Levi68

Fact is M4 is looks boring, ugly and old.

Z3NK1

iTrader: (2)

natnut

Opinion : EVO stated that the M4 is the better car despite being a worse daily driver and a handful on the track

Fact : EVO tested RCF as faster than M4 on the racetrack

Preach

DrRick

the RS5 was in the comparo because its in the segment. the RS5 weighs what it does because it has AWD. and that AWD helped produce a 2.5 sec gap on the field in this test. what part of the RC-F's weight benefits it in performance? give me ONE thing where its extra heft benefits it?

so when you look at it like that...you should understand why the Audi's weight is given a pass. even with AWD its still 120+ lbs lighter than the F. maybe instead of asking why the Audi gets a pass for its weight, you should ask why the F weighs so much with only one driveshaft and differential?

or.....you can just enjoy the car for what it is. a fantastic grand touring car that is both luxurious and fast.

05RollaXRS

No that is not the point. Final drive is completely irrelevant since shorter final drive allows easier access to a much higher redline (7100 rpm vs 8000 rpm) while retaining similar speed range per gear. The test weight of the black series was insignificantly smaller (3710 lbs for the SLS AMG black series vs 3800 lbs for the SLS AMG GT. Both by Motor Trend).

The standard SLS AMG was rendered basically only good for drifting (both Clarkson in Top Gear and Motor Trend made fun of that. There are videos on that) because like the M4, it does not have the suspension and chassis capability to put the low end torque down effectively especially coming out of corner. That is precisely why after decades of rejecting AWD, finally BMW has made the decision to embrace it. Porsche also puts AWD on all of its high low end torque cars.

Just looking at the peak torque numbers at one point on the rpm band does not tell the whole story especially what happens in low and midrange. Mercedes officially moved the torque curve up significantly even if the peak of 10 ft-lbs less happens just 750 rpm later. The torque at the low end (in the 1800 - 4000 rpm range) on the SLS AMG black series dynos is significantly less than that of the SLS AMG GT. The SLS AMG black series has much a gradual and progressive surge of torque as the rpm rise (in one dyno, it was making only 320 ft-lbs of wheel torque at 3500 rpm relative to the peak of 401 ft-lbs at ~ 5000 rpm) while the SLS AMG GT gets suddenly majority of its torque around 1500 - 2000 rpm like a ton of bricks just like the BMW M4 does.

DrRick

the majority of its torque around 1500-2000 rpm, huh?



now, forgetting what the numbers say and just looking at the shape of the graph, lets compare that to a dyno of the Black Series...





I would almost defy you to find a non-pushrod, high revving, 4 valve per cylinder V8 that made 'most of its torque between 1500-2000 rpm' without turbo charging. It's just not the way it works...

no offense...but it sounds like youre just making stuff up or being willfully ignorant. i mean...for you to say that a final drive ratio is 'completely irrelevant' when talking about acceleration is just silly. again...no offense.

and if we are gonna use Clarkson's opinion as a benchmark, with respect to the SLS, do we also care what he says about the engine in the IS-F (which is obviously very similar to the one in the RC-F)? remember when he said that the torque was on a shelf that you can never quite get to?

i promise im not trying to be argumentative but what youre saying just isnt correct...

05RollaXRS

According to the dyno you just posted (I will only compare their own percentages relative to peak since the dynos are not comparable as the black series is putting less down tha the standard SLS AMG), the SLS AMG is making 68% of its peak torque at 2000 rpm.

I don't know what your definition of majority is, but that is a very strong clear majority of its peak at 2000 rpm.

The SLS AMG black series in the dyno you posted, does not start until 2700 rpm, but it is very clear looking the trend of the rise of the torque curve, it will definitely be significantly less than 300 ft-lbs, but still I am not going to speculate what it would be for the SLS AMG black series at 2000 rpm.

At 3000 rpm, SLS AMG is making 86% of its peak torque compared to 82% for the SLS AMG black series. Relative to their own peak on their respective dynos, in the low end and midrange the standard SLS AMG is always making 4 - 5% more torque in the midrange and low end. That is not a huge difference, but a difference nonetheless.

At 4000 rpm, the standard SLS AMG is making 94% of its peak torque already while the SLS AMG black series at 4000 rpm has a significant comparative deficit at 89%.

Case in point, your own dynos proved the SLS AMG makes 4 - 5% more in the low end and midrange than the SLS AMG black series.

Again, 68% is a clear majority. It is more than 2/3rd of its peak torque available. That is majority. Unless you have your own definition of 'majority'. Of course, no N/A engine with OHC is going to make something like 80 - 90% at 2000 rpm.


