llcoolpass

I've found material that seems to be coming from only a couple people on the whole internet that claim they had a tachometer or have other source that the red line is 6600 RPM and the fuel cut is 7200 RPM.

but on my car, this is not so. the speedometer and tachometer, which are independent devices, corroborate their readings when my engine won't speed past I think 6600 RPM without a fuel or ignition cut occuring, and the speedometer is verifying this in 1st gear.

anyone able to observe higher RPM?
[guys with automatics don't go torturing your trans if you haven't already, but I think yours prevents you from over 6200 RPM anyway]

5ltrbeater

...any particular reason you're torturing your poor baby by revving her that high? if i'm mistaken, i thought peak HP is around 5500 and then falls off from there.

llcoolpass

shifts are not determined by peak hp, they are determined by interaction of torque curve and gearing. yes, on this engine and gearing, you are well served shifting between 6000 and 6200 RPM depending on the gear. but in first gear, and just out of curiousity, I want to know if someone is really in a camry or es 300 able to spin the engine past factory spec redline of 6500 or 6600 RPM.

in everyday driving I shift at 2000 or 2500 rpm, depending on whether or not people are in front of me, because this engine has so much avail torque between 1000 and 2000 RPM.

its not bad to redline an engine once in a while, it's actually doing more good. this engine has a rare design of rod to stroke ratio, and decent valve train, it's hard to imagine catastrophic engine damage from using the full rpm range once in a while, but cleaning out the carbon is an imaginable benefit, and obviously for max accel

i still want to put it out there that if anyone has info on the redline, come forward

5ltrbeater

they aren't determined...but you would post a quicker pass in the 1/4 by managing to keep your car within it's peak HP.

when i used to be a rookie "street racer", i always thought you were supposed to redline everything!

then i learned from professionals that letting your engine fall out of peak HP just gain a few more 1/10ths in the same gear, will always result in a lower ET's.

...oh trust me.....you don't have to preach to me about redline being good for the engine once in awhile! just look at my screen name!

llcoolpass

what i said about gearing and torque is 100% right, shifting at the peak hp point may have been beneficial but only so far as it fits in with the scientific fact i mentioned first, but its not shall be beneficial because of the scientific fact.
the scientific fact is that optimal shift points for maximum acceleration of the vehicle are determined almost exclusively by the gearing and torque curve of the engine.
if this is so shocking to you, i can spend time explaining how it works, but i might get you to think about it by reminding you of all the people that get faster acceleration shifting past the peak hp.

unfortuantely, due to marketing and no one to teach you, you , like many, have become confused by the marketing of a car's/engine's torque @ RPM and HP@ RPM figures. one car company represents their engines the way it shouuld be, and makes engineers happy, when they show their engines torque curve-- better showing what the engine is capable of. technically, with some facts [like torque @ RPM and HP@ RPM figures] you can guestimate the torque curve -- so you can get an idea of what the engine is capable of -- the reason they originally gave the figures. but, most people have no clue of that, so it makes me wonder why they continue the confusion of the hp and tq -- but then from marketing , i realize they love when the consumer is confused.

but if I tell you my engine has 200 lbft torque at 4800 RPM, you have no idea what its output is at 1000 RPM. If I tell you it has 195 lbft from 2400 to 4600, you still don't know, but you're starting to get a better idea, and you have more info too ,so you would be wise to consider the engine. for the everyday driver, if they showed torque curves, the optimal engine would have a fairly flat one from idle to red line. at least in the past, nowadays, it would be confusing because the engines today have different torque curves depending on the sophisticated variable valve systems.

the point at which one shifts for maximum acceleration [this doesn't necessarily include 1/4 mile drag strip] is the point when torque curve at the wheels in the selected gear intersect with the torque curve at the wheels in the next higher gear. said different, each higher gear multiplies the torque less, and the torque getting multiplied is measured at the wheels, and the torque at the wheels is what finally motivates the vehicle to accelerate [final torque / "tire + wheel"radius to the ground], and the point to shift is when the engine's torque falls off consistently to a point where despite the better multiplication, shifting to a higher gear will put the engine at an RPM that lets it put out as much [then more] torque which multiplied less is still more than the waining final torque from first gear.

in my es 300, yes, there is a sharp fall off after 5000RPM, but, due to transmission efficiency and gearing, it's not smart to shift at 5500 RPM, but instead a bit higher. never use peak hp as some kind of determination of when to shift, by itself. optimally, you will make your decision based on the torque curve and gearing, and if you get really sophisticated and have to , you would also consider drag, suspension settings, shift times on specific shifts, efficiency of the selected gear, and possibly a few more things. in a 1/4 mile, sometimes, its smarter to stay in gear towards the end due to the shift time coming right before the end. that kind of situation was the case in my 626 v6 5spd.

