands weigh 15-20 pounds each thats what torque is...

DougNuts

Ah, I see what you guys are saying. Since we're so displacement limited (with D and B-series anyway), the best way to make more power is to spin more RPMs. Makes perfect sense.

No, I didn't do the math or realize how big the displacement was for the motor in post #21, I should've paid attention to that 97mm stroke. My apologies, I was more focused on the graph and his comparison with his friend's car - how it drives.

And you're right, to do what I'm talking about doing does present a tuning challenge at high load and low RPM operation.

raverx3m

iTrader: (1)

with these motors. you add in one spot that takes away from another.

you gain low end at a big expense on top end and vise versa.

going from 1.8 to a 2 liter is alot. that .2 liter gets you from 200 hp to 250 on built motors.. and lots more torque..

94eg!

iTrader: (2)

It's just different schools of thought on how to get the same results going different ways. With limited displacement, you generally need to rev higher to increase power. This then also allows you to shorten your final drive and put down more torque. This allows you to maintain the same speed in each gear, with greater acceleration.

If you are not limited by displacement, you can bump torque via bore/stroke. If you are able to maintain the same powerband, you don't need to re-gear. This also results in increased acceleration while maintaining the same speed in each gear.

Both ways have their pro's & cons. Higher rpm motors are generally shorter lived, and shorter final drives are less civil. On the other hand a bored & stroked bottom end will certainly cost more to build (or take more mechanical expertise).

In the end, the NA setup that goes quickest/fastest will do all of the above (more power & torque).

EG1834

It's like I said on page one, you have to optimize the torque in the RPM range that is most important. My DD spends most of its time between 750 and 3000 RPM, so for me it is hard to justify sacrificing torque in that RPM range for a little more peak power above 6000 RPM. For someone else, it may be a different story.

If the torque output won't meet your horsepower goals, you need to decide whether or not to turn more RPM and sacrifice your low end torque, or build a larger engine to increase torque at the lower RPM range.

raverx3m

iTrader: (1)

thats kinda what i meant

honda makes different engines for different people.

you want low end torque then get LS or b20 motor thats what they do.

you want more power on high rpm get a vtec motor...

buying a high rpm vtec motor and converting it to a low end torque motor makes no sense when you have many other motors available for either choice...

yes people use b20 for race because its cost effective compared to resleeving the gsr block...

plus each engine design has its limitations you cant optimize too much without changing alot of parts.

like optimizing a race horse to tow a horse carriage with 10 people just not gonna happen buddy...

DougNuts

Exactly what I was trying to say. Sure, I probably sucked at communicating it, but that's it in a nutshell.

I never meant to imply that tuning cam/ignition timing, intake runner length, dynamic compression, etc for low rpm power was going to make the fastest car. If it came across that way, I apologize.

Kozy.

I don't understand this belief that you have to sacrifice low end for top end for a given displacement? Are you all tuning domestic pushrod engines or something?

You are aware that we have a variable cam profile right? VTEC allows a set displacement to be setup for torque peaks in TWO locations. If you can get 70lbft/litre out of the engine, with two profiles to play with you should be able to hit that target at 3000rpm and again at 7000rpm, with the overall effect being a fairly high, flat torque band right across the rev range. The K-series just takes this further by altering the timing to suit the conditions.

Bearing this in mind, I'm not really sure how are you lot are 'killing the midrange' to gain horsepower at high RPM?

4piston

Horsepower is gay

EG1834

Cam profiles are only part of the equation, even with VTEC and/or cam phasers. Port/runner/valve sizes are also major players in determining torque curves.

If you're really serious about high RPM power, you're most likely taking out VTEC anyways.

94eg!

iTrader: (2)

Now I'm confused. Last time I checked, when driving around town minding my own buisness, I'm not at WOT. If your not at WOT, then what do numbers matter? If your running too restricted by the throttle plate, simply press down more with your right foot. If you still don't have enough to torque to pull away from that stop light, your probably in the wrong gear.

EsotericImage

iTrader: (8)

EG1834

If you're not making much power at WOT, what do you expect when the throttle isn't fully open? More power? I hope not.

When the powerband is much higher that your cruising range, the engine is unresponsive to low RPM throttle input. It takes the higher RPM, or as you acknowledged, a lower gear to get into the RPM range where the air is moving efficiently and the engine is in its powerband.

EsotericImage

iTrader: (8)

the way I look at it is this:

For street high torque is needed to propel the car from a stop or low MPH to get to higher speed.

For track: your staying in the upper band most of the time and a car in motion doesnt need alot of torque to propel it like if it was still or under 20mph. So the horsepower power band can do most of the accelerating.


I still choose torque. its what actually moves the car. then again, I have a street car.


Exploit it however u want to

flyrod

http://en.wikipedia.org/wiki/Gear_ratio

rich7777

Facepalm @ What ???

raverx3m

iTrader: (1)

To raise post count lol

94eg!

iTrader: (2)

^Because what was posted just prior makes no sense if you truly understand the relationship between torque & rpm.


So what? If your driving conservative, you don't need torque or power. If your hot footing, you drop a gear and rev it up. BFD! The problem is when people don't know how to drive a setup with a power-delivery like that. And I seriously doubt a B18C5 would be considered "unresponsive" relative to a B18B. Because the rpm allows such short gearing, it puts more torque to the ground in every gear at every rpm no matter what the throttle position.

That is the whole point of this argument. Same torque, more rpm/power = quicker car. That's been Honda's performance philosophy for AGES!!! Hell, Mugen de-strokes a Prelude 2.2 to 2.0, makes 300hp, and an Accord Racecar can then run 12's!!! Meanwhile the Accord SiR-T isn't having any trouble running around the streets w/ only 2 liters and 220hp.

EG1834

What do you mean you don't need torque or power, how do you expect the car to move? LMAO.


If you really think you can just move the powerband as high as you want, and then gear the transmission or rear axle to compensate in any application, you are mistaken. You must take into consideration that not everyone is building a racecar, which has been my point from page one. If everyone built their streetcar to your philosophy, then we would all be running around at relatively low road speeds with relatively high engine speeds because we've geared our cars for a high RPM powerband. I subscribe to a different philosophy where I built my engine to generate torque in the RPM range I would use most, and allow the car to be geared so I can cruise at lower engine speeds and cause less wear on the engine.

raverx3m

iTrader: (1)

lol this is like domestic vs import

the question is so general it can be twisted in many ways and go on forever.

horsepower AND torque are both measures of your engine output.


the only difference is domestic cars use torque to look at power output because thats what they have
and imports use HP to measure engines output with more precision because past 5252RPM torque doesnt show anything on the dyno chart.

take away the HP curve and see how usefull that dyno chart is for honda

EG1834

That makes no sense whatsoever.

Twenty47

why do people feel they have to contribute to arguments when they havent got the slightest clue what they are talking about. please go

josephcmiller2

why didn't a mod lock this thread 3 pages ago?


Posted from Honda-tech.com App for Android

raverx3m

iTrader: (1)

Twenty47 do you know what u talking about or just copying what the poster above you said?

EG1834

Sorry if my post came off harsh, I don't want to sound like I was talking ****. I agree with the statements you started off with, but you lost me on the last part.