No offense, I am not being ignorant nor making any stuff up. I am talking in context of the area under the curve on the dyno in relation to final drive. It is just that you don't understand that a final drive ratio is completely irrelevant when it comes to the shape and form of the torque curve at the low end of the rev range. I don't know why it is so hard to understand.

If you think dyno torques would magically go up because of a shorter final drive then you are the one who is being ignorant.

Will it result in improved acceleration if swapped on the same car assuming everything else remains the same on the engine? Absolutely yes, especially in lower gears, but in higher gears it will result in acceleration loss because it will reach the overdrive gears sooner. Will it make a difference on dynos especially on the low end/midrange? Absolutely not.

Final drive ratio does not impact the shape of the torque curve especially on dynos where closest to 1:1 gear ratios are selected in order to eliminate skew due to torque multiplication through gears (general 5th or 6th gear depending on the gear ratios of the car) and the transmission is not turning fast at only 2000 - 3000 rpm. That is why the peak torque is equal/less when a shorter final drive is swapped out. My 2ZZ-GE despite heavily overpowering over a 1ZZ-FE engined car makes the same 130 ft-lbs of torque despite having a 4.5:1 gear ratio compared with 3.8:1 ratio of the 1ZZ-FE transmission.

If that was the case, high revving cars that have generally low final drive ratios (> 4.0:1 and in the case of 458 Italia, 5.3:1) would be making ungodly torque numbers at the dyno especially at the low end and midrange. However, they don't since the measure of torque on dynos is done in the gears where torque multiplication through gears is at the least without going into gears where it is less than 1:1.


Those were two mere examples. Every single review Motor Trend, AutoCar, EVO, Car magazine had said the standard SLS AMG is a GT car rather than a precise car that is intended to go around the track as quick as possible. The biggest reason is that the rear suspension, chassis and axle are not competent enough to exit fast out of the corner.

As a matter of fact, a pro racer like Randy Pobst basically put down the same lap time around Laguna Seca with C63 AMG Black Series as he did with the "supercar" SLS AMG.

DrRick

kinda looks like it makes the 'majority' of its torque is made from 5000 to redline, to me. but whatever...

but this is a pointless exercise. youre being obtuse. the SLS AMG torque curves...neither one...look like the torque distribution of the M4 that you tried to compare em to. reason being...because they arent turbo'd.

and who said anything about a final drive ratio affecting a torque curve? maybe go back and see why i introduced final drive into the discussion and argue THAT point instead creating strawmen?

but im ejecting from this convo. i'll let someone else argue with you about unicorns and flying cows...

DrRick

last thing...i think that bolded part is my favorite. it really is. but speaking of 'majority'....



i cant begin to tell you how hard it is for me to drive my car with a whopping 84% of my torque at only 3000 spins.

05RollaXRS

95% at 4000 rpm is majority, whether you admit that or no. Sudden jump from 68% to 95% of total peak in a space of 2000 rpm from 2000 rpm - 4000 rpm will cause easily the chassis and rear axle to unsettle unless they were extremely well designed to handle that much change in torque in a window of the rev band. Around a track in the slow corners, 3000 - 5000 rpm is what is normally used coming out of the slow corners typically in 2nd gear.

The proof is in the pudding. I posted Carlos Lago and Randy Pobst's impressions. They both said the car is too difficult to control in, through and out of the slow corners where it uses more of its midrange and low end torque. In high speed corners, it is less of an issue since it is much more about retaining the flow and momentum. It would be impossible to do, if the car did not make gobs of torque down low.


I ignored it in the previous post, but you should really stop being insulting, if you cannot hold your conversations and arguments in a mature and civilized way. Capiche?

Yes, you initially responded to him when he said "why would I need that much torque at 2000 rpm?" To which you responded by saying "Acceleration?". My response to you that he has a point if he prefers less low end torque and more higher revving character of the powerband suits his need and that does not necessarily mean a disadvantage in acceleration. My whole argument is, sometimes having less low end torque actually helps the car's dynamic character particularly for RWD setup. Whether the SLS AMG BS was a good example or not, that is a separate debate. Again, strictly talking about the area under the curve across the rev band. Nothing to do with gear ratios. Somehow you brought the final drive into the conversation knowing I was talking strictly about the dyno torque curve. Nowhere was anything mentioned about the gear ratios until you brought it up.

Yes, your consistent vendetta against the RC-F is more than apparent in everyone of your post. Believe me, everyone notices it. You can insult me by claiming I argue about "unicorns and cows", but your arguments are always merely that - just argument for the sake of arguments.

