jpvarghese

iTrader: (1)

Are you kidding me? Even when I show you a link directly from the manufacturer, you still don't see it? Depending on what racing venue you are talking about, go check out the rules about about these type of gearboxes in Formula 1 and other racing sanctioned by the FIA.

For privateers, there aren't aftermarket double-clutch gearboxes available. Either it came with your car, or you have to custom spec one out. FYI, the unit from the GT-R and Veyron, cost $20k and $125k, respectively. That's not including the computers to control it. The gearbox is recently becoming mainstream and costs will come down over time.

And you want proof of the advantages. Here you go. The blue line records longitudinal acceleration. The kink is where the shifts occur. Look at the kink and the change in velocity between both types of gearboxes. This is a common test among the Euro boards. 60-130 mph.
F430 F1 gearbox


M5 SMG


GTR w/DSG


M3 DCT


997.2 Turbo PDK


Ferrari Italia


Please tell me what advantages a single clutch transmission has. I'm sorry for being rude, but you cannot state things without supporting evidence.

jpvarghese

iTrader: (1)

The advantage of a rear heavy car comes at launch. It is more clearly seen in Porsches. Although the Italia is technically a mid-engined car, having the engine stradled in the back with a little more rear-bias helps with traction. This is not the same as having radiators and such in the back to balance out the weight. The concentration of weight is different than the distribution of it in the rear. There is no way a LFA will out launch and out accelerate the Italia. I know you love the car, but this is almost certain.

WRT the above video, both cars are equipped with a double clutch unit. What are you trying to prove? The rear-mid engined Italia already outlaunches it.

05RollaXRS

Like I said before, I never claimed LFA will outlaunch the 458 Italia in a straight line. Nor am I claiming it is faster in a straight line.

I have a video of a single-clutch LP550-2 versus the 458 Italia upto 300 km/h and never once did the single-clutch LP550-2 lose any ground to the 458 Italia during shifts. The differences in real world are negligible.

Both cars much like this SLS AMG and 458 Italia video I posted were neck and neck all the way to 300 km/h. Neither gaining nor losing any ground to the other.

It goes regardless of LFA. I am not fan of double-clutch transmission for various reasons. It has been since before LFA came out. It feels too automatic like. I like the single-clutch design far more especially on the race track.

My point is, in real life single-clutch has its own advantages one of which is more consistent shift times.

Also, AutoZeitung tested the Lexus LFA vs SLS AMG and both cars were neck and neck in all acceleration tests. LFA was 0.1 secs slower to 60 mph since the prototype did not have launch control, but both cars were neck and neck at high speeds.

https://www.clublexus.com/forums/lfa...s-sls-amg.html

I posted in my previous posted this:'

jpvarghese

iTrader: (1)

Your gripes with the double-clutch box makes no sense since the same can be said about the single clutch. Consistent shift times? WTF? Have you driven a car with either gearboxes? You can't even compare the two, even for daily driving. Where are you getting your information from? You can continue to try and 'one-up' me, but this is getting ridiculous.

I show you an acceleration and velocity chart with a visible difference. You show me a video. You see that the Lambo doesn't lose composer b/w shifts and conclude that the difference is negligible. I can show you a thousand videos where it wouldn't be, but datalogs don't lie. Here's a good one. Twin turbo Gallardo E-gear vs. modified GTR. Single clutch vs. Double clutch. Circa same hp with massive weight difference.

http://www.youtube.com/watch?v=vafdWLS-enk

Look what happens after each shift.

05RollaXRS

Talk about new LP550-2, LP560-4 or LP570-4. Don't talk about old gallardos with ancient e-gears. They were horribly inefficient just like the older BMW SMG I, II and III transmissions and had slow shift times. The single clutch these days are far improved and faster like night and day over the old days with shift times consistently less than 200 ms.

p.s. Yes, I have driven a BMW M3 E90 sedan with M-DCT transmission.

Automobile magazine, September 2010 LFA vs SLS AMG

"In our tests, these two supercars are separated by one-tenth of a second in the 0-to-60-mph sprint, where red eclipses white by completing the task in 3.8 versus 3.9 seconds. In actuality, it's all down to tire wear, tire temperature, surface quality, and launch success. Both vehicles must shift once before they exceed the 60-mph mark, and even after a dozen or so full-throttle side-by-side sprints, the results were pretty much a dead heat."

jpvarghese

iTrader: (1)

Let me summarize for you what you've said here.
Basing real-world results from a speedometer and comparing it to measured results from other cars.

Did not for once provide the charts showing this, but continued to mention marketing fluff from Lexus.com.

Apples to orange comparison. Apples to apples would be an E-diff vs. LSD.

Now if I understand you correctly, the LFA makes more torque than the Italia in the upper rpm band. Knowing that hp is a function of tq, you are also implying that the LFA makes more power than the Italia although the factory and quarter-mile tests show that Italia makes more. I provide you a video from an owner. No dyno charts from you.

