Buger

Another ridiculous statement but then again, we're getting used to hearing them from you. ;-)

It appears that you either have a habit of misrepresenting other peoples views or that reading English (not your native language?) causes you to misunderstand where people are coming from.

Begging the question is arguing against a viewpoint that you attribute to someone else although they never said anything about it. An example would be someone saying that black is darker than white and you coming back with an argument that 1 + 1 does not equal 3. You can hope that people will remember that you were right and that people forget that it has nothing to do with what was being discussed.

You first say that a high redline causes you to shift all the time. Rpm_pwr writes about his personal experience with a high revving wide powerband car (3rd gen rx-7) to point out that a high redline doesn't necessarily cause you to shift all the time. You then back off and say that you were just talking about s2000 (a notoriously peaky motor) and made some sarcastic comment about bigger engines even existing? WTF?

I mentioned that this thread was not just talking about the narrow s2000 powerband and that a thread like this on the rx8forum would probably have something to do with the latest version of the rotary (which has always had a very wide and usable powerband). You then argued that a v6, v8, v10, v12 has more sheer power than a variable valve timing 4 cylinder?!?!? WTF? Who was arguing that?

You then asked a rhetorical question meant to get across to people that there were never any expensive sports cars with a high revving 4 cylinder (then answered yourself no) then posed a ridiculous rhetorical question asking if one car would have a better engine than another if it had a higher redline by 700 rpms. WTF?? Who was arguing that??!?!?!

Cshepley then addressed your rhetorical question about expensive high revving sports cars by bringing up the Lotus cars. You answered that they didn't have Lotus engines. WTF???? Who was arguing that?!?!?!??!?!

You then said that only "cheap Lotuses" (Loti?) had 4 cylinders. When Cshepley asked about the STS, you tried to quote the specs from older Lotus engines and didn't want to address whether it was an "expensive sports car with a 4 cylinder engine".

When it was pointed out that you didn't quote the correct specs, you then complained that people actually addressed your previous statements with actual examples to counter them (Lotus, Buick, Ferrari, etc). Would you have liked it have been better if they didn't use actual examples to counter your statements and if they had instead pulled something from their **** orifice like the hot effluvia that you have been spouting ;-)

Sorry to go off on you but if you quit with the attitude and actually take some time to try and understand what people are saying, you would look less like a pedantic kid looking for attention and might have people taking your word more seriously.

Brian

spwolf

wow... I guess you try to insult everyone that doesnt agree with you? interesting... wont get you far in life... seems like you are a bit childish here... you managed to invert each one of my sentences to your liking... once again, wont get you far...

Buger

True to form, you didn't respond to the points made.

Your assumption about me insulting everyone that doesn't agree with me is wrong again. I just don't have any compunction about responding to others in the same way that they talk however.

Your assumption that I wont get or haven't gotten far in life is wrong again.

Brian

Grimace

Ok guys and gals, lets take a deep breath and step away from the keyboard... :D

The original question was "why do people want a high redline".

ALL OTHER THINGS BEING EQUAL: for example:
Engine A: constant torque from 2000-5000 rpm redline
Engine B: constant torque from 2000-7000 rpm redline

-identical gearing, vehicle weights, etc., the car with engine B will accelerate faster.

To extend the argument any further to include other variables (gearing, engine type, etc.) introduces too many unknowns, and its impossible to make direct comparisons.

Besides, I really doubt we'll see a V8 or 4 banger RX-8, and this forum is about the RX-8, right?

spwolf

Grimace, yep I agree...although, if engine A has more torque, it will accelerate faster (all other things being equal)


Buger: once again, you invert my words... it seems as if you are well practiced in it...

cshepley

If you are talking about the torque output of the torque multiplier I agree with you.

Buger

Hi Spwolf,

Keep the pucker and hopefully no more effluvium will escape ok? Unfortunately for you, whether I inverted your words or not will be easy enough for anyone who reads through the thread to determine. Just because you post something doesn't make it true. ;-)

Hi Grimace,

It's nice to hear someone post something relevant to the thread again. Hopefully we can all stay on topic this time.

I remembered reading about a page about horsepower vs torque awhile ago and found it again recently. The below link may be an interesting and informative read for anyone who hasn't seen it yet:

http://www.vettenet.org/torquehp.html

The page is relevant to this thread as he makes several references to how a higher redline (with the same torque) would make a difference. A snip from the page:

"The Integra GS-R, for instance, is faster than the garden variety Integra, not because it pulls particularly harder (it doesn't), but because it pulls *longer*. "

It has a pretty good comparison of how 2 corvettes with the same torque but different horsepower and rpm numbers would fare against each other in a race:

Engine Peak HP @ RPM Peak Torque @ RPM
------ ------------------- -------------------------
L98 250 @ 4000 340 @ 3200
LT1 300 @ 5000 340 @ 3600

Extreme examples are often used to illustrate points more clearly and the page also has an example of how fast a water wheel with a calculated torque of 2600 ft/lbs (but only 6 hp) would pull a car.

The page concludes with the following statement from the author:

"It is better to make torque at high rpm than at low rpm, because you can take advantage of *gearing*." :-)

One of the great things about previous rotaries (and of course even more so in the new renesis) is that the wide powerband and high redline make them well suited to high gear ratios which is what rpm_pwr mentioned at the beginning of this thread.

Does anyone know of another engine with a powerband of 90% or greater of over 5000 rpms?

Brian

spwolf

Buger,

who ever argued with that? *scratches his head*

Also, while 90% of torque from 3250 rpms is really nice, you do realize that renesis has 25% (?) less torque than FD?