Just to remind you, I have been critical of places where RC-F could have been better. My last post was my wish for adjustable suspension on RC-F allowing the user to select one notch higher stiff setting for the track, if he wishes to. I also have been less than happy about the weight, but nowhere near how it has been blown out of proportion on most of these posts.

DrRick

::sigh::

A vendetta against the RC-F? This isn't about the RCF. It's about an absurd assertion that torque at low revs is unnecessary. This is a CAR discussion. Because guess what...under your definition...the RCF makes a 'majority' of its torque down low, as well.

So no...I'm not about to wear the 'RCF hater' clothes you're trying to dress me in. They don't fit...

You wanna sit here and ignore sooooo many other vehicle dynamic and blame that sinister 'torque' as the culprit for the M4's lack of ability to put the power down. We'd be in much more agreement if you said that the rear suspension is too stiff (sways, springs, shocks, etc). Or...they could stiffen up the front to make it grip a bit less and make the car more neutral. THOSE things are the real downfall of the M3/4 because it's obvious that there is a balance problem.

Notice that there are a myriad of turbo'd cars that don't have this problem. So blaming it on a 'majority' of low end torque rings hollow to folks that actually know cars. Not just engines...but cars.

05RollaXRS

Where did I say unnecessary? I said having less of it at low end is not necessarily a bad thing like you tried to make that. How hard is that for you to understand?

According to the dynos I have seen of the RC-F, it does makes close to 90% of its torque between 3000 and 7100 rpm, but the amount of torque made is not that much relative to its weight, which is why your argument is moot in the case of the RC-F. It is a very linear torque curve all across the rev range with no sudden surges or dips especially at the low end, but the amount of torque relative to its weight is not overwhelming for the chassis to begin with. As the article above says, RC-F has been fitted with relatively tall gear ratios, which make it even more controllable.

You always seem to be on the opposite arguing end when someone makes a case hat RC-F was being unfairly criticized or if someone is in general defending the RC-F. You seriously want me to quote your last say, 10 - 15 posts?



With RWD? You remember we are talking about RWD. Which car, for example? BMW admitted looking into AWD for next generation M cars. Porsche only did it with GT2 and GT2 RS, but despite having ultra sticky super slick tires, they were both handful cars with unpredictability written all over them. Rear engine configuration + turbo lag of the Metzger + sudden surge in gobs of low end torque = an extremely expert being able to exploit the limits while putting the quickest lap time down.

DrRick

Wanna talk about insulting? You bandy this 'how hard is that to understand' about but say that EYE am insulting you? Anywho...

Never said that I was talking about YOU on that particular topic. Go back in the thread and notice who I replied to and when you jumped in. That may give you some context...

One...I would love to see those Dyno graphs. Not for any 'gotcha' moments but I've never seen a graph of an RCF dyno and would love to compare it's shape to my ISF.

Two...if it's making 90% of its torque at 3000 spins then I can pretty much guarantee that it's got AT LEAST '68%' of that available torque at 2000. Remember your argument saying that the SLS non Black made the majority of its torque at 1500-2000 and the condescending 'I don't know your definition of majority' quip (again...insulting) when I posted the dyno graph?


I'm always 'on the opposite arguing end' because people like you constantly ignore facts when either denigrating the opposition or propping up the RCF. I'm on my phone now....so I can't see when you joined...but I can pretty much guarantee that I've been here (and a lexus fan) longer than you. Defend the car all you want...hell, I'll prolly join you (as I have when trying to convince my wife to BUY one) but that doesn't mean I throw all objectivity out the window.

Do you really think that I'm just on this forum to troll? After being on this site for almost 15 years???


Obviously with rwd. So...does the 12C/650S have this problem? What about the M5/6? The supra never had such nervousness and that was yester-tech. Not the 300Zx.

No...bmw screwed the pooch with the suspension. We aren't talking about 600 lb/ft of torque here. And...just like lexus did with the isf...they will realize it and update it. Soften the rear so when the weight transfers on throttle the car has more grip. Or...they won't. I couldn't care less because the wife doesn't like the car because it doesn't have electric control of the tilt steering wheel. Women...

In the end...I would appreciate it if I wasn't branded a hater because I want to talk objectively about cars. Not necessarily the RCF. ESPECIALLY when I'm addressing a topic that has to do with someone asserting that low end torque is basically useless.

Mr Bond

Have you seen this comparo guys ? The Alpina D3 has a lot more torque than M4 and handles very well. This is all about chassi settings, apparently.

DrRick

its ALWAYS been about the chassis!!! but thanx for the illustration. i couldve saved myself a lotta keystrokes...