Repeated at least 3 times although I've shown hard proof that you were wrong.

This is completely fabricated. You made this up and confirm it with a video of the speedo. I asked again for proof, you couldn't come up with any.

Someone is confused with the whole argument.

Unsubstantiated.

Huh?

Using video as proof because the LP didn't "buck" when upshifting.

This is why?

I thought single clutch was more "generous".

I didn't refuse to acknowledge anything. You are arguing with yourself and posting more irrelevant info.

This is all you wrote about it. What are the advantages?
Because of a video? There are numerous variables when it comes to roll racing. Have you thought about the weight differences or the engine displacement in affecting the outcome? The Lamborghini has 0.7 Liters on the Italia. That plays a huge roll in roll racing.

You've been on a race track with both?

But I thought it was....
Explain how it has more consistent shift times. In what situation are you speaking of?

This is funny because as I recall I was flamed for calling the LFA's gearbox archaic. Please tell us how fast the shift times are for the LFA. (200ms).

Here's the issue. You pick and choose what you want to disclose and respond to. You pick and choose your sources. I've provided hard evidence of a double-clutch box outperforming and single-clutch unit. You grasp to a single video and fabrications. I didn't understand a single thing you're trying to say.

The Italia was quoted between 3.1-3.3 seconds and you state that the LFA is around the same ballpark? The bottom line is this. As far as straight-line performance goes, the LFA is NOT even close to the Italia and cars like it. You can make excuses for the tires, but you will not see a half-second gain to 60 mph or 6-7 mph improvement in the quarter-mile with tires or LC alone. The car shines incredibly on the track and that's what it's meant for. I, too would love to see this car with Italia-like straight-line speed, but lets stop making excuses for it. The car is what it is and if drag or roll racing is what you are expecting from the car, you are looking at the wrong one.

DaveGS4

iTrader: (2)

jpvarghese, you're getting a bit hostile and insulting in the post above. Please review and edit your wording to be polite & mature in your conversation.

If you can't discuss the topic without making it personal, don't push the reply button.


05RollaXRS, same goes for you with the post immediately prior to his. Please edit your wording and keep this civil.

If either of you don't see what I'm talking about let me know and I'll remove the posts.

TF109B

Your posts take up way too much room. Do you really have to quote word for word everything Rolla says? It's annoying. We get it already. You believe the 458 is the superior straight line car. That's great. Can we move on? Obviously from this video weve seen just how fast the LFA really is, and it was still a bad launch. The poster of the video said he hit 100kmh in 4.4 seconds. Considering that's a second off of the official time, we should therefore take a second off the time it took for the LFA to reach speeds like 200kmh. Maybe even more. Lets just put it this way. Just because Ferrari says their car makes more power, doesn't always mean it does. Like Chris Harris said. You have to have permission from Ferrari to even test the car, or drive it in comparisons. That doesn't sound to me like they're too confident in their fire catching machine. While the LFA just showed it can hit 160mph in around 18 seconds without the aids of slick rubber, the 458 has to have special permission of the magazines or publishers. Chris harris pretty much confirmed what I've knew all along. The press cars are much better off than the owners units. Let the LFA have the same tires as the 458, then come back and say how much better it is. There hasn't even been a full test of a production unit. 552HP (LFA) isn't far from 562HP (458). You're making it seem like it's much more powerful when it really isn't.

TRDFantasy

Does the 458 have any traction problems? Have any production (non-ringer) 458 models been clocked hitting the 10 second 1/4 mile range, or have all 458s so far only hit low 11s in the quarter? I ask because I do not know.

Yes the LFA does not have a torque vectoring differential or direct injection, but not all modern supercars do. Not sure what your point is . The LFA's V10 makes heavy use of titanium alloys and forged titanium, which is more "high tech" than a lot of other supercars. It also has independent electronically controlled throttle bodies on the engine, which is "high tech" and something a lot of modern supercars lack. Additionally, the LFA exceeds Euro 5 emission levels in Europe without direct injection partly thanks to clever techniques like early light-off of the catalytic converters on cold starts. How is that not high-tech?

The LFA's intakes feed into a resonance chamber for the special acoustic sound the V10 makes, which was tuned using high-tech equipment. Then there are the sound passages in the interior specifically tuned for certain frequencies that directly pipe the V10's sounds into the interior.

The LFA also has "high tech" details like an electronic brake booster, which provides consistent braking power no matter what the conditions are. The LFA's brake booster does not rely on engine vacuum as some other competing supercars do. That's not even talking about the "high tech" interior which features airbag seatbelts, and the moving and customizable gauge cluster.