btw, peak hp is not at 5500 in my engine. if i remember correct, it's supposedly 5200 RPM.

one of my fav cars mostly from the looks is the '03 infiniti m45. i think that's the year. you know what generation I'm talking about. great engine in it, too. but the looks are cool as hell. i am glad it never took off, makes it nice and rare.

and i still welcome anyone in the future with hard knowledge of the red line to get er done here

5ltrbeater

scientific? are you sitting in a laboratory with schematics and bunsen burners to get to that conclusion?

what you stated is partially right. let me correct you: shifting at the peak HP point is always (not "may") beneficial, granted when you fall off peak HP, you fall back into a point on the dyno graph that allows you build back up to peak HP again quickly. you've probably never driven a boosted car before which would explain why you stand by your comment .
over-revving on a boosted car, depending on your gearing, can rob you of 1/10ths of a sec to wait untill you build back up boost again.


..the only thing shocking, is the fact that your're trying to redline a 16sec car to get into the 15's and you haven't spun a bearing yet.




....google "valve float" :

"Valve float is an adverse condition which occurs when the poppet valves on an internal combustion engine valvetrain do not remain in contact with the camshaft lobe during the valve closure phase of the cam lobe profile. This reduces engine efficiency and performance and potentially increases engine emissions."


"marketing" and "no one to teach you"

i think i've read more engine knowledge in the Vtec forums than the rant you just provided here! and that's saying something!




car company? who said anything about car companies? i'm referring to dyno charts and what a car can put to the wheels!




...you mean they "under-estimate" the torque curve. nobody "guestimates" anything! as much as you may think!

in the end it boils down to marketing, politics and the NHTSA!




they don't "love" when the customer is confused

if the customer was confused, people would choose a Honda Accord over an M5 and not notice a diffrence.

where do you come up with this stuff?

your last comment actually made me laugh! 1 because i can imagine if people were really confused and 2, because you actually believe what you're saying!





now you are just contradicting yourself and here is why: the point at which one shifts for maximum acceleration is always because of the 1/4 mile strip! period!

why would you want near perfect acceleration in everyday traffic?

torque only applies for a split second to get your car moving. Torque gets you off the line and HP keeps you moving.

proof you ask?

ill use the example that was used on me years ago when i used to have a "muscle car" (2002 Z28)

me: why is it when i race mustang GT's, they are able to hang with me throughout 1st and i cant leave them untill i shift into 2nd,3rd etc

answer i was given at the time: look at the torque specs of each car. despite the GT's low HP numbers, the torque is almost the same: 302lbs of torque to 340lbs of torque for the camaro.

the numbers explain that the reason that car is able to hang off the line with a car with more HP is due to the near same amount of torque that is being put to the ground. obvioulsy, once both cars are moving, torque is no longer a factor, and HP comes into play, deciding what the outcome of the race will be. camaro 305, GT stang 260.

this is just a simple example and of course other factors such as weight, gearing (your favorite word) , ambient temp, elevation, etc... may all come into play to offer slightly differnt outcomes but the basics stay the same.


good way to put it! and as you just stated, torque only "motivates" the vehicle to accelerate faster, not push it.

and your final torque equation is a little off

torque = the constant 5252 (33,000 divided by 3.14 x 2 = 5252) x the total engine HP. and then divided by the RPM's



according to what you just said, you are correct, but without a dyno sheet showing your claim, the above statement is useless and therefore you are just speculating.


yes, the rare Y34 M45 body styling (aka GLORIA in japan) has the VK45DE. same motor that's under my hood.
it's essentially just a VQ motor with 2 more cylinders. there is a small problem with oil consumption but it can be fixed.

i have to disagree with you (again) on its looks, i think it looks like a faster version of a crown victoria. hell you can just paint it yellow and stick in new york and call it the day!

llcoolpass

you made numerous errors and illogical statements. you also misinterpreted couple things. this is not the first I've encountered someone , like you, who didn't quite have the hang of torque. that's why I suggest you do the research yourself. you can start with the hypothesis "optimal shift points for maximum acceleration of the vehicle are determined almost exclusively by the gearing and torque curve of the engine." I was the same way and had to do the same thing to understand it..... perhaps we are more similar than it seems.

I would try to correct you on much of what you just did, where you actually went wrong, but I'm scared you will not read what I say before you disagree, and won't look up what I'm saying if you disagree first.

on cars, i think we both like nissan v8s. i like their original, ground-breaking, awesome v8 the most -- the vh45de. the vk45de follows closely in the tradition. i honestly had not heard of a big oil consumption problem on them. they are in MANY vehicles and nissan has many plans for in the near future, in different variations. i dont like the vq35de [fwd] that much, but I do have a love for the VQ30de[k]