Theoretical question: Low-Mid RPMs @ WOT VS. High RPMs @ partial throttle

[Snail iMAGED]

Theoretical question:
Which is harshest on an engine, WOT or RPMs?

More specifically,
Low-Mid RPMS at WOT
VS
High RPMs at partial throttle?

If I had to guess, it would be I don't know. I just like to suppose questions. ;)

[talonXracer]

Higher rpm's cause more stress than lower revs at WOT.

[TTownEP]

Somehow I am subscribed to this, and now that I come here, I see this thread is tagged with "doggy style."
Someone is going to be real disappointed when their dirty search turns up this thread.

But on topic, how would WOT be stressful at all in a low RPM range?

[MadLorEP3]

whats WOT?

how do you check what threads your subscribed in? sorry for thread jack

[talonXracer]

LOL,,,,,,, W ide O pen T hrottle

[Snail iMAGED]

Somehow I am subscribed to this, and now that I come here, I see this thread is tagged with "doggy style."
Someone is going to be real disappointed when their dirty search turns up this thread.

But on topic, how would WOT be stressful at all in a low RPM range?

I am glad my creative tagging has already been a success.

I don't know much about the "nitty gritty" of engines past the general explanations of websites like howstuffworks.com and popular mechanics, so i am not entirely sure how much stress WOT is at low rpm range.
Though, after thinking about it, I agree with talonXracer.

:first:talonXracer FTW! :first:

[Passenger]

Somehow I am subscribed to this, and now that I come here, I see this thread is tagged with "doggy style."
Someone is going to be real disappointed when their dirty search turns up this thread.

But on topic, how would WOT be stressful at all in a low RPM range?
:pound:
I figured it wouldn't be great for it cause the load that's on the engine.. If you start off in third by accident like I have before I figured it's pretty bad for it.
whats WOT?

how do you check what threads your subscribed in? sorry for thread jack
User Control Panel (that button that says notifications)

[kyoo]

WOT at low RPMs is way worse than at high rpms, causing a ton of load on the engine

[TTownEP]

Higher rpm's cause more stress than lower revs at WOT.


WOT at low RPMs is way worse than at high rpms, causing a ton of load on the engine

Does anyone have any facts to back up these statements? Or at least believable theories, haha.
I don't claim any kind of special knowledge or anything, but personally, I'm with TXR. I mean, I can see the dangers of high RPMs. There's all kinds of timing issues, fuel supply, etc etc. But WOT at low RPMs just seems to me like dumping a wad of air and a wad of fuel, and it just won't go in, because there's no room in the chamber until everything from the last cycle is burned and gone. The engine is only going to take what it needs, it's not being forced in unless you are forcing the induction (ie a turbo or supercharger) and even then they only make boost when the revs go up anyway, since they are relying on the exhaust gases or the crank speed.

Does any of this sound unreasonable?

[talonXracer]

WOT at low RPMs is way worse than at high rpms, causing a ton of load on the engine

NOT A CHANCE !!!

rpm's develop far more stresses as the pistons change direction, valves open and close and springs float.


I don't claim any kind of special knowledge or anything, but personally, I'm with TXR. I mean, I can see the dangers of high RPMs. There's all kinds of timing issues, fuel supply, etc etc. But WOT at low RPMs just seems to me like dumping a wad of air and a wad of fuel, and it just won't go in, because there's no room in the chamber until everything from the last cycle is burned and gone. The engine is only going to take what it needs, it's not being forced in unless you are forcing the induction
Does any of this sound unreasonable?


There is NO EXCESS fuel in there if the calibration was proper, there is no WAD of fuel/air, the engine pulls in EXACTLY the amount of air needed.


I have NEVER seen a engine blow at low rpm's, but miss a shift and hit those high rpm's and see what happens.....................................LOL

Run around at redline continuously for a month, the engine will be toast.

[TTownEP]

There is NO EXCESS fuel in there if the calibration was proper, there is no WAD of fuel/air, the engine pulls in EXACTLY the amount of air needed.

Well yeah, that's what I meant, you open the throttle, but nothing's going to happen.

I know wad is a totally scientific term, and is totally acceptable in technical discussions. :mbiggrin:

[talonXracer]

I specifically lowered the rev limit to enhance longeviety. and with almost 200k miles on the cammed engine, I do believe I succedded.

