05RollaXRS

As the description says, one of the people in the crowd watching went inside and bought this LFA

Marzabella

So this shows the LFA has drivetrain losses typical of just about any other vehicle in the lexus range? Well boo, I was kind of hoping that lexus was being conservative and deliberately understating the true power/torque figures.

05RollaXRS

RWD front engine cars have a typical drivetrain loss of 17 - 20% (IS350, for example has a 19% drivetrain loss putting down 245 - 255 HP and IS-F puts down ~ 333 wheel HP stock). If you were to go by that standard, LFA actually is putting down 580 - 590 HP at the crank as multiple dynos have shown

Insideline - 515 wheel HP
Forged Performance "heart-breaker dyno" - 451 wheel HP (a 300 HP STi dyno'ed at 199 wheel HP the same day and a stock Nissan GTR dyno'ed at 390 wheel HP)

And then this is 480 - 490 WHP

Justin2JZ

The whole video I was like do a pull to 9500 RPM already lol.

SChema

iTrader: (2)

This is why a dyno is not a precise gauge of true performance. Dyno numbers fluctuate widely across the country/world, not to mention that they can be manipulated to read differently.

Dynos should only ever be a tool to help tune a car. A time-slip is the true gauge of power.

CrazyMPG

iTrader: (4)

Very true. Too many variables like temp, different dynos, dynoing in wrong gear can change the figures drastically.

05RollaXRS

True. Different condition dynos have variables.

However, all of the three dynos show fairly consistent results when put in their context (all done in 5th gear which is closest to 1:1).

For example. the 451 wheel HP sounds lower than the other two dynos, but when you factor in how much a stock STi and stock GTR dyno'ed in the same event at the same time, it puts things into context consistent with what Forged Performance stated that the dyno shows lower than usual numbers.

Regarding timeslips, I agree they give the real world acceleration, but circumstantially they have no less variables that can contradict what the dyno says and are equally incomparable.

The variables would be:

- What type of tires the car was wearing?? Sticky tires?? summer performance?? or all-season etc.
- How good the driver was at launching?? Does he know how to launch or not??
- Was it an automated box or a manual box?? If automated, does it get the best performance from launch control or some other method??
- Was the surface sticky and was there any track grip compound put on it (many dragstrips do, but some don't).
- What altitude was the test performed at?? The temperature etc.??? Is it N/A or Turbo?? Turbo lose less power at high altitude than N/A?? etc.

I guess, you get the point.

BNR34

iTrader: (1)

What makes you think that?

All test data indicate the car makes exactly the hp/torque that Lexus claim it has, if anything, the car is slower then the spec suggest.

TF109B

^What makes YOU think that? It's not wearing slicks so acceleration numbers are kinda off compared to other cars with around the same power, which might I add usually come better equipped in the tire category. If the car only loses 15%, the wheel hp would be around 470hp from 552hp. If it lost 17% it would be around 458hp at the wheels, which is close to the 'Forged Performance' reading. And a 20% loss would be around 440hp at the wheels, 10hp lower than any dyno has read.

05RollaXRS

Agreed.

Raising questions on the numbers could easily make it possible to find some explanations. There are tons of 800 wheel HP Supras that run 11 second 1/4 mile. That does not mean, they are not that powerful. It simply means they cannot put their power down most efficiently. Their first gear complete goes up in smoke.

For someone interested in facts, LFA has troubles launching off the line properly. LFA's tires are already notorious for poor traction off the line and have been criticized by many expert professional drivers.

All I know is, a 124 - 126 mph trap speed even with a poor 4.0 seconds 0-60 mph is simply unheard of. 115 - 118 mph is the highest cars see with a 0-60 mph like that. A 490 HP Ferrari F430 does 0-60 mph in 3.5 seconds and traps at only 118 mph, for instance.

It shows how fast LFA would be in terms of potential, if the 0-60 mph could be improved (0-60 mph is ALL about traction off the line).

CrazyMPG

iTrader: (4)

Some one needs to slap some Volk Racing TE37SL with some Mickey Thompson drag radials!

SChema

iTrader: (2)

If you're trying to run your best time at the strip you, of course, come prepared. I agree 100% that there are variables in running at the strip just as the variables are present when on a dyno. At the end of the day, if a 1000+ whp Supra goes to the track with anything but slicks, you're asking for trouble.

At the end of the day, running at the track will always give the driver a gauge of how powerful a car really is, even though it's not running at it's full potential. If conditions are correct, a car can only run up to its potential. A dyno number will only give the driver something to chase, at times, that something is unobtainable because how a dyno can manipulate the numbers. Toss that same Supra making 1000+ on another dyno and it makes 800, which number do you trust?

Old school, tried and true method is all based on Trap Speed, ET and weight. Those numbers never lie.

Crazy's GTR making ~715 weighing in at ~3800 with all-wheel drive and paddle shifters is probably good for consistent mid 10's all day and probably crack off a couple of lower 10's. Crazy can you run some tests for us over the weekend?

CrazyMPG

iTrader: (4)

Haha I don't have much time to drag race the car anymore. I did get a full set of 18" Volk Racing TE37sl with Mickey Thompson drag radials but I haven't used it much. I think I'll go back but I want to change my first gear and clutch so I can handle more power upgrades. LoL

TonyAtRWHP

I know I'm resurrecting this thread from the dead, sorry. The video was pieced together from multiple people there who had cameras. The posted numbers were inaccurate, and part of one of the spectators videos.

The MPH is irrelevant. I can't post a pic or attachment of the graph because my post count is too low.

The run was done in 5th, to redline. Back to back

Car made 451hp and 320 ft/lbs. I'm not really sure where they got their numbers from.

We have dyno'd 4 of these cars to date, in all sorts of situations, using the industry standard SAE correction which corrects for weather, altitude, etc.

All 4 cars have made within 5hp and 5 ft/lbs of each other.

Yes, a spectator watching us dyno it went inside and purchased.

05RollaXRS

That is 20 wheel HP lower than what LFA typically dynos at. This is what LFA dyno'd on a Mustang dyno where an STI before it dyno'ed at 195 WHP and '12 GTR at 390 whp right after.

Member on here consistently dyno'ed at 470 - 471 wheel HP in 5th gear with SAE correction.

Then again, LFA's engine at 9500 rpm requires massive amount of air flow directly going to the engine to make maximum power, which clearly your dynos don't have. That clearly explains why LFA was dyno'ing much lower than what it should since the engine is not able to make max power due to lack of proper air flow for optimal compression.