So my point still stands; if you actually look deep into the LFA, and not just superficially look at the main features, then it's obvious the LFA is not "archaic" at all.

jpvarghese

iTrader: (1)

I posted a video few pages back of a production Italia taken to the track by its owner hitting 132 mph traps. That was not a press car. I picked it because it's similar to the LFA in power and weight and this was an independent test. I agree that the production LFA would be a better car to test, but making statements about its performance based on a speedo like you all have been doing isn't entirely an accurate way of gauging times. What part of that bothers you? The only think we can gauge from all the tests is that the car goes to 60 in mid-to-high 3s and traps the quarter-mile at around 125 mph. This has been consistent and GPS verified. LC and tires may improve the E.T., but will need more than that to improve the trap speeds. All I'm saying is that if this Italia represents all the production models out there, there is no way a production LFA can keep up with a car with 132 mph traps, with what has already been reported.

MR_F1

Fanboyism is really blinding you isn't it?

TRDFantasy

Yes I understand this, but I'm still curious about some of the questions I asked. Trap speeds excluded, have production (non-press) 458s hit the 10 second range in the 1/4 mile? The video you posted of the 458 shows it hitting low 11s in the 1/4 mile, which is about the same as some pre-production LFAs have been able to do.

jpvarghese

iTrader: (1)

Nothing that affects the dynamics of the car is stuff that hasn't been done before. Dynamics, as in, the car in motion. Everything else you mention is valid. There are quicker versions of the same type of gearbox. 200 ms is slow for today's standards when Ferrari is cutting close to 60 ms in the Scuderia. This would be considered archaic. Direct injection is found in all modern day cars and supercars and the Italia with a smaller engine utilizing it makes more power. This engine not having it would be considered archaic. Supercars today are using smart differentials. This car not having it would be considered archaic. Supercars today are using a magnetic suspension which allows for race and street compliancy. Not having it would be considered archaic. I am in no way suggesting that not having any of this is bad. Lexus may have their reasons for it, but for the general public, questions like this will arise. I am still very impressed with the car and would choose it over anything out there. It's appeal to me is how raw and 'basic' it is in the sense that it does so well without the electronics. My ONE and ONLY gripe is the 'slow' shifting gearbox. I put that word in quotes because 200 ms isn't really slow, but it is considerably slower than what everyone else offers.

For the first part of your question, the Italia's launch control works brilliantly without wheel hop and plants the rear end to give fantastic results. The double clutch gearbox, magnetic suspension, and the engine placements helps with off the line traction. This gives consistent straight-line results. As much as I'm aware of, the car has not hit 10's, but cars with traps speeds that high do.

jpvarghese

iTrader: (1)

This is my major gripe with some of the posters. They can't grasp reality or understand the car for what it is. Everything they read on the Lexus site is copy/pasted into this thread to make a point of an issue that never arose. Then on top of that is the speculation. All I'm trying to invoke is a reality check.

The video I posted shows the owner making a run in AUTO mode. He did not use launch control. Using it would automatically put the car in manual mode, which was what he didn't want. Like I said those are 10 second trap speeds.

05RollaXRS

That is correct, TRD. There is absolutely zero evidence that 458 Italia is less than low-11 seconds in the 1/4 mile.

There is not enough testing on LFA available yet and all of it has been on ragged on prototypes that had 8000 - 9000 abusive miles on them. The production models never have been tested since they started arriving this month. Basing entire LFA's prowess on abused prototypes is just plain idiocy. TRD, you do remember C&D comparo of LFA and 599 GTB HGTE?? Yet, there is insufficient testing of LFA with the new launch control system, which is bound to improve its 1/4 mile speed and time.

In CarAndDriver head to head test, LFA prototype beat the 599 GTB HGTE in acceleration tests, which also has had the typical 1/4 mile numbers of 11.1 - 11.2@130 - 131 mph. LFA ran 11.6@125 mph versus 11.8@125 mph for the 599 GTB HGTE because the test was conducted in wales, which has a 1000 meter higher elevation above sea level. Higher elevation results in loss of power.

http://www.caranddriver.com/reviews/...t_drive_review

http://www.caranddriver.com/var/ezfl...8a72dc3b2f.pdf

http://www.motortrend.com/roadtests/...test_data.html



Regarding the acceleration in a straight line, the Top Gear video was the biggest proof where it was dead even with SLS AMG that has the fastest time on the internet of 11.6@125 mph. Never any quicker than that.




Again, 458 Italia versus Ducati by MotorTrend scan:






Again watch this video of SLS AMG versus 458 Italia and they were dead even right uptill 170 - 180 mph

http://www.youtube.com/watch?v=DF6lt...layer_embedded


Some further evidence of dual-cluth versus single-clutch e-gear.

545 HP LP550-2 Balboni (single clutch e-gear) versus 458 Italia dual-clutch (550-2 wins 2-1):

Notice despite having an "ancient" single clutch, the LP550-2 never loses any ground to the 458's so-called superior dual-clutch during shifts. The pull is just linear. 458 wins the first race and then loses the other two to the 550-2.

http://www.youtube.com/watch?v=dv_YApsenG8