[kyoo]

I see motors blow all the time from people who WOT at low RPMs.. But then again my experience is with all forced induction cars - talking about this particularly brings the Mazdaspeed3 to mind -

Of course if you overrev the engine it's going to blow... And run around at redline continuously for a month? Ryan Gates' internally stock 4B11 did for MONTHS during the 2009 Red Line Time Attack series... finally blew last month

Ok, considering the car at hand, perhaps not. A lot of turbo 4s - evos, stis, ms3s, produce a ton of torque at low rpms, and a huge amount of load/strain on the motor if WOT at low RPMs. I guess not the case for EP3s, or most Hondas in general.. but for the aforementioned cars, way worse to WOT at low RPMs

[Snail iMAGED]

Ok, considering the car at hand, perhaps not. A lot of turbo 4s - evos, stis, ms3s, produce a ton of torque at low rpms, and a huge amount of load/strain on the motor if WOT at low RPMs. I guess not the case for EP3s, or most Hondas in general.. but for the aforementioned cars, way worse to WOT at low RPMs

My intention when starting the post was for our specific engine, but the discussion is still interesting also considering forced induction engines.

[talonXracer]

The stresses from the torque loading are substantially less than the stress of high rpms, I do not consider a 4G63 capable of high revs, nor the Mazda3. Never seen low rpm's damage a V8 or a diesel, but RPM's sure do. Sure any engine can be built to withstand some additional rev's, but longeviety suffers.

[Deadphishy]

Low RPM's on a V8 is not like low RPMs on an I4, the rate of fire is twice as fast, making the motor far smoother at lower RPMs. Leaving the crank with a more stready powered rotation.

I can see points to both arguments. If i had to take a bet. I would say taking an A3 to 6800 RPMs every once and a while is better then driving around at WOT at 1k in 5th gear.

I have nothing to back that up. Other then the pure sound of pain, the a3 makes when you are in to low of gear.

[talonXracer]

WOT at 1K in 5th gear is not very hard on the A3 engine at all, as long as it is properly tuned, there is not nearly the stress that you believe, not much torque being produced down low. You will add some stress with boost.

[kyoo]

The stresses from the torque loading are substantially less than the stress of high rpms, I do not consider a 4G63 capable of high revs, nor the Mazda3. Never seen low rpm's damage a V8 or a diesel, but RPM's sure do. Sure any engine can be built to withstand some additional rev's, but longeviety suffers.

There is a difference between overrevving and revving high - which are you talking about? what's "high" revs? Obviously neither are good. For the aforementioned engines, WOT at low RPMS (1kish-2kish) is worse than shifting at or slightly past redline. Obviously, most honda motors are designed to produce power at higher RPMs, so they do not have as much of a problem with too much torque down low. The boosted motors do. I feel comfortable shifting at 8k in my car - don't feel comfortable WOT at 1500 rpms.

Again, if you're talkin about overreving, that will most certainly blow any motor. If we're talking about shifting at or slightly above a car's redline, WOT at low RPMs will blow the motor way before shifting at high RPMs. You can't say 'i don't consider that motor to rev high' - it's a completely different engine and design - what's "high" for one car doesn't mean it's "high" for another. Some bikes rev to 12, 15k - what you're suggesting is just subjective. I don't care what you think high revving means - the facts are the facts - too much torque down low causes way too much load at WOT. Hondas don't make the torque to cause the load that would strain their engines down low

I mention how high bikes rev to mock your post a little - basically what you said as your argument earlier was -

I don't consider the 4G63 to rev very high. Revving as high as my Honda is way worse than going WOT at low RPMs on the 4G63.

= Same as:

I don't consider Hondas to be able to rev very high. Revving as high as my bike is way worse than going WOT at low RPMs on your Honda. It's a completely useless point, the motors are completely different. And for a side note, 4G63s take up to around 7800 rpms easily - after that just needs valve springs to go to about 9k. 4B11s will go to 9k on stock motor without any issues.

[talonXracer]

That was meant as rpm vrs rev potential, not as engine vrs engine, that would be coparing apples to oranges.

Listen, go ahead and drive however you decide to, but your theories are wrong.

Do not even think you have the theories to overturn 35 years of dealing with engines and 20 years worth of machinist experience.

At 1500rpm's on a A3 there is what a whole 45 ftlbs of torque? Not even enough to even stress the internals to 20% of max. sheeesss!

[Deadphishy]

Yes lets get back to the main question.

WOT at Low rpm
or High RPM at part throttle.

I don't know what the TS thinks is high. But on a motor with a rev limitor at 6800 rpm. I would say anything over 5k is high. as that is the top 27% of possible RPMS

[kyoo]

That was meant as rpm vrs rev potential, not as engine vrs engine, that would be coparing apples to oranges.