Besides, most effective gearing is when revs fall down to max torque after upshift... in FD max torque was at 5k and redline was at 8k, that was pretty nice... while with renesis you have hp peakin at 8500 while max torque peaks at 7500...

so perforamance wise, I dont see renesis beating FD, all other things being equal....

at the same time, because of all these "other" things, I would much rather get RX-8 than RX-7.

besides, what I was arguing about was merits of for example rensis as supposed to LT1 engine, not L98 to LT1...

maybe next time you should not read and understand everything as a personal attack on you and try to insult other people less... I for one was definetly trying to discuss things while you kept and keep trying to turn it into fight

Buger

You lost the pucker again.

What are you talking about again?

I'm posted a link discussing torque, hp, gearing and how it relates to high redlines and your trying to turn this back into something else again? :D

Everyone can see that anytime somebody disputed one of your statements (rpm_pwr, cshepard or I) you did anything but try to address what they were saying.

Oh well, I tried. All future comments from you will get the "You lost the pucker again" line. :D

Anyways, back to the subject...

Brian

spwolf

huh?

are you usually on something? you posted facts, that no1 was arguing, I wasnt arguing merits of high redline in similar engines but compare different engines...

what is so hard to understand?

FD vs renesis comparison was due to your constant "90%" of torque reminders that no1 has anything against... it just seemed to me that you might not understand that 90% of torque is worse than more torque

on the other hand, i pretty much summed it all here:
now which one dont you understand? maybe you need it in a form of picture book?

sorry, couldnt resist :D

Buger

You lost the pucker again.

Brian

spwolf

right, so much about that... if I ever find nice picture book, I will make sure to bring it to your attention...

btw... I have no clue what exactly does "You lost the pucker again" means... although you are probably just trying to "not respond to the points being made".

can I say... You lost the pucker again.

spwolf

lol

Buger

As stated earlier, I've already tried reasoning with you (as have others) and found it a waste of time.

Look up "pucker", "effluvia", "****", and "orifice" in a dictionary then read the context from the previous posts in this thread...

You lost the pucker again.

Brian

spwolf

so picture book it is...

NOTA V6

Why don't you two take the flames to PMs or e-mail, and leave this thread on track. Toad? Velo? Are you guys seeing this?

rpm_pwr

As probably the only person on the forum with a dual-axis accelerometer kicking around I think I should clear a few things up that some people (buger etc) have touched on:

1)
Your accelaration graph is *PROPORTIONAL* to your torque graph for in gear acceleration

2)
The proportionality constant is

= (tyre radius * gear reduction) / mass

3)
The important factor here is gear reduction (diff ratio * current gear ratio). In other words you can double your acceleration (wind resistance ignored) by doubling you diff ratio. But by doing this you can detract from the usability of the car by reducing the max speeds in each gear.

Now here is the important bit:
ENGINES WITH HIGHER OPERATING RANGES CAN USE HIGHER RATIO DIFFERENTIALS FOR THE SAME AMOUNT OF DRIVABILITY. THIS MULTIPLICATION EFFECT GIVES MORE GROSS TORQUE AT THE REAR WHEELS GIVING MORE ACCELERATION END OF STORY.

4)
Torque spread only affects how wide you can spread the gear ratios. It does not matter where in the RPM range the spread is because this can be traded with diff ratios rather it is the RPM range that affects how close you can make the ratios. So a car with power from 5000rpm to 8000rpm can have ratios just as wide as a car with power from 2500 to 5500 with the added advantage that it can run a higher diff ratio to increase acceleration.

5)
so say
car a makes 200lb.ft from 3000 to 6000 with a 4.11 rear (FD?)
car B makes 150lb.ft from 5500 to 8500 with a 5.82 rear (rx8?)

car a has 822rw lb.ft GROSS
car b has 873rw lb.ft GROSS

but here's the catch - both cars have identical speeds in each gear! It gets better the higher torque numbers give a higher top speed as well!

6)
With all this messing around with mulitpliers, dividers, NET torque gross torue isn't there an easier way? Yes. It's the often neglected POWER curve. Power at the flywheel = power at the wheels - gear losses. So you can simply overlay two RWHP graphs with shift points marked to figure out which will accelerate harder. It's a lot easier. That's why we can't bench race the rx-8 yet - because there is no power graph yet. Although if the torque spread stays that good then it will be ONLY the diff ratio stopping the rx-8 from being an FD rx-7 killer.

-pete
if this thread gets locked you can email me @ pete@autospeed.com if you have any questions

ZoomZoom

And on that note I second that we lock this thread…:D

Buger

Hi rpm_pwr,

You said it better than I could've.

The production gearing and diff ratios have been what I've been hoping would be leaked by Mazda but I think they want to surprise everyone.

Having an engine with the powerband and redline of the renesis gives Mazda a great opportunity to increase either the gear ratios or the final diff ratios so that the ratio for all gears will create much more wheel torque than people will expect.

I personally hope that they have a very high ratio because of two reasons.

First of all, the car was designed to seat 4 people and the gearing/diff ratios should take that into account and be much higher than the ratios on the last rx-7 which I believe had the below #s:

1st - 3.483
2nd - 2.015
3rd - 1.391
4th - 1.000
5th - 0.719
Diff - 4.1

and could only fit 2 people.

I would much rather have better acceleration than a high top speed. Even if the top speed were only 130 mph, I would (probably) never get to there (damn tickets).

Does anyone know what the highest ratio rear diff a maker has put in production car? Would it be easier (read cheaper) for Mazda to put higher ratios for all gears in the transmission and use a off the shelf 4.1 rear diff or would it be easier for Mazda to put a higher ratio rear diff and use an off the shelf transmission?

Brian

Toadman

There's good discussion in here despite the mud-slinging. Let's keep it on topic and we'll leave it open for the time-being.

cshepley

Congratulations, you said the magic words that spwolf seems to ignore so often, "wheel torque"! Unfortunately, I don't know if there are any prizes.