Listen, go ahead and drive however you decide to, but your theories are wrong.

Do not even think you have the theories to overturn 35 years of dealing with engines and 20 years worth of machinist experience.

HAHAHA ok - HOW DARE I DO SUCH A THING

i WILL continue to drive exactly as I have - no WOT at low RPMs, an ripping through the engine when I autocross and drive on the track.

What exactly are you trying to say? 9000 RPMs for a MS3 is going to blow/strain it's motor? DUH - will 6500? Sure, more then driving casually anyway. Is WOT at 1500RPMs worse for the car? Hell yea it is. I've seen a crapload of these MZR motors blow from regular people just pulling onto the freeway.
Does the same apply for engines designed to rev high/don't produce the torque down low? No. With your experience you'd think you'd understand that different motors like different things.

[TTownEP]

http://i22.photobucket.com/albums/b329/gryanholland/9b0b5f37.jpg

[kyoo]

http://i22.photobucket.com/albums/b329/gryanholland/9b0b5f37.jpg

lolol yep, i just discovered cars 10 posts ago.. what are these things??

[Deadphishy]

At 1500rpm's on a A3 there is what a whole 45 ftlbs of torque? Not even enough to even stress the internals to 20% of max. sheeesss!

I think the theory stems from the idea that at 1500 RPM the Gyroscopic effect is far less then at a higher RPM. This means that the 45 foot pounds Hit more directly and push longer on the matting surfaces then when the motor is spinning faster. in this argument we might need to Include load time as well as load duration.

[Deadphishy]

Let us not forget that at 1000RPM the piston is moving much slower then the flame front. Meaning it will obsorbe less of the impact in to the rotation and transfer more of the force for a longer period of time to the Pin, and bearings.

[kyoo]

truth - and for the MS3, it produces over 100 lb ft of torque to the wheels at 1500 rpm - 150lb ft by 2500

[dirtyMETHOD]

My intention when starting the post was for our specific engine, but the discussion is still interesting also considering forced induction engines.
so, engine specific...

talonXracer, you're right about this.

How about staying on topic.

& how did ms3s get in the picture? didn't know they swaped A3s in those.

[kyoo]

so, engine specific...

talonXracer, your right about this.

How about staying on topic. how did ms3s get in the picture? didn't know they swaped A3s in those.

it's called having a conversation smart ass, OP never said which engine, I just offered the fact that for boosted motors, its worse to WOT at low RPMs

[dirtyMETHOD]

ok............ wooooohhhhhhhhhhhh Saaaahhhhh ................

I feel some digital tension coming from you man. like you said, a conversation. lets keep it like that and on topic, no?

So tell us about n/a vs boosted K engines and the load stresses on those at WOT in low rpms.

No need to get your knickers in a bunch.

this is a great way to get your post count up to Talon's

[kyoo]

ok............ wooooohhhhhhhhhhhh Saaaahhhhh ................

I feel some digital tension coming from you man. like you said, a conversation. lets keep it like that and on topic, no?

So tell us about n/a vs boosted K engines and the load stresses on those ay WOT in low rpms.

No need to get your knickers in a bunch.

this is a great way to get your post count up to Talon's

my fault lol - anyway topics already discussed. just responding to that comment - anyway i dont care about post counts, just stating the facts. honda engines arent the only ones in the world so just bringing up that point when talking about engine talk in general

and talon talking like he's the end all in terms of motors.. can't apply one theory to all motors, and he tried to and make us all eat it up? im not gonna stay quiet if I disagree

[Snail iMAGED]

kyoo:

Theoretical question:
Which is harshest on an engine, WOT or RPMs?
More specifically,
Low-Mid RPMS at WOT
VS
High RPMs at partial throttle?
If I had to guess, it would be I don't know. I just like to suppose questions. ;)
I should have been more specific and started with:
~1-3K = Low
~3-5K = Mid
~5-7K = High

My intention when starting the post was for our specific engine, but the discussion is still interesting also considering forced induction engines.

Talon:
Once again, thank you. You demonstrate your point clearly and without sounding like a dick.
So once again: :first: = talonXracer

[kyoo]

yea and I definitely agree for the EP3 that high revs/redlining is harder on the motor than low rpm WOT -

my only problem was that guy trying to make a very general statement for all motors, and then when he was challenged said something like "do not even think you would know better than me and my experience blah blah" - sounded like a dick to me - like we should all just shut up and listen to what he says since he's had the most time with motors (and this forum) and i mean - he was pushing that high rpms are worse than low rpm WOT for ALL engines.. which he was